10023 Genetic Screening and Testing Options During Pregnancy

Genetic Screening and Testing Options during Pregnancy 

While most babies are born healthy, there is a 2-3% chance for any baby to be born with a birth defect or chromosome condition.

Several testing options are available during pregnancy to provide you with more information about your specific risk to have a child with Down syndrome or other birth defects. Genetic testing is optional - not all individuals choose to have testing. Genetic counseling is available to help review the available options, and your family history, to help you determine what testing might be best for you. Testing options are either screening tests – which provide a specific risk estimate for certain birth defects, or diagnostic testing – which is usually offered to high-risk individuals and will give you a definitive answer about certain birth defects.

Screening Tests

Cell Free Fetal DNA (also called NIPS) is the newest and most sensitive screening test. It involves collecting DNA from the pregnant person’s blood that represents the baby. This test can be done at any time after 10 weeks of gestation and assesses the risk for Down syndrome, and other chromosome abnormalities. Because it is a blood test, it does not involve a risk to the pregnancy.  Not all insurance covers this test and it can be expensive. However, the genetic counselors can help determine your cost.

Quad Screening is performed between 15-22 6/7 weeks of pregnancy and tests for Down syndrome, trisomy 18 and spina bifida with a single blood test. It has a lower detection rate for chromosome abnormalities than NIPS testing, but is useful for women in the second trimester whose insurance may not cover NIPS testing.

Diagnostic Tests

Diagnostic testing involves getting some cells from the baby so that more accurate genetic testing can be performed. This testing can diagnose chromosome conditions and certain other genetic conditions. 

• Chorionic Villus Sampling (CVS) is done between 11-13 weeks of pregnancy and involves taking a sample of the placenta.
• Amniocentesis can be done after 15 - 16 weeks of pregnancy and involves taking a sample of the amniotic fluid that surrounds the baby.

These tests are the most accurate but there is a small risk for miscarriage associated with the procedures. Even so, most women who have them will not have a miscarriage and go on to deliver a healthy baby.

Genetic Counseling, Family History Assessment, and Carrier Screening

A genetic counselor can help you determine what your risk is for chromosome problems, birth defects or other genetic conditions by talking to you about your family health history and your ancestry.

Carrier Screening

All individuals have a chance to be a carrier for a genetic disease.  Carriers typically do not have symptoms of the condition but can pass the gene on to their children.  If both parents are carriers, then their chance to have an affected child is greater.  Often there is no family history of these conditions and some conditions are more common in certain ethnic groups.

While Carrier Screening is offered to all individuals, it is optional. If one member of a couple is found to be a carrier, the other partner will be offered testing as well. Carrier screening may or may not be covered by all insurances and we can provide you with information you may need to check with your insurance company.  The following are the most common carrier screening tests offered during pregnancy:

Cystic Fibrosis (CF) is a serious inherited lung and digestive disease. Currently, there is no known cure for CF but there is lifelong treatment which may help extend the life-expectancy.  CF does not affect intellectual functioning but it can be life-limiting.  CF is most common in individuals of Northern European ancestry but is seen in all populations.

Spinal Muscular Atrophy (SMA) is an inherited neuromuscular disease that affects the ability of certain muscles to function. Some forms are mild and some forms are severe, leading to infant or early childhood death. There is no known cure but recently there have been some new treatments that may be beneficial. Treatment is life-long and its ability to extend muscle functioning is currently unknown. SMA is more common in individuals of European ancestry, but is seen in all populations.

Sickle Cell Disease/Thalassemias are inherited blood diseases that affect hemoglobin. Hemoglobin is the protein in red blood cells that carries oxygen to all parts of the body. Currently, there is no cure for these conditions and many people have frequent hospitalizations or blood transfusions. These diseases can be life-limiting. These conditions are more common in individuals of African American, Mediterranean, Hispanic, Middle Eastern and Asian ancestry. This screening is typically offered to all patients at the first prenatal visit.

Expanded Carrier Screening.  Large carrier screening panels, which can include many genetic conditions, are available. These panels include genetic conditions that are common in all ethnic groups, and many of these conditions are life-limiting or cause significant life-long health concerns. Not all insurance plans cover the cost of expanded carrier screening.

Newborn Screening in Virginia

All states, including Virginia, offer a blood test performed at birth that will test babies for different genetic conditions that are common in the population, and for which early detection and treatment is essential in preventing long term consequences such as developmental delay or early death. The Virginia Newborn Screening panel currently includes more than 30 conditions, including CF, SMA and sickle cell disease/thalassemia. Your baby will be tested before leaving the hospital regardless of whether or not you had carrier testing during pregnancy. Your pediatrician will receive the results when completed