Stress and Pregnancy - Page 2
© March of Dimes Foundation
Recent studies suggest that high levels of stress may increase the risk of preterm labor, low birthweight and, possibly, miscarriage.
A 1995 study by Laura Fenster, PhD, of the California Department of Health Services, and other researchers, found that job stress was not associated with an increased risk of miscarriage for most pregnant women. However, the risk of miscarriage increased two- to three-fold for certain women who reported high levels of job stress. These women included those over age 32, women pregnant for the first time, and smokers.
A number of studies suggest a link between high levels of stress and preterm delivery and low birthweight. A 1993 study by Pathik Wadhwa, MD, PhD, of the University of California (now at the University of Kentucky), and other researchers, evaluated a group of 90 highly educated, middle-class women who received good prenatal care and had healthy lifestyles (few of the women smoked, drank alcohol, or used illicit drugs), characteristics that generally reduce the risk of preterm delivery and low birthweight. This study found that women who reported more life-event stresses (such as death in the family, divorce, loss of a job, financial difficulties) had a significantly increased risk of having a low- birthweight baby (less than 5-1/2 pounds). A 1996 study from a Copenhagen, Denmark, university hospital reported similar findings among women from diverse socioeconomic levels.
In the University of California study, middle-class women who experienced high levels of pregnancy-related anxiety (such as worries about the health of their baby or fear of labor and delivery) were significantly more likely to deliver prematurely. A March of Dimes-supported study published in 1992 by Marci Lobel, PhD, of the State University of New York at Stony Brook, and Christine Dunkel-Schetter, PhD, and Susan Scrimshaw, PhD, of the University of California at Los Angeles found that the low-income women in their study who suffered from high levels of stress and anxiety throughout their pregnancies were more likely to deliver prematurely. And their babies were more likely to be born with low birthweight even when born at full term.
Although these studies are highly suggestive, they do not prove that stress causes preterm labor and low birthweight, and researchers are seeking to clarify how stress might contribute to these outcomes.
It appears likely that stress increases the levels of a group of hormones which can constrict blood flow to the placenta, so the fetus may not receive the nutrients and oxygen it needs for optimal growth. These same hormones also play a role in triggering labor and, therefore, increased levels of these hormones may increase the risk of preterm labor.
