Early pregnancy waist-to-hip ratio and risk of preeclampsia: a prospective cohort study.

Preeclampsia is a major cause of maternal death and morbidity. Body mass index (BMI) predicts an increased risk of developing hypertensive disorders and preeclampsia. However, waist-to-hip ratio (WHR), as a central obesity index, has not been assessed in predicting this disorder in pregnancy. We assumed that WHR might be more sensitive in predicting the risk of preeclampsia, compared with BMI. The aim of this cohort study was to investigate the relationships of BMI and WHR with preeclampsia. This was a prospective cohort study of 1200 pregnant women with singleton pregnancies. Anthropometric indices included WHR and BMI, which were measured at the first antenatal visit (⩽ 12 weeks of gestational age). The incidence of preeclampsia was assessed after 20 weeks of gestation. Maternal demographic data and obstetric outcomes were also recorded for each subject. All of the statistical tests were performed using SPSS software, version 16. The overall incidence of preeclampsia in the study population was 4.2%. The maternal WHR and BMI at the beginning of pregnancy were significantly associated with the occurrence of preeclampsia (P = 0.006 and P = 0.001, respectively). WHR ⩾ 0.85 and BMI ⩾ 25 kg m(-2) in the first 12 weeks of pregnancy had relative risks of 2.317 (confidence interval (CI): 1.26-4.27) and 3.317 (CI: 1.6-6.86) for preeclampsia. BMI and WHR were anthropometric indicators that presented correlations with preeclampsia. Of these anthropometric indices, BMI had greater predictive value in preeclampsia.