# Episode 140 - Baby Brain

An episode of [The Great Birth Rebellion](https://invisiblenetwork.ai/podcast/1639430316), 2 Mar 2025, 1 h 08 min.

Audio: https://episode.flightcast.com/sg81kbqw21siwicj7q6yxm8c.mp3

The incredible science of how our brains change during pregnancy, birth and parenting with Neuroscientist Dr Sarah McKay. Sarah is the author of The Women's Brain Book—The Neuroscience of Health, Hormones and Happiness, Baby Brain—the surprising neuroscience of how pregnancy and motherhood sculpt our brains and change our minds (for the better) and neuroscience for dummies. Sarah is the director of The Neuroscience Academy, which offers professional development training in applied neuroscience and brain health. Get Mel's ‘Guide to giving birth without pain medication’ here. @drsarahmskay www.drsarahmckay.com Get more from the Great Birth Rebellion Podcast • Join the podcast mailing list to access the resource folder from each episode at www.melaniethemidwife.com • Join the rebellion and show your support! Grab your Great Birth Rebellion merchandise now at www.thegreatbirthrebellion.com • Follow us on social media @thegreatbirthrebellion and @melaniethemidwife • If this podcast has improved your knowledge or pregnancy, birth or postpartum journey please consider thanking us financially by leaving a tip to support the ongoing work of this podcast. Disclaimer The information and resources provided on this podcast does not, and is not intended to, constitute or replace medical or midwifery advice. Instead, all information provided is intended for education, with it’s application intended for discussion between yourself and your care provider and/or workplace if you are a health professional. The Great Birth Rebellion podcast reserves the right to supplement, edit, change, delete any information at any time. Whilst we have tried to maintain accuracy and completeness of information, we do not warrant or guarantee the accuracy or currency of the information. The podcast accepts no liability for any loss, damage or unfavourable outcomes howsoever arising out of the use or reliance on the content. This podcast is not a replacement for midwifery or medical clinical care. All transcripts are generated by ai and may contain errors

## Transcript

[0:00] Welcome to the Great Birth Rebellion podcast.
[0:02] I'm your host Dr Melanie Jackson.
[0:05] I'm a clinical and research midwife with my PhD and each episode I cast a critical eye over current maternity care practice by grappling with research and historical knowledge to help you get the best out of your pregnancy, birth and postpartum journey.
[0:22] Welcome to today's episode of the Great Birth Rebellion podcast.
[0:25] Today, I'm joined by my guest, Dr. Sarah McKay, who's a neuroscientist with a special interest in how women's brains work and change through their unique life stages.
[0:37] And today, we're exploring the neuroscience behind how pregnancy and motherhood sculpt our brains and change our minds.
[0:46] For the better.
[0:48] For the better.
[0:49] Exactly.
[0:50] I'm glad you added that.
[0:52] So we get an upgrade.
[0:54] Our brains change for the better.
[0:57] Before we start on all of that, Sarah, can you introduce yourself, your qualifications in your work?
[1:04] Okay.
[1:04] So, well, I have a PhD in neuro.
[1:07] I've got three degrees in neuroscience, I should say.
[1:09] So I've got a Bachelor of Science Honours Degree in Neuroscience from Otago University in New Zealand because I grew up in New Zealand.
[1:16] And then I have a master's in neuroscience and a DPhil, which is from Oxford University.
[1:23] And a DPhil is just the fancy Oxford University way of saying PhD.
[1:28] So bachelor's, master's, and PhD all in neuroscience.
[1:33] And mom, I suppose book author.
[1:36] Yeah.
[1:39] I just turned 50, so I feel like that's a qualification.
[1:42] It's a qualification.
[1:44] Yeah.
[1:44] I have always, so I literally met and fell in love with neuroscience in first year uni in 1993.
[1:48] I thought it.
[1:50] you know, it was really cool learning about synapses.
[1:53] I was just like blown away by that little biological mechanism.
[1:57] And one of the reasons why I still love neuroscience, although I'm not an academic researcher anymore, is that it's still cool to find out new things about the brain and how it works.
[2:09] And luckily what I –
[2:13] focused in on which is around women's health across the lifespan there's lots of people that want to talk to me about the stuff I find cool so that's how I spend my time I've spent a lot of time in the last few years writing last year I wrote two books don't write two books in one year it is a lot of work I literally had like 12 hours between submitting one and starting the next
[2:37] And I've written in the last few, and Baby Brain came out in 2023.
[2:43] I've updated a lot of courses that I teach, wrote two books last year.
[2:46] So I'm taking a gap year, turned 50 at the beginning of the year.
[2:49] And so I'm taking like,
[2:51] A little gap here, except I'm doing podcasts and things because that's kind of fun.
[2:55] Yeah, I'm doing like watercolor classes.
[2:58] I'm like going to dog training.
[2:59] I'm going to the gym.
[3:01] I might then play pickleball.
[3:03] I don't know.
[3:04] Me too.
[3:04] I'm just having a year to just take my foot off the accelerator because the last few years I've just been doing too much and trying too hard.
[3:14] Trying too hard.
[3:16] But thankfully your brain is upgraded to its optimum format.
[3:19] Well, yeah, I think it might be just at its time.
[3:21] like it's like, like kind of reached its limit.
[3:24] Reset.
[3:26] I love that you're getting a gap year and doing things.
[3:31] I took up banjo this year and knitting, so I can crochet as well.
[3:36] But I thought I'm going to learn some new things too.
[3:38] But can you tell me the names of the books that you've written?
[3:43] So the first book, I don't love the name.
[3:46] I didn't want to call it that.
[3:48] However, it is called The Women's Brain Book, The Neuroscience of Health, Hormones, and Happiness.
[3:54] I wanted to call it all on her head.
[3:56] However, the publishers at that time in the marketing department thought, oh, it's a bit like the girl on the train or the woman in the window.
[4:05] So they thought all in her head might sound a bit too much like domestic noir.
[4:09] Sure.
[4:10] Not like neuroscience.
[4:12] So that was a bit disappointing.
[4:14] But that's okay.
[4:15] The second book then, so that was 2018, beginning of 2018 that came out, then in 2020,
[4:22] 23, I published Baby Brain, which we have already said, the surprising neuroscience of how pregnancy and motherhood sculpt our brains and change our minds for the better, 2023.
[4:32] And then earlier this year, so the first half of last year, I spent writing Brain Health for Dummies, which is part of the For Dummies brand.
[4:39] So that's just come out in the last month or two.
[4:44] And the second half of last year, because there has been so much new, cool neuroscience,
[4:52] In women's health, I felt like the Women's Brain Book needed an upgrade.
[4:58] It needed to be updated with all of this new neuroscience because I was starting to get a little bit, not embarrassed, but I'd hand it over to people and go, oh, but there's so much new stuff and some of it's outdated and read some of it but not all of it.
[5:10] And so then I thought, I'm just going to update that.
[5:12] So I spent the second half of last year updating that.
[5:15] So the updated version of that with the same title but a different cool new cover comes out in July this year.
[5:22] Brilliant.
[5:23] I love that.
[5:24] So I say there's three and a half books.
[5:27] Three and a half books.
[5:29] That's three and a half more than most of us.
[5:32] So hats off.
[5:34] Tell me, along with the little bit of research that I did about you before kicking off this podcast episode, what's your familiarity with Andrew Huberman?
[5:46] Oh, Andrew Huberman.
[5:49] I was like, what's she going to say my familiarity with him?
[5:51] So back in the last century –
[5:56] So my PhD topic was looking at this sort of development of the visual system, very early postnatal development of the visual system.
[6:05] And I was really interested in how neurons and the visual pathway wire up.
[6:10] very early in development and what kind of guides those connections.
[6:14] So is it like nature?
[6:16] Is it nurture?
[6:16] And when it comes to visual system, is it like completely genetic or is it determined by actually what we see?
