This study aimed to investigate how maternal birthweight is related to early pregnancy obesity, gestational diabetes mellitus (GDM), and offspring birthweight. Females born term and singleton in Sweden between 1973 and 1995 (N = 305,893) were studied at their first pregnancy. Information regarding their birthweight, early pregnancy body mass index, and pregnancy complications was retrieved from the Swedish Medical Birth Register, as were data on their mothers and offspring. High maternal birthweights (2-3 standard deviation scores (SDS) and >3 SDS) were associated with greater odds of early pregnancy obesity, odds ratio (OR) 1.52 (95% confidence interval (CI) 1.42-1.63) and OR 2.06 (CI 1.71-2.49), respectively. A low maternal birthweight (<2 SDS) was associated with greater odds of GDM (OR 2.49, CI 2.00-3.12). No association was found between high maternal birthweight and GDM. A maternal birthweight 2-3 SDS was associated with offspring birthweight 2-3 SDS (OR 3.83, CI 3.44-4.26), and >3 SDS (OR 3.55, CI 2.54-4.97). Corresponding ORs for a maternal birthweight >3 SDS were 5.38 (CI 4.12-7.01) and 6.98 (CI 3.57-13.65), respectively. In conclusion, a high maternal birthweight was positively associated with early pregnancy obesity and offspring macrosomia. A low, but not a high maternal birthweight, was associated with GDM.
Keywords: Birthweight; gestational diabetes; macrosomia; obesity.