Introduction: Gestational diabetes mellitus (GDM) prevalence is increasing rapidly, affecting 1 in 7 pregnant women. It has been shown that offspring exposed to GDM in utero are at increased risk of poor cardiometabolic health later in life, therefore it is important to elucidate the physiological changes that could be occurring at a young age to promote impaired metabolic health, in order to devise treatment and preventative strategies in this cohort. Insulin resistance is the first stage of diabetes development, and to date, there has not been a comprehensive systematic review and meta-analyses which has assessed markers of insulin resistance in offspring exposed to GDM in utero.
Methods: Studies assessing markers of insulin resistance (HOMA-IR, insulinogenic index, abdominal obesity, b-cell function) in offspring exposed to GDM in utero were screened throughout the literature. We included studies that defined GDM based on the International Association of Diabetes and Pregnancy Study Groups (IADPSG) definition, or prior definitions. The PRISMA guidelines were followed in conducting this systematic review. Methodological quality was assessed using the National Heart, Lung and Blood Institute (NHLBI) Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies
Results: A total of 2,165 studies were identified from the literature search, of which 96 studies were eligible for full text review, and 49 were included in the systematic review and 23 analysed within the meta-analyses. Offspring exposed to GDM in utero had higher waist circumference (MD 2.40 (95% CI 1.59, 3.21, 21,138 participants) and a lower insulin sensitivity based on Matsuda Index (SMD -0.91 (95% CI -1.72, -0.09, 263 participants). Subgroup analyses for age at assessment revealed that waist circumference was greater in offspring exposed to GDM in utero who were >=10 years of age at assessment compared to those that were exposed to normoglycemic pregnancy in utero (MD: 3.21 95% CI 2.06, 4.37, 1,943 participants).
Results: Offspring exposed to GDM in utero have higher abdominal waist circumference than those who are exposed to normoglycemic pregnancy. These offspring may benefit from monitoring of obesity and insulin resistance to reduce the risk of chronic disease later in life.