Parents-to-be usually receive the option of prenatal testing for genetic defects and genetic counseling to help decipher the results of these tests. Not all pregnant couples choose to undergo these tests, while some couples consider genetic counseling even before pregnancy begins. Understanding how prenatal testing and genetic counseling work can help couples decide whether they should or want to opt for these things during the course of the pregnancy.
Purpose
Prenatal testing can determine the genetic health of the unborn baby. Genetic counseling provides parents-to-be the opportunity to discuss potential problems and solutions with someone trained in genetics. Sometimes, parents and doctors use this information to help decide whether to continue or terminate the pregnancy. Couples determined to continue the pregnancy even in the face of serious birth defects may use the information to help them prepare for the care of a special needs child.
Types of Tests
According to the Mayo Clinic, an ultrasound is a non-invasive test that may detect physical abnormalities indicating potential genetic defects. Amniocentesis, performed between weeks 15 to 20 of pregnancy, uses a needle to take a sample of amniotic fluid, to analyze chromosomal defects. Chorionic villus sampling, usually done between weeks 10 to 12, uses a needle to remove cells from the placenta, to look for genetic abnormalities. A maternal blood screen taken between weeks 15 to 20 of pregnancy, also called a triple screen or multiple marker screen, can indicate the need for further testing if a high risk for chromosomal defects is detected.
Who Needs It
Some pregnant women prove more prone to having babies with genetic birth defects or other problems and the University of Maryland Medical Center recommends that these women undergo prenatal testing and genetic counseling. This includes women who are 35 or older, who have had multiple miscarriages or who already have a child with a genetic disorder. Also, couples who have a history of genetic diseases in either of their family histories and people of African-American, French-Canadian, Mediterranean, Jewish or Asian descent may also need counseling, since these groups may have a higher risk of genetic birth defects. Women who have been exposed to radiation, illness and medication or illegal drugs may also need testing and counseling.
Results
Often, the results of prenatal genetic testing proves inconclusive or cannot give an accurate depiction of how serious a particular defect might be. Discussing the results with a genetic counselor can help parents-to-be understand these results and what the likely outcome will be for the child. However, these counselors cannot make any ultimate decisions about the fate of the pregnancy or baby and this will be left up to the parents.
Considerations
Some parents choose not to undergo specific prenatal tests or genetic counseling. Couples who have decided to continue the pregnancy no matter what typically make this decision. In some cases, genetic counseling can be done before conception occurs, to help couples decide whether to pursue specific options, such as using gender selection techniques and in vitro fertilization to choose a specific gender if the parents have a risk of passing on a sex-linked genetic defect.
