Five-year follow up of a low glycaemic index dietary randomised controlled trial in pregnancyno long-term maternal effects of a dietary intervention

ObjectiveTo 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. DesignRandomised control trial of low glycaemic index (GI) diet in pregnancy with longitudinal follow up to 5 years post-intervention. SettingDublin, Ireland (2007-2016). PopulationIn 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. MethodsFasting 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. OutcomeMaternal diet, HbA1c, and weight retention at 5 years post-intervention. ResultsThere 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. ConclusionsThe 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.