Cigarette smoking and reproductive function.
OBJECTIVE
To perform a systematic review of the literature on the relationship between cigarette smoking and reproductive function. Whenever possible, this review is focused on the most recently published studies (mainly the past 2 years). Nevertheless, in many instances older literature was too relevant not to be taken into account.


RESULTS
Tobacco compounds exert a deleterious effect on the process of ovarian follicle maturation. This effect is expressed by worse in-vitro fertilization parameters in cycles performed on women with smoking habits. Also, uterine receptiveness is significantly altered by the smoking habit. In men, cigarette smoking reduces sperm production, increases oxidative stress, and DNA damage. Spermatozoa from smokers have reduced fertilizing capacity, and embryos display lower implantation rates. Even in-utero exposition to tobacco constituents leads to reduced sperm count in adult life.


CONCLUSIONS
A strong body of evidence indicates that the negative effect of cigarette smoking on fertility comprises fairly every system involved in the reproductive process. Couples in reproductive age should be strongly discouraged to smoke.
Soares
Sérgio R
SR
Instituto Valenciano de Infertilidad, IVI-Lisboa, Lisbon, Portugal. sreis@ivi.es
Melo
Marco A
MA
D005260:Female; D005298:Fertility / Q000502:physiology*; D006801:Humans; D007247:Infertility, Female / Q000209:etiology; D007248:Infertility, Male / Q000209:etiology; D008297:Male; D009865:Oocytes / Q000187:drug effects; D012661:Semen / Q000187:drug effects; D012907:Smoking / Q000009:adverse effects*; D014026:Nicotiana