[6:22] Does seeing guide visual system development?
[6:25] And so his PhD was at the same time on a very similar topic.
[6:29] And then, um,
[6:32] I went to like neuroscience summer camp for PhD students, which is so nerdy, but was very cool.
[6:41] I do like a little like, you know, excursion with fellow scientists.
[6:45] So I went to Cold Spring Harbor Lab in Long Island near New York, where they run science camp for academics.
[6:53] And I did structure and function of the visual system, and Andrew Huberman was also doing the same program.
[6:59] So we spent about three weeks hanging out, and so I met him then.
[7:03] And then later that year, then I went back over to the U.S., and we hung out a bit more doing neuroscience, going to a conference.
[7:11] And then I went back and had Thanksgiving at his mum's house, which was very nice of him to put me up there.
[7:18] And then we kind of kept in touch briefly because we were both doing –
[7:22] same topics and then lost contact but then like kind of reconnected again a few years ago before he became famous um and um he did some teaching on one of my because i run online professional development courses and he did some teaching on one of my courses and
[7:40] And then one day he said, I think he was starting a podcast.
[7:42] And I was like, oh, that's a really good idea.
[7:44] I think there's a market for people talking about neuroscience.
[7:48] He said, you'll probably do quite well.
[7:50] And now, like, you can't even ring him up on the phone.
[7:52] Like, he's trying to get hold of the king or something.
[7:56] Yeah, he's proper famous now.
[7:57] So, really.
[7:58] Yeah.
[7:59] It's kind of wild.
[8:00] He's done really well.
[8:01] Yeah?
[8:02] He's done very, very well.
[8:03] Fantastic.
[8:04] Amazing.
[8:04] That's my Andrew Heumann story.
[8:06] Yeah.
[8:07] Just would like to add that there was never any romantic connection because people seem to think that because we went to summer camp together, there must have been never a touch.
[8:16] I was already dating my now husband at the time.
[8:19] It was professional friendship only.
[8:22] Fantastic.
[8:23] I assumed as much.
[8:24] People always like the juicy gossip.
[8:26] There's none.
[8:28] No, you're just friends.
[8:29] That's completely fine.
[8:31] All right.
[8:31] So today we're going to talk about the topic of matrescence.
[8:38] And can I just say that Google and spellcheck don't recognize matricence as a word yet?
[8:45] No, it doesn't.
[8:46] No.
[8:46] It's the best word.
[8:47] I wish I had known that word when my boys were little because they are now 15 and 16, turning 17.
[8:55] And had I known that word 16, 17 years ago, I think things would have made, I mean, sometimes one word can just shift your way of thinking.
[9:08] And like, I don't even think the internet was a thing then, but it was, there was no, there wasn't that much information out there about this.
[9:16] I thought that like you had a baby, you got pregnant and it was this event and then you had the baby and that was another kind of event and then you looked after the baby and
[9:27] And it was some parts were great and easy and other parts were like the hardest thing I've ever done.
[9:33] And had I known that matricence and kind of encompassed that whole process as a journey of becoming, and had I known it was neurological and social and spiritual and psychological and physical and all of the things, in the same way adolescence is, like we can say matricence is a bit like adolescence, then I think I just would have given myself a whole lot more grace.
[9:56] because I was pretty tough on myself and I found it hard and I thought that I shouldn't find it hard.
[10:04] And people didn't talk then about how it was hard.
[10:10] And had I known that matrescence was a process of becoming, then I think it would have given me insights into what was happening.
[10:20] a growth process, not a failure, not a problem to be solved, not a thing I didn't manage to do right.
[10:28] Yes.
[10:29] And I love that inference that you make in your book that matrescence is like adolescence.
[10:34] And society recognizes that it's a huge transition for children to go from being children into adolescence and the amazing changes that happen in their body and their brains.
[10:47] And you talk about matrescence,
[10:50] It's the maternal version.
[10:51] Yeah.
[10:52] I thought, I didn't know that, because I always said parenting, like the easy part with the babies, because my boys are very straightforward and I didn't, you know, I had very straightforward pregnancies and deliveries and straightforward babies who ate very well and slept very well and they were, by all accounts, what you would say easy.
[11:14] But it was so hard.
[11:16] So it wasn't them that was hard, it was me that was hard.
[11:19] I couldn't understand who I was and what I was doing and why I felt so different.
[11:27] Right.
[11:27] Because I didn't know that that was part of the process.
[11:30] I thought it was just like having a new friend.
[11:33] You don't yet look up.
[11:35] Like that you looked up.
[11:35] I don't know what I was thinking.
[11:38] You know, like you meet someone and they're just this new person in your life.
[11:41] It doesn't alter every cell in your body.
[11:44] Let's talk about the altering of cells in your body.
[11:48] So from what you know of neuroscience, what happens to us when we get pregnant?
[11:53] Yeah.
[11:54] So in short, the way I like to sum it up is that pregnancy prepares the mind for motherhood.
[12:02] So we are very familiar with the idea that pregnancy and then, you know, you deliver a baby and then you nurture the baby.
[12:10] A large part of what happens to your body is growing the baby, but then also growing.
[12:16] preparing your body to nurture the baby so if you choose to breastfeed but
[12:21] That process is also shaping and sculpting your brain.
[12:24] A process that we're very familiar and comfortable with talking about happening to other animals, other mammals, and we're just biological mammals too.
[12:31] So the process of pregnancy doesn't just shape our bodies.
[12:36] It actually shapes and sculpts our brain.
[12:38] And a lot of the shaping and sculpting and changing that takes place in our brain, the neurological shifts and changes take place during pregnancy.
[12:47] We now understand that and they're driven largely by the hormones of pregnancy
[12:51] and they completely reorganize the brain and even change it structurally with the intention, because we understand which networks change, of being able to respond and nurture and care for your baby.
[13:04] We know that it's about responding to the baby's cues and needs and wants because the parts of the brain that change most, all the parts of the brain change, but those that change most are involved with social cognition or reading social cues.
[13:18] So what someone else is thinking or what someone else is feeling.
[13:21] I mean, you don't really need, you know, pregnancy isn't changing your brain.
[13:25] So you need to worry about what your boss thinks or feels.
[13:27] It's to keep your baby alive.
[13:28] You know, the evolutionary mandate is to keep this new baby alive.
[13:31] So your brain has changed to enable you to do that.
[13:35] We are largely social creatures and we also learn how to parent.
[13:40] Not all of knowing how to take care of a baby as a human mammal is important.
[13:45] innate, the baby doesn't pop out and we know what to do.
[13:48] We need to learn how to do that from other people.
[13:52] But I think that what the intention, and I'm using those words loosely, Mother Nature's intention is that the learning curve is a little less steep.
[14:03] because our brain is kind of being primed to learn how to respond to our baby's cues.
[14:08] That is in much the same way as every other sort of mother, particularly in the mammalian kingdom that we have studied.
[14:14] We know that pregnancy shifts their brains so that they deploy the appropriate kind of maternal behaviours
[14:22] We can talk about maternal instinct and what that means because that's a very loaded term, but the appropriate parenting behaviors to keep that baby alive.
[14:31] What we've now, I mean, it started in 2009, the research, but it started being published about 20%.
[14:37] 2017 so we've kind of got what like eight years now it's not a lot actually of research in this maternal brain space and it's continually new new stuff is coming out all the time new research is always emerging this really cool women involved with doing that research yeah we're now understanding the specifics about the brain structural reorganization what's driving it and kind of why and i mean it's the why is for the baby
[15:02] Of course.
[15:02] I mean, we're entering into a new phase of life.
[15:05] Yeah.
[15:06] We need a new brain for it.
[15:08] Yeah, yeah.
[15:09] And that's what I said.
[15:10] It's not like getting a new friend who's just like hanging out in the house with you.
