Individualized nutritional intervention versus routine care for gestational diabetes prevention: A randomized controlled trial.

Abstract

Background: Gestational diabetes mellitus (GDM) affects millions of females and their children. Effective dietary strategies for early prevention are controversial.

Objective: To investigate whether an individualized nutritional intervention reduced GDM incidence in high-risk females.

Methods: A randomized trial was conducted at three tertiary hospitals in Shanghai, China. We randomly assigned (1:1) pregnant women in the first trimester who were identified to be at high risk of GDM by a prediction model to either an individualized nutritional intervention or usual care. The intervention consisted of three dietary consultations by dietitians based on Chinese dietary guidelines before the oral glucose tolerance test (OGTT) at 24-28 gestational weeks. The control group received usual care. All participants provided 3-day food records at each follow-up. The primary outcome was GDM incidence using the International Association of Diabetes and Pregnancy Study Group criteria. Key secondary outcomes were dietary alterations, gestational weight gain (GWG), maternal metabolic profile, perinatal and pregnancy outcomes. Intention-to-treat analyses were conducted.

Results: A total of 519 females were enrolled, of whom 261 were assigned to the intervention and 258 to usual care. GDM was diagnosed in 85/245 (34.7%) females in the intervention group compared to 89/244 (36.5%) in the control group (adjusted relative risk 0.91 [95% CI: 0.73, 1.15], p=0.44]. More females in the intervention group had an appropriate GWG than the control group (1.38 [1.06, 1.79]) and lower levels of fasting and 2-hour insulin during the OGTT (p<.001). We observed a reduction in the rate of small for gestational age in the intervention group compared with the control group (0.11 [0.01, 0.80]) and neonatal hypoglycemia (0.14 [0.04, 0.57]).

Conclusions: Among females at risk of GDM, an individualized nutritional intervention based on Chinese dietary guidelines provided before the OGTT did not prevent GDM but helped to manage GWG appropriately and improved pregnancy outcomes.

Trial registration: ChiCTR 1900026963 registered on Oct 27, 2019, with initial participant enrollment on May 5, 2020, noted at URL: https://www.chictr.org.cn/searchproj.html?regno=1900026963.