Anticipating your baby's arrival can be an exciting time. Along with the excitement, you may worry if your baby will be healthy.
Prenatal genetic tests, which can provide some important answers, are routinely offered during pregnancy. However, you need to weigh the benefits of undergoing these tests against the risks in order to make personal choices that are right for you, says Dr. Jose De La Mota, a board-certified OBGYN with Sharp Rees-Stealy Medical Group.
"Prenatal genetic tests give you information to help determine — with varying degrees of certainty — if your unborn baby is healthy, or might have a genetic disorder," says Dr. De La Mota. "While knowledge is power, when it comes to deciding on whether to undergo genetic testing, you should consider very carefully what you would do with information about your test results."
Prenatal screening tests vs. diagnostic tests
Screening tests, which usually take the form of a blood test or ultrasound exam in the first or second trimesters of pregnancy, typically do not pose any risk to the mother or fetus, Dr. De La Mota explains.
"These tests indicate the degree of risk of the fetus having certain common birth defects — but without any certainty. A positive result from a screening test is not as accurate or reliable as a diagnostic test," he says.
Dr. De La Mota notes that unlike screening tests, the two most common diagnostic tests are invasive — they involve the extraction of cells from the fetus through a chorionic villus sampling (CVS) test or amniocentesis.
"While these diagnostic tests can more accurately indicate a disorder in the fetus than a screening test, they also carry a slight risk of miscarriage," he says.
Genetic testing is a choice for pregnant women
Dr. De La Mota suggests you talk to your doctor first before undergoing any prenatal testing procedure, as a positive result can cause anxiety and conflicting emotions.
"It's important to note that prenatal genetic screenings and tests are strictly optional and not required," he says. "You'll want to ask yourself how knowing beforehand whether your baby may be born with a genetic abnormality or birth defect might affect you."
Dr. De La Mota adds that while all parents hope for normal results, news of a potential abnormality can be seen as an opportunity for you to plan and prepare for any care that your child may need when he or she is born.
"A common misconception about prenatal testing is to end the pregnancy because of a positive result," he says. "While there are situations in which parents may choose to end the pregnancy, most want to know the risk before the baby is born in order to make plans or gain further knowledge. There are various ways to decide what to do, but there is no right or wrong answer."
Dr. De La Mota also recommends considering these questions before undergoing genetic testing:
- How accurate are the results? The rate of inaccurate results, known as false-negative or false-positive results, varies from test to test.
- What are the risks? How do the risks of specific tests — such as anxiety, pain or possible miscarriage — weigh against the value of knowing the results?
Lastly, insurance coverage can vary for prenatal tests, so it's important to decide whether you're willing to pay for a test that your insurance won't cover.
For more information about prenatal genetic testing, including the types of screening and diagnostic tests, visit sharp.com.