The influence of male smoking on success rates after IVF/ICSI.

Objective: It has been established that male cigarette smoking has a negative effect on the semen quality and that it can induce DNA damage leading to worsening of reproductive outcomes. The aim of our large retrospective study is to determine the influence of male cigarette smoking on assisted reproduction, more specifically in IVF and ICSI outcomes.

Materials and methods: Our study included all consecutive infertile couples (with a nonsmoking female partner) having their first IVF/ICSI cycle. All patients had smoking assessment. Smokers were further classified into mild (1-10 cigarettes/day), moderate (11-20 cigarettes/day) or heavy smokers (>20 cigarettes/day). The primary outcome was live birth rates (LBR).

Results: The overall number of patients analyzed was 4004 and among them 433 (10.8%) were smokers. Baseline characteristics, such as female age and BMI differed significantly between nonsmokers and smokers. The crude analysis showed higher positive hCG and LBR in smokers (positive hCG 28.34% in nonsmokers vs 33.95% in smokers, p = 0.015; LBR 23.55% in nonsmokers vs 28.64% in smokers, p = 0.019) However after adjustment for relevant confounders (female age, BMI, cause of infertility, number of oocytes retrieved, insemination procedure, number of embryos transferred and day of embryo transfer) the smoking status was not significantly associated with fresh LBR (OR = 1.16, CI = 0.92-1.48; p = 0.2). The results were replicated after classification of smoking into mild/moderate/heavy [OR for nonsmokers (reference category) vs. mild vs. moderate vs. heavy= 1, 1.17, 1, 2.99; p = 0.18)].

Conclusion: Male smoking does not seem to impair live birth rates in patients undergoing IVF/ICSI treatment.