Mild Maternal Stress May Actually Help Children Mature

Contrary to popular belief, mild to moderate levels of maternal psychological stress during pregnancy may actually enhance fetal maturation, according to researchers from the Johns Hopkins University and the National Institute of Child Health and Human Development. The findings are contrary to expectations, generated primarily by animal studies, which have reported that stress during pregnancy interferes with normal development. The Hopkins study found that the opposite was true in a study of pregnant women and during a follow-up of their 2-year-old children. The study is published in the May/June 2006 edition of the journal Child Development.

“We found that modest anxiety and daily stress during pregnancy is associated with more advanced early child development. These findings remained even after accounting for levels of stress and anxiety women experienced at six weeks and at two years postpartum. Prenatal maternal stress also didn’t interfere with children’s temperaments, attention capacity or ability to control behavior and did not cause hyperactivity,” said Janet A. DiPietro, PhD, lead author of the study and a professor in the Johns Hopkins Bloomberg School of Public Health’s Department of Population and Family Health Sciences.

The authors found one exception to their study results: the children of women who regarded their pregnancy as more negative than positive showed slightly poorer emotional control and attention capacity.

The researchers followed 137 women from mid-pregnancy though their child’s second birthday. Self-reported anxiety, pregnancy-specific and nonspecific stress and depressive symptoms were collected from expecting mothers during mid-pregnancy. Ninety-four children were assessed for mental and motor development, as well as their ability to control their behavior and regulate their emotions, at 24 months of age.

“Our findings should provide relief to women who are experiencing the normal anxieties and stresses common to the demands of modern life. In essence, women can stop worrying that their emotional state is harming their unborn baby. Obviously, we don’t recommend that women seek out stress, because maternal exhaustion is not good preparation for labor and delivery and the demands of child rearing,” said DiPietro.

Addressing the difference in their study findings when compared to previous animal studies on the same topic, the Hopkins researchers note that the timing and severity of prenatal stressors, as well as the controlled environment in animal studies, differ greatly from the day-to-day lives of actual expectant mothers.

However, the authors caution that because the participants in the study were mostly well-educated, financially stable women who did not have clinically diagnosed psychological problems, the results may not extend to more disadvantaged women or those with mental health disorders. Further research is necessary to determine whether the findings are a result of biological changes to the pregnancy as a result of stress or whether women who are more anxious or feel more stress are more likely to raise their children in ways that may encourage child development. There may even be a genetic component, explained DiPietro.

Study authors include Janet A. DiPietro, Matthew F. S. X. Novak, Kathleen A. Costigan, Lara D. Atella and Sarah P. Reusing.

The study was supported by grants from the National Institute of Child Health and Human Development and the Maternal and Child Health Bureau.