Latest / The Biological Psychiatry Podcast / Prenatal Income Instability and the Parental Brain
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- Elvisha Dhamala: That's all for today's episode. Thank you to Dr. Kim for joining us to share her work on the effects of income instability during pregnancy on postpartum outcomes. For our listeners, you can find the full paper in Biological Psychiatry, Cognitive Neuroscience and Neuroimaging, and we'll include the link in our episode description. To learn more about our journals, please visit biologicalpsychiatry.com. Pregnancy is widely recognized as a time of profound physical changes, but the brain undergoes equally dramatic transformations during this time. These neurobiological changes prepare birthing parents for the demands of caregiving and help establish the foundation for parent-infant bonding. However, pregnancy is also a time of heightened vulnerability, not just physically, but economically and physiologically as well. Financial stress during pregnancy is common. joining me Dr. Pilyong Kim from the University of Denver, first author of a recent paper Biological Psychiatry: Cognitive Neuroscience and NeuroImaging. Dr. Kim, welcome to The Biological Psychiatry Podcast. You can find The Biological Psychiatry Podcast wherever you get your podcasts. now so you don't miss our next episode and follow us on our social media channels for highlights and updates. Thanks listening. ⁓ This is for informational purposes only and does not constitute medical or professional advice. ⁓ The expressed are those of the participants and do not necessarily reflect those of the Society of Biological Psychiatry, ⁓ Pilyoung Kim: Yeah, thank you so much for having me. Elvisha Dhamala: Pregnancy involves brain changes that prepare individuals for parenthood. Can you tell us what's actually happening to the brain during pregnancy and the early postpartum period to prepare for caregiving? ⁓ From the Biological Psychiatry family of journals, is the Biological Psychiatry podcast, ⁓ we discuss the latest research on psychiatric disorders and their treatments. ⁓ you for joining us. I'm your host and Social Media Editor, Elvisha Dhamala. ⁓ but we're only just beginning to understand how economic instability might affect the developing parental brain. how income changes during pregnancy influence brain responses to infant cues in early postpartum period. Pilyoung Kim: it's sometimes I think it's a surprise to people that it's not just a body that changes so drastically during pregnancy and early postpartum period. The brain also changes drastically during this period. But there is very interesting differences what happens during pregnancy versus during the early postpartum period. So during pregnancy, Elvisha Dhamala: its family of journals, its editors ⁓ rights reserved, including those for text and data mining or use in AI systems. ⁓ Pilyoung Kim: across several studies, actually across different countries. What researchers have seen that people's brain overall, the size and the structure decreased. Another word, it shrinks actually a little bit over the course of pregnancy. But people should not worry because we think that it's a good thing. that's happening, because that changes that happens during pregnancy, that specific brain regions that go through this structural reorganization seem to support people's parenting and their emotional bond with their baby after they have their baby during the postpartum period. So you can kind of think of it as this structural reorganization is that the brain is just kind of, like reorganizing itself to make sure that you know any connections that it doesn't need it just kind of cut it away and clean it away so that there is actually more room to create more connections we call pruning we also see this happening a lot during adolescent period and it's so interesting that during pregnancy individuals are actually experienced this as well in in the brain ⁓ so that the brain is ready the very important experience that people are very excited about when they actually welcome their baby. So ⁓ what when they welcome their babies then, that people go through quite period ⁓ to care their ⁓ And this provides, you very enriched experience of parenting and very for them to kind of build that foundation of deep deep emotional connections with their baby. And this seems to actually help and support creating new brain connections. So during about the three to six months postpartum across the studies that's been published, including the ones that research team. that there are actually growth in the brain in very similar regions that actually show the shrinkage during the pregnancy. And now we see the growth and new connections in this brain ⁓ seems to be very important for people to be parent ⁓ have this very strong emotional tie with their babies. Elvisha Dhamala: So shifting into that aspect of parenting, your paper focuses on how the brain ⁓ responds to infant cry sounds. Why are those brain responses cry sounds so important and how does that provide an insight into parental adaptation and bonding? Pilyoung Kim: So we, as researcher, would love to actually measuring people's brain activations while interacting with their babies in time. ⁓ But to be able to the specific brain imaging technique, is