XXplored Podcast – The Neuroscience of Motherhood

Narrator:

Welcome to "XXplored: Women's Brain Health," a Dementia Researcher podcast exploring the many factors that shape women's brain health across the lifespan.

Narrator:

Welcome to "XXplored: Women's Brain Health," a Dementia Researcher podcast exploring the many factors that shape women's brain health across the lifespan.

Dr Laura Stankeviciute:

Welcome to another episode of "XXplored: Women's Brain Health." And today, we're going to be discussing the transition to motherhood, the neuroscience of matrescence, becoming a mother, and what it means for long-term brain health. Around 80% of women worldwide will experience this biopsychosocial transition at least once in their lives. We know that pregnancy incredibly changes the woman's physiological body. And in concert with these bodily changes, women experience psychological alterations, but also motherhood leaves a remarkable imprint on the brain and literally brain starts rewiring during pregnancy through its structural changes, but also it has a huge impact on its function.

So today, we will try to dissect these changes and follow the story from the very beginning of those hormonal changes to the brain changes and what it means for the mothers to feel it and for the symptoms, cognition, and also the superpowers that maternity comes with. So I've been really, really looking forward to this episode and recording it today. It's a huge pleasure because I'm joined by two incredible scientists that are really leading the charge of maternal brain research in the neuroscience field.

And not only are scientists themselves, but they are also at the mument navigating what it means to be a mother, what it takes for the brain to change, and what it takes for the brain and the body and the new baby to bond all together. So, I'm really excited for this conversation and a very warm welcome for Dr Magdalena Martinez-Garcia and Dr Laura Pritschet. Thank you so much for taking the time of your busy scientist and mother schedules to join me today.

So usually, I start by describing our guests, but your biographies are so rich and so full of achievements that I would rather pass the microphone to both of you and actually give you a little bit of a mument to describe what you do, what's your research about. And what is mostly for me and for some of our listeners interesting is what brought you to this field. What was that thing that really motivated you to study women's health and specifically maternal brain health? So, I would like to start with Dr Magdalena. I know that you are a scientist and scientific director of the Maternal Health in the Ann S. Bowers Women's Brain Health Initiative at the University of California Santa Barbara.

So, what does this role mean? What do you do?

Dr Magdalena Martinez-Garcia:

Hello, thank you for having me. Yes, I recently joined the Ann S. Bowers Women's Brain Health Initiative as Scientific Director of Maternal Health. And it means that I have this incredible opportunity to think about the research programme dedicated to study the human maternal brain. So basically, we have different studies, mostly longitudinal studies, to track how the maternal brain changes during the perinatal period. So before pregnancy, during pregnancy, and then the postpartum period. And we also try to identify collaborators worldwide to leverage these unique data sets and advance maternal health. What brought me to this field, it was actually, it was just chance. I was a neuroscientist.

I was studying neuroscience in the University of Barcelona, and then I met my previous supervisor, Dr Susana Carmona, and she was, she really launched this field of the human maternal brain. And at that time, 2016, she was wrapping up this paper that was going to be published in Nature Neuroscience discovering for the first time how pregnancy profoundly changes a woman's brain. And I joined her lab as a PhD student and that's how my journey started.

Dr Laura Stankeviciute:

Wow, this is so beautiful to just see how one mument in your life can bring you to building such a big career out of it. And I obviously like know of Susana Carmona herself and she's a great pioneer of the field and obviously a great mentor to people like you who then followed her footsteps. So what about you, Laura? Did you also have a similar kind of fall into the rabbit hole?

Dr Laura Pritschet:

Yeah, so I got interested in women's brain health because as an undergrad, I was surrounded just by the timing of life, menopausal women. So women going through menopause, experiencing fog and hot flashes, simultaneously training in psychology to study cognition and neuroscience. So, it was sort of a merge of those two interests. And I found Emily Jacobs at the University of California Santa Barbara. Magda and I are linked there, who was kind of at the forefront of studying the neural underpinnings of menopause fog and other aspects of women's health. And I thought, this is all I want to do ever. I want to understand and get answers for these women and help improve their lives.

So, I'm a traditionally trained cognitive neuroscientist. I'm a postdoctoral scholar now at the University of Pennsylvania. And I am exploring many different parts of the female reproductive lifespan. I, you know, still very interested and involved in menopause research, but in order to understand menopause and how it influences brain ageing, I think we have to go back a bit. And I think we have to look at accumulation of reproductive events. So, I'm really knee-deep in pregnancy research right now, and I'm sure we'll talk about the various studies Magda and I have done.

But I'm just trying to chart what normal brain trajectories look like over the perinatal period and then later link all of those events together.

Dr Laura Stankeviciute:

Yeah, this is very interesting and I love that you are kind of zooming out from that one event being a menopause and actually asking questions what is happening before and whether things that are happening early in the reproductive lifespan actually has to do something with menopause or the risk of Alzheimer's disease that we all have already talked about this podcast, but obviously there is never enough research, but never enough time to discuss the research. And it's beautiful to see how these long-term effects can potentially impact the brain health in later life. So before anything starts to change, the first changes, the first incipient blocks that start to alter are our hormones.

