Pregnancy is a time of high hopes – and sometimes, high anxiety.

Many parents-to-be worry if their babies are at risk of being born with genetic conditions, birth defects, or other health issues. As medical technology continues to advance, more families are now choosing to pursue genetic testing in the early stages of pregnancy.

Genetic testing during pregnancy has become an essential component of prenatal care, providing expectant parents with valuable insights into their baby’s health and development. These tests can screen for many genetic conditions, chromosomal abnormalities, and inherited disorders – often before any symptoms or complications arise.

But with so many types of prenatal genetic testing available – from non-invasive prenatal screening (NIPS) blood tests to diagnostic procedures like amniocentesis – you might be wondering what tests are right for you, when you should have them done, and what the results could mean.

TopLine MD Alliance is giving you all the facts about genetic testing during pregnancy, including who should have it done, how accurate the tests are, and what to do if your test shows abnormal results. The experienced OB/GYNs and maternal-fetal medicine specialists in our network are here to support you through every step of your pregnancy journey.

What is genetic testing during pregnancy, and why is it done?

Genetic testing during pregnancy provides information about your growing baby’s health that can help give your family peace of mind and guide you when making health-related decisions. Unlike many routine prenatal tests, such as ultrasound or glucose screening, genetic tests are optional. But today, genetic testing during pregnancy is more common than ever.

Every person has genes and chromosomes, which are the source of genetic disorders. Genes contain the genetic material (DNA) that controls how your body runs and operates. Chromosomes are thread-like structures within the cells that carry your genes. Each cell normally contains 23 pairs of chromosomes – half from one parent and half from the other.

Genetic conditions are caused by changes or abnormalities in your baby’s genes or chromosomes. Fortunately, genetic testing during pregnancy can identify if your baby has a higher risk of developing certain conditions and even determine if your baby has any conditions before the baby is born, allowing parents to make well-informed decisions about their baby’s health.

What’s the difference between prenatal screening tests and prenatal diagnostic tests?

The two main types of testing for genetic conditions during pregnancy are prenatal screening tests and prenatal diagnostic tests.

Prenatal screening tests

Prenatal screening tests are used to find out if your baby is more or less likely to have certain genetic conditions. These screening tests are offered during the first and second trimesters of pregnancy:

  • First trimester – During the first trimester, your TopLine MD Alliance Network provider will likely offer a genetic blood test and a nuchal translucency test via ultrasound. The blood test screens for chromosomal abnormalities present in your blood, such as Down syndrome or Trisomy 18. The nuchal translucency test measures the size of the clear space in the tissue at the back of your baby’s neck, which is larger in babies with Down syndrome and other genetic conditions.
  • Second trimester – In addition to a routine ultrasound of your baby’s anatomy in the second trimester, your TopLine MD Alliance Network provider will likely offer another genetic blood test called a quad screen, which measures the levels of four substances in your blood. This test is also referred to as maternal serum screening. Again, the results can reveal your baby’s risk of having Down syndrome, Trisomy 18, or other genetic conditions. This test also checks for conditions involving your baby’s brain or spinal cord, known as neural tube defects.

Non-invasive prenatal screening (NIPS) is another blood test that can be performed as early as 10 weeks of pregnancy or later in the second trimester. This test analyzes fetal DNA in your blood to screen for genetic conditions like Down syndrome, Trisomy 18, and more. It can also reveal the baby’s gender.

Prenatal diagnostic tests

Unlike prenatal screening tests, prenatal diagnostic tests are used to confirm if your baby has a genetic condition. These tests are only performed when a screening test is abnormal or if you are at higher risk of having a baby with a genetic condition (see below).

The most common prenatal diagnostic tests are:

  • Amniocentesis – Your TopLine MD Alliance Network provider inserts a needle through your abdomen into your uterus to remove a small sample of amniotic fluid from the amniotic sac. Amniocentesis typically occurs between 16-20 weeks of pregnancy.
  • Chorionic villus sampling (CVS) – Your TopLine MD Alliance Network provider inserts a needle through your abdomen or vagina into your uterus to remove a small sample of cells from the placenta. CVS typically occurs around 11-13 weeks of pregnancy.

What conditions can genetic testing detect in a baby?

Genetic testing during pregnancy can reveal a wide range of conditions, including:

  • Down syndrome
  • Trisomy 18
  • Trisomy 13
  • Trisomy X
  • Cystic fibrosis
  • Sickle cell disease
  • Tay-Sachs disease
  • Thalassemia
  • Turner syndrome
  • Klinefelter syndrome
  • Fragile X syndrome
  • Spina bifida
  • Spinal muscular atrophy
  • And more

Who should consider genetic testing during pregnancy?

The main reason that parents opt for genetic testing is to know as much as possible about their baby’s health. Some prenatal testing finds health conditions that can be treated during pregnancy. If the baby has a genetic condition, parents can decide if they want to continue the pregnancy. Or they can plan for their baby’s care in advance, especially if the condition must be addressed quickly after birth.

Other reasons to consider genetic testing during pregnancy include:

  • Abnormal results on a prenatal screening test or ultrasound
  • Family or personal history of genetic conditions
  • Age (women who are 35 and older are at higher risk for Down syndrome and other genetic conditions)
  • Personal history of miscarriage or stillbirth

The decision to get prenatal genetic testing is a personal choice. TopLine MD Alliance Network providers offer genetic testing to all expectant parents as part of their prenatal care.

How accurate are prenatal genetic tests?

No prenatal genetic test is perfect, and the rate of incorrect results varies from test to test. A test result called a “false-positive” shows a health risk for your baby when there isn’t one, while a test result called a “false-negative” shows no health risk for your baby when there is one.

Ask your TopLine MD Alliance Network provider for more information about the accuracy rates for any genetic tests you are considering.

What are the risks associated with genetic testing?

Prenatal screening tests only require a blood sample, which carries no risk for the mother or baby. However, there is a slight risk of bleeding, infection, or miscarriage if you move forward with a prenatal diagnostic test. For instance, the miscarriage risk for amniocentesis is an estimated one in every 300 (or less than 1%).

The emotional toll of genetic testing is also a risk to consider. Receiving news about potential genetic conditions can be stressful and overwhelming, with false-positive results causing unnecessary anxiety. Parents may face moral, ethical, or religious dilemmas if their baby tests positive for a genetic condition that will impact the baby and the family’s quality of life.

Only you can decide if these risks are worth the value of getting answers from genetic testing. Your TopLine MD Alliance Network provider can explain the risks and benefits of each test in more detail to help you make the best decision for yourself and your baby.

What happens if a prenatal genetic test shows abnormal results?

If a prenatal screening test shows abnormal results, it means your baby has an increased risk of a specific condition, not that your baby has a genetic disorder. Your TopLine MD Alliance Network provider will likely recommend further testing, such as amniocentesis or CVS, to confirm or rule out the diagnosis.

You have the right to choose whether or not to proceed with prenatal diