Overweight and obesity determined by body mass index criteria for Asian populations adversely affect assisted reproductive outcomes among Chinese women with polycystic ovary syndrome

Abstract

Abstract Background: Obesity is a common feature in women with polycystic ovary syndrome (PCOS) and associated with multiple adverse reproductive outcomes. However, the impact of overweight and obesity on reproductive outcome of PCOS women underwent the in vitro fertilization-embryo transfer (IVF-ET) is currently controversial. Since appropriate body mass index (BMI) levels differ across ethnic groups, this study was performed to investigate the effects of BMI on IVF outcomes among women with PCOS using BMI cut-off values proposed by the World Health Organization for Asian populations. Method(s): This was a retrospective study including 1066 women with PCOS receiving IVF treatment at our institution between January 2018 and June 2021, among whom 960 underwent their first fresh or frozen embryo transfer. Participants were categorized according to their BMI as follows: patients with normal weight (BMI < 23 kg/m2), patients with overweight (BMI: 23–24.9 kg/m2), and patients with obesity (BMI ≥ 25 kg/m2). The effect of BMI on IVF outcomes (the numbers of oocytes, two pronuclear zygotes, and good-quality embryos; the rates of implantation, miscarriage, clinical pregnancy and live birth) was evaluated by descriptive statistics and logistic regression models with confounders adjusted. Interventions: no Result(s): High BMI was associated with significantly lower numbers of total oocytes retrieved, mature oocytes, two pronuclear zygotes, and good-quality embryos among women with PCOS. PCOS patients with a BMI ≥ 23 kg/m2 had significantly lower live birth rates (41.9% vs. 49.1%; adjusted odds ratio [aOR], 0.75; 95% confidence interval [CI], 0.57–0.97) and implantation rates (35.8% vs. 43.9%; aOR, 0.76; 95% CI, 0.61–0.93) than those with normal BMI. Conclusion(s): PCOS patients with a BMI ≥ 23 kg/m2 have lower live birth rates than those with a BMI < 23 kg/m2. Defining obesity and overweight with ethnicity-specific BMI cut-offs may help to improve IVF outcomes among PCOS patients.