Impact of maternal work outside the home during pregnancy on neonatal outcome.

The impact of mothers' work during pregnancy upon neonatal outcome has not been fully elucidated. A study of maternal health habits and neonatal outcome conducted from 1977 to 1979 at Boston City Hospital assessed the effects of paid work outside the home during pregnancy, particularly third trimester work in a standing position, upon duration of gestation and intrauterine growth, while controlling for potentially confounding variables. Postpartum, 1,690 low-income women were interviewed to provide detailed information on their sociodemographic and health characteristics. Of the 1,507 women whose work status during pregnancy could be classified, 55% did not perform paid work outside the home or attend school, 7% worked into the third trimester in a standing position, and 38% had other work histories or attended school. Infants were examined according to a standard protocol by pediatricians blind to mothers' work history. There was no significant relationship between the mothers' work history during pregnancy and the infants' length of gestation, weight, or head circumference at birth, when confounding variables were controlled statistically by multiple regression analyses. However, women who worked in a standing position into the third trimester delivered infants who were longer than infants born either to mothers with other work histories or to mothers who did not work or attend school. Healthy women with uncomplicated low-risk pregnancies who feel well enough to attend school or work during pregnancy, even in a job requiring some standing, may do so without fear that their infant will suffer shortened gestation or impaired intrauterine growth.