ObjectiveUsing propensity score matching (PSM) to eliminate the interference of confounding factors, to expbre the influence of body mass index (BMI) on the perinatal outcome of polycystic ovary syndrome (PCOS).

MethodsThe clinical data of 500 PCOS patients who underwent a systematic obstetric check-up and gave birth were retrospectively analyzed.According to the pre-pregnancy BMI, the patients were divided into the normal BMI group (BMI 18.5- < 24 kg/m²) (n=264) and high BMI group (BMI ≥ 24 kg/m²) (n=236).The baseline data of the two groups were compared.The PSM was used to balance the confounding factors of the two groups, and the baseline data and perinatal outcomes after PSM were compared between the two groups.

ResultsBefore the PSM matching, there were significant differences in age, family history of PCOS, history of pregnancy, history of preterm birth, history of miscarriage, pre-pregnancy diabetes, pre-pregnancy hypertension, PCOS course, assisted reproduction, and weight gain during pregnancy between the normal BMI group and the high BMI group (P < 0.05 to P < 0.01).After the PSM matching, there was no significant difference in general data between the two groups (P>0.05).The incidence of gestational diabetes mellitus (GDM), hypertension in pregnancy (HDCP), abnormal thyroid function and premature delivery in the high BMI group was significantly higher than that in the normal BMI group (P < 0.05 to P < 0.01).There were no significant differences in cesarean section, abnormal amniotic fluid, premature rupture of membranes, low birth weight, macrosomia, neonatal asphyxia, and neonatal hypoglycemia between the high BMI group and the normal BMI group (P>0.05).

ConclusionsA high BMI has a significant impact on GDM, HDCP, abnormal thyroid function and premature delivery in PCOS patients.The proper weight control is helpful to improve the perinatal outcome of mothers and babies.