Risk and adverse outcomes of gestational diabetes in migrants: A population cohort study

To evaluate the risk of gestational diabetes (GDM) and of neonatal/maternal complications (macrosomia, large for gestational age (LGA), cesarean sections, preterm deliveries, neonatal distress and fetal malformations) among women coming from High Migration Pressure Countries (HMPC), compared to native (Italian) mothers.

Risks of GDM and related neonatal/maternal complications were evaluated in a cohort of 581,073 Italian compared with 105,111 HMPC women of age 15-45 yr, resident in Tuscany, Italy along years 2012-2017, delivering 122,652 singleton live births (18,596 from HMPC mothers).

HMPC women, compared to Italian ones, were at higher risk of GDM (OR: 1.586; 1.509-1.666;p < 0.0001), peaking for women originating from South Asia (OR:3.0.49; 2.618-3.553;p < 0.0001). GDM was associated with increased risk of preterm delivery and cesarean sections, while migrants, regardless of GDM, were burdened by a higher risk of all considered complications. The rise in all these risks, including macrosomia or LGA however, disappeared, after addition of interaction term GDM × HMPC ethnicity.

Compared to Italian mothers, HMPC women had higher risk of GDM and of all considered adverse events. The addiction of the interaction term GDM × HMPC ethnicity in the predictive model, however reversed the rise in risk of all HMPC associated adverse outcomes.