Some factors that influence fertility are hard to overcome due to their addictive nature. But smoking and drinking less, or not at all, can improve the chance of becoming pregnant naturally. Given that only you can influence these factors, your overwhelming desire to have a child can provide the motivation to stop these or cut down on them.

Smoking can affect the fertility of both men and women. In the case of women, smoking can lead to menstrual problems, ectopic pregnancy and disorders of the cervix and fallopian tubes. A relationship has also been found between smoking in women and a poor outcome for assisted reproduction: the ovaries are often less responsive to drugs reducing success rates. It is also strongly established that smoking during pregnancy can harm the health of the baby. Children of mothers who smoke have, in general, a lower birth weight and a more difficult birth. In the case of men, smoking can lead to problems of semen composition. Clearly, stopping smoking must be a serious consideration for couples trying to get pregnant, especially couples with unexplained infertility and men whose sperm counts are borderline. This is important for both partners because of the risks of passive smoking during pregnancy or after a child is born. Studies have shown that children who are exposed to passive smoking have an increased chance of health problems.

High use of alcohol and marijuana or other illegal drugs can sometimes significantly reduce the quality and quantity of sperm.

For example:

• Marijuana is associated with many problems of sperm production.
• The use of anabolic steroids can cause sterility.
• LSD can cause damage to chromosomes.
• Excessive drinking can affect sexual performance.

Alcohol, in particular, can reduce testosterone - the male hormone that plays a part in sperm production. This effect is reversed in the months after drug and alcohol misuse is stopped.

In the case of women, drinking can lead to irregular menstrual cycles and non-ovulatory periods (menstruation that occurs without ovulation). Alcohol can also increase the chances of a miscarriage after a woman has become pregnant and can cause a number of serious birth defects, which are known as Foetal Alcohol Syndrome or FAS.

In general, it is best to avoid the use of alcohol while you are trying to get pregnant and during pregnancy.