To maximize the chance of having a successful preg­nancy and a healthy baby, a couple should examine their health habits before pregnancy occurs. Both partners-but especially the woman-should eat a balanced diet and should avoid alcohol, tobacco, and all drugs except those taken in consultation with a physician. Women with metabolic disorders, such as diabetes mellitus, should ensure that their condition is controlled. Advice should be sought if either partner is aware of a disorder that runs in his or her family.

Genetic counseling

About one child in 50 is born with a physical, metabolic, or mental defect. Many of these defects are due to an abnormality in one or more of the genes inherited from the parents. In some cases, the parents are unaware that one (or, rarely, both) of them carries a defective gene, usually studied under a high-powered microscope. Occasionally, the defect is a new one that is caused by a genetic mutation occurring during the formation of the sperm or ovum. Sometimes, however, a couple planning a family knows that one or more of their relatives have had children with a gene­tic disorder. In such cases, the couple should seek genetic counseling before their first pregnancy. The counselor can often perform tests to determine if there is a risk of a genetic disorder being passed on to the children and, if that is a possibility, may be able to quantify the risk involved. This allows the couple to make an informed decision as to whether they wish to continue with the pregnancy.

Treating infertility

Approximately one in every 10 couples finds it difficult to have children. In about 40 percent of such cases, the man is subfertile or infertile; in another 40 percent, the woman has a fertility disorder. In the remaining 20 percent, both partners have some degree of infertility. Methods employed to improve the likelihood of pregnancy include microsurgery using obstetrical instruments to repair damaged fallopian tubes in women or to reverse vasectomy in men; drugs or hormones to stimulate ovulation in women or improve male fer­tility; and in vitro fertilization (”test-tube baby”) techniques, although the success rate for this pro­cedure remains low.