Research has shown that smoking may triple your chances of not being able to conceive. If your partner smokes, he needs to give up as well. Smoking can damage his sperm as well as exposing you to passive smoking. In addition, smoking robs the body of vitamins, especially vitamins B and C, and can cause a build-up of free radicals in the body.
Free radicals are molecules that can damage blood vessels, such as those supplying the placenta, thus reducing the supply of nutrients for the developing baby. Smoking is a powerful addiction and so can be very difficult to stop. However, if you do stop smoking, your fertility will go back to normal. So it is important to stop smoking prior to pregnancy. If your partner also smokes, it would be best if you gave up together.
If you drink heavily, this can affect your fertility. Alcohol can upset the production of eggs from the ovary. A Danish study conducted in 1998 found that women drinking four or fewer units of alcohol a week were twice as likely to conceive as those drinking 10 or more units a week. If your partner drinks heavily, this can affect his fertility by upsetting the function of his testicles and their production of both the male hormone testosterone and sperm.
Moderate alcohol intake does not seem to cause male fertility problems, but there are some reports that if the father drinks regularly before conception this is associated with a lower birth weight in the baby. The ideal is that you both give up alcohol while you are tying to conceive, or keep your alcohol intake very moderate, as no one knows what the ‘safe’ level of alcohol is.