[15:15] Really, you need to be doing nothing else except focusing in on that baby to keep it alive.
[15:21] Much and all is we think we're still going to keep on doing all of the other things that we've always done and nothing will change.
[15:26] Yeah.
[15:28] you know, there's some other, there's some neurological shifts.
[15:31] So we're growing, it's not just our uterus that changes and we're not just pumping blood to this tiny little baby while it grows, while we're pregnant.
[15:40] Our actual brain is changing.
[15:42] You said the whole brain changes.
[15:46] Yeah, the first studies that came out, um,
[15:49] which have got a really cool origin story, which I can talk about.
[15:51] We're looking at just the struck.
[15:53] They were like doing brain scanning studies.
[15:55] So like MRI, like let's look at a group of women before their first pregnancy, very important that they haven't been pregnant before.
[16:03] And the same group of women after that first pregnancy,
[16:06] It's actually really hard to do because you scan a woman who isn't pregnant yet, and then she has to actually go away and get pregnant.
[16:13] And then you scan her afterwards, and the process isn't always, as everyone knows, isn't always straightforward.
[16:18] So to get enough women to run a study and you didn't scan her brain and then have to wait five years for the baby, it's hard science to do, but we're getting better at that now.
[16:29] This field is blossoming.
[16:30] And so looking at the structure of women's brains before and after that first pregnancy,
[16:35] we could see that the parts of the brain, particularly the grey matter, which is kind of like the wrinkly grey matter, if you're looking at a whole brain, you're holding it in your hands, what you kind of see on the outside has got slightly thinner, particularly in parts of the cortex,
[16:51] involved with social cognition.
[16:52] Now, that sounds like, oh, my brain is dissolving or is, you know, diseased or is dysfunctional.
[16:59] But we see the same during adolescence.
[17:02] So that's why I said adolescence is a bit like matricence, when as a very normal healthy part of brain development during teenagehood, the brain gets slightly thinner.
[17:12] And we understand very well from teenagers, both looking at animal models and looking at humans,
[17:18] that that is involved with the emergence of new behaviors and new skills, like growing up and becoming a bit more of a capable human.
[17:26] And that's a process of pruning and fine tuning of the connections in the brain.
[17:31] And the brain almost becomes streamlined.
[17:33] And that's a much better way of thinking about pruning and tuning and streamlining versus degeneration.
[17:39] So when we say shrinkage, that implies loss, whereas when it comes to the brain's
[17:47] Volume change, volume loss can sometimes mean it's kind of improving.
[17:52] It's like kind of getting leaner and meaner.
[17:54] And so we think the same thing is happening in the pregnant brain.
[17:57] Overall, what we see, the difference between before and after
[18:00] that first pregnancy, we see a 4% volume loss, which is actually quite a lot.
[18:04] 4% doesn't sound like a lot, but there's a lot when it comes to an event that takes place in the brain.
[18:09] And, like, we scan the brain immediately after the baby's born, and then we scan it a few months later.
[18:15] You see a little bit of a bounce, like the brain kind of bounces back.
[18:19] But the changes remain enough that if you were to scan the brains of women in their 80s,
[18:27] we've now got enough data to say mother, not mother, mother, not mother.
[18:30] So the changes are permanent.
[18:33] So it doesn't just change in its function.
[18:35] It's not like it fires differently.
[18:38] It actually physically looks different.
[18:39] It physically looks different in that the gray matter is slightly thinner.
[18:43] Like if you were just to look at it, it would look slightly thinner, which might look like degeneration, but it's not.
[18:48] It's streamlined.
[18:49] It does also function differently as well.
[18:52] So we can look at the structure of a brain, but we can also look at the function of a brain.
[18:56] So we can take a photo of its structure or we can take a video of it in action and look to see how does one part of the brain communicate with another.
[19:04] So we're looking to see often how efficient the different networks in the brain, like how well organised are they, how easily do they connect and communicate.
[19:14] And interestingly, if you look at a new mother's brain, a lot of those networks are actually far more efficient and flexible and well connected.
[19:24] So the entire focus...
[19:26] which I'm trying to change away from talking about motherhood and brains as being just like one of dysfunctional, emotional kind of foggy messes is actually, if we look at it objectively at that brain is far more efficient and well connected and is actually working better than it, than it did before it had the baby.
[19:48] You know, we can see the function change as well.
[19:50] What they have tried to do is,
[19:53] is look to see do the structural changes relate to the functional changes.
[19:59] And so they've done some kinds of studies where they're able to look
[20:02] look to see how responsive is the mother to her new baby.
[20:06] Not necessarily around attachment, because that's, again, a loaded term, but if a mother's listening to sounds of her baby cry versus another baby's cry, how strongly is her brain reacting?
[20:18] The brains that have changed more structurally also have a stronger functional response.
[20:23] There's definitely an underlying reason for that.
[20:25] It's enabling us to tune in to the baby.
[20:29] We don't have, I would love this data to come out.
[20:32] This is from rats and mice.
[20:35] but everyone who hears it goes, oh, I reckon that's in humans too.
[20:39] There is some work in rats and mice that's looking at hormones postpartum, in particular oxytocin, which we know is involved with breastfeeding and love and cuddles and snuggles and attachment with the baby.
[20:54] In rats and mice, oxytocin changes the wiring and auditory cortex, so the part of the brain that hears things
[21:03] So a baby mouse's cry is like ultrasonic.
[21:06] It's so high-pitched you can't hear it.
[21:09] In fact, adult mice can't hear baby mice crying unless they're lactating.
[21:14] And it's the oxytocin that has changed the auditory cortex so it can hear the baby cry.
[21:20] So what happens when you have like a new baby and like you're asleep at night and then the baby, you hear the baby's eyelids open before it even cries, like you wake up.
[21:28] I reckon that oxytocin is doing something to our sensory perception and input.
[21:34] Maybe our auditory cortex is so finely tuned to our baby.
[21:38] I don't think we hear its eyelids open.
[21:40] I'm being a bit silly.
[21:41] But it doesn't take much to wake you up and to tune into the baby.
[21:46] We've got some data that shows that the processing in a brain of a new mother is responding much quicker to the sound of a baby crying, particularly her own baby.
[21:59] than a brain that's not a mother.
[22:02] The few things that really stuck out to me was firstly that a lot of the research seems to be less than 10 years old.
[22:08] Have we even missed any of this?
[22:10] Yeah, yeah.
[22:12] It's super new.
[22:13] Yes.
[22:14] New.
[22:14] I mean, so I was a midwife six years before the very first research came out on this, so I wouldn't have even been told that in my training.
[22:22] No.
[22:22] So what you're saying is when we get pregnant, our brain, obviously our body reorganizes itself in lots of different ways in order for a baby, but our brain does the same thing.
[22:32] And on an elementary level, we see production in grey matter, and that's not about.
[22:40] less function in the brain.
[22:42] It's what you called prune and tuning.
[22:45] So we almost get the brain.
[22:48] Yeah, it's almost like prioritizing various tasks over others.
[22:53] It's prioritizing us to respond to the baby.
[22:56] Right.
[22:57] And so a reduction in volume of grey matter doesn't mean a reduction in function or, you know, that we're less brainy.
[23:04] Correct.
[23:05] Correct.
[23:06] Yeah.
[23:08] And the timing about you being a midwife is interesting because the first paper that was published was end of 2016, early 2017.
[23:17] But the idea for that came out in 2009.
[23:20] So that's how long it takes to do science a lot of the time.
[23:23] and I have to tell this story because it's a very cool story.
[23:26] It's these three Spanish women, one Dutch, Alselina Hoxiemitz, and Erica Barbara Muller, and a woman, Susanna Kamona, who's done such an amazing job leading this field.
[23:37] And they were like...
[23:38] just driving a car off to the pub to celebrate Erica's honors thesis or master's thesis that she'd submitted.