fMRI, participants are very limited in their ability to move around. So the best way to actually creating very similar experience is for us is that when parents are inside the fMRI scanner, which takes like 3D images of the brain and record brain activation, ⁓ we play infant sound kind of simulating their parenting So it is not real parenting experience, but it's close. ⁓ And because infant cry is very, very emotionally salient, important cues from infants because infants cannot talk. So what can they do when they need attention from parents? They cry, right? So it's ⁓ salient and signals from infant that grabs parents' attention right away. ⁓ So we found that over and over across many, studies that when we play infant cry, parents' brain activates very strongly. And those brain regions that sensitively responds to infant cry are also very involved in those responses that parents show in their behaviors, right? So typically when we have our baby cry, parents run to them. pick them up sing a song and try to really kind of do their best effort to kind of console them, right? And the moment when really seem to be happy and calm down and stop crying, that is also a moment for parents. They feel happy. ⁓ So all of those are brain activations and also specific brain regions that are being activated. including, parental motivation brain regions, ⁓ people to be motivated to care for infants, right? So it's very important brain regions being activated. ⁓ The other brain is emotion regulation brain region. So it's very important for parents to be regulating their own emotional reactions and really focusing on understanding the baby's cues. Why is my baby crying? You know, Is she hungry? You know, does she want diaper change? So we also another group of brain regions that we see to be very strongly responding to infant cues. Cry cues is this theory of mind, empathy, ⁓ cognition regions. ⁓ then we actually have a chance to see parent participants, interacting with their own baby. And then when we're analyzing those for, you their warm and sensitive care levels, ⁓ the brain activations in these brain regions that I just mentioned tend to be related to more sensitive, more caring, more warm behaviors they when they're interacting with their baby. Elvisha Dhamala: So most research on socioeconomic factors in parenting focuses on poverty or overall income level, but your study took a very different approach focusing on income changes, both in terms of gains and losses. Can you tell us why income instability is potentially more important and valuable to look at than just income level? Pilyoung Kim: our actually show the poverty level during pregnancy and early postpartum period to impact on parents' brain activation to infant cry and also parental sensitivity to infant cry, largely related to the stress that parents experience due to living in poverty leads like a lower brain sensitivity to infant cues. Stress can do that to the brain. we were very concerned about poverty itself. ⁓ And that's why ⁓ funded our study really focusing on that. ⁓ As we're conducting this longitudinal study looking at the impact of exposure to poverty during pregnancy on parental brain responses to infant cry, we also notice in our sample that not just the low income level that is stressful, but the changes in income reported to be quite stressful experience among our pregnant individual participants. ⁓ So found it to be very interesting. And then there are some more growing number of literature of suggesting that ⁓ these very unpredictable, unstable in the environment can create a really high level of stress So, you know, I can kind of make a contrast in this case that during pregnancy, if I have low income, I am unsure whether I can pay the bill at the end of the month. I don't know whether I have enough food until the end of the month. So that is very stressful. But it's also something that I can kind of plan. I know how much income I have. But if I suddenly lose a lot of income, that brings ⁓ shock into experience, Suddenly I need to figure out whole range of things that I used to be able to pay ⁓ rent, I can't, right? I have to find a new job. So all this kind of changes seems to be a whole like another range of the stress that people are experiencing. I do have to mention though, unfortunately, it is also true that people who living in lower income tends to experience more instability in their incomes as well. So they're not completely separate. ⁓ Also, when we actually looking at non-human animal research, Often the way that the researchers creating very stressful experience during pregnancy to looking at the impact of stress during pregnancy on the maternal brain or the fetal brain they use this very unpredictable stress paradigm. So that was also reason that we thought in ⁓ human experience, the income changes and income and stability comes ⁓ close to that type experience. Elvisha Dhamala: So would it be accurate to say that it's not just stress, it's also stress unpredictability that plays a big role? Pilyoung Kim: Exactly, exactly. Elvisha Dhamala: So you measured income using the income to needs ratio ⁓ household income. ⁓ you explain that ratio is and why it's a more accurate way to assess economic well-being? Pilyoung Kim: Yes, so there's just kind of average annual income. And then there's