Menstruation Cigarette smoking alters bodily concentrations of several hormones, including estrogen. They are also likelier to have menstrual irregularity in middle age. Menopause tends to begin earlier in smokers. Thus, the reproductive window is longer in nonsmoking women. Clinical reports and evidence from animal experiments suggest that nicotine may be principally responsible for menstrual effects of smoking.
Cigarette smoking increases concentrations of the hormones epinephrine and vasopressin.
The fallopian tubes are the most common sites of ectopic pregnancy. If it is not detected early, ectopic pregnancy can result in fallopian-tube rupture and even death. Of the approximately 140,000 cases of miscarriage per year in the United States, approximately 19,000 have been attributed to cigarette smoking. Evidence from numerous studies suggests that cigarette smoking adversely affects the immune system. Some scientists have speculated that such changes may result in infertility through an increase in the frequency of fallopian-tube infection.