That then lead to changes in the brain, and then the whole cascade what is happening in the postpartum. So, they are the real chemical architects of pregnancy, if I may say. So, I'd really like to unpack what kind of hormones are kind of, you know, orchestrating the whole cascade of the pregnancy and postpartum, the whole perinatal process. And I think it's very interesting for our listeners to understand that apart from these traditional sex hormones such as oestrogen and progesterone and testosterone that we've talked already quite a lot on this podcast, there are other very important players, especially prolactin and oxytocin in the bonding between the mother and the child.

So, I would really like to ask Laura, what is really happening?

Dr Laura Pritschet:

Yes, exactly. Pregnancy in the perinatal period is marked by massive changes in hormones. The biggest degree of change you're going to experience in your life. So, I like to benchmark it really against the fluctuations that are occurring across the menstrual cycle. So across the menstrual cycle, typically we see about a 12-fold rise in oestrogen that falls right around the ovulatory window, and then about an 80-fold rise in progesterone in that second half of the cycle, the luteal phase. Now when we think about pregnancy, we're seeing surges into the hundreds to thousandfold increase in hormones. So, let's walk through it.

So when pregnancy begins, we start to see this dramatic rise of oestrogen, progesterone, these sex steroid hormones peaking in the third trimester. Again, they're going to be the highest levels of hormones you're going to have in your lifespan. Other hormones like cortisol, prolactin, they're going to show more of a gradual increase over that period. Then when we talk about labour and delivery right around birth, we're going to see this big peak in oxytocin. And then, what's really interesting and very important is what happens in the postpartum period, especially immediately postpartum. You're going to see a precipitous drop in oestrogen and progesterone.

Again, the highest drop that you're going to experience in your life. So it's very, very critical window. Followed by a gradual decrease in those other hormones, like prolactin and oxytocin, depending on certain lifestyle and behavioural factors like breastfeeding and stress, sleep disruption, eating patterns, things like that. So, what we like to always say when we're exploring the effects of hormones on the brain, especially when it comes to mood and behaviour, is that it's not necessarily about the absolute concentrations themselves because those will range from person to person, but it's pretty textbook. You're going to see a, you know, linear rise in these hormones.

But what matters a lot is your sensitivity to those changes. Those can trigger an onset of affective dysregulation and are implicated a lot in these mood disorders and perhaps cognitive fog that we're seeing. So, it's a very important and complex hormonal transition period. And just to set the stage, sex hormones are neuromodulators. So ask yourselves the question, what does it mean for the brain when I have a hundred thousand fold rise in oestrogen? Obviously, it's going to play a role and help shape the brain. It's there for a reason.

Dr Laura Stankeviciute:

Yeah, well, that was such a great introduction and kind of a run through what is happening throughout the whole gestational period and postpartum. And I think what is interesting, do hear a lot of talk about oestrogen and progesterone kind of peaking and being very important in the first trimester that is being the most kind of vulnerable. But then, I feel like oxytocin in the societies kind of still talks as only the hormone of love or kind of relationship. But I do think that being a scientist is probably a bit of an oversimplification if we can say it.

So could maybe you, Magdalena, explain a little bit more the importance of oxytocin in pregnancy and specifically obviously in the postpartum after giving birth, what it means, what does this hormone and neuromodulator do for the brain of the mother, but also for the infant itself.

Dr Magdalena Martinez-Garcia:

Yeah, oxytocin is a really interesting. Neuropeptide hormone, I know it's known as the love hormone, but it does many other things. It's very interesting. It's a very interesting hormone because it's produced in the brain in these really like subcortical areas within the brain. And it can be released to the brain and also in the periphery. So, one of the main things that oxytocin does at late pregnancy, and we know this from rodent studies is it participates in the activation of maternal behaviour. So, it reaches specific receptors in the brain and it switches like switches on this neural circuit that makes the mother to behave maternally with the pups.

And probably this is also true in humans, also it's a little bit more difficult to quantify. Then when it's released in the periphery, it can it's part of the hormone cascade that stimulates uterine contractions for childbirth. And then immediately after childbirth, it is also responsible for the letdown of breastfeeding, so like milk ejection. So, I would say those are the three main things that oxytocin does across the perinatal period.

Dr Laura Stankeviciute:

That's great to know that. And also understand that this is not what the kind of the popular science only tells us, but there are different pathways, as you said, express in the brain, then it has a target in the brain, but also in the periphery. So, that is very important to distinguish. And now we have covered the ebbs and flows of these hormones through pregnancy and postpartum. So, I think it's the perfect time to now segue into the actual science of matrescence and what is happening in the brain during this. And obviously, Magdalena, you have really done a lot of work in this area. You came from the lab of one and only Susana Carmona leading the first steps, the first building stones of the science.

So, you have found a lot of very fascinating discoveries about pregnant brain actually shrinking in a way that is obviously put very, very simply, but we are observing very strong structural changes across different areas of the brain. And I feel like a lot of women, when they hear that, oh, my brain is shrinking. I'm losing grey matter volume or cortical thickness. Is it a sign of the neuronal loss that is actually disadvantages, that is bad simply put for the brain or is it actually having a different mechanism? So, could you explain what's what this volumetric or volume loss really means?

Dr Magdalena Martinez-Garcia:

So, this all started a decade ago now in Spain. I think I was at the right time in the right place when I met Susana Carmona and I joined her lab. And she was she had done this really like beautiful type study following first-time mothers before pregnancy, and then after pregnancy. So two time points, they were scanned with magnetic resonance imaging also known as MRI. And Susana and her collaborator, Elseline Hoekzema, they discovered for the first time that pregnancy led to these really pronounced grey matter reductions. So when we were comparing before pregnancy and after pregnancy, we observed, as you were saying, grey matter reductions. Now, what does this mean?

