Follow-Up of Genetic Defects

Aug 21 2007

As invasive procedures carry risks, some experts believe they are unjustified in the situation where a woman knows she will carry the pregnancy regardless of the outcome of the test. Some women and their families, however, feel that they can be better prepared to cope with a baby with a health problem if they can anticipate it. In some cases, still relatively rare, diagnosis can allow for fetal treatment. Whether to carry a pregnancy or consent to fetal treatment is a personal and family decision, although, of course, the medical implications of the discovered defect and the safety of proposed treatment will play an important role in the decision making. Prior to any invasive procedure, the mother should be informed of the likelihood of having the condition for which the procedure is being performed and of the risks to her and to her fetus, including the possibility of errors in diagnosis. The decision whether to have an abortion is entirely the woman’s. Selective abortion, where one fetus in a multiple pregnancy has a defect, is possible, as is selective abortion-sometimes called selective reduction or selective birth-when large numbers of embryos develop after infertility treatment. This is technically a difficult procedure, though high success rates have been reported.Obviously, if chromosomal or genetic defects occur in your family or if you are over the age of 35, you should get as much information about your individual situation as possible. Ask your physician or midwife for information and request a referral to a genetics counselor early in pregnancy. Genetic counseling is available at major medical centers in the United States. If you live in a small town or rural area and are not near such a center, which is usually a large hospital associated with a medical school, you are well advised to make a trip to such a center for at least one visit if you fall into a category, or if your physician or midwife recommends such a visit. A genetic counselor also can be located through the National Society of Genetic Counselors. Follow-Up of Genetic Defects

The role of the genetic counselor and the obstetrical care provider is to explain the genetic, pediatric, developmental, and social implications of the particular genetic problem involved. A genetic counselor will be able to teach parents, or prospective parents, about the genetic aspects of the particular problems with which they are most concerned, as well as the influences of environment and other relevant factors on genetic inheritance. For example, although a plant may have a gene for tallness, which is dominant over its gene for shortness, it may end up short because it is growing in a shallow pan or is not exposed to sufficient sunlight.

Your partner should attend the counseling session so you can make an informed decision together. For some mothers or couples, there is no alternative to abortion if the presence of a defect is verified, regardless of whether or not the extent of disability can be determined prenatally. Other families may want to consider the extent of the potential burden. They may consider what familial supports they have, what community services are available, how their particular life situation might influence the difficulties involved in raising a child with serious disabilities. Many mothers wish to share their problem with a spouse, a counselor, a parent, or a friend, to help them choose a comfortable course of action.

In most cases, genetic counseling will be reassuring about the outcome of the pregnancy, but if that is not possible, it will point the woman and her partner in the direction of competent diagnosis and care, as well as possible alternatives, such as use of donor sperm or ova.