[23:46] And then they said, oh, what are you going to do next in life?
[23:48] She says, oh, I might have a baby.
[23:50] And then they went, oh, what will happen to your brain?
[23:52] Ha, ha, ha.
[23:53] And then they started going, what will happen to your brain?
[23:55] And they worked in a brain imaging lab.
[23:57] And then it was 2009.
[23:59] What would you do now?
[24:00] You look on your phone.
[24:01] You, like, start reading the research on your phone.
[24:03] But it was 2009.
[24:04] You couldn't read research on your phone then.
[24:07] So they turned the car around and went back to the research lab.
[24:10] They didn't even go to the pub.
[24:11] They didn't hate the pub.
[24:12] They went back to the lab and then started, like, because they wanted to, like, they were so captivated by the idea that,
[24:18] And they started going through the research and they were going, there's nothing.
[24:21] There was literally nothing.
[24:23] There was a little bit on animals.
[24:25] And so then they were like, well, why don't we do the study?
[24:27] And so then they stayed up all night and they literally designed the study.
[24:30] They said, we're going to get women who've never had a pregnancy and scan them before and after.
[24:35] And so they ended up scanning themselves at the time none of them had babies.
[24:39] And then they were like, we need a control.
[24:40] And so they scanned the father.
[24:42] These were all heterosexual couples.
[24:43] And so they scanned the father's brains as well.
[24:46] which has proven to be super interesting in its own right, looking to see what happens with the male brains.
[24:51] And now they've just recently published a study where they've got lesbian couples.
[24:56] So they've got like the mother who's given birth and then they've got the other mother who didn't give birth but went through that whole process to like do that kind of comparison.
[25:05] So they've done a lot of research and it almost blasted open the door of this like entire new discipline.
[25:12] They're still putting new stuff out all the time.
[25:14] and there's just so many cool women and there's mostly women involved in the space doing this research.
[25:21] Some of the newer stuff that's published, a lot of the, a lot of it, it's like this kind of like really pioneering research, like, like kind of Marie Curie that they're, they're doing the experiments on themselves.
[25:35] So one woman, she was in a brain researching group and she,
[25:40] She knew she was about to go through IVF and she said to her friends, why don't we scan my brain through my pregnancy because we'll know the exact date I'm going to fall pregnant and it was successful.
[25:50] So we'll know the date of conception.
[25:52] And then they were able to scan her brain at multiple points through her pregnancy, which is very hard to get ethical approval of to do it with people.
[25:59] But she was informed enough to be able to do that and they took her bloods every day that they scanned her so they've got this like,
[26:06] They call it dense sampling.
[26:08] So they've now got this brain scan of this one woman's pregnancy.
[26:12] And that's all open access data.
[26:13] So that data is all now being shared.
[26:14] So we're now able to see exactly when in pregnancy the changes start to happen and take place, mostly in the third trimester, mostly correlated with estrogen levels.
[26:27] And then there's some really wild data, which hasn't been picked up.
[26:32] more broadly and perhaps for some people is uncomfortable in that women who have had labour and delivery versus women who didn't have any experience labour, the structural changes are greater.
[26:46] It's almost like labour and delivery, as they say, gives the final push of plasticity.
[26:51] It kind of makes those changes bigger, the structural changes bigger, which is essentially the brain responding to the hormones of labour and delivery in that process.
[26:59] brain has responded to that.
[27:01] It's not to say it makes the brain better.
[27:03] It's just the brain has responded to that as well.
[27:06] So there's so much exciting new work coming out.
[27:10] I did read all about that study.
[27:12] That one was called Pregnancy Leads to Long-Lasting Changes in Human Brain Structure.
[27:19] And I guess, yeah, partly I want to highlight to people that this was the first, 2016.
[27:24] Yeah.
[27:25] And if you've never heard this before, this is why.
[27:28] Yeah.
[27:29] We knew that pregnancy is spectacularly transformative of women's bodies, but it's the same of women's brains.
[27:35] And as you're saying, labor and birth is all part of that transformation as well.
[27:41] Yeah, and it was women in these positions asking these questions and being able to get the funding and being able to do the studies that have driven the field as well.
[27:52] No one was asking the questions before because –
[27:56] And I think it's almost like it's a generational shift that we've seen in the last 10 years of women working their way up kind of in the research fields and being able to ask questions at it.
[28:08] We've got thousands of studies on left-handedness.
[28:12] I know.
[28:13] Do you know, I was mortified.
[28:14] I'm currently doing some researching for some podcasts on preeclampsia.
[28:20] And the number of research papers that talk about the importance of the women having exposure to their partner's sperm by any means outnumber some of the other more important topics that,
[28:32] And I'm like, how did we get so many papers on the importance of exposing yourself to male sperm?
[28:40] And we still have really only recently discovered not only that women's bodies and brains change in pregnancy, but, you know, things like the anatomy of the clitoris is pretty brand new as well.
[28:51] When I wrote my first book, Along Those Lines, I...
[28:55] I was writing about the neurobiology of orgasms, which was rather interesting.
[28:59] And then I was like, oh, multiple orgasms.
[29:01] Like surely there's a basic neural circuit there involved with the repetition in women versus habituation in men.
[29:10] And I found about three or four papers on it and three were on multiple orgasms in men.
[29:18] They weren't even looking in the biological sets where they happen.
[29:23] They were trying to figure out how they could make it happen where it doesn't.
[29:26] Of course they were.
[29:27] You've just got to laugh.
[29:28] That said, because I'm an eternal optimist, I just find it exciting that the research is now emerging at a time when I just get to watch it from the sidelines and share it on instead of it all being done 30 years ago.
[29:42] It's contemporary and it's new and it's exciting.
[29:47] So I'm just a bit selfishly grateful that it's happening now.
[29:50] I think it's great.
[29:51] And, I mean, this even came out before.
[29:54] So I finished my PhD in 2014 and I actually was doing it while I was pregnant.
[30:01] And I remember, I mean, I felt the change.
[30:07] occur in me where I literally just wanted to crochet and watch cartoons and I thought what is going on I was usually you were nesting absolutely I thought but I was capable of writing a PhD but not in that moment so I wanted to ask you women describe baby brain but what is baby brain oh I've got many thoughts on this that's why I call the book baby brain so um
[30:34] I'll caveat by saying I never experienced it.
[30:37] However, I didn't know it was a thing.
[30:41] And I had boys, and there's like one weird study saying mums of boys are less likely to experience memory loss than mums of girls.
[30:50] That's never been replicated.
[30:52] So I don't know.
[30:53] I went into this not experiencing it.
[30:56] And so I did take a little bit of my bias in there, which I've tried very hard to shake off over time.
[31:03] because lots of women experience it.
[31:05] And I was really interested in what it was and is it real and what's the evolutionary kind of mandate for becoming forgetful.
[31:13] So baby brain is this, you know, how a woman would experience, describe, not so much like what you were doing, which I would call more like nesting, just kind of wanting to be cosy and just kind of at home.
[31:24] And, you know, there's a drive to isolate yourself because it's biologically you don't want to get infections and stuff before you have the baby.
[31:30] That's a woman on a kind of nest and that's healthy and be expected in some cases.
[31:36] But baby brain is more about feeling forgetful and foggy and not being able to pay attention and not being able to remember all of the things and using the wrong words or not remembering the aims or putting your purse in the fridge, all of the stories that you hear.
[31:50] I think it's really important, though, to look at it in terms of during pregnancy and then after pregnancy because they're entirely different neurological and physiological states.
[31:59] But we tend to use them colloquially across both.
[32:03] So I was kind of interested in that and kind of interrogating them separately.
[32:09] So first I looked at, well, I mean, not me, I looked at the data that other people have explored looking at what do we see during pregnancy.