We actually, one decade ago, we can't answer that question. We don't know what does it mean in terms of like the, you know, like the cellular mechanism behind this. We need more research. But what we know is that these patterns of grey matter change that, grey matter reductions that then recover, they are really consistent. We observe them with cohorts of over 100 women, but we have also seen this in one individual woman tracked at many time points. Laura will talk more about this. They are very consistent. And then, the other thing we know is that they are associated with postpartum maternal bonding. So the more the grey matter is reduced across pregnancy, the more attachment the mother feels with her infant.

So, that association suggests that these grey matter changes are adaptive for motherhood. Now, this doesn't mean that they make you a better caregiver. Caregiving is a learning process. It means that it allows you perhaps to better bond with that baby, to have that motivation to care for the baby. And then you were also asking about if these changes are transient or we see them long-term. We did a follow-up study of these first-time mothers and we followed them through the years up to six years postpartum. And we saw that these brain changes or part of these brain changes persisted up to six years postpartum. So, way longer than the immediate postpartum.

So these results, even they are preliminary, we need to replicate them with higher sample sizes, but they suggest that these pregnancy-induced brain changes may be long-lasting and even permanent.

Dr Laura Stankeviciute:

Wow. This is fascinating. And just knowing that these hormonal changes in preparation for giving birth and in preparation for the bonding leads to this pronounced alteration and neuroplasticity in the brain that are just beautiful to witness from the science perspective. And another follow-up to this question would be more about that specific reductions in the areas such as the theory of mind, obviously related to the bonding, important for the maternal and child relationship in the future. We see those in mothers who were the first time mothers, first-time mothers initially in the studies, but what about the cumulative effect?

Do we have any research on whether a mother has gone through pregnancy twice or three times? Do these effects kind of stack up or there's no change between the one-time pregnancy and more pregnancies?

Dr Magdalena Martinez-Garcia:

So for many years, we have been studying first-time mothers because we really wanted to characterise the impact of that first pregnancy. But actually recently, I think this year, Elseline Hoekzema just published a study where she scanned women before and after pregnancy in a first pregnancy, and then a second pregnancy, and then compare those changes. And the team found that a second pregnancy also induces these grey matter reductions, but they are less pronounced. So there seems to be a cumulative cumulative effect, but the first pregnancy is kind of the most pronounced change, and then following ones may induce just more nuanced changes.

We are now leading a couple of studies to really characterise these trajectories across the second pregnancy, both at the individual level and at the cohort level, tracking women also during pregnancy. So just stay tuned for those results in a couple of years. And then, we also have evidence from the UK Biobank. So, this is a large scale data set in the UK + where many people, including women, are scanned in their midlife just once. So, they are cross-sectional studies. And then, they also have information about how many children they have. So, these dataset has led to a couple of studies that suggest that the more children you have, up to four, the more brain changes you have in your brain.

Like there's a trace of having children in your brain long-term. So we now need, you know, to complete the dots and have longitudinal studies that follow women across a full reproductive period, ideally. That would be a dream project to really see if these long-term changes are due to pregnancy or just lifestyle associated with being a parent or caregiving them so.

Dr Laura Stankeviciute:

Yeah, you are touching on so many interesting points that I would like to really kind of unpack in the next 20 or so minutes. But now, I'd like to actually bring Laura into the conversation because you, Magdalena, were talking about these changes where you measured the brain before pregnancy and after pregnancy. And I know that both of you were involved in the study. And Laura, you are the first author of this fascinating publication where from 2019 to 2022, you were following one person, a single subject, and that subject has been scanned 26 times throughout the whole pregnancy period. So, that is a truly what we call in the field precision medicine and precision imaging study, right?

So could you explain to our listeners, what does it mean if that the study can be called precision imaging? And what did you do during that work? Because obviously, scanning was one big part of it, but definitely not the full iceberg.

Dr Laura Pritschet:

So, we were extremely motivated by work out of the Carmona lab looking at how the brain changes from before pregnancy to after pregnancy. At the same time, our lab at the Jacobs Lab at UCSB was trying to kind of push the envelope of studying hormones in the brain via this sort of precision imaging approach, where we're kind of flipping that cross-sectional model where you may get data from a lot of people, but only at a couple time points or one time point typically.

And then saying, "What if we take a smaller set of people but we scan them or study them over, you know, several days, several weeks, several months to explore how hormonal fluctuations influence the brain?" And so that together kind of came, we kind of came up with this idea to say, "Okay, we know, you know, pretty replicably, it's one of the most consistent findings in neuroscience now that grey matter volume is going to change in the perinatal period. But how do we get from point A to point B?" And you know, until a few years ago, we really hadn't explored that period at all and what I mean is pregnancy gestation for a variety of reasons. But that's when a lot of the interesting things are happening.

You know, how do we again get from point A to point B? Is it linear? Is it not? Do all of those changes in the brain happen in the second trimester, the third trimester, or in the first week postpartum? We just didn't know. And, so we had a wonderful volunteer, Liz Krastel, who was professor at the time who self-disclosed that she was going to go through this process starting with IVF and said, and volunteered as the superwoman she is, "Why don't we just start with one person and scan my brain as I go through this through pregnancy?" So, every few weeks from preconception through IVF, through every couple weeks of her pregnancy into two years postpartum, we would scan her brain.

