Objective The objective of this study was to assess the relation of some maternal job characteristics to the risks of delivering a small-for-gestational-age or preterm infant.Methods Altogether 4390 women who lived in Quebec City, Canada, and the surrounding area, and who gave birth between January and October 1989 to a singleton liveborn neonate were included. Information on gestational age at delivery, job characteristics, nonoccupational physical activities, and several potential confounders was obtained in a telephone interview a few weeks after the delivery. Birthweight was recorded from the birth certificate.Results The risk of having a small-for-gestational-age infant (birthweight lower than the 10th percentile for gestational age and gender) was increased among the women who worked at least 6 h a day in a standing position. The adjusted odds ratios (OR) were 1.00, 1.13 [95% confidence interval (95% CI) 0.83--1.55], and 1.42 (95% CI 1.02--1.95) for the women working in a standing position