Skip Navigation


April 24, 2001


A lack of time or money for "non-essentials," such as socializing with friends, going out to dinner, or taking care of one’s appearance, may be among the many factors contributing to the risk of delivering a baby prematurely (prior to 37 weeks of pregnancy), according to a study by researchers at the Johns Hopkins Bloomberg School of Public Health. The study is among the first to look beyond medical reasons for preterm delivery and examine social and psychosocial influences among a unique group already at high risk -- low-income, African-American women. The findings appear in the April issue of Blackwell Science’s Paediatric and Perinatal Epidemiology journal.

Previous research indicates that infant mortality in the United States continues to decline, yet the rate of preterm births has not shown any improvement over the past decade. 75 percent of newborn deaths are attributable to preterm delivery. "In order to decrease the rate of preterm births, which currently account for 11 percent of all deliveries in the United States, we must increase our understanding of the causes of preterm delivery," says Dawn Misra, PhD, MHS, assistant professor of population and family health sciences at the Johns Hopkins  Bloomberg School of Public Health. "Our findings suggest that lacking what might be deemed ‘non-essential’ may lead to a woman feeling stressed or hopeless, without control or power. These feelings, in turn, increase her risk of delivering preterm."

Research on social factors -- poverty, education, race -- has often included low income and African-American women. Yet much of the previous research into psychosocial causes of preterm delivery -- stress, locus of control, depression -- has focused on middle-class white women. Dr. Misra and her colleagues studied social and psychosocial factors as well as medical variables in a sample of 735 low-income, African-American women using information collected for a study of prenatal care and drug use. Data were gathered by interviewing the mothers following delivery and by abstracting information from their medical records. This was a high risk sample of women as indicated by the fact that nearly one in four women delivered preterm as compared to 11 percent overall in the United States.

The researchers discovered that even within this group of low-income participants, there was still a high degree of variability in poverty levels. Among social factors, they found that it was not life's absolute necessities, such as shelter and heat, affecting the risk of preterm delivery, but rather, having the time and money to obtain what they termed "non-essentials," such things as being alone with a partner, socializing with friends, or going out to the movies or a restaurant. The lack of either time or money for these activities increased the risk of preterm delivery significantly, and a lack of both time and money increased the risk threefold.

Among psychosocial factors, they found stress to be an influential factor as well as the feelings a woman had about her pregnancy and life in general. Those women who felt they did not have control or power over their lives (a concept measured as "locus of control") were at an increased risk.

The researchers next determined the effects these identified factors had on one another. They found that once problems of stress and powerlessness were considered and included in the model, the lack of resources for non-essentials had less of an impact on preterm deliveries. This suggests that the lack of resources may be related to the feelings of stress and powerlessness. When measured biomedical factors were added into the mix, a lack of resources was no longer an influence, yet feelings of stress and powerlessness continued to independently influence the rate of preterm deliveries.

"Social and psychosocial factors have rarely been comprehensively examined among low income and/or African-American women. Our findings suggest that these factors are, indeed, an important contributor to preterm birth, with stress and locus of control nearly doubling the risk of preterm birth for these women," Dr. Misra concludes. "While further research is needed, development of effective interventions to prevent preterm birth must continue."

Other authors of this study were Patricia O’Campo, PhD, associate professor, and Donna Strobino, PhD, professor, both from the Department of Population and Family Health Sciences at the Johns Hopkins Bloomberg School of Public Health.

Funding for this study was provided by a grant from the National Institute on Drug Abuse.

Public Affairs Media Contacts:
Tim Parsons @ 410.955.6878 or