THE EFFECT OF SOCIAL DEPRIVATION ON BIRTH-WEIGHT, EXCLUDING PHYSIOLOGICAL AND PATHOLOGICAL EFFECTS

Objective To study the effect of social deprivation on birthweight, ex cluding the effect of known physiological factors and exploring the ef fect of possible pathological factors. Design Retrospective analysis o f computerised obstetric database. Setting Two teaching hospitals and an associated district general hospital which provided a defined catch ment area in the East Midlands. Subjects The final analysis included 7 493 women with complete datasets and gestations of between 259 and 300 days at delivery, dated by ultrasound scan. Main outcome measures Smo king habit, alcohol consumption, weight gain during pregnancy, systoli c and diastolic blood pressures at booking, bleeding during pregnancy and Jarman score; also, the effect of these variables on birthweight, adjusted for the effects of physiological factors using the individual ised birthweight ratio. Results Smoking during pregnancy reduced birth weight but the effect is not linear, becoming less marked as the numbe r of cigarettes smoked increases. Alcohol intake, diastolic and systol ic blood pressures at the booking visit and vaginal bleeding during ea rly pregnancy were not significantly related to birthweight. Pregnancy weight gain was significantly positively related to birthweight espec ially in the normal weight range (60-99 kg), A multivariate analysis i ncluding physiological and pathological factors found increasing Jarma n score to be negatively related to birthweight. Conclusions In this c entral British population social deprivation is correlated negatively with birthweight : the most socially deprived mothers have the smalles t babies. This association cannot be explained in terms of physiologic al differences in the population nor in a higher prevalence of known p athological factors.