The effect of smoking on the outcome of in-vitro fertilization--embryo transfer.

This study investigated the influence of cigarette smoking on the outcome of in-vitro fertilization-embryo transfer. Forty-one women under the age of 37 years, suffering from mechanical infertility, were suppressed with gonadotrophin releasing analogue from day 21 of the cycle. Twenty women were smokers and 21 women were non-smokers. Gonadotrophin releasing analogue was injected daily before ovarian stimulation with gonadotrophin was begun. The follicular phase was longer and the number of human menopausal gonadotrophin ampoules required to reach adequate stimulation were higher in smokers. The peak serum oestradiol level was not significantly different in smokers compared to non-smokers. However, follicular fluid levels of oestradiol were significantly lower in smokers than in non-smokers (657 +/- 367 versus 1077 +/- 786 ng/ml) respectively. Furthermore, the fertilization rate was also lower in smokers than in non-smokers (40.9 versus 61.7%) respectively. Four pregnancies were achieved in the non-smokers group, while only one ectopic pregnancy was diagnosed in the smokers group. These findings suggest that cigarette smoking has a detrimental effect on the outcome of in-vitro fertilization and embryo transfer.