Objective:To explore whether the body mass index (BMI) of women with regular menstruation is associated with ovarian response to ovarian hyperstimulation and the outcome of in vitro fertilization-embryo transfer (IVF-ET). Methods:This retrospective cohort study uses data of IVF during the study period from the Center for Reproductive Medicine of the Third Affiliated Hospital of Guangzhou Medical University. According to the Asian BMI classification standard recommended by World Health Organization (WHO), the patients who met the inclusion criteria were divided into 4 groups: low BMI group (BMI<18.5 kg/m 2, n=212), normal BMI group (BMI 18.5-23.0 kg/m 2, n=1076), high BMI group (BMI 23.0-25.0 kg/m 2, n=308) and obesity group (BMI≥25.0 kg/m 2, n=287). The main outcome measures were the number of oocytes retrieved, ovarian response and ongoing pregnancy rate. Results:There were no significant differences in the number of oocytes retrieved and ovarian response among the four groups ( P>0.05). Outcomes of embryo culture (including M II oocyte rate, fertilized number, numbers of available embryos and high-quality embryos) and the number of transferred embryos were not statistically significant in high BMI group and obesity group when compared with normal BMI group ( P>0.05). Furthermore, no significant differences were found in the rate of high-quality embryo transferred, the freeze-all rate due to ovarian hyperstimulation syndrome (OHSS) risk, rates of implantation, clinical pregnancy, early miscarriage and ongoing pregnancy among the four groups ( P>0.05). In addition, after adjusting for confounding factors by logistic regression analysis, no association was found between BMI and ovarian response and ongoing pregnancy rate. Conclusion:The increase of BMI in women with regular menstruation has no influence on ovarian response and IVF pregnancy outcome.

Objective:To explore whether the body mass index (BMI) of women with regular menstruation is associated with ovarian response to ovarian hyperstimulation and the outcome of in vitro fertilization-embryo transfer (IVF-ET). Methods:This retrospective cohort study uses data of IVF during the study period from the Center for Reproductive Medicine of the Third Affiliated Hospital of Guangzhou Medical University. According to the Asian BMI classification standard recommended by World Health Organization (WHO), the patients who met the inclusion criteria were divided into 4 groups: low BMI group (BMI<18.5 kg/m 2, n=212), normal BMI group (BMI 18.5-23.0 kg/m 2, n=1076), high BMI group (BMI 23.0-25.0 kg/m 2, n=308) and obesity group (BMI≥25.0 kg/m 2, n=287). The main outcome measures were the number of oocytes retrieved, ovarian response and ongoing pregnancy rate. Results:There were no significant differences in the number of oocytes retrieved and ovarian response among the four groups ( P>0.05). Outcomes of embryo culture (including M II oocyte rate, fertilized number, numbers of available embryos and high-quality embryos) and the number of transferred embryos were not statistically significant in high BMI group and obesity group when compared with normal BMI group ( P>0.05). Furthermore, no significant differences were found in the rate of high-quality embryo transferred, the freeze-all rate due to ovarian hyperstimulation syndrome (OHSS) risk, rates of implantation, clinical pregnancy, early miscarriage and ongoing pregnancy among the four groups ( P>0.05). In addition, after adjusting for confounding factors by logistic regression analysis, no association was found between BMI and ovarian response and ongoing pregnancy rate. Conclusion:The increase of BMI in women with regular menstruation has no influence on ovarian response and IVF pregnancy outcome.