We would get structural sequences to look at anatomy. We'd get functional sequences and diffusion sequences to look at white matter, paired that with hormone measurements and cognitive testing to just ask for the first time, what does the brain do over this whole period? And the results are really interesting but it really compliments the approach, the sparser sampling or cross-sectional approach, yeah.

Dr Laura Stankeviciute:

Wow, this definitely sounds like a huge work, not only for the scientists, but for Liz herself who volunteered her brain and the body and the child to be born for the science. And one thing you already kind of mentioned that I wanted also to ask Laura is that Liz was going through the IVF, which stands for the in vitro fertilisation. So I wanted to ask, do we have any evidence of whether natural kind of pregnancy or IVF pregnancy does have different effects on the brain whilst it's going through the gestational period and after pregnancy?

Dr Laura Pritschet:

In a zoomed out way, this is work that was in the original Nature Neuroscience piece from the Carmona lab, where they explored spontaneous conception versus those with IVF. They show largely the same degree of magnitude of change, if I'm right in characterising that Magda. So, there's not this massive difference between them. If we were to study this acutely where we looked at someone deeply as they go through the IVF process versus compared to say just a menstrual cycle, we may see subtle differences there. But as I like to show in the figure where we have her hormonal levels during IVF, it's a blip compared to the hormonal change that happens over pregnancy.

So you can assume, yes, you could isolate that effect and maybe see some subtle differences, but really what's happening over pregnancy itself, there isn't much of a difference between the ways in which you conceive. So not a tonne of difference there, but it's an interesting question.

Dr Laura Stankeviciute:

Thank you so much for delineating this because obviously, we are seeing a huge increase nowadays in IVF pregnancy. So, I think a lot of audience may want to ask questions like that. And now, I'd like to move a little bit to a perhaps more vulnerable territory and discuss something that is a bit less discussed in science, but also in the general public when it comes to the conversations about the maternal health. Because mostly when we talk about the maternal health, we assume that it ends in a living birth, right? But it's not always for all women. And some women definitely experience pregnancy that doesn't end that way. We have a lot of people who actually have abortions, who have stillbirths and miscarriages.

So does the brain, by that point, has that changed enough? Obviously, there are like different trimesters, but do we have any evidence on these difficult type of pregnancies that don't end up in living births? Magdalena, what can you comment on that?

Dr Magdalena Martinez-Garcia:

First of all, I would like to point out that we should start appreciating more those stories and listening to women that have gone through miscarriages, stillbirths, or abortions. Let them tell their stories and don't diminish their experiences, because it's really therapeutic for women to talk about their experiences. And sometimes, these kind of experiences are very silent. So, I just wanted to mention that. I wish one day we could, you know, talk freely about this and not having to listen something like, "Oh, you know, you'll get pregnant again," or, "That's okay, that was not meant to be," because that really hurts.

For the science we, I mean, we know from the data sets that we have in Spain and the ones in California that the brain starts changing already in the first trimester. So technically, yes, if you have a miscarriage, that late first pregnant, late first trimester or second trimester, third trimester, your brain technically, yes, has started to change. But I have to say that we haven't included those women and those experiences in our research so far. But hopefully, we have a dedicated study in the future just with just perinatal loss, so we can understand how these interruptions of pregnancy, you know, result in different brain trajectories.

And if those brain changes revert, if they revert, the same as healthy pregnancy after, you know, in the postpartum period. Those are really interesting questions. And I think in the beginning, we always think that maybe those women, they don't want to participate in science, but I think that's not true. I think women that have bad experiences across a reproductive lifespan, I think that they are the most motivated participants, so yeah just. I just wish that, you know, researchers that are listening are motivated to also start these kind of studies.

Dr Laura Stankeviciute:

Yeah, thank you so much. And I think what you said at the end, that women who had difficult reproductive experiences, they definitely don't want to be silenced, but I think sometimes the society pushes them to be, but they have strong voices. And women have been deprived for so many years of answers that they are very keen and very eager to understand what is happening to the body. So with that, I would actually like to pivot to not only mothers, but also other caregivers, such as fathers, potentially grandmothers, and any other people who not necessarily have gone through the process of giving birth themselves. But what is what do we know about these changes?

Is it just specific to mothers themselves who have given birth or also caregivers like fathers or other people responsible for child rearing also express some changes in the brain or if not in the brain in different psychological adaptations? I know that Magdalena probably knows a little bit on this, and then if Laura can add some comments, that would be great.

Dr Magdalena Martinez-Garcia:

Yeah, so we know from rodent studies that just the experience of taking care of a baby, of your offspring induces neuroplasticity. In our studies, we not only scanned mothers, we also scan their partners. So, we scanned fathers as well to be able to disentangle or differentiate between the effects of pregnancy, and then the rest of caregiving and kind of social factors of becoming parent. And we found that fathers also experience a degree, some certain degree of brain changes, but it's not as pronounced as the mothers. So basically, our studies suggest that pregnancy factors are the main contributors to the really pronounced brain changes that we are observing.