[32:18] The best way to do any kind of study is a longitudinal study, like is to take a big group of women and follow them before pregnancy, during pregnancy and after pregnancy, not comparing a group of pregnant women here and a group of non-pregnant women there.
[32:32] You've got to look at how one woman works.
[32:35] or a large cohort kind of change.
[32:38] And all of the large cohort studies that have tested memory and attention and all of these different cognitive skills before, during, and after don't find any kind of alterations.
[32:50] We're not picking up any objective changes in memory whatsoever.
[32:55] And that's kind of interesting because if you say to the woman, look, here's your test scores, she'll go, well, I don't believe you.
[33:02] Because I feel different, but objectively the test scores aren't.
[33:05] So there's something going on there.
[33:07] If we look at just during pregnancy, some studies do find in the third trimester, which interestingly is when most of the brain reorganization takes place, do find some, you might normally get 20 out of 20 or 19 out of 20 on a test result.
[33:24] you might get 17 out of 20.
[33:26] So you might just drop a couple of marks.
[33:29] It's not clinical.
[33:30] It's not anything that we would worry about.
[33:32] But women are noticing that in their everyday life.
[33:36] There's also a big difference from going and sitting in a nice, calm, quiet cognitive testing lab with no distractions versus trying to do all the things in everyday life.
[33:47] So third trimester, we find sometimes there are little aspects of different types of memory loss.
[33:54] By the same token, there is some research being done that's found memory enhancement in the third trimester, particularly for, like, instead of just remembering random items, remembering baby-related items, so things that you're kind of already paying attention to.
[34:07] So there's some data showing enhancement then as well.
[34:11] And the tests that have been done in motherhood, we're not really picking anything up at all.
[34:16] So it's pretty unclear.
[34:18] We can't say women lose their...
[34:21] unforgetful during pregnancy and motherhood the data's not supporting that but women are saying that they're feeling that so how can we kind of interrogate that paradox and that's when it gets really interesting because if we look at say a group of women who say they have baby brain but their test scores are fine there's a quite a strong correlation there with overall well-being so like how are you getting enough sleep do you have lots of social support networks around you are you feeling like you're coping yeah
[34:48] physically how well are you, mentally how well you are, the higher someone scores on overall wellbeing, the less likely she is to rate her memory as bad.
[34:56] For instance, if she's scoring very poorly on overall wellbeing, she's much more likely to relate to her memory as bad.
[35:02] And it's also important to think about memory.
[35:06] This is how I always explain it.
[35:08] It's not just like memory.
[35:10] like you've got memory but you've got attention and attention is kind of like a funnel that determines what information comes in and what to filter out.
[35:17] So when you've got a new baby and your brain has been reorganized to focus in on the baby, your brain hasn't been reorganized to also remember what?
[35:28] all of the things that you have to do in the workplace, to also remember the grocery list, to also remember where your kid put his shoes and who's got homework due and the dog needs to get vaccinated and all of the other things.
[35:40] It's primarily focusing on the new baby.
[35:44] And you can't remember all of the things
[35:48] But because we've been told, oh, baby brain, you'll become stupid and forgetful when you have a baby, women are blaming their own neurobiology for not remembering everything when it's not their brain that's letting them down.
[36:01] It's the support that she's not getting.
[36:05] You can't do all of the things.
[36:07] It's not that you can't do all the things.
[36:10] You shouldn't be having to do all the things.
[36:12] Women who are well-supported and nurtured and looked after and have lots and lots of support systems around them are much less likely to report baby brain because they're not trying to do all of the other stuff.
[36:20] They're only trying to look after the baby.
[36:22] There's lots of sort of social aspects in this sort of narrative we have as well.
[36:28] Yes, and I wondered if it was something like that in a sense of, I'm actually only going to remember the things that are most important to me at this point.
[36:37] Anyway, and that's why I'm subconsciously forgetting or not paying attention to some things.
[36:44] Yeah, and especially if it's your first baby and you're in the third trimester, it's really hard to, like you're constantly being reminded the baby's there.
[36:51] You're not sleeping.
[36:52] The baby's moving.
[36:54] It's full on.
[36:55] It's exciting.
[36:56] It's scary.
[36:57] You've constantly got this internal physical distraction inside you.
[37:03] So it is hard to focus and remember.
[37:06] but I suppose Mother Nature intended us to be trying to do all of the things and all these expectations that we have on ourselves or responsibilities that we have.
[37:17] It's interesting because throughout in Baby Brain I've spent a lot of time
[37:22] surveying my sort of audience and putting lots of questions out and getting information back.
[37:27] And I had a few women kind of respond saying that they didn't have baby brain and they had really good experiences.
[37:35] The two that I remember most clearly, you know, that were like, so I just had baby brain.
[37:43] No, I had a great experience.
[37:44] And then both of them were expats living in Asia and they had live-in nannies and live-in help.
[37:51] Yes.
[37:52] Yeah.
[37:52] And I was like, well, there you go.
[37:55] That's we all need extra wives.
[37:57] I know.
[37:59] Extra help and extra – that's – and that was almost like, well, there we go because they weren't trying to do absolutely everything as well as tend to their new little bubby.
[38:10] Well, is there anything that we know about – is there anything women can do to facilitate or nurture the changes that are going to happen in our brain already?
[38:19] Yes.
[38:21] Are there known factors that can enter this process?
[38:25] Well, I mean, the changes that take place structurally to do all the reorganization are driven by pregnancy hormones.
[38:31] So you have as much control over them as you do over the onset of labor or how big your boobs grow.
[38:40] That's a pretty biologically driven process.
[38:44] I mean, we can only but support ourselves in all of the other ways that we know
[38:50] power to make sure you know you've got no sleep and you've got lots of good food and all of those kind of health and well-being things that we know would support us are also going to support our brain i think once the baby arrives then you know this i do talk about baby rain there's kind of like three sort of three kind of main themes in terms of women who have a
[39:16] easier time of it or healthier outcomes versus those that don't who are around sleep and around social support and then just this sort of self-identity.
[39:26] So sleep is really hard to come by.
[39:28] And that's when we're not, you know, we didn't evolve to parent alone.
[39:34] We're co-parenting mammals, but we're still parents.
[39:37] think that we have to do it all.
[39:39] If there's some way to sort of share the care, you can't obviously do that if you're breastfeeding and you're trying to establish breastfeeding.
[39:45] But if there's some way to, there is a psychiatrist I spoke to in the book who says she gets her patients to kind of do these really super detailed maps and timetables of the day for every member in the family to kind of map out and plan out
[40:00] when there are times in which more sleep can be scheduled in.
[40:04] Yeah.
[40:05] Because if you've got more capacity for sleep, you've got more capacity for everything.
[40:11] Everything is harder without it.
[40:13] It's not necessarily easier with it, but it's harder without it.
[40:20] Understanding how sleep cycles work is also really important.
[40:23] And I know lots of,
[40:25] new mums or women like, you know, the kids and the baby go to bed and then they don't want to go straight to bed because they just want some alone time.
[40:34] And the only time is at night when everyone else is asleep.
[40:37] But what we do know is when you fall asleep, the first sort of third of the night or maybe the first two or three hours of the night are when you fall into your deepest sleep.
[40:47] And that's your deep, restorative, healthy sleep.
[40:50] Now, you know, when you fall into that and you're in deep, deep sleep, you've been asleep for like one hour and the baby wakes up, it's so hard to wake up.
[40:59] But if you've got that locked in and then you move into your shallower sleep, your more dreamy sleep and the baby wakes up and you've had six hours sleep, or even five, it's much easier to wake up and it feels less disturbing.
[41:12] So if we can somehow, and if you're a single mum or by yourself, it's going to be very hard.
[41:18] But if you're not, then there are other adults who can help facilitate you getting that good solid block of those first few hours undisturbed sleep.
[41:26] because then everything is easier.
[41:28] But that requires like the cavalry, right?
