Temporal trends in pregnancy weight gain and birth weight in Bavaria 2000-2007: slightly decreasing birth weight with increasing weight gain in pregnancy

Aims: To assess temporal trends in birth weight and pregnancy weight gain in Bavaria from 2000 to 2007. Methods: Data on 695,707 mother and infant pairs (singleton term births) were available from a compulsory reporting system for quality assurance, including information on birth weight, maternal weight at delivery and at booking, maternal smoking, age, and further anthropometric and lifestyle factors. Pregnancy weight gain was defined as: weight prior to delivery minus weight at first booking minus weight of the newborn. Results: Although mean weight gain during pregnancy increased considerably from 10.10 to 10.73 kg in seven years, the mean birth weight in mature singletons decreased slightly from 3433 to 3414 g. These trends could not be explained by concurrent changes in the rates of primiparity, smoking and gestational diabetes. Conclusions: These German data confirm an increased weight gain during pregnancy with adjustment for potential confounders.