Background: The aim of the study was to examine the outcome of the pregnancy and neonatal period in 1) women with gestational diabetes mellitus and non-diabetic pregnant women, and 2) in women with early and late diagnosis of gestational diabetes mellitus.
Methods: Included were 327 women with gestational diabetes mellitus and 295 non-diabetic women, who were screened with a 75 g oral glucose tolerance test because of risk factors for gestational diabetes. Women with gestational diabetes mellitus were treated with low-caloric diet and insulin when appropriate, while women in the control group received routine antenatal care.
Results: Gestational age at delivery was significantly lower in the group with gestational diabetes mellitus, both when considering all deliveries (39.1+/-1.7 weeks versus 39.8+/-2.0 weeks, p<0.05) and only those with spontaneous onset of labor (38.8+/-2.0 weeks versus 40.0+/-1.6 weeks, p<0.05). The frequency of macrosomia was increased, although not statistically significant (8% vs. 2%, p=0.07), and the rate of admission to the neonatal ward was significantly increased (18% vs. 9%, p<0.05) in the group with gestational diabetes. Women with early diagnosis of gestational diabetes mellitus had a significantly increased need for insulin treatment during pregnancy (36% vs. 9% p<0.05) and a significantly higher occurrence of diabetes mellitus at follow-up from two months until three years postpartum.
Conclusions: This study of women with gestational diabetes mellitus and non-diabetic pregnant women showed that gestational diabetes mellitus was associated with a significantly lower gestational age at delivery and an increased rate of admission to the neonatal ward. Women diagnosed with GDM before 20 weeks of gestation had an increased need for insulin treatment during pregnancy and a high risk of subsequent overt DM, compared with women diagnosed with GDM later in pregnancy.