The Effect of Male Partner Smoking on Cumulative Live Birth after In vitro Fertilization (IVF): a Large Prospective Cohort Study.

OBJECTIVE

To compare the cumulative live birth rates after one oocyte retrieval among smoke-free couples and couples where only the male partner smoked cigarettes (after using fresh and frozen embryos).

DESIGN

Prospective cohort study SUBJECTS: : 1,388 couples undergoing in vitro fertilization (IVF) treatment (one oocyte retrieval each) between 1 August 2019 to 10 June 2021 at a tertiary level hospital IVF center in Kunming, China. Follow-up data were collected for up to three years and nine months after embryo transfer and four years after recruitment of the first couple.

EXPOSURE: Cigarette smoking among male partners MAIN OUTCOME MEASURES: : Cumulative live birth and early pregnancy loss rates

RESULTS

: After adjusting for woman's age, man's age, woman's BMI, man's BMI, woman's educational level, man's educational level, duration of infertility, primary versus secondary infertility, insemination method and baseline infertility cause variables, the relative risk (RR) for achieving a cumulative live birth for couples where the male partner consumed < 20 cigarettes per day was not significantly different from smoke-free couples (RR = 0.92, 95% CI 0.84 - 1.02) but 19.0% lower for couples where the male partner consumed ≥ 20 cigarettes per day (RR = 0.81, 95% CI 0.71 - 0.93). The adverse effect of male partner smoking was significant before achieving a fetal heartbeat in both groups of smokers, but more obvious in heavy smokers (RR = 0.89, 95% CI 0.81 - 0.98 and 0.78, 95% CI 0.68 - 0.89). Once a fetal heartbeat had been established, there was no evidence of any further impact on cumulative live birth rate.

CONCLUSION

Couples who need IVF treatment should be counselled that male partner smoking could reduce their chances of having a baby.