Employment in pregnancy: prevalence, maternal characteristics, perinatal outcome.

Data from the Cardiff Births Survey was used to examine the relation between the nature of employment and perinatal outcome. The proportion of all expectant mothers who work during pregnancy increased from 38.7% in 1965/69 to 43.9% in 1975/79 (p less than 0.001). The percentage of working primiparas, however, remained unchanged at approximately 80%, whereas the percentage of working multiparas rose from 15.1% to 22.1%. The non-employed primiparas were more likely than the employed primiparas to be at the extremes of maternal age, to have a history of medical problems and previous abortions, and to attend less often for antenatal care. Perinatal outcome (measured in terms of perinatal mortality, birthweight, and length of gestation) was significantly better among the employed mothers. Non-employed mothers in social classes I and II seemed to be a particularly high risk group. Exclusion of mothers with an adverse obstetric or medical history considerably reduced the differences in perinatal outcome between the two groups. The findings suggest that healthy women without an adverse obstetric or medical history can safely continue in employment during pregnancy.