income to needs ratio. So income to needs ratio is calculated based annually adjusted federal poverty line. that is also by each state and by like specific household members. So whether there are two and two children or just one single person, that the poverty line is adjusted And If there's a one-to-one ratio, the income-to-needs ratio will one. If their annual income will be half of the family at the federal poverty line, the income-to-needs ratio for that family will ⁓ be 0.5. poverty is defined by income-to-needs ratio below one. In low income status, it's typically defined by income to needs ratio below two. Elvisha Dhamala: So in this study, it was a prospective study that followed pregnant individuals from through the postpartum period. You've already told us a little bit about the imaging session that was conducted. ⁓ you tell us what exactly participants were listening to in the scanner and what you were measuring in response to what they were listening to? Pilyoung Kim: So before the come to the fMRI session, we ask participants to record their babies cry sounds, ⁓ typically during the diaper change. So fun fact that parents can actually distinguish baby's cry sounds, whether baby is in pain or ⁓ or diaper change. But diaper change is just about pretty like average intensity in terms of infant cry. So we asked participants to record their own baby cry. And we actually have another matched infant cry sounds we call control sound. ⁓ that is also someone else's babies. cry sound diaper change, which has about that average intensity across the people. ⁓ when participants come to the fMRI session, while they're inside fMRI scanner, they listen to two different types of infant cry sounds. ⁓ One their own baby cry sound. And then the other is that control unknown baby cry sound. And what we're looking for is the their brain response to baby cry sound, but more specifically the differences between when they're listening to their own baby cry sound versus unknown, unfamiliar baby cry sound. Elvisha Dhamala: what did you discover about the relationship between prenatal income losses ⁓ and the actual ⁓ postpartum brain responses to the infant Pilyoung Kim: Yes, so ⁓ we wanted to see the income losses. So income instability can be conceptualized in both directions, income losses and income gains. The literature suggests any changes can be stressful, but it's not hard to imagine for the audience that income losses will be a bit more stressful. ⁓ than income gains. And that's been shown ⁓ in the literature that income losses can be linked to more negative health outcomes. we expected that income losses more specifically can have much greater impact on parental brain responses to infant cry sounds. ⁓ we actually also control for ⁓ their income level during pregnancy. So What we're looking for is ⁓ specific link between the income losses that occurred throughout the pregnancy and post partum parental brain response to infant cry above and beyond the impact of the average income level during pregnancy. And what we saw was that the more number of income losses that pregnant individuals experienced was related to lower brain responses to infant cry in quite a number of, I think there were like 10 different brain regions. ⁓ those regions, including some those that I mentioned before, like empathy, like processing the meaning of infant cues, as well as ⁓ some regions that are related emotion regulations. then in addition to the brain findings, we also saw that The higher number of the income losses were related to higher depressive and anxiety symptoms during pregnancy. So it seems to kind of supporting that, you Individuals, when they're experiencing a lot of changes in their especially losing income, ⁓ makes them more depressed and anxious. And then unfortunately, I think that negatively influences brain plasticity during pregnancy, which then leads to more dampened and lower sensitivity to picking up the infant cues in the brain. Elvisha Dhamala: So in terms of these dampened responses overall that you're describing, how does that actually relate to functional outcomes or behaviors? ⁓ Pilyoung Kim: so what we see like in the past and across the studies is that especially this brain regions that are important for emotional regulation and empathy, when we see the lower brain activation to infant cues, they tend be related to more difficulties in providing sensitive care to infants. We're talking about differences, but still, you know, it seems be that when brain due to stress have a bit more difficulties in catching up those infant cues. It's probably also causing people's ⁓ in like sensitively interpreting and deciding what they're the best next steps to respond, ⁓ So the link that we tend to see that lower brain responses to infant cues ⁓ related ⁓ lower behaviors that they might show. ⁓ during interactions with infants. Elvisha Dhamala: you found that income gains overall a very different pattern than income losses. Can you tell us a little bit about what income gains represented? Pilyoung Kim: the income gains show opposite pattern of the associations with the brain activations. And the income gain effect was very specific to their own infant cry. So when I mentioned the income losses, the impact of income losses were actually ⁓ more across both their own baby cry and