But you know, the caregiving environment also produces some changes that are worth studying and exploring. We also know that fathers can also experience postpartum depression as mums. So yeah, it's worth exploring.

Dr Laura Stankeviciute:

Yeah, thank you so much. It seems that there's not only the hormones, the endogenous drivers that are inflicting those huge changes in the brain of mothers, but there's also this environmental effect and the actual bonding with the child itself that can lead to some neuroplasticity in father's brain. And obviously, we have been talking a lot about the brain, the changes, the different areas of the brain. We definitely see these changes in amygdala, in the hippocampus that are very important for emotional regulation, for the memory.

But when I hear about maternal brain in the kind of social media, there is this huge discourse, huge noise about the baby brain or sometimes we also hear terms like mumnesia basically kind of being very forgetful, having lapses and attention, being very easily distractable. So, is this baby brain like a cliche? Is it just a stereotype or does it have like real grounding when we talk about the cognitive functioning? Not just like the structure, which obviously is very closely related, but does it actually lead to pronounced memory difficulties such as subjective cognitive decline or memory issues? So Laura, what what can you tell about this? Can you bust the myth or are you going to back it up with some science?

Dr Laura Pritschet:

So this is a really important topic, something that Magda and I are asked probably every day, "Can you lay claim to mummy brain?" There's two really important things here to note. One is I think generally researchers in our field want to reframe it a little bit, but at the same time, and we'll talk about our own experiences with this, there are subjective reports of change. I'm feeling different than I was preconception. Postpartum, I'm feeling like my memory is not the same or my attention is stretched. So I don't want to ever just say, "Oh, that doesn't exist. There's no evidence for it, " because women are telling us constantly that they're feeling differently. And I think that's important to acknowledge.

There is a slew of research to suggest that, yes, subjective reports of cognitive change are occurring. And in various stages of the perinatal period, we see slight objective differences, but that isn't long-lasting. And in fact, we have evidence that increased cognitive load, which is what we think is kind of happening there, can be advantageous later on in life. So it's not all bad, but how I like to think about it and frame it is that anytime your brain is changing, it's a period of opportunity for plasticity and a period of vulnerability, whether it's neurological or psychological. And so much is happening when you're pregnant and in the postpartum. And your attention, it can be all over the place.

Your sleep is disrupted. You're thinking about new things. Your theory of mind is evolving. And so yes, you may have pregnancy brain if I dare say the term, but I like to always say the anecdote of yes, you may have forgotten where your keys were or texting someone else back and that may be really pervasive and feel very different than how it was in pregnancy. But at the same time, you should acknowledge, address, and take comfort in the fact that you are also exerting a lot more memory capacity. You're remembering how often that child ate when they slept, feeding yourselves, feeding your partner, and maybe thinking going back to work and having to do that too.

So you'll have an increased cognitive load, but that also means increased demand. So, things are going to feel a little bit different and it's not forever. And in fact, we can say and suggest that it's going to be perhaps advantageous because if you even look at studies of retirement, right, they take care of a plant or a dog or they're doing word puzzles or something, the outcome is better. The cognitive outcome is better. You can think of that in terms of caregiving and parenting as well. But I never want to mitigate the fact that women are telling us that this is what's happening. Even if it doesn't show up in a standard scale as this big significant effect of change, that matters.

My perception of how I'm feeling and how I am, even if it's not a, you know, it's not out of the realm of like a clinical, you know, or it's not a clinical diagnostic level still matters and I want to study it a lot more. And certainly, there's a subgroup of people who have more extreme say cognitive change, cognitive dysfunction that we should explore, but it's normal and it's happening for a reason and be nice to yourselves because it's very hard.

Dr Laura Stankeviciute:

Yeah, thank you so much. I do feel that this is going to be very comforting for a lot of women who are just entering pregnancy and having to deal with these huge changes in what they were before conception to who they are now and God knows what's going to happen to them when they going to give birth to the baby. And I think this very nice parallel of like cognitive demands obviously are going to be way bigger than before pregnancy with all the things related to the baby, but also the self. And I know there are other superpowers that recently, recent mums do report. So maybe Magdalena, you can share a little bit of that as well.

I've heard from so many colleagues and friends of mine that new mums have this certain perception or a sixth sense or the intuition about their baby even after giving birth that some of them report that they feel the physical connection even though the baby's not in the womb. So, what is it all about? Like is it just the sense that we can't quantify or there's some evidence? Have you experienced something like this or still are experiencing something like this yourselves, Magdalena?

Dr Magdalena Martinez-Garcia:

Yes, I think we have superpowers as mums, and it's not- I like to say that it's not magic. It's rooted in biology. So during late pregnancy, different hormones bind to this small region in the brain, the hypothalamus. And this region acts as the gateway of the maternal behaviour circuit. So, I like to think of it as a key opening to a door. And then when that door is open, so when the hypothalamus is active, it reaches to other regions in the brain and two things happen. First if we are talking about rodents again, pups become extremely rewarding for the mum, but also all their senses become hyper-tuned. So this heightened perception that you were mentioning. And the same is happening in human mothers.

So for instance, I can recognise my daughter's cry and distinguish it from any other cry. This is really incredible for me. And I also feel like this need to hug her and to be close to her. It's really weird because it's like at the same time, I want my space. But if I see her, I kind of want to hold onto her. It's really weird, but really magical. And yeah, so this is my maternal brain circuit working and it's really specialised for my baby. So, that's the superpower that we have.

