When Russia attacked Ukraine in late February, Ukrainian civilians were immediately caught in the crossfire. Over the last month, people have been fleeing to neighboring countries, waiting out the nights in bomb shelters, and getting by without running water or electricity.
Pregnant people are among those caught in the middle. Some of the most horrific images from the war so far have come from a maternity hospital in Mariupol that was bombed by Russian troops in mid-March. The upheaval spurs a troubling question: Could the stress and condition of war affect a fetus in the womb?
Research suggests that the answer is possibly, yes. Certain factors, like the nutrition and mental health of a pregnant parent, can potentially influence the development and eventual health of their child, a concept known as fetal programming.
“It’s basically thinking about what happens during the 9 months of pregnancy that can help program, and help determine, the lifelong health of the offspring,” says Karen Lindsay, an assistant professor of pediatrics in the College of Health Sciences and researcher who specializes in maternal nutrition in pregnancy at the University of California, Irvine. “And that can be in a positive or a more negative direction.”
Fetal programming is difficult to study directly – researchers don’t subject pregnant people to extreme stress or malnourishment on purpose to see what happens – so there is a lot scientists do not know about what is really going on in the bodies of pregnant parents and their offspring.
In the research we do have, elevated levels of stress during pregnancy have been linked to increased risk for conditions like ADHD and depression. Malnourishment has been linked to a host of developmental issues, as well as heart disease and diabetes later in life. For parents, this is cause for concern. But nothing is set in stone, says Vivette Glover, professor of perinatal psychobiology at Imperial College London. While children may be born with a higher risk for developing certain conditions, it is far from guaranteed that they actually will. What’s more, parents can take steps to reduce these risks further after a child is born.
Malnourishment during pregnancy can impact a child throughout their life. “Our research over the last 70 years or so has shown that those babies who are maybe malnourished during fetal development and born small, they actually have an increased risk of obesity and heart disease later in life,” Lindsay says.
This seems counterintuitive, she says, and researchers theorize that after being in starvation mode during development, the child’s body tries to catch up and ends up overcompensating for the lack of nutrients during early life. Those starvation signals “may program the offspring to be more susceptible to storing fat throughout life, rather than lean muscle mass,” Lindsay says. This in turn might increase a child’s chance of developing obesity.
Not getting enough nutrients may also impair the development of the pancreas, which could put the child at risk of developing type 2 diabetes later in life, says Jessian Muñoz, MD, a maternal-fetal medicine fellow at UT Health San Antonio. If the pregnant parent develops diabetes during pregnancy (which happens in about 2 % to 10% of pregnancies in the U.S. every year), it could change the way the fetus responds to certain hormones and sugars, potentially setting the child up to develop diabetes later, he says.
It is important to note many of these findings are based largely on studies that look backward, perhaps at a specific event like a famine or that trace health over decades, and on research conducted on animals like mice and rats. With animal and retrospective studies, scientists can’t conclusively say that malnourishment during pregnancy in humans leads directly to conditions like obesity, heart disease, or diabetes, only that they see a connection.
Proper nutrition is also critical for the physical development of all the baby’s organs in the womb. The micronutrient folate, for instance, has been shown to be critically important for preventing neural tube defects, which are serious defects of the brain and spine and can lead to death or severe disability, Lindsay says. That’s why people who are pregnant or trying to get pregnant are instructed to take folic acid, she says.
Similarly, the micronutrients iodine and choline are critical for fetal brain development and preventing fetal hyperthyroidism, which can affect the baby’s health from birth, Lindsay says. And long-chain omega-3 fatty acids, often found in oily fish, are important for the development of the brain and eyes, she says.
Research also suggests the mental health of the pregnant parent can influence a child’s development, and increase their risk for developing mental health issues later in life.
