It may also be helpful for women to avoid alcohol, at least during the third week of their menstrual cycles. Not drinking during days 14 to 21 of the menstrual cycle increases chances of conception. Of course, if conception occurs, then the expectant mother should avoid alcohol throughout her pregnancy. Drinking coffee, tea, and soft drinks that contain caffeine, unlike alcohol, has no effect on the developing baby. In women who have endometriosis, however, drinking coffee, in particular, greatly reduces chances of conception. Decaf is OK.
Prolonged foreplay reduces the probability that a woman will become pregnant from that particular act of intercourse. During foreplay, the front wall of the uterus rises. This creates a longer path for the sperm to reach the egg. The missionary position is more likely to result in conception than other positions for sexual intercourse. In the missionary position, the man's penis assumes a "boomerang" configuration during ejaculation. This sends sperm further into the cervix than other arrangements for intercourse. Men seeking to become fathers should wear boxer shorts rather than briefs or Speedos. Underwear that keeps the testicles next to the body heats the sperm and makes them less viable.
Margarines made with cottonseed oil are especially detrimental to men's fertility. Cottonseed contains gossypol, which is being investigated as the principal active ingredient for a contraceptive Pill for men. There is no single nutritional supplement that corrects infertility problems. Both men and women, however, may benefit from taking a complete vitamin B supplement. Just the minimum recommended daily intake can be enough. Folic acid is known to assist fertility in both men and women. Men may also benefit from taking up to 30 mg of zinc every day, in a formula that combines zinc with at least 1 to 3 mg of copper per daily dose.