Maternal and neonatal outcomes and time trends of gestational diabetes mellitus in Sweden from 1991 to 2003.

AIMS: To determine maternal and neonatal outcomes for women with gestational diabetes mellitus (GDM) in Sweden during 1991-2003, and to compare the outcomes in the two time periods.

METHODS: This is a population-based cohort study using the Swedish Medical Birth Register data for the period 1991-2003. There were 1,260,297 women with singleton pregnancies registered during this time, of whom 10 525 were diagnosed with GDM, based on a 75 g oral glucose tolerance test. The main diagnostic criteria were fasting capillary whole blood glucose>or=6.1 mmol/l and 2 h blood glucose>or=9.0 mmol/l.

RESULTS: Maternal characteristics differed significantly between the GDM and non-GDM group. Adjusted odds ratios (OR) were as follows: for pre-eclampsia, 1.81 (95% confidence interval (CI) 1.64-2.00); for shoulder dystocia, 2.74 (2.04-3.68); and for Caesarean section, 1.46 (1.38-1.54). No difference was seen in perinatal mortality, stillbirth rates, Apgar scores, fetal distress or transient tachypnoea. There was a markedly higher risk of large for gestational age, OR 3.43 (3.21-3.67), and Erb's palsy, OR 2.56 (1.96-3.32), in the GDM group, and statistically significant differences in prematurity<37 weeks, birth weight>4.5 kg, and major malformation, OR 1.19-1.71. No statistically significant improvement in outcomes was seen between the two study periods.

CONCLUSIONS: Women with GDM have higher risks of pre-eclampsia, shoulder dystocia and Caesarean section. Their infants are often large for gestational age and have higher risks of prematurity, Erb's palsy and major malformations. These outcomes did not improve over time.