[41:30] Those social support networks.
[41:32] And I wish that women didn't have to sort that out themselves.
[41:36] Yes.
[41:36] I wish it wasn't up to the women to ensure that there was the people there to help because that's another thing that we have to organise.
[41:42] Yeah.
[41:43] That's right.
[41:44] But that's our lot, it seems, sometimes, that we also have to ensure that we have organized the helpers instead of them being embedded or organized.
[41:52] Yeah.
[41:53] Well, we have to reorganize society so that we can prioritize our brain reorganization.
[41:58] Of course, we're responsible for that.
[42:01] But in your book, you talk about in baby brain that the major changes happen in the maternal brain in the third trimester, you were saying.
[42:11] The biggest structural reorganization changes, yeah.
[42:15] And we think that then the brain becomes very plastic, which just means it's really easy for it to learn by experience.
[42:24] That's why I think it puts you in a state where the learning curve isn't so steep as it would be, as if the new baby arrived and you haven't gone through that pregnancy.
[42:35] Yeah.
[42:35] And you touched on it earlier.
[42:38] If that process is interrupted, so let's say even hypothetically a woman has her baby at 32 weeks or 34 weeks, earlier than a full gestation.
[42:48] We already know about the impact of early term birth on a baby's brain.
[42:54] Do we know anything about the impact on a woman's brain?
[42:58] Sarah, shaking her head for anybody else.
[43:00] Yeah, no, we haven't got that data.
[43:01] We haven't got that research in yet.
[43:03] I think it would be ethically quite difficult to, you know, you've got a mum who's given birth to a baby who's 12 weeks preemie.
[43:12] Can we scan your brain?
[43:15] Yeah, I mean, I just want to say.
[43:16] Yeah, I'm not sure we've got, we haven't got that data.
[43:21] Yeah.
[43:23] yet, that doesn't mean it's not going to turn up.
[43:26] It's, I mean, I'm just trying to think of the ethics and the logistics of getting those new mums who are going to be so vulnerable anyway is, yeah, they're going to have to be pretty altruistic to want to offer themselves up just.
[43:39] Have their brains scanned to say, oh, can we see what happened to your brain when you've had a preemie baby?
[43:43] Or you've lost a baby?
[43:44] We don't know.
[43:45] The only data that we do, there's some data, because women are often rightly so, interested in what happens if they lost a baby very early in pregnancy.
[43:56] Yeah.
[43:57] So there is some cool research that's very sparse, looking at this phenomenon of microchimerism.
[44:05] Because the placenta isn't just like kind of a wall between the mother and the baby.
[44:11] It's kind of like this biological interface that allows some things through and not others.
[44:16] And it does allow some of the baby's cells to come into your bloodstream, which now we kind of understand because now I think you can even get a blood test to find out the sex of your baby.
[44:26] Is that correct?
[44:27] And also people don't understand the placenta has a biological sex because it's from this fertilized egg.
[44:34] and then half of it becomes the baby, the other half becomes the placenta.
[44:37] So you've got a male placenta or a female placenta, which I think is very interesting.
[44:41] And we think the male placenta is maybe slightly more vulnerable to like insult or, you know, stress or whatever in utero, which is why male babies are slightly more vulnerable to neurodevelopmental disorders.
[44:57] And they're often born a little bit smaller and they're often, you know,
[45:01] Little girls are often a little bit more robust at birth than little boys.
[45:05] It might be to do with the biological sex of the placenta, but that's pretty new research, but I think it's fascinating.
[45:10] But anyway, the placenta, male or female, does allow the passage of cells through.
[45:13] And some of these fetal cells, because they're so immature, they're almost like stem cells and they can kind of embed all throughout your body and your brain and your heart and your lungs and then can be detected naturally.
[45:27] throughout your life because they all kind of become integrated and become like a functional part of you.
[45:32] So if you had a male baby, even if you lost it very early, there are some cases where older women, autopsies have been done or tissue being taken.
[45:44] Obviously, you can't take tissue from your brain when you're still alive.
[45:48] That has got XY chromes, like these individual cells just kind of specked through
[45:53] that have got XY chromosomes that came because she had a male pregnancy.
[45:57] Yes.
[45:58] And then sometimes the woman was like, well, I only had daughters, and they were like, did you ever lose a pregnancy?
[46:03] And she will have, and it would have been a male.
[46:06] Yes.
[46:07] So there is this lovely idea that you carry a little bit of each of your child within you, even if you lost them.
[46:14] So it may not have completely reorganized your brain, but there's still a little bit, which who knows what the kind of the,
[46:21] what's the adaptive evolutionary benefit for that?
[46:24] Maybe there's not one for everything.
[46:26] Maybe it's just so when we found out it comforted us.
[46:29] Yeah.
[46:30] Yes.
[46:31] I think I'm going to go with that.
[46:33] I always posted about that on Instagram and someone said, you know, you should be far more scientific and I think you're making far more of this.
[46:39] And I was like, oh, well, if it makes someone feel better who's lost a pregnancy, then I'll
[46:46] I think each pregnancy and each baby does change us as people.
[46:52] And, you know, and I've heard people say, and it's true, you know, even a mother of a baby who didn't survive is still a mother.
[47:01] because you had a baby, you know.
[47:03] Yeah.
[47:05] But you did, yeah, and you alluded to, you know, just when we interrupt that change by either a preterm birth or miscarriage or, you know, pre-labor cesarean section, that there's, I guess, a loss of that finishing off of the transformation that happens in women's brain.
[47:27] Yeah.
[47:28] So the research, this is kind of one study that's looked at, is there a difference between the method of delivery?
[47:36] So if someone went through labour versus not, and the changes are kind of, but it's not massive, but you can pick it up, the changes, the structural changes are kind of greater in the woman who had labour and delivery.
[47:48] So there's something about that biological process, which kind of, they called it the final push, which kind of also...
[47:57] changes that brain structurally.
[47:59] Yeah.
[48:00] When Dr. Sarah Buckley, who does a lot of research on oxytocin, talks about the hormonal gap of cesarean section where there is that oxytocin gap.
[48:11] But then there's been some research in the oxytocin field that talks about how you can fill the...
[48:18] hormonal gap.
[48:19] And for women who've had cesarean sections, they can fill the oxytocin gap by things like extended skin-to-skin and breastfeeding.
[48:28] Yeah, because breastfeeding, you know, is a pretty – I mean, you know, you've got oxytocin and prolactin kind of working together, you know, for however many years you want to breastfeed.
[48:43] So I think there is that, like, kind of gap, but I think –
[48:48] I reckon the dose of oxytocin could be eventually accumulated if you were breastfeeding or skin to skin.
[48:56] And, you know, there's plenty of people who have wonderful, amazing parents who didn't give birth.
[49:05] I just think we need to be careful about how we present the data because some people can get quite – people tend to personalise this kind of stuff and you have to be compassionate.
[49:16] Of course.
[49:19] Does it change each pregnancy?
[49:21] Like do we get cumulative changes?
[49:23] If we have more babies, do our brains get better and better and better?
[49:26] Or is it just – No.
[49:27] I think the biggest change is that first pregnancy.
[49:30] And most of the research – and that's where some of the like earlier sort of studies looking, you know, mucked up the research a bit because they were sometimes looking at first-time mothers, sometimes looking at women that had three or four babies –
[49:46] And so they weren't like doing science very carefully.
[49:51] But it does appear, the biggest change is that first pregnancy.
[49:54] Right.
[49:54] Like you, that's, your brain is now a mother.
[49:57] And the pregnancies after that, there doesn't seem to be the same massive reorganization as,
[50:03] And it's also interesting because there's been a little bit of research looking at kind of those early stages, those kind of first few weeks of motherhood, when particularly with the first baby, you're very, very hypervigilant as well, and your nervous system is kind of quite dialed up.