Dr Laura Stankeviciute:

This is beautiful. It's beautiful how biology for women has done such an incredible thing that we can sense and feel even kind of this paranormal above any senses experience. And obviously, I'm not yet pregnant, but even just listening to you gives me this kind of shivers of how beautiful women's bodies. So, thank you so much for sharing this. So now, I would like to take a little bit of a step back from the mother's brain topic itself and zoom a little bit to the later life. And Magdalena, you've already alluded initially when you were talking about the brain changes and them being not just transient, but actually permanent to a certain extent.

And you've mentioned UK Biobank studies that have showed interesting insights about the number of pregnancies and what it does for the risk of Alzheimer's disease, for the risk of dementia and cognitive health later in life. So I'd like to unpack this a little bit because this is something that I'm very interested about. I studied the midlife brain and the risk factors that lead to the higher vulnerability for Alzheimer's disease and cognitive decline. And what I read and came across this publication, I was really fascinating by this protective effect of pregnancies.

And in the field, there's still, I wouldn't say like one specific number because there's one study that says one number, another study says the other. But it seems to be this kind of dose-dependent effect between the number of pregnancies and the risk or protection against the disease. So, can you comment on that?

Dr Laura Pritschet:

Yeah, so I will start by saying this is an incredibly nascent area of research. So us trying to understand the effects of pregnancy or even menopause on risk factor later in life, as you know, Laura, is very new. In that paper that Magda was referencing about brain protection or brain age estimates in response to parity or the number of births that you've had, they didn't see the sort of linear as more and more childbirths occurred. You see the same degree. It kind of levelled off around four or five. However, it's important to note that there are just fewer numbers of people who have experienced up to five childbirths.

But it's true, I mean, you got the protective effects of pregnancy in terms of its, you know, not only the hormonal landscape, but the cognitive and behavioural changes that accompany pregnancy, parenting, and caregiving at large over many decades. But you also, anytime you're pregnant, it's a period of risk. So, that's when we see a lot of hypertensive disorders of pregnancy or metabolic issues. And so as you have more and more pregnancies, there's a likelier chance maybe that you can experience that just by the numbers game, which can then play a role in midlife health and later ageing health. But we don't yet have those studies that have really linked that super well.

A lot of the ageing research, we're looking retrospectively, right? So, we're asking people about their menopausal experiences from, you know, two decades ago and especially their pregnancy experiences from decades prior to that. So, we need to do a lot of research on the ground and build these cohort studies of studying women and their brains and their health outcomes during pregnancy through menopause. That intersection is still also an area that's, you know, not well developed. And then, see how that changes perhaps risk profile or not.

See if we can cluster women into their various experiences and see if maybe there's a more susceptible group and whether, you know, having, whether there is this optimal cognitive balance of I have, you know, this amount of kids and that's my cognitive max or my financial max, my resource max, or maybe not. And how, what that looks like in the decades to follow, but still very new.

Dr Laura Stankeviciute:

Yeah, for sure. From this very little research that we have, regardless of how fascinating it is, we can't prescribe women to have X amount of children as a recipe for, you know, dementia-free life later on. But it's definitely fascinating and interesting just to see how events that happen so far earlier in the lifespan, in like lifespan actually still carry impact later on. So I feel like, as you said, we need to really think about the approaches, how we can study brain health at the larger scale, at the lifespan approach, rather than kind of this snippet of time where we freeze and we look, and then we correlate to our outcomes.

Kind of paying attention to the clock and I know that there's so many questions that I want to ask, especially about the specific parts of the brain like (indistinct) MTL that are so relevant in my research, but I think that may necessitate another episode. And I just want to move to the last part of the conversation, which is probably the most fascinating for a lot of people who are listening, because it's all about the personal experiences. And we really have a very rare mument to talk to scientists who do the maternal brain research, but are also experiencing the data that they have looked into, but now being the data points themselves. So, I would like to start with Magdalena.

How does it feel to be a neuroscientist, but also a recent mother? Has the neuroscience career that you have been working in for a long time in this field prepared you for what is going to happen or what happened throughout the pregnancy and the first months postpartum? Can you share a bit?

Dr Magdalena Martinez-Garcia:

I think that for many neuroscientists in this field, it's actually like the other way. Like they are first mums and then they are, they become interested in the maternal brain field. For me and I think for Laura too was the other way around. We were interested in the research first and now we are mums. And it's a really unique experience to feel that you know things. But at the same time when you become pregnant, I think you are... I felt very humble in how much I didn't know. So, that's the first thing I want to say that I think no matter how much you know, how many books you read, then your experience is always something new. You always feel different than what you expected.

Personally, I think one thing that I was not prepared for is how conflicted you can be during the perinatal period. I have never felt more secure in my life in one way. Like I know 100% that I'm the best mum for my baby. But at the same time, especially the first months postpartum, I felt very conflicted about many things, breastfeeding and just putting my baby to sleep, just many things. I was like, "Oh, am I doing this correctly or if I, you know, choose this, why am I feeling so guilty?" And I think I was not prepared for that. I felt that I had all the tools to be prepared and secure throughout the immediate postpartum. And then, here I was struggling to make the decision of just switching to formula.

And I just... Yeah, I remember I was feeling really conflicted. I knew Fely's best. And at the same time, I was feeling like I was going to miss something important by not breastfeeding. So yeah, I think that would be my one part of my experience.

