Characteristics of maternal employment during pregnancy: effects on low birthweight.

BACKGROUND: Although maternal employment is considered a risk factor for low birthweight (LBW), the manner in which employment might affect birthweight is poorly understood. In this analysis, selected characteristics of employment during pregnancy were examined for effects on pregnancy outcomes. METHODS: Work characteristics included the number of hours per week, physical activities, and environmental conditions. The outcomes of interest were fetal growth retardation (less than 2500 grams at term) and preterm delivery (less than 37 weeks). The study population consisted of 2711 non-Black, married mothers who participated in the 1980 National Natality Survey (NNS). The NNS data were merged with data from the 1977 revision of The Dictionary of Occupational Titles (DOT) from which measures of occupational physical activities and environmental exposures were obtained. Logistic regression was used in the analysis. RESULTS: Those who worked 40 or more hours per week were more likely than women who worked fewer ...