The effect of BMI on the clinical pregnancy outcomes in vitro fertilization

Objective To demonstrate the effect of body mass index(BMI) on pregnancy outcomes for women receiving IVF treatment and estimate the interaction effect of BMI,age and basal antral follicle count(AFC).Methods Five hundred ninety-six women reporting infertility according to the diagnosis of WHO were included in the regression analysis.According to the BMI,all these patients were categoried into four groups,that was,group Ⅰ(underweight,BMI18.5 kg/m2),group Ⅱ(normal weight,18.5 kg/m2≤BMI25 kg/m2),group Ⅲ(overweight,25 kg/m2≤BMI30 kg/m2),group Ⅳ(obese,BMI≥30 kg/m2).Relevant pregnancy results,patients response arguments and IVF parameters were analyzed by ANOVA,chi-square test,Logistic regression analysis and multiple regression analysis.Results Clinical pregnancy rate of group Ⅱ were significantly higher than that of group Ⅰ,group Ⅲ and group Ⅳ.Age had negative impact on clinical pregnancy rate,and the interaction effects of BMI and age had statistical significance.As to the influence of patients response and IVF relevant parameters,the start dose increased obviously accompaning with the augment of BMI,while no crucial differences were shown in other parameters.Conclusions Compared to the normal group,the data of other groups all show negative effects of BMI,and the interaction effect of age and/or AFC is minimal.Based on this result,we conclude that BMI is an independent risk factor.