Centiles of weight at term birth according to maternal nationality in a northern Italian region

Country specific birthweight curves may reflect the ethnic composition of that population and may offer information on the “true“ birth weight distribution of new births from native and foreign mothers. In consideration of the fact that in Italy now about 30% new births born in foreigners, we analyzed the centiles of weight at birth separately for the native Italian women and foreign ones. We considered data of all deliveries in a Northern Italian Region (Lombardy) with a population of about 10 millions inhabitants, in period of time between 1st January 2010 and 31th December 2014. Gestational age was considered as completed week of gestation. On the basis of these data we computed the 10th, 50th and 90th centile values of neonatal birthweight from the 37th to 42nd week of gestation at delivery for the total population and separately for native Italian and the five more common nationality of non Italian women (i.e. women born in Morocco, Albania and Romania, China and Egypt). These nationality were considered since they represent at least the 5% of all foreigner mothers. The values of centiles were higher in males than in females in all the gestational weeks and the different maternal nationality populations. Lower centiles values were observed in babies born by Italian women, the higher been observed in babies born by Chinese women and Maroccan and Egyptian ones with differences of about 100-200gr among babies born form mother with these nationality in comparison with babies born by Italian mothers. This descriptive analysis of centiles of weight at birth in Lombardy provides Italian obstetricians and neonatologist with curves of fetal growth more closely representing the population under curve.