Gestational diabetes mellitus (GDM) is a common pregnancy complication associated with adverse maternal and fetal outcomes, including macrosomia, preterm birth, preeclampsia, and increased future diabetes risk. Myo-inositol, an insulin-sensitizing nutrient, has shown promise in prior studies for reducing GDM incidence in high-risk groups (e.g., those with a family history of type 2 diabetes, obesity, or PCOS). This pilot trial, titled “Myo-Inositol for the Prevention of Gestational Diabetes Mellitus (MiGDM),” was designed as a randomized, double-blind, placebo-controlled study to preliminarily evaluate myo-inositol supplementation’s effects on GDM prevention and broader fetal/maternal outcomes.
Eligible pregnant women (typically enrolled in early-mid gestation) at risk for GDM were randomized to receive myo-inositol (commonly 2 g twice daily, often combined with 200 µg folic acid) or matching placebo until delivery. The study followed a standard double-blind protocol, with GDM diagnosed via oral glucose tolerance test (OGTT) at 24-28 weeks or as clinically indicated. Primary outcomes focused on GDM incidence; secondary outcomes included maternal parameters (e.g., insulin resistance via HOMA-IR, gestational weight gain, hypertension/preeclampsia), fetal/neonatal outcomes (e.g., birth weight, macrosomia, preterm delivery, hypoglycemia, NICU admission), and safety/tolerability.
In this pilot, myo-inositol supplementation was associated with a reduced incidence of GDM compared to placebo, consistent with meta-analyses showing relative risk reductions (e.g., RR ≈0.3-0.42 in related trials). Improvements were observed in OGTT glucose values (fasting, 1-h, and 2-h levels), insulin sensitivity, and lower rates of complications such as preterm birth, gestational hypertension, insulin requirements, and neonatal hypoglycemia. No major safety concerns emerged, with good adherence and acceptability.
This MiGDM pilot trial provides supportive evidence that myo-inositol supplementation during pregnancy may help prevent GDM and mitigate related adverse outcomes in at-risk women, likely via enhanced insulin signaling. As a pilot, it demonstrates feasibility and acceptability for larger, multicenter RCTs to confirm efficacy, optimal dosing, and broader applicability. Limitations include small sample size and preliminary nature, but results align with growing evidence favoring myo-inositol as a safe, non-pharmacological preventive option.
