THE CORRELATION BETWEEN OBESITY AND THE PREGNANCY OUTCOMES IN FRESH EMBRYO TRANSFER CYCLE

Abstract

To evaluate the effect of obesity on in vitro fertilization (IVF) outcomes in fresh embryo transfer (ET) cycles, and further investigate the effect of obesity on IVF outcomes in women with polycystic ovarian syndrome (PCOS) undergoing fresh ET. A total of 7663 fresh IVF or Intracytoplasmic sperm injection (ICSI）ET cycles and 760 fresh ET cycles in PCOS patients from January 2010 to December 2019 in the reproductive medicine center of the Sixth Affiliated Hospital of Sun Yat-sen University were retrospectively analyzed. Patients were divided into four groups according to Asian body mass index (BMI) classification: underweight (BMI <18.5kg/㎡), normal weight (BMI 18.5-22.9kg/㎡),overweight (BMI 23-27.4kg/㎡), and obese ( BMI ≥27.5kg/㎡). Patients’ characteristics and pregnancy outcomes were compared among these groups, and multivariate analyses were conducted to determine the effects of BMI on the live birth rate and perinatal outcomes. Compared with overweight women, significantly higher clinical pregnancy rate (CPR), live birth rate (LBR) and small for gestational age (SGA) rate, and lower large for gestational age (LGA) rate were associated with normal weight women (P< 0.05). Multivariate logistic regression analysis showed that whether or not the patients are obese had no correlation with the chance of live birth (OR=0.994,95% CI:0.770-1.283,P=0.962), while the female age was an independent risk factor for LBR（OR=0.920,95% CI:0.905-0.935,P=0.000）. Underweight women had a significantly higher likelihood of SGA (OR=0.497,95% CI: 285-0.869,P=0.014), while overweight women were more likely to give birth to LGA（OR=4.346, 95%CI: 1.330-14.204, P=0.015). There were no correlation between obesity and the LBR, SGA rate and LGA rate in PCOS patients. Female obesity did not correlate with the chance of live birth in fresh ET cycle. A higher chance of SGA was associated with underweight, and obese patients were more likely to give birth to LGA infants. In PCOS patients, the degree of obesity had no effect on the LBR, SGA rate and LGA rate.