Scientists have looked specifically at the effects of stress from major disasters or conflicts on pregnant parents and their babies. For example, an analysis of seven natural disasters, including the 2011 Queensland Flood in Australia, the 1998 Quebec Ice Storm in Canada, and the 2010 earthquake in Haiti, found experiencing these events was linked, perhaps not surprisingly, to higher rates of stress in pregnant people. This stress in turn was associated with certain physical and mental development outcomes for their babies, including higher BMI and worse cognitive and behavioral outcomes after birth. Another study found people exposed as fetuses or early childhood to the Chinese Famine between 1959 and 1961 were at higher risk for cognitive decline in adulthood.
Glover, the professor in London, and her colleagues have looked specifically at the impacts of stress during pregnancy on brain development. While the researchers don’t know exactly what’s happening in the pregnant parent’s body, they believe cortisol, the hormone responsible for the body’s stress response, is crucially important. “We think that the fetus being exposed to more cortisol in the womb is one of the things that changes the development of the brain,” making the child more likely to develop anxiety and emotional, behavioral, and cognitive problems, Glover says.
There’s an enzyme responsible for breaking down cortisol, reducing levels of the stress hormone in the body. But stressed out pregnant rats and really anxious pregnant people both seem to have lower levels of this enzyme in their placenta, the organ that acts as a filter between parent and fetus. This could mean more of the parent’s cortisol actually reaches, and can affect, the fetus. In this way, Glover and her colleagues also think stress works in tandem with individual genetic vulnerabilities. “We all have different genetic vulnerabilities; if a mother is stressed while pregnant and the child has a genetic vulnerability to ADHD, say, then they’re more likely to get it,” Glover says. High levels of cortisol in the pregnant parent could also influence the development of other organs, like the kidneys, which could put the baby at higher risk for high blood pressure and other conditions, Muñoz says.
Stress and nutrition are related, Lindsay says. Not only can feeling stressed influence what people eat, but stress may also affect how their bodies metabolize certain foods, she says. A pregnant person might eat a meal they think is healthy, but because they are eating while feeling stressed instead of calm, the healthy meal could potentially boost their blood sugar level higher than expected. This in turn could influence how the fetus receives nutrition from the parent, she says.
Scientists also think some of the effects from stress and nutrition could be happening at the molecular level, inside a child’s DNA. Factors like anxiety or malnourishment could influence the chemicals that determine whether or not certain genes are switched on or off, Glover says. While there’s a lot of research interest around this idea, the evidence is still fairly sparse. “I wouldn’t say the epigenetic evidence is the strongest, by a long way,” Glover added.
Only a small percentage of children are impacted by high stress during pregnancy in this way, says Glover of her research. In one study, for example, 12% of the children born to the most anxious or depressed parents (ranking in the top 15% of all the parents surveyed) had double the risk of a probable mental disorder at age 13. In contrast, only about 6% of the children born to the remaining parents had a similar risk. “We’re talking about increasing risk and it really matters … but most children aren’t affected.”
For many people, it may be impossible to avoid stress during pregnancy, whether that stress is from work and daily life, an ongoing mental health condition like depression or anxiety, or from a geopolitical conflict, like the war in Ukraine. What’s more, not all parents have access to highly nutritious foods; perhaps they live in a food desert or are just struggling to survive. This isn’t the fault of the pregnant person, Glover says. “We must support them as a society,” she says.
The good news is, research indicates many of the effects of stress during pregnancy can be reduced after birth, Glover says. Paying special attention to these children, ensuring they feel securely attached to their parents or caregivers, and breastfeeding can all help mitigate the impacts of stress, she says.
The same holds true when it comes to malnourishment, Lindsay says. A child’s susceptibility to a condition like diabetes could be alleviated with proper nutrition, activity, and other interventions, she says. A susceptibility is not an inevitability (That said, some physical defects, like neural tube defects, cannot be rectified later).
In Ukraine, the shelling around major cities like Kyiv continues and people live life on high alert. In Mariupol, families who can’t escape the artillery are running out of food and water. “The stress going on in Ukraine must be tremendous,” Glover says. While it’s impossible to say exactly how the war will impact children born during the Russian invasion, past disasters have shown the effects could be lifelong, perhaps manifesting as early mental decline, depression, or increased risk for heart disease. Glover says it will be crucially important to take care of these children after birth, in any way possible.
