The Influence of Male and Female Overweight/obesity on IVF Outcome: A Cohort Study Based on Registration in Western China

Abstract Background: Overweight/obese couples are more likely to present with a lower fertility, but it is still unclear whether the Overweight/obese can reduce the successful rate of in vitro fertilization-embryo transform (IVF-ET).This systematic review uses strict Chinese BMI criterias to evaluate whether male and female overweight/obesity will affect embryo quality and IVF outcomes, and whether there are gender differences.Methods: We reviewed the IVF-ET data of Northwest Women and Children's Hospital from 2015.01 to 2019.06, and divided the included population into four groups: Group 1 (n = 3413, male and female BMI: 18.5≤BMI＜24kg/m2, the control group);Group 2 (n = 1437, female BMI≥24 kg/m2 and male BMI18.5≤BMI＜24 kg/m2, the experimental group 1); Group 3 (n=4283, female BMI18.5≤BMI＜24 kg /m2 and male BMI≥24 kg/m2, the experimental group 2) and Group 4 (n=2176, female BMI≥24 kg/m2 and male BMI≥24 kg/m2, the experimental group 3). .Primary outcomes were clinical pregnancy rate,（CPR), live birth rate(LBR)，available embryo rate and normal fertilization rate.Results: The study found that the overweight/obesity of the independent female group or the combined male and female group manifested with a much less number of available embryos and a much less number of high-quality embryos (p <0.05). Meanwhile, the independent male group displayed a significant reduction of IVF-ET cleavage rate (p=0.019) and the independent female group displayed a significant reduction of the fertilization rate (p=0.029) and the normal fertilization rate (p=0.004). The combined male and female group manifested with a significant reduction of the available embryo rate (p=0.026), the fertilization rate (p=0.010) and the normal fertilization rate (p=0.003)，but overweight/obesity has no significant effect on CPR、LBRand abortion rates. Conclusion: overweight/obesity affects the embryo quality, the fertilization rate, and the cleavage rate, and there exists gender differences. Therefore, in order to improve the embryo quality, the fertilization rate and the cleavage rate of IVF of overweight/obese couples, it is still recommended that one partner or both couples should manage to reduce their weight to a normal value before IVF treatment.