Babies born with low birth weights often struggle to keep up physically and mentally with their peers. In some cases, their lean beginnings lead them to suffer from chronic conditions, such as high blood pressure, heart disease, and diabetes. A new study finds that maternal internal stressors of abuse and anxiety are linked to low birth weights, possibly due to their effect on hormone levels. Further, high-crime neighborhoods, an external stressor, may also lead to low birth weights because mothers may perceive their neighbors as threatening, not supportive.
Of the 554 pregnant women (mostly black, poor, and unmarried) seen at obstetric clinics in Memphis from 1990 to 1991, researchers found that just over 15 percent delivered low-birth-weight babies. Mothers who experienced either verbal or physical abuse during their pregnancies delivered babies that were, on average, 98.2 grams lighter than the average-weight babies delivered by mothers who did not suffer abuse. Additionally, anxious mothers delivered babies that were 71 grams lighter than average, and moms who experienced neighborhood stress delivered babies 64.7 grams lighter than average.
The authors suggest that while neighborhood stress probably does not wreak havoc on hormones like abuse and anxiety do, it likely does affect expectant mothers' access to good-quality food or safe areas to exercise. To combat these stressors, the authors suggest improving access to mental health services, expanding interventions for abuse to include men, and adopting a Federal demonstration program in which families are relocated to better neighborhoods. This study was funded in part by the Agency for Healthcare Research and Quality (T32 HS00044).
See "The effects of stress on birth weight in low-income, unmarried black women," by Margaret L. Holland, Ph.D., M.P.H., Harriett Kitzman, R.N., Ph.D., and Peter Veazie, Ph.D., in the November/December 2009 Women's Health Issues 19(6), pp. 390-397.