The independent effects of maternal obesity and gestational diabetes on the pregnancy outcomes

BACKGROUND Obesity and gestational diabetes (GDM) in pregnancy are recognized risk factors for adverse outcomes, including cesarean section (CS), macrosomia and preeclampsia. The aim of this study was to investigate the independent effect of GDM and obesity on the adverse pregnancy outcomes at term. METHODS A retrospective cohort of postpartum women, in King Khalid University Hospital, were stratified according to body mass index (obese ≥30 kg/m2, non-obese <30 kg/m2) and the results of GDM screening into the following groups, women with no obesity and no GDM (reference group), women with no obesity but with GDM, women with obesity but no GDM and women with both GDM and obesity. Adverse pregnancy outcomes included high birth weight, macrosomia, CS delivery and preeclampsia. Multiple logistic regression used to examine independent associations of GDM and obesity with macrosomia and CS. RESULTS 2701 women were included, 44% of them were obese and 15% had GDM. 63% of the women with GDM were obese. There was significant increase in the percentage of macrosomia, P < 0.001, high birth weight, P < 0.001, CS, P < 0.001 and preeclampsia, P < 0.001 in women with GDM and obesity compared to the reference group. Obesity increased the estimated risk of CS delivery, odds ratio (OR) 2.16, confidence intervals (CI) 1.74-2.67. The combination of GDM and obesity increased the risk of macrosomia OR 3.45, CI 2.05-5.81 and the risk of CS delivery OR 2.26, CI 1.65-3.11. CONCLUSION Maternal obesity and GDM were independently associated with adverse pregnancy outcomes. The combination of both conditions further increase the risk.