A new Ohio State University research study finds that stress during pregnancy may change how the placenta sends messages to the fetus and could affect early brain development.
WOSU’s Debbie Holmes spoke to Dr. Tamar Gore, endowed director of Ohio State's Soder Women's Health Research Program.
Debbie Holmes: What were you looking at in the pregnancy of women in the study?
Dr. Tamar Gur: Actually, this is a really neat study because we started the study in mice and then we extended it to human pregnancy. So, what we were looking at is how does a level of stress during pregnancy, which we measure in humans by asking them questions about how many times in the last two weeks they felt stressed, how their concentration is, how often they feel overwhelmed, things like that. And we found that we were interested in how that could affect their placenta and expression of really important genes in your placenta.
Debbie Holmes: Was there anything that prompted you to do this study now? Were you seeing things that were happening to women or anything?
Dr. Tamar Gur: Yes, you know, I think stress is ubiquitous, it's everywhere, and I would never want anyone to think like, oh, I'm telling women to calm down. I don't think that works in the history of time, telling a woman to calm down so that's not what this is at all. We were just interested. We know that stress is everywhere. Stress is ubiquitous and how could that be affecting not just pregnancy but the developing brain as well. That's really, we were coming from that place with a hope that maybe we could develop something that could help women.
Debbie Holmes: How many women were involved in this research?
Dr. Tamar Gur: So, in this study, it was a small pilot study. It was 20 placentas is what we looked at in this study.
Debbie Holmes: Let’s talk then about the results of the research that you found a biological link with the placenta, which delivers oxygen and nutrients to the fetus and removes waste and carbon dioxide.
Dr. Tamar Gur: That's right. So, you know, the bulk of the work was done in mice, which we can, of course, do things in mice that we can't and shouldn't do in humans. And so, we looked at both stress and infection in mice. And we were really interested. We know that there's many studies that show that stress and an infection in pregnancy lead to an increased risk of psychiatric disorders in the next generation. So, we really wanted to tease that apart. And we originally thought that they'd be working the same way, but what we found in mice was they actually were working in opposite directions in pathways important for oxygenation and nutrition. And so, we wanted to see if that was the case in humans. And so, in humans, we just looked at stress, as I mentioned, but what we found was actually we were able to replicate these findings and extend these findings in the human placenta. So, I think we're really onto something in our model and in our research that we can hopefully develop treatments that could pinpoint those pathways and improve outcomes.
Debbie Holmes: Let me understand, do mice have placentas?
Dr. Tamar Gur: Yes, mice have placentas. Mice litters are generally seven to eight. And each little baby mouse has its own placenta. So, we can really get very elegant, detailed understandings of placentas. They're not exactly the same as humans, but there's a lot of conclusions and information that can be drawn from them. And so, we weren't surprised to see that the same pathways were pinpointed by stress and infection, but we were surprised to see that it was in the opposite direction. So, it's a really complicated story. But I think really what's important is, you know, oftentimes we think of the placenta as something that just gets thrown out at the end of delivery. But I think it could hold a lot of secrets and a lot of promises for thinking about how it might be playing a role in your baby's neurodevelopment. I think basically the placenta is underestimated and I think that there's a lot happening there in terms of not just what...the toxins it's taking out and not just the nutrients it's giving the baby, but how its different pathways are working in a way that could help shape neurodevelopment. I think we're at the start of a very exciting line of research.
Debbie Holmes: How serious can this be then for the fetus before birth having the stress and affecting the placenta?
Dr. Tamar Gur: In terms of seriousness, there are serious obstetric complications out there, but what we're thinking about is much more nuanced. And so again, I never want a mom to feel like she's stuck between a rock and a hard place. So, I think that we're just at the beginning of our understanding, but hopefully if we can figure out a way to buffer a mom from stress with different treatments, then that will give her placenta and her baby the best shot at healthy and normal development.
Debbie Holmes: All right, in the mice, did you see something with the baby mice that were born?
Dr. Tamar Gur: Yeah, so we do see in the baby mice that are born in our model following stress, we do some changes in their social behavior, some reductions in social behavior, some long-term changes in their microbiome and some increases in neuroinflammation, which is inflammation in their brain. And so again, I think it's really important so we can think about ways to counteract that. But I think that the idea that we are extending this into human placentas really lets me know that I think we're onto something and that we should continue this line of research so that we can try to implement treatments.
