Birthweight by gestational age and its effect on perinatal mortality in white and in Punjabi births: experience at a district general hospital in West London 1967-1975.

At Hillingdon Hospital in West London two main ethnic groups: 'UK' (i.e. white European) and 'Indian' (i.e. Punjabi) account for the bulk of obstetric work load. Birthweight by gestational age graphs were calculated for some 6000 Indian and 18000 UK infants born between 1967 and 1975 inclusive. A mean weight difference at term favoured UK male babies by 240 g and UK female babies by 230 g. Though the crude perinatal results in the two populations were not significantly different, the perinatal mortality of infants less than 2500 g in birthweight was lower in the Indian than the UK population, particularly in the 1500-2400 g group. This is attributed to a levelling off in intrauterine growth from 36 to 37 weeks gestation onwards in Indian compared with UK pregnancies, so that they were more mature than UK births of the same weight. However light-for-dates births, defined as birthweights below the 10th centile of weight-for-gestational age on their own ethnic and sex specific standards pose problems, irrespective of ethnic background.