PREVENTION OF GESTATIONAL DIABETES MELLITUS AND NEWBORN'S HIGH BIRTHWEIGHT BY LIFESTYLE COUNSELLING -A CLUSTER-RANDOMISED CONTROLLED TRIAL

IntroductionTo examine, whether gestational diabetes mellitus (GDM) or newborns9 high birthweight can be prevented by lifestyle counselling.MethodsA cluster-randomised trial in 14 municipalities, where 2271 women were screened at 8–12 weeks9 gestation. Euglycaemic (N=399) women with at least one GDM risk factor were included. Intervention included individual intensified counselling on physical activity, diet and weight gain at five antenatal visits. Main outcome measures were incidence of GDM and newborns9 birthweight adjusted for gestational age. Multilevel analyses took into account cluster, maternity clinic and nurse level influences in addition with other covariates. Compliance to the individual behavioural objectives varied from 39 to 85.9% depending on the objective and week9s gestation.Results23.3% (50/216) of women in the intervention group and 20.2% (36/179) in the usual care group were diagnosed for GDM (p=0.49). Birthweight was lower in the intervention than in the usual care group (absolute effect −133 g, 95% CI −231 to −35, p=0.008) as were also birthweight per gestational age (absolute effect −3.08; 95% CI −5.3 to −0.9, p=0.006) and proportion of large for gestational age newborns (26/216, 12.1% vs 34/179, 19.7%, p=0.042). The effect sizes were significant after taking cluster, maternity clinic, nurse, age, education, sex of the newborn, parity, pre-pregnancy BMI and smoking into account.ConclusionsIntervention was effective in controlling birthweight of the newborns, but not GDM. Offering lifestyle counselling especially for women at risk for GDM is important in order to prevent high birthweight and the related health problems.