[50:19] Also, possibly because you haven't quite...
[50:22] figured out how to look after the baby yet so it doesn't want you to like forget the baby's there so you're like really on but and how that manifests is all of those intrusive thoughts that so many of us had particularly with our first baby's going to fall down the stairs or out the window or on the floor or out of the car or we just are filled with like the disaster scenarios I guess it's almost like we're trying to rehearse how to keep the baby safe
[50:48] And our mind is trying to make meaning of the fact that we're very, very hypervigilant, which I think is, again, kind of an adaptive mechanism to keep us on while we're figuring out this motherhood business.
[51:01] Because people don't typically have it as much for second or third or subsequent babies.
[51:06] We don't see women reporting the same feelings of catastrophe and having the same intrusive thoughts.
[51:15] And also we don't see that same nervous system kind of.
[51:18] hypervigilance.
[51:20] And the kind of the thing that's really important is that you typically should kind of dial off over, you know, kind of weeks or months.
[51:28] And if it doesn't, that's a very strong risk factor for developing postnatal anxiety and then depression.
[51:34] Right.
[51:36] It's completely normal.
[51:38] Yeah.
[51:38] But you hope that you're not still, you know, six months later, consumed with a thought about something terrible happening to your baby every minute of the day.
[51:47] It's pretty normal in the first few weeks.
[51:50] So we're initially dialed in and wired to be hypervigilant to the safety of our babies, but it should peter off over time.
[51:57] Yeah, and it's not usually as strong with the second baby.
[52:02] You're usually just a bit more like casual and then I'm sure once you get up to baby three or four or five, they don't probably, you would never consider that they would fall out the window.
[52:13] Because by then, you know what to do.
[52:17] You know how to keep them safe.
[52:19] Yeah.
[52:20] And in your book, you talked about the maternal motivation system and anxiety.
[52:27] We know how our brains change, but why do they change?
[52:30] How does this change benefit the woman and the baby?
[52:33] And, you know, you've alluded to the fact that our brain has to change so that we are wired to care for our newborns.
[52:40] Yeah, I mean, I suppose it's – and I've tried to be really careful with a lot of the language because –
[52:46] And I kind of wanted to go a bit deeper and kind of interrogate it, I suppose, in terms of these ideas about maternal instinct and maternal motivations and maternal behaviors.
[52:56] Because you don't want to assume that simply because you had a pregnancy that you know how to look after the baby and you're going to be a brilliant mother.
[53:03] Because we have to figure it out.
[53:05] Not everyone is.
[53:06] And I often get people say to me, oh, well, my mother was neglectful or abusive and she carried me.
[53:13] Like, why didn't her brain make her look after me appropriately?
[53:17] And that's because so much of that is, as I say, needs to also be learned.
[53:22] But I was really interested in some of these ideas around maternal instinct and the motivations to care and what they mean.
[53:31] So first of all, I just wanted to sort of survey everyone asking them, what does that word even mean?
[53:36] And it has very diverse meanings for people.
[53:40] Some people mean it to be like –
[53:47] I desperately wanted to have a baby before I had one, that kind of almost like biological clock.
[53:52] Some people were like, I never wanted a baby, so I never had one.
[53:54] Other people were like, I desperately wanted to have babies and I knew.
[53:56] So some people take that to mean.
[53:57] maternal instinct others took it to mean like the moment you first laid eyes on your baby what that felt like and whether you were like i knew i loved them from i knew who they were straight away whereas other people are like i don't know shit like they had no feeling like they're just detached which is also normal um and then others took it to mean down the track you know you've got a kid coming home from school and they walk in the door and you know they've had a terrible day before you've even
[54:24] consciously registered that you just feel it in your in your chest because you're a mother and that's your maternal instinct um so i was kind of interested in and understanding all of those different meanings and what we understand about about the biology under them and then i've you know humans are so complicated and we vary so much of the
[54:48] We bring our own stories and our histories and everyone else's tales and we know quite a lot about the maternal brain from other animals.
[54:56] Mice and rats in particular are super interesting because I talk about this one study where they developed this kind of mouse-pup delivery system.
[55:08] So one of the main kind of maternal behaviours that rodents do
[55:13] display is kind of they gather their pups up from wherever they are in a lab, it's in a cage, kind of bring them all together in the nest.
[55:20] And then if you put a pup in different parts of the cat, they'll just always constantly eat.
[55:25] be gathering the pups.
[55:26] And sometimes they'll be doing so much gathering that they'll see their own tail and they'll gather the tail and they'll see their own foot and they'll gather their own foot.
[55:34] And so this researcher years ago developed this pup delivery system whereby he, every time the mother kind of gathered the pups and we would kind of put them in this delivery chute.
[55:46] And so, you know, he said he got and she would gather the pup and then the pup would go back in the chute and gather the pup.
[55:52] So there was this constant conveyor belt of her few little pups.
[55:55] And he said the experiment stopped because he got bored and tired.
[55:59] She kept gathering and gathering and gathering.
[56:02] She was just utterly motivated and driven to nurture and care for her babies.
[56:08] And then they would do things like put electrical grids.
[56:10] So she would get electrical shocks on the way to get the pups.
[56:13] And she would still go and get electrical shocks to gather the pups back.
[56:18] So, you know,
[56:20] as mammalian mothers are very, very, very driven to care and nurture and keep theirs safe, and different mammals have different ways of deploying those behaviours.
[56:32] So a dolphin mother isn't going to be gathering her babies, but it's a large part of the maternal behaviours, like a mother dolphin and a baby dolphin will be about recognising each other
[56:44] each other's like squeaks.
[56:47] So, you know, there's a lot of auditory recognition there.
[56:49] And herding animals like sheep, you know, the herd of a flock of 100 sheep and 20 of them gave birth on the same day.
[56:58] So how does the mother know the mother and the baby go together?
[57:03] Well, that's all about smell recognition.
[57:05] So the mother learns the smell of her baby lamb as she has her process of labour and delivery puts her,
[57:14] olfactory brain and this massive state of plasticity and learning and as she's like licking all of the birth fluids and you know the placenta and everything off her baby she learns her baby's smell and then the baby learns who she is basically by default he just goes around randomly around all the mums and then the one that's not his mum kicks him away or ignores him and he learns which one's his mum because she's the only one that pays him attention so
[57:44] So there's different animals depending on the ecology will deploy different behaviors and will be motivated to behave in certain ways.
[57:56] Yeah.
[57:58] We, all humans everywhere on the whole planet, are very motivated and driven by.
[58:04] to respond to baby's cries.
[58:05] So, wherever in the world, if the baby cries, we've got to pick it up and we cuddle it and stop it crying.
[58:09] That seems to be almost one of our maternal behaviors that we deploy and we love cute things.
[58:16] We love cute puppies.
[58:17] We love cute cartoons.
[58:19] We love, you know, big eyes and there's this whole field of study about cuteness and how we are driven towards cuteness and babies are super cute.
[58:29] They smell cute.
[58:30] They sound cute.
[58:34] which is good because they are really annoying and disruptive and make life very difficult, but we're still driven to care for them despite everything, all the chaos that they bring.
[58:48] Well, and you mentioned in your book that, so and I've written a sentence here that I wanted to, you know, remember, that pregnancy triggers neuroanatomical adaptations that prepare a woman's reward circuit to maximally respond to cues of her infant, thereby increasing the incentive value of their newborns.
[59:07] So they get like a dopamine hit.
[59:10] Yeah, yeah.
[59:11] And it's an addictive process to respond to your baby.
[59:15] Yeah, it does.
[59:16] They are almost addictive.
[59:17] And you know that smell that a newborn baby has?
[59:20] Because the smell is – and so we've got all of these cues which just make us want them.
[59:26] And so the reward system essentially teaches us what was really good or bad last time so we do it again or don't do it again.