Dr Laura Stankeviciute:

Thank you so much. This is very interesting and it's definitely something very vulnerable and very personal. And I really appreciate you sharing this. And in preparation to this podcast, I was reading the book by Lucy Jones on the matrescence and she was telling a lot about her own experience and the same things that you also mentioned and alluded to about kind of the breastfeeding, the formula, different people giving different opinions. But what you said as well at the end of the day, you are the mother of your child and you know the best and you will take care of your child the best. So Laura, you are in it.

You are actually now experiencing all these brain changes and all of these different ideas of how to prepare your body, how to prepare your brain for the best motherhood. How does that feel and how being a scientist helps you to actually distil what is the real thing, what is the real advice, or what is probably something that you should just like scroll down to?

Dr Laura Pritschet:

Yeah, it's a massive... So, I'm halfway through my pregnancy and I've learned from the guidance of other women and I lean on Magda a lot for this. I'm following her footsteps and bothering her all the time. Especially as scientists in this space, there's such thing as too much information. So, the best advice I've received from the women around me is find your bubble of women who you trust, who can be vulnerable and can be honest and give guidance without judgement. And go to them and stay off of Reddit and other sorts of sources. And that has, you know, I've tried to stay even keeled in that front.

But I find it really interesting because yes, I'd also joined this space and this research topic prior to this experience. And I see already myself and my ideas and my questions evolving because of my experiences. And I do, I want to echo something that was brought up before, which is this idea of disclosing and making it so much more normal to talk about the experience of becoming, of getting pregnant and going through pregnancy. And I had experienced miscarriages and I did not understand, even though I'm steeped in this space, the emotional and cognitive toll that that would take. It took over my mental space.

And I also at the same time said, you know, back from 2018, the minute I get pregnant, I'm scanning my brain. So I'm still every two weeks scanning my brain, taking my blood, doing the assessments, and I had to do that through this whole process. And in some ways, that can feel a bit overwhelming and very vulnerable, but in other ways, it's incredibly empowering. And the questions I want to ask now, which I'm a little bit behind on, because I didn't incorporate them into the protocol and that's the scientist hat I'm wearing. But in my future lab is I want to understand the just what is going on in the mind as pregnancy advances in this extensive data way.

I want to probe women's minds throughout the day and say, "What are you thinking about right now?" And looking at how that might evolve or might expand over pregnancy and into the postpartum. And what I don't know, I don't know. So, I'm waiting to see what that experience is like. But it is a lot of what I've been reading and listening to women about is true. I find my attention is, you know, evolved, I'll say it in a very positive way, which some of my working memory feels a little bit like it's taken a hit. But I'm trying to say a lot of the same mantras as I had said before, which is you're going through something, you're good.

You spent three months just trying not to throw up and you're doing the best you can. And this is actually just evolving who I am. And I'm excited to see how it goes further and hopefully, it goes well. But it's all data points into this scientific experiment.

Dr Laura Stankeviciute:

Thank you so much for sharing this, Laura. And I think it's very important that obviously you can talk about this freely and more women can hear these stories that not always it is very linear, and successful, and easy from the first time, but now it's beautiful that you are pregnant and even more so you are going through the experiment yourselves. You are being a volunteer for science, for obviously for your own research, but in order to help and understand women's brain for the future mothers who are going to be giving birth as well.

So, we have been talking a lot about neuroplasticity and science and the great discoveries, but what do you think is society doing for the woman's brain health in this transition? Has the society already recognised that this is a fascinating renaissance rewiring of the brain?

Dr Magdalena Martinez-Garcia:

When you talk about society, to me, research is absolutely acknowledging the perinatal period as a neurological transition. So as scientists, we are already using the term matrescence in our papers, in conferences, in how we think about this period and how we frame our studies. Now, the healthcare system is not catching up and I've experienced this in my own transition to motherhood and I'm sure most of women will relate. I think we have a close like care during pregnancy because we have a baby inside. As you say, it's a very baby-centric view. But then postpartum, we have one visit, six weeks postpartum, and that's all. I think the next one I'm going to have is one-year postpartum. That to me is crazy.

And if there's one thing that I want to see in my life is more support during postpartum. And we always talk about that, like more support, more support. What does that mean? To me it means if like we have 10 visits to our OB during pregnancy, let's have 10 more with... It can be OB. It can be a reproductive psychiatrist, psychological like a perinatal psychologist. Included in our healthcare systems, covered by insurance here in the US. In Europe, you know, we have other systems, but let's make that a routine. That would be a dream, and it needs to be something easy. It can be like routine calls to the mums because in the postpartum period, you're very busy.

So actually if you have to go, let's say once a month to your doctor in person, that could be like a disadvantage for many. So just having a call that checks on the important things and then if there's anything that needs more attention, then you can be referred to a doctor, you can be prescribed things and delivered to your home. I think that's what we need at postpartum. And I think, yeah, to me, that would mean that society and that the healthcare system understands that this is a neurological transition, including pregnancy and postpartum. Yeah, That's just my dream. - Thank you so much.

