[Studies on relationship between occupation and pregnancy outcome]

To study the effects of maternal occupation on reproductive outcomes, including pregnancy outcome and neonatal status, and complications of pregnancy and delivery.

Data were extracted from 12 224 obstetric records of eight hospitals in Beijing, and all the subjects recruited in the study were interviewed before discharge during from May 1992 to April 1993. Pregnancy and reproductive outcomes were analyzed according to their occupational classifications, adjusted for the potential confounding factors, such as age, smoking and drinking during pregnancy and history of spontaneous abortion.

Incidence rates of pregnancy induced hypertention, low birth weight, intrauterine growth retardation and postpartum hemorrhage were higher in the workers than that of the average levels. Incidence rates of threatened abortion, gestational anemia, stillbirth and uterine atony in professional persons, of prolonged pregnancy and neonatal asphyxia in farmers, of low birth weight in housewives, of gestational anemia and of uterine atony in administrative persons all were higher than the average levels.

Occupation undertaken by pregnant women was associated with the adverse pregnancy and reproductive outcomes to certain extent.