Five‐year follow up of a low glycaemic index dietary randomised controlled trial in pregnancy—no long‐term maternal effects of a dietary intervention

Objective To determine whether a dietary intervention in pregnancy had a lasting effect on maternal outcomes of diet, HbA1c and weight retention 5 years post‐intervention; and to establish whether modifiable maternal behaviours were associated with these outcomes. Design Randomised control trial of low glycaemic index ( GI ) diet in pregnancy with longitudinal follow up to 5 years post‐intervention. Setting Dublin, Ireland (2007–2016). Population In all, 403 women of 759 (53.1%) were followed up at 5 years. A total of 370 (intervention n = 188; control n = 182) were included in this analysis. Methods Fasting glucose was measured at 13 and 28 weeks’ gestation and HbA1c (mmol/mol) at 5‐year follow up. Weight retention (kg) from early pregnancy to 5 years post‐intervention was calculated. Dietary intakes, anthropometry, and lifestyle factors were measured in pregnancy and 5 years post‐intervention. Multiple linear regression models, controlling for confounders, were used for analysis. Outcome Maternal diet, HbA1c, and weight retention at 5 years post‐intervention. Results There was no difference between the intervention and control at 5 years post‐intervention for any long‐term maternal outcomes measured. HbA1c at 5 years post‐intervention was associated with early‐pregnancy fasting glucose ( B 1.70, 95% CI 0.36–3.04) and parity ≥3 ( B 1.04, 95% CI 0.09–1.99). Weight retention was associated with change in well‐being from pregnancy to 5 years ( B −0.06, 95% CI −0.11 to −0.02), gestational weight gain ( B 0.19, 95% CI 0.00–0.38), and GI ( B 0.26, 95% CI 0.06–0.46) at 5 years. Conclusions The ROLO low‐ GI dietary intervention in pregnancy had no impact on maternal dietary intakes, HbA1c or body composition 5 years post‐intervention. Maternal factors and lifestyle behaviours in pregnancy have long‐term effects on glucose metabolism and weight retention up to 5 years later. Tweetable abstract Pregnancy factors are associated with maternal glucose metabolism and weight retention 5 years later—findings from the ROLO Study.