Obesity Impaired Oocyte Maturation And Embryo Implantation Rate In Chinese Women Without Polycystic Ovary Syndrome Undergoing In Vitro Fertilization-Embryo Transfer

This study aimed to evaluate the effect of body mass index (BMI) on the in vitro fertilization-embryo transfer (IVF-ET) outcomes in Chinese overweight/obese women without polycystic ovary syndrome (PCOS). A retrospective cohort study was performed in 411 non-PCOS patients aged less than 38 years old undergoing their first IVF-ET treatment between January 2011 and January 2013. According to the criteria of Chinese BMI classification, patients were divided into 3 groups: 47 obese (BMI >= 28 kg/m(2)), 130 overweight (24 <= BMI=27.9 kg/m(2)) and 234 normal weight (18.5 <= BMI=23.9 kg/m(2)). The correlation between clinical treatment characteristics and IVF-ET outcomes in their fresh IVF cycles was analyzed. Obese women suffered a longer infertility duration than normal weight women (P<0.01). Higher doses of gonadotrophin were used in overweight/obese patients than in normal weight patients (P<0.001), but their Estradiol (E2) level on human chorionic gonadotropin (hCG) day was lower in obese patients (P<0.01). There were no significant differences in the number of retrieved oocytes, rate of Good Quality Embryo (GQE), transferred embryos or endometrial thickness, but overweight/obese patients had statistically less mature oocytes, fertilization rate, blast formation rate and embryo implantation rate (P<0.05). Clinical pregnancy rate and live birth rate also showed a decreased trend in overweight/obese patients. Conclusions: Female obesity indeed affected fertility in Chinese women. During IVF-ET treatment, obesity had an adverse impact on gonadotropin (Gn) response, oocyte maturation, blast formation and embryo implantation.