[Consequences on women's fecundity and on assisted reproductive technology].

Knowledge of the detrimental role of cigarette smoking on human reproduction is constantly improving. In natural fertility, time to pregnancy is longer, frequency of infertility is increased and fertility rate declines 10% to 20% with a dose-effect relationship. Moreover, women exposed in utero also have lower fertility. Cigarette smoking is also a risk factor for menstrual disorders and for early menopause. In assisted reproductive technology, where many parameters are controlled, the deleterious effects of smoking on fertility have been clearly demonstrated: lower estradiol levels, decreased pregnancy and implantation rates, and poorer oocyte morphology. The two published meta-analyses have concluded that the effects are the same in natural and assisted reproduction. These results are in accordance with biological hypotheses on the local and general effect of tobacco and other cigarettes components. In conclusion, women should be informed about the effect of cigarette smoking on their fertility. Education is very important since in many countries, like France, the percentage of smokers is increasing among women, especially among young women.