To assess in women at high risk of gestational diabetes mellitus (GDM) the effect of a lifestyle intervention on the metabolic health of their offspring around 5 years after delivery.

For the original Finnish gestational diabetes prevention study (RADIEL), 720 women with a prepregnancy body mass index (BMI)≥30kg/m² and/or previous GDM were enrolled before or during early pregnancy and allocated to either an interventional (n=126) or conventional (n=133) care group. The present 5-year follow-up substudy assessed the metabolic health outcomes of their offspring. Age- and gender-standardized residuals of metabolic health components (waist circumference, mean arterial pressure, high-density lipoprotein and triglyceride levels, and fasting insulin/glucose ratio) were also combined to determine the accumulation of metabolic effects. Body composition was assessed by electrical bioimpedance.

Offspring of women in the intervention group had a less optimal metabolic profile after the 5-year follow-up compared with offspring in the usual care group (P=0.014). This difference in metabolic health was primarily related to lipid metabolism, and was more prominent among boys (P=0.001) than girls (P=0.74). Neither GDM, gestational weight gain, prepregnancy BMI, offspring age nor timing of randomization (before or during pregnancy) could explain the detected difference, which was also more pronounced among the offspring of GDM pregnancies (P=0.010). Offspring body composition was similar in both groups (P>0.05).

The lifestyle intervention aimed at GDM prevention was associated with unfavourable metabolic outcomes among offspring at around 5 years of age.