Effect of a lifestyle intervention during pregnancy-findings from the Finnish gestational diabetes prevention trial (RADIEL)

To assess the effect of lifestyle counseling on perinatal outcomes among women at high risk for gestational diabetes. A total of 492 women with obesity and/or prior gestational diabetes were allocated to intervention (four sessions of lifestyle counseling, n = 249) or usual care (n = 243) before 20 weeks’ gestation. Lifestyle indicators, gestational weight gain, or obstetric and perinatal outcomes did not differ between the two groups. An oral glucose tolerance test in the first half of pregnancy was pathological in 37.7% (n = 87/144) of intervention and 36.5% (n = 72/197) of control group women (p = 0.81). The total incidence of gestational diabetes diagnosed in the first or second half of pregnancy was 44.8% (107/239) in the intervention and 48.1% (111/231) in the control group (p = 0.48). The high prevalence of impaired glucose metabolism was observed already in early pregnancy, which may have contributed to the lack of effect of the intervention.