Dr Laura Stankeviciute:

That was a very big dream, but it also sounded like a very firm call to action. And I really hope that whether this conversation or more conversations like this actually move the needle, not only in the field of science, but actually in the practical applications in the clinics for the postpartum. So we talked about the society, but what about our many societies, our many families? There were some questions from the audience in kind of expectation of this episode. Some of the people asked me, what do actually dads, what do actually men can do practically? How can they step in and help the mothers through this process?

Dr Laura Pritschet:

Yeah, I think it's a really important question to ask and discussion to have with supportive partners. To me, you know, I'll say this word, this phrase one more time, cognitive load. It needs to be dispersed. I think not having to tell someone what you need and having them take care of it so that you have less on your plate and less on your mind is incredibly important and very helpful, whether that is your husband, your wife, your parents, your network, your community who can come in and just take care of things.

So you don't have to have those extra steps to say, "I actually need you to go do this and I need this from you." Of course, it's never going to be a perfect system because sometimes you don't know what you need. But just having people in there to help anticipate needs and take care of things on their own I think will be really helpful. And I also just want to say that I do see obviously a spotlight on women's brain health, not only in the research space, the foundation space, and kind of in society among women themselves. I've seen, I think there's been a big evolution of change in the last five years even.

But something else that really matters, especially when it comes to the United States is leave and having protected time and a protected bubble for both parents and the caregivers. This is a neurological transition that does not stop when you give a birth and in fact, ramps up. And we need to have that sort of protected time legally, federally mandated. Other countries do it a lot better. But that and having care and seeing your doctors in a routine way can help catch some of those really subtle or very obvious risk factors and changes in mood and symptomology that can help people. Maternal health and mental health is really important. It's often a leading cause of morbidity, mortality in women.

And so just adding those protective barriers to this period is going to be incredibly important.

Dr Laura Stankeviciute:

Thank you so much. So, I hope those who are listening and if you're not a mother yourselves, but you're going to be a partner, a father, or a caregiver, please do take care of the cognitive load throughout and especially after. And I do feel like me being from Europe, I have this privilege of this protected time window when women give birth. Obviously, it varies by countries, but we do have that. Whereas in the States, it's not the case. Magdalena and Laura, that has been a truly fascinating conversation. I wish we could talk for more hours because I think there's so many questions that can be teased and followed up upon.

But I know that you have important responsibilities to take care of yourselves and also Magdalena to take care of your baby. So I would like to just ask one final question, which has become a little bit of a tradition on our podcast. So I would like to finish today's conversation by asking you, Laura, what does women's brain health mean to you? Briefly in one sentence.

Dr Laura Pritschet:

I can do it in one word. It's everything. Both in my research and my personal life, studying and understanding women's brains and women's minds and their health is incredibly important. It's not only important for making lives better for women, but the entirety of society. I'm really driven and motivated to understand what the mind looks like over the lifespan with all of these hormonal changes and sex and gender experiences that we have. I think there's a lot of burden, mental burden, cognitive burden, physical burden placed on women and we owe it to them to really provide answers. And we are playing catch up from a history of biomedical sciences that have excluded females from research, important research.

And so to me, it's the goal to provide answers for people now and into the future so they can live healthier, better, longer lives.

Dr Laura Stankeviciute:

Thank you so much. So women's brain health, it's all encompassing thing to you, Laura. And what about Magdalena?

Dr Magdalena Martinez-Garcia:

So for me, I hope that our research in the maternal brain translates into a better care for women across the perinatal period. That would be the dream to me. So we characterise this matrescence neurological transition, and then healthcare systems and politicians, they take action to better care of women. And I'll say it again, we need better postpartum care. We need postpartum regular visits. We need a healthcare system that advocates for us instead of the other way. We don't have to advocate for ourselves. That's a lot of cognitive load as Laura was saying. We need providers that advocate for ourselves. We need parental leave for both parents. We need subsidised childcare.

And when we have all this support, then women's brain health is going to thrive and we are going to be healthy to be part of this society in a better way.

Dr Laura Stankeviciute:

Thank you so much. I think we really started from those tiny molecules of hormones and how they lead to these incredible changes to the brain, what we see on cognition. But I think what you really well summed up is that science only thrives and only progresses if we have a good system that then allows that science to be implemented, those discoveries to be implemented to support the brain health of women throughout the life, either it's pregnancy but also later on. And I think my mind is really buzzing with a lot of ideas and a lot of questions. It's already quite late for me in my hemisphere and my time zone, but it's going to be keeping me awake for sure.

So, that is it for today's "XXplored: Women's Brain Health." A huge thank you immensely. Thank you so much, Dr Magdalena and Dr Laura, for such open conversations, for being vulnerable and not being afraid of sharing your personal experience and obviously bringing all it to the science that you are doing through which you are advancing the field. And thank you for our listeners to tuning in. We'll see you next time on the "XXplored," where we will be continuing to uncover the many other areas of women's brain health that need deeper understanding, louder conversations, and more calls to action.

I'm Dr Laura Stankeviciute and you've been listening to "XXplored: Women's Brain Health," on Dementia Researcher podcast.

Narrator:

Thank you for listening to "XXplored: Women's Brain Health," podcast from Dementia Researcher, with generous support from the National Institute for Health and Care Research, Alzheimer's Association, Alzheimer's Research UK, Alzheimer's Society, and Race Against Dementia. From hormones to cognition, from risk to prevention, we feature conversations with researchers, clinicians, and changemakers working to challenge assumptions and close the gaps in how we understand and support the female brain.