When Russia attacked Ukraine in late February, Ukrainian civilians were immediately caught in the crossfire. Over the past month, people have fled to neighboring countries, spending the night in bomb shelters and getting by without running water or electricity.
Pregnant women are one of those caught in the middle. Some of the most horrific images of the war so far come from a maternity hospital in Mariupol, which was bombed by Russian forces in mid-March. The upheaval raises a troubling question: Do the stress and conditions of war affect a fetus in the womb?
Research suggests the answer may be yes. Certain factors, such as the nutrition and mental health of pregnant parents, may affect the child’s development and ultimate health, a concept known as fetal programming.
“Basically, thinking about what happens during the first nine months of pregnancy can help plan and help determine the lifelong health of the offspring,” said researcher Karen Lindsay, assistant professor of pediatrics in the College of Health Sciences and Pregnancy at the University of California, Irvine. Maternal nutrition. “That could be a positive or a negative.”
Fetal programming is difficult to study directly—researchers don’t intentionally subject pregnant women to extreme stress or malnutrition to see what happens—so scientists don’t know exactly what’s going on in pregnant parents and their bodies.
In our study, elevated stress levels during pregnancy were associated with an increased risk of conditions such as ADHD and depression. Malnutrition is linked to many developmental problems 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 of certain diseases, there is far from a guarantee that they will actually develop the condition. What’s more, parents can take steps after their child is born to further reduce these risks.
Malnutrition during pregnancy may have consequences for the child’s lifetime. “Our research over the past 70 years or so shows that babies who may be malnourished during fetal development and are born smaller actually have an increased risk of obesity and heart disease later in life,” Lindsay said.
It seems counterintuitive, she said, and the researchers speculate that after being in starvation mode during development, a child’s body tries to catch up but ends up overcompensating for the lack of nutrients early in life. These hunger signals “may make it easier for offspring to store fat instead of lean muscle throughout their lives,” Lindsay said. This, in turn, may increase the chance of obesity in children.
Jessian Muñoz, MD, a maternal-fetal medicine researcher at UT Health at San Antonio, says nutritional deficiencies may also impair pancreatic development, putting children at risk for type 2 diabetes later in life. If a pregnant parent has diabetes during pregnancy (which occurs in about 2 to 10 percent of pregnancies in the United States each year), it can change the way the fetus responds to certain hormones and sugar, possibly causing the child to develop diabetes later in life. Diabetes, he said.
Notably, many of these findings are based largely on retrospective studies, which may look at specific events such as famines or track health over decades, and on animals such as mice and rats. Through animal and retrospective studies, scientists cannot conclude that malnutrition during pregnancy in humans directly causes diseases such as obesity, heart disease, or diabetes, but they have found a link.
Proper nutrition is also crucial for the physical development of all the baby’s organs in the womb. For example, the micronutrient folate has been shown to be critical in preventing neural tube defects, serious defects in the brain and spine that can lead to death or severe disability, Lindsay said. That’s why people who are pregnant or trying to become pregnant are asked to take folic acid, she said.
Likewise, the micronutrients iodine and choline are critical for fetal brain development and preventing fetal hyperthyroidism, which can affect a baby’s health after birth, Lindsay said. Long-chain omega-3 fatty acids, often found in oily fish, are important for brain and eye development, she said.
Research also shows that the mental health of pregnant parents can affect their children’s development and increase their risk of mental health problems later in life.
Scientists have specifically studied the effects of stress from major disasters or conflicts on pregnant parents and their babies. For example, perhaps not surprisingly, an analysis of seven natural disasters—including the 2011 Queensland floods in Australia, the 1998 Quebec ice storm in Canada, and the 2010 Haiti earthquake—found that experiencing these events was associated with increased stress in people. people. This stress, in turn, is associated with certain physical and mental developmental outcomes in infants, including higher body mass index after birth and poorer cognitive and behavioral outcomes. Another study found that people who experienced the Chinese famine of 1959 to 1961 as fetuses or as young children had a higher risk of cognitive decline as adults.
Glover, the London professor, and her colleagues specifically studied the impact of stress during pregnancy on brain development. While researchers don’t know exactly what’s going on in pregnant parents, they believe cortisol, the hormone responsible for the body’s stress response, is crucial. “We believe that fetal exposure to greater amounts of cortisol in the womb is one of the factors that alters brain development,” making children more susceptible to anxiety and emotional, behavioral and cognitive problems, Glover said.
There is an enzyme responsible for breaking down cortisol, reducing levels of stress hormones in the body. But stressed pregnant mice and really anxious pregnant women both seemed to have lower levels of this enzyme in their placentas, which act as a filter between parents and fetuses. This may mean that more of the parent’s cortisol actually reaches and affects the fetus. In this way, Glover and her colleagues also suggest that stress is closely related to individual genetic vulnerability. “We all have different genetic vulnerabilities; if the mother was stressed during pregnancy and the child has a genetic predisposition to ADHD, then they are more likely to develop ADHD,” Glover said. High levels of cortisol in pregnant parents can also affect the development of other organs, such as the kidneys, which could put babies at higher risk for high blood pressure and other conditions, Munoz said.
Lindsay says stress and nutrition are related. Stress not only affects what people eat, it can also affect the way their bodies metabolize certain foods, she said. Pregnant women may eat a meal they think is healthy, but because they feel stressed rather than calm while eating, the healthy meal may cause their blood sugar levels to be higher than expected. This, in turn, may affect how the fetus receives nutrients from its parents, she said.
Scientists also believe that some of the effects of stress and nutrition may occur at the molecular level of children’s DNA. Factors such as anxiety or poor nutrition may affect chemicals that determine whether certain genes are turned on or off, Glover said. Although there is a lot of research interest surrounding this idea, the evidence is still rather sparse. “I wouldn’t say the epigenetic evidence is the strongest,” Glover added.
Glover said in her study that only a small percentage of children are affected by high levels of stress during pregnancy. For example, in one study, 12% of children born to the most anxious or depressed parents (those in the top 15% of all parents surveyed) developed a possible mental disorder by age 13. The risk is doubled. “We’re talking about increased risk, which is really important … but the majority of children are not affected.”
For many people, stress may be unavoidable during pregnancy, whether it comes from work and daily life, ongoing mental health conditions (such as depression or anxiety), or geopolitical conflicts (such as 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 simply struggling to survive. Glover said it’s not the pregnant woman’s fault. “We have to support them as a society,” she said.
The good news, Glover said, is that research shows many of the effects of stress during pregnancy can be mitigated after birth. She said by paying special attention to these children and ensuring they feel safe with their parents or caregivers, breastfeeding can help reduce the effects of stress.
The same is true for malnutrition, Lindsay said. Children’s susceptibility to diseases such as diabetes can be reduced through appropriate nutrition, activity and other interventions, she said. Susceptibility is not inevitable (that is, some physical defects, such as neural tube defects, cannot be corrected later).
In Ukraine, shelling continues around major cities such as Kiev and people live on high alert. In Mariupol, families unable to escape the gunfire are running out of food and water. “The pressure on Ukraine must be enormous,” Glover said. While it’s impossible to say with certainty how the war will affect children born during the Russian invasion, past disasters suggest the effects may be lifelong, possibly manifesting as early mental decline, depression, or an increased risk of heart disease. Glover said it’s crucial to care for these children in any way possible after they’re born.
