Low birthweight and preterm delivery, Scotland, 1981-84: effect of parents' occupation.

The relation between prematurity and parenteral occupation was examined in a national study of 252,147 liveborn babies delivered in Scotland between 1981 and 1984. Information about mothers' and fathers' work was routinely collected at the first antenatal visit, and birthweight and gestational age were recorded at delivery. Preterm delivery (less than 37 weeks' gestation) and low birthweight (less than 2500 g) were more frequent in the children of mothers and of fathers employed in manual rather than in non-manual jobs. The risk of preterm delivery and/or low birthweight was more than 50% higher in the children of women who worked with electrical, metal, or leather goods than in the children of other female manual workers. These findings were not explained by maternal age, gravidity, marital status, previous perinatal death, baby's sex, or father's social class. For male manual workers, only the children of ceramic workers had an increased risk of prematurity. The risk of a baby being small-for-gestational age (less than or equal to 5th gestation-specific birthweight percentile) varied little with mother's or father's occupation. Overall, the results suggest that parental occupational exposures do not have a pronounced effect on the risk of prematurity, and when there are adverse effects they are associated with maternal rather than paternal exposures.