Moderate drinking during pregnancy and foetal outcome.

Although there are many reports of the adverse effects of alcohol on the infant in ancient literature the first modern report was by Sullivan, Physician to Liverpool gaol. He showed an increased incidence of growth retardation and stillbirth in children of alcoholic mothers using their non-drinking relatives as a control. The literature on moderate drinking is contradictory and suffers from poor control of factors known to confound pregnancy outcome such as social class, parity and smoking habit. The other major problem in assessing the effect of moderate drinking is the difficulty in obtaining accurate drinking histories and the many and varied ways in which these are taken. All histories however, should be regarded as an underestimate. Moderate drinking (less than 40 g alcohol/day before and during pregnancy) has been related to growth retardation, a higher incidence of congenital abnormality, poorer behavioural and neurological scores in the newborn. Recent American surveys have shown an increased relative risk of mid-trimester abortion in women who drink more than three times a week in early pregnancy. Recent work in this country has demonstrated a trend toward smaller head circumference and reduced weight in the babies born to mothers consuming more than 100 g alcohol a week in very early pregnancy. The interaction between smoking and drinking is particularly important for this effect. Using logistic regression analysis the effect of drinking and smoking on birth weight can be clearly seen together with the effect of social class. For any impact to be made on this problem educational intervention is necessary before pregnancy is planned, and thus should be directed at pre-conception clinics, family planning clinics and the general practitioner's surgery.