Impact of comorbid polycystic ovarian syndrome and gestational diabetes mellitus on pregnancy outcomes: a retrospective cohort study

Background Gestational diabetes mellitus (GDM) and polycystic ovarian syndrome (PCOS) have been associated with adverse maternal and neonatal outcomes, but the evidence on the impact of coexistent PCOS and GDM is rather limited and inconclusive. We investigated the impact of comorbid PCOS on pregnancy outcomes among women with GDM. Methods This retrospective cohort study included women diagnosed with GDM on 75 g oral glucose tolerance test on routine antenatal screening tests at Liverpool Hospital between February 2015 and January 2019. Women were then grouped into those with and without PCOS based on the Rotterdam criteria. The demographic details, clinical data and pregnancy outcomes were compared between the two groups. Results Among the 1545 women with GDM included in the study, there were 326 women with PCOS. Women with GDM and PCOS (GDM(+)PCOS(+)) were younger (29.5 years vs 31.5 years,p < 0.001), more likely to be primigravidae (31.9% vs 20%,p < 0.001), as well as of Caucasian descent (37.4% vs 21.7%,p < 0.001). PCOS was an independent risk factor for the development of preeclampsia on regression analysis (OR 2.06,p = 0.021). Women with PCOS and GDM had a higher body mass index (31.5 kg/m(2)vs 27.7 kg/m(2),p < 0.001), significant gestational weight gain (12.6 kg vs 11.5 kg,p = 0.016), and more frequent use of pharmacotherapies to manage their GDM (57.7% vs 45.2%,p < 0.001). There was no statistically significant difference in the rates of adverse neonatal outcomes in both the groups. Conclusion Among women with GDM, PCOS was an independent risk factor for the development of preeclampsia and significant gestational weight gain, warranting vigilant monitoring of blood pressure, blood glucose levels and body weight, and implementing timely interventions to improve obstetric and neonatal outcomes.