control baby cry. And we actually saw this in some other studies too that I think when the stressful experience is so significant, that the impact seems to be broader in the way that the brain's sensitivity is not just very specific to their own baby cry, but like more broadly any infant cry, But when it comes to a different of income gains, we interpret it as more kind of promoted, more supportive experience that seems to have a more specific impact on people's brain response to their own baby ⁓ And in a way that also critical brain regions that are important for empathy and emotion regulation. When you know people during pregnancy, they more income gains and had more money ⁓ over time that might have actually probably their stress pregnancy and they probably feel more secure, more supported. So when it comes to the time that when they have their own babies, their brain seems to be more sensitive, more ready to respond to their baby's cues, which then potentially into closer emotional cues, which actually we saw from the survey. So ⁓ income gains during pregnancy was related to ⁓ levels of the post-natal emotional attachment to their own baby that participants reported. you know, again, kind of showing that that financial security, the financial support can be a positive predicting the more positive experience and more positive changes in the brain for becoming parents. Elvisha Dhamala: ⁓ really interesting finding was that income losses had ⁓ broader effects on the brain just consistently low income. What does that tell us about the effects of unpredictability itself rather than just financial hardship? Pilyoung Kim: so actually a bit of a surprising finding for us too because poverty is such powerful ⁓ experience ⁓ for some I say I necessarily that income losses have ⁓ really significant impact like above and beyond the impact of poverty. But then ⁓ when I reflected on it, when we had those findings, especially the conversations that we had with pregnant individuals. ⁓ found that During pregnancy, a lot of parents, they're very concerned about their safety, their ability to secure environment for their ⁓ So it's also possible that during pregnancy, this instability, especially losing income, are particularly very, very stressful that might be that's reflected in these findings that not just the poverty, but when I cannot predict my income, I don't know what might happen next month because of the income that I just lost. and can I continue to be providing supportive environment ⁓ for and for my baby, I think it seems to be very, very stressful for people going through that experience. Elvisha Dhamala: Do you think you have seen the same effects in higher income individuals or do think this be specific to lower income groups? Pilyoung Kim: So income changes happen more often lower income people. However, though, in our studies income losses and infant gains were happening across the socioeconomic status. So the was done across all income levels, not just limited to low income. So that means at any income level, ⁓ these income loss and income gain can have impact on parents' brain sensitivity to infant cues. So when we are actually thinking about some ways to supporting I think it's very important to also consider the people across all income ranges. Elvisha Dhamala: ⁓ if we identify pregnant individuals who are experiencing income losses, ⁓ what of interventions do you think might help? Pilyoung Kim: So I want to say while it's very concerning to see how much of the strong impact that income loss has during pregnancy, ⁓ I it's encouraging to see that also how income gain has a positive impact. So that I think seems to suggest that if there are some ways that we can help the parents during this period to kind of secure their income. So one example that comes to my mind is parental leave policy is I think, ⁓ widely available in different states to ensure this income stability ⁓ pregnant parents or also postpartum parents as well. So we want provide the best supportive environment to parents, I think providing a little bit that security net that they can kind of fall back on. be really great, I think, ways to intervene. ⁓ The other would I think in the clinics and other places can consider screening for income loss as one of the kind of factors. ⁓ that parents are experiencing high levels of stress. Very often we ask about their income levels some other stressful life experience, but I don't think that we ask a lot about any recent changes in their income. ⁓ our study seems to suggesting that at a certain level, that income loss can provide levels of stress. than the low income itself to the pregnant individuals. ⁓ Elvisha Dhamala: So if there's one key message that you'd want clinicians, researchers, and policymakers to take away from your work, what would that be? Pilyoung Kim: The one take home message will be that during pregnancy, people can experience income instability and particularly the income loss they experience during pregnancy can negatively influence adjustment to parenthood, both at a brain and also emotional level. ⁓ So I think it's very important to consider the importance of instability addition to poverty. ⁓ But also think it's important to consider that income gain can have positive impact for parents then their readiness to become parents.