[59:34] And so the first few times you experience something that's just so –
[59:38] like smell of a new baby.
[59:40] It's just so, you could eat them.
[59:42] It's so captivating.
[59:44] And it's just feels so good that you just like constantly been driven to your baby.
[59:50] And that's despite there being aversive cues, like they're pooey nappies and they're crying and you're sleep deprived and the chaos.
[59:59] They have something that's our maternal brain, part of that plastic process, makes our reward system so super sensitive to the tiny little reward we get from them.
[1:00:09] We will respond despite the aversion.
[1:00:13] And that's perhaps what could go wrong.
[1:00:15] And some women who don't attach properly, especially women who some really interesting work's been done over many years from a group in Israel looking at women who, let's say, hadn't
[1:00:28] serious depression and give birth to their baby, even from day sort of one, two, three in the hospital they've been studied and they won't necessarily, they'll find early motherhood hard and they won't necessarily as attach to the baby as closely and they're able to kind of see those consequences play out if there's no intervention.
[1:00:47] So, you know, it's really important to understand what are these drives and what is happening so when it goes wrong we can intervene early.
[1:00:56] And there's no long-term consequences.
[1:00:59] So then we know like the pregnancy changes that happen in our brain kind of prime us to parent our baby.
[1:01:06] Does that,
[1:01:08] active parenting change our brains what impact is there on the the non-birthing parents or if you're posturing or adopting or maybe through surrogacy or something yeah yeah yeah so that's that's super interesting the first um sort of look was at the dads the male the males of the male partners of the mothers from that first study and initially in comparison to the mothers it was like there's no change
[1:01:34] like the mother's friends were so, the children were so big, the fathers were just like, nah, flat line.
[1:01:40] But then like they looked just at the fathers and they got some more data and they kind of looked more closely.
[1:01:45] And then when you just looked at that data set, you were able to see, well, there are some like subtle differences between different dads.
[1:01:51] And it's kind of,
[1:01:53] interesting because the degree of change seen in the brain is what we would call dose-responsive.
[1:02:00] So how much they parent, so how much interaction they have with the baby, how hands-on they are as a father.
[1:02:08] They've kind of quantified the degree of care or involvement.
[1:02:12] And obviously, you know, the father can be there for conception only and never be seen again.
[1:02:17] Or he could be the primary caregiver.
[1:02:20] And so the more caregiving that is done, the greater the change.
[1:02:24] Which, like the more, like, you know, you hit a golf ball once versus being a professional golfer, your brain will be different.
[1:02:31] So we see that with anything.
[1:02:32] The more you perform any task, the more changes you'll see.
[1:02:38] Are there changes, like, super specific towards caregiving?
[1:02:42] Or are they just changes that have come about by performing a task regularly?
[1:02:46] is kind of, I suppose, where we're at and what we're trying to figure out because there's very different parts of the brain change in the males.
[1:02:53] I haven't looked closely yet because the data came out when I was in Antarctica on the lesbian mums to see, but I know that there's not a significant change in comparison to the birth mothers.
[1:03:07] I don't know if they've compared those non-birthing mothers to the,
[1:03:13] fathers.
[1:03:15] They have done some study comparing like adoptive mothers versus birth mothers in terms of
[1:03:22] not looking at structure, but like doing EEG, so putting like a cap on and recording brain waves.
[1:03:27] And that's pretty interesting because that's showing the response to the baby is the same.
[1:03:32] You couldn't differentiate between the two.
[1:03:34] So, you know, the adopted mums love the babies just as much as the birth mums.
[1:03:41] So that was really nice, that research.
[1:03:45] But, you know, it's pretty – it's so new.
[1:03:47] All this work is just sort of coming out.
[1:03:53] Yes.
[1:03:54] That's so interesting.
[1:03:55] I mean, I feel like those are the questions I had from just my reading of one of your books, Baby Brain.
[1:04:03] Do you feel like there's anything we haven't touched on in the work that's in there?
[1:04:07] Yes.
[1:04:09] I think it's a really, it's a very exciting time.
[1:04:12] I touched very briefly, I suppose, what we haven't really talked about is the kind of
[1:04:17] the long-term effects of motherhood and parenting on the brain and that we, we definitely see traces of pregnancy or motherhood and the brains of women and much, you know, even women in their eighties.
[1:04:30] Now we've got big data, big data sets.
[1:04:32] We've got machine learning and AI.
[1:04:35] We can ask some pretty sophisticated questions and do some pretty sophisticated data analysis.
[1:04:40] Couldn't do years ago.
[1:04:41] And so now, you know,
[1:04:43] AI is able to pretty reliably say mother, not mother, mother, not mother, even someone who was in the 80s.
[1:04:49] So the traces last.
[1:04:52] There is a little bit of research suggesting that women who have had a pregnancy and raised children are perhaps slightly protected against unhealthy brain aging or against dementia, right?
[1:05:07] um just stop you getting it just lowers your risk slightly so long as you don't have more than four babies um and we don't know whether that's the big doses of hormones of pregnancy because the dose of estrogen you get in one pregnancy is greater than the dose that you get in the entire rest of your life combined so that's a very significant amount of
[1:05:28] hormone that you're receiving in one go.
[1:05:31] And we don't know whether those massive doses, if you have three or four babies, build resilience against aging or whether it's motherhood and like all of the constant up-leveling and gamification of your family that you have to do that is like building cognitive reserve.
[1:05:49] But once women have more than four babies, that sort of benefit seems to wash away, but that could be because having more than four is really stressful.
[1:05:58] And malnourishing sometimes to have that amount of pressure on your body.
[1:06:02] 100%, yeah.
[1:06:02] So...
[1:06:05] We're starting to, you know, so there's lots of interesting sort of research emerging.
[1:06:11] I think it's really exciting.
[1:06:15] A new research focus and thankfully on women and at this really important stage of our lives.
[1:06:23] Thank you for writing the books.
[1:06:24] I know it probably felt really challenging at the time, but we appreciate it.
[1:06:27] Yeah, the second one was Baby Marie was fun to write.
[1:06:31] I think the challenge was the first book because I'd never done it before.
[1:06:35] And then the second, it was like, and after that, I was like, I'm never doing this again.
[1:06:38] It was exactly like having a baby.
[1:06:40] Then I put her back to tears and I was like, oh, I could do that again.
[1:06:43] Like I kind of, it's that after all.
[1:06:46] So the second time was much easier because I knew what was happening.
[1:06:49] But it's fun.
[1:06:50] But now I'm on a.
[1:06:52] I'm on a long service leave.
[1:06:56] I'm on a long break.
[1:06:58] I'm going to put the names and links to your books underneath in the show notes of the podcast, and so people can click on through and find any of Sarah's stuff if this is of interest to you.
[1:07:08] She's having a break, but you can still consume all of her books.
[1:07:11] Yeah, you can.
[1:07:12] Yeah, you'll get more of the story as well.
[1:07:14] We kind of glazed over as much as we could in this episode, but for all the details, have a look at the books there, and that will be in the show notes.
[1:07:22] Thanks for being here, Sarah.
[1:07:24] Oh, well, thank you so much.
[1:07:25] It was great fun.
[1:07:26] I like the vibe.
[1:07:27] It's good.
[1:07:28] Vibe.
[1:07:29] Yeah, I mean, people seem to like it.
[1:07:31] We try.
[1:07:32] Amazing.
[1:07:33] Well, that's been this episode of the Great Birth Rebellion podcast, and we will see you next week.
[1:07:39] To get access to the resources for each podcast episode, join the mailing list at melaniethemidwife.com.
[1:07:46] And to support the work of this podcast, wear The Rebellion in the form of clothing and other merch at thegreatbirthrebellion.com.
[1:07:55] Follow me, Mel, at Melanie the Midwife on socials and the show at The Great Birth Rebellion.
[1:08:01] All the details are in the show notes.

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