Association between female waist-hip ratio and live birth in patients undergoing fertilization: a retrospective cohort study.

BACKGROUND

Maternal obesity is associated with adverse pregnancy outcomes. It negatively affects IVF/ICSI outcomes and offspring health. However, it is unclear whether waist-hip ratio (WHR) has an impact on outcomes of fertilization (IVF) or intracytoplasmic sperm injection (ICSI) cycles.

METHODS

A retrospective cohort study screened 943 patients who underwent IVF/ICSI treatment between February and June 2020 in Shanghai, China, and 828 patients were finally included in the analyses. The body weight, height, waist circumference and hip circumference were measured before ovarian stimulation, and their IVF/ICSI outcomes were followed up. The cut-off point of WHR was determined by the area under the receiver operating characteristic (ROC) curve. Live birth rate from the first embryo transfer cycle was the primary outcome. The secondary outcomes included cumulative live birth, miscarriage rate and birthweight.

RESULTS

Women with relatively high WHR (≥0.783) showed lower live birth rate (adjusted odds ratio (aOR): 0.657, 95%CI: 0.466-0.926), lower cumulative live birth rate (aOR: 0.580, 95%CI: 0.413-0.814), and higher miscarriage rate (aOR=2.865, 95%CI: 1.300-6.316) as compared with those with low WHR (<0.783), independently of BMI. Joint WHR and BMI analyses showed that, compared with the reference group (those with low WHR and normal weight), those with high WHR and normal BMI had lower live birth rate (aOR=0.653, 95%CI: 0.447-0.954) and cumulative live birth rate (aOR=0.600, 95%CI: 0.413-0.872), and higher miscarriage rate (aOR=2.865, 95%CI: 1.229-6.676), Whereas the patients with both high WHR and high BMI only showed a significant lower cumulative live birth rate (aOR=0.612, 95%CI: 0.404-0.926). Moreover, there was no significant association between BMI and pregnancy outcomes, or between maternal WHR and birth weights.

CONCLUSIONS

Our results demonstrated that higher WHR was associated with lower fecundability in women undergoing IVF/ICSI cycles, independently of BMI. Interestingly, the adverse effects of central obesity were more evident in patients with lower BMI. Thus WHR appears to be a better predictor of female fertility treatment outcomes as compared with BMI.