In most women, the menstrual cycle continues for at least 40 years
from puberty. Between the ages of 45 and 55, the levels of hormones
change; the menstrual cycle becomes less regular and eventually stops.
This stage, called menopause, marks the point at which a female is no
longer capable of reproducing. Menopause is a normal occurrence in all
women; however, the effects of menopause vary widely from one woman
to another. In men, by contrast, sperm production continues throughout
life, although the number of healthy sperm likely declines with age....
American men face a staggering array of health concerns. According
to the Centers for Disease Control and Prevention, 70 percent of
American men are overweight, a key predictor of future health problems.
Almost 25 percent smoke, another key risk factor. One in five
American men has heart disease, and 29 percent aged twenty and
older suffer from hypertension. More than 11 percent of men face a
limitation in their usual activities due to chronic health conditions.
In addition, the medical concerns men face often differ from those of
most concern to women.
Recent reviews have addressed issues of cigarette smoke
exposure and various facets of reproduction including
delayed time to conception, ovarian effects and premature
menopause, implantation failure, fetal growth restriction
and growth retardation, placental abnormalities, reduced
fecundity, congenital abnormalities, and effects on male
reproduction [32-34]. However, most prior reviews have
not considered smoke's interaction with the oviduct, an
organ vital to reproduction.