Toxic effects related to tobacco, marijuana, and other drugs
Smoking may cause infertility in both men and women. In experimental animals, nicotine has been shown to block the production of sperm and decrease the size of a man's testicles. In women, tobacco changes the cervical mucus, thus affecting the way sperm reach the egg. It also increases the risk of an ectopic pregnancy by affecting the fallopian tubes.
Marijuana may disrupt a woman's ovulation cycle (release of the egg). Marijuana use affects men by decreasing the sperm count and the quality of the sperm.
The good, if not great, news is that the latest advances in infertility treatment have made
it possible for more people than ever before to become parents. The bad news is
that growing numbers of couples may be jumping the gun and seeking infertility treatments without giving Mother Nature a
chance. Infertility treatments, such as drugs that stimulate
ovulation, are not without their risks -- namely a risk of multiple
pregnancies, which can be dangerous for moms and babies.
Heroin, cocaine, and crack cocaine use induces similar effects but places the user at increased risk for PID and HIV infection associated with risky sexual behavior.
In women, the effects of alcohol are related more to severe consequences for the fetus. Nevertheless, chronic alcoholism is related to disorders in ovulation and, therefore, interferes with fertility. Alcohol use by men interferes with the synthesis of testosterone and has an impact on sperm concentration. Alcoholism may delay a man's sexual response and may cause impotence, the inability to have or sustain an erection.