FRIDAY, July 16, 2004 (HealthDayNews) -- A woman who is anxious or stressed while pregnant is at greater risk of bearing a child who will develop an anxiety disorder or behavior problems, a new study says.
The period between 12 and 22 weeks of pregnancy were found to be particularly crucial for increasing risk, said Bea Van den Bergh, a psychologist at Catholic University of Leuven, Belgium.
Van den Bergh is lead author of the study, published in the July/August issue of Child Development.
Maternal anxiety during that period was associated with a heightened risk of a child developing hyperactivity symptoms, "acting out" behavior problems, and their own anxiety problems, Van den Bergh found.
Doctors have known for years that a woman's emotional state during pregnancy can affect her unborn child.
The new study adds to previous research finding the same link, said Van den Bergh, but with an important difference.
"The strength of this study is that questionnaires on the behavior of the child were not only completed by the mother, but also by the teacher, by an independent observer and also by the child," Van den Bergh said.
In the study, Van den Bergh's team evaluated data on 71 mothers and their 72 first-born children, collecting information while the mothers were pregnant and then when the children were age 8 or 9 years old. The mothers reported on their anxiety levels throughout pregnancy. When the children were 8 or 9, questionnaires were completed by the mothers, a teacher and an impartial observer, with complete data collected on 52 children.
The data found that "anxiety during pregnancy explained 22 percent of the differences children show in hyperactivity symptoms, 15 percent of the differences in "acting out" and aggression problems, and 9 percent of the differences in anxiety, after controlling for other factors such as smoking during pregnancy, birth weight and mothers' anxiety after the birth," she said.
Van den Bergh subscribes to the "fetal programming hypothesis," which states that certain upsetting factors that occur during sensitive periods of a fetus' development can "program" certain biological systems in the unborn child. This programming can predispose the child to certain diseases and emotional disorders, she said.
The finding doesn't surprise Dr. Diana Dell, an assistant professor of obstetrics and gynecology and psychiatry at Duke University. "I think it's very much in line with what animal data has been suggesting for a long time and human data for a shorter time," she said.
"What this study is saying is, moms who are under constant stress in the second trimester, those children have increased rates of some developmental disorders in childhood. When a mother is anxious or depressed during pregnancy that's not a neutral impact," Dell said.
If a woman needs help dealing with anxiety during pregnancy, Dell suggests she consider working with a therapist, learning calming techniques, or asking her doctor about other options.
Stress during pregnancy is partly society-driven, Dell said: "Women are under enormous pressure to make perfect babies." Even if her obstetrician asks if she's feeling stressed, a woman may not own up to feelings of anxiety or depression, Dell said.
It's not easy for pregnant women to feel stress-free, but Van den Bergh suggests they try to relax as much as possible. "Try to understand that when you are stressed or anxious the body reacts and that [stress] hormones go to the fetus," she tells them.
"Try to cognitively cope with the situation, for instance when you are in a traffic jam, to keep control," she said.
For more tips on raising a healthy child, visit the American Academy of Pediatrics.