Antenatal booking and perinatal mortality in Scotland 1972-1982.

Data from Scottish maternity hospital discharge returns (SMR2) were analysed to determine the relationship between gestational age at antenatal booking and perinatal mortality during 1972-82, controlling for maternal age, parity, socioeconomic and marital status. Maternal youth, multiparity and unmarried status were independently associated with both a high perinatal mortality and a low proportion of maternities booked before 17 weeks gestation. However, among primiparae and mothers aged 30 years or more relatively high perinatal mortality rates were associated with high proportions booking early for antenatal care. Socioeconomic status amongst married women, independent of age and parity, influenced perinatal mortality but had little effect on booking behaviour. Between 1972-75 and 1980-82, there was a general increase in the proportion of maternities booked before 17 weeks gestation, but no significant difference was found between the standardized perinatal mortality rates for pregnancies booked before and after 17 weeks gestation. More detailed analysis for different gestational ages at booking during 1980-82 revealed no trend of increasing risk with later booking. Despite technological advances, antenatal care during the first half of pregnancy is unlikely to have made a substantial contribution to the fall in perinatal mortality over this period.