Entering the world of genetic testing may bring fear of the unknown; but couples will gain an understanding and receive emotional support dealing with the decisions they may have to face.
Those early moments when a couple learns that they are expecting are filled with anticipation, imagination, and dreams. Is it a boy or girl? Will he have the gentle disposition of his mother? Will she inherit her daddy’s sparkling green eyes and golden hair? Yet amidst the daydreams, many expectant parents neglect to consider the possibility of their baby inheriting a genetic problem. The hidden realm of genetics can cause fear and anxiety; however, with the help of experienced professionals like genetic counselors, couples will gain an understanding of their situation and receive emotional support dealing with the decisions they may have to face.
In the United States, the risk of a genetic defect is between two and four percent, and it is estimated that most people are carriers of five to seven recessive genetic conditions. Abnormal genes can contribute to genetic prenatal defects or genetic diseases. At times, these defects may also occur from environmental factors such as exposure to harmful toxins in the workplace, or substance abuse, while others can be a combination of the factors.
According to the March of Dimes, a small percentage of couples will learn through prenatal diagnosis that their baby has a birth defect. This prenatal diagnosis sometimes can improve the outlook for the baby, since advances in prenatal therapy now make it possible to treat some birth defects before birth.
Genetic counseling should be seriously considered among couples, both expecting and those who are considering conception, who have unanswered questions or concerns about the origins of diseases or traits among their respective families. This can be unnerving to any expectant parent or those who are planning a pregnancy. However, genetic counseling and trained professionals help these couples identify and understand the traits that they may pass on to their children, as well as their options.
First Steps
Normally during your first prenatal appointment with your physician, you will begin a discussion about genetic traits, testing, and your and your partner’s backgrounds or worries. If certain issues and concerns arise during the discussion, your physician will then refer you to a trained genetic counselor experienced in assisting couples in their understanding of inheritance, defects, and risks. Expectant couples can also seek recommendations for genetic counselors through contacting organizations such as the National Society of Genetic Counselors or locating your local community chapter of the March of Dimes.
At a typical counseling session, couples will discuss their respective family histories, determining the risk factors, and ultimately, deciding which, if any, tests are appropriate. “Couples will work together with their genetic counselor to make sure about the true risks and variety of issues that can affect their children,” says Dr. Neil Silverman, MD, medical director of inpatient obstetric services with the Department of Obstetrics and Gynecology at Cedars-Sinai Medical Center in Los Angeles, California. “While meeting with a genetic counselor, couples are often very surprised at what they thought would not be pertinent. The role of the genetic counselor is to work hand in hand with a couple to explore the risk factor—not to frighten them, but to help them discuss the options and to educate.”
Genetic counseling can be an extremely valuable tool for couples that fall into one or more of the following categories:
- The mom-to-be will be age 35 or older on her due date.
- The expectant woman, her partner, children, or any other family member have a genetic disorder, birth defect, or developmental delay.
- An expectant woman whose ultrasound and/or blood testing reveals that her pregnancy may be at risk for certain medical complications or a variety of birth defects.
- A woman who has had previous babies who died in infancy, or three or more miscarriages.
- A couple with an “at risk” background or ethnicity. This includes families of Eastern European Jewish ancestry, particularly those who are Ashkenazi Jewish, who are at risk to be carriers of multiple genetic conditions, including Tay Sachs. Families with Mediterranean/African/Asian backgrounds are at risk for two crippling blood disorders, Thalassemia and sickle cell anemia, as well as other medical conditions including cystic fibrosis.
The genetic counselor will make a record of your family history, environmental risk factors, and will then forward his or her report to your primary care physician or obstetrician. “By gathering this detailed family history of genetic traits, occupational and environmental exposure, ethnic-religious backgrounds, we are better able to risk assess each individual patient,” explains Dr. Genevieve Sicuranza, MD and chief of maternal fetal medicine in the Department of Obstetrics and Gynecology at Winthrop University Hospital in Mineola, New York.
Genetic Prenatal Screening Tests
Genetic tests available today have greatly increased a couple’s ability to determine the likelihood of genetic disorders being diagnosed in their children. The most common forms of prenatal genetic screening exams are amniocentesis, chorionic villus sampling (CVS), and expanded alpha-fetoprotein (AFP).
Amniocentesis involves extracting and examining a small sample of the amniotic fluid that surrounds the developing baby. Amniocentesis is usually performed during the second trimester. Although this procedure does pose a slight risk of miscarriage, the March of Dimes estimates that the rate of miscarriage is between one in 400 and one in 200 procedures, and has an accuracy rate of between 99.4 and 100 percent in diagnosing chromosomal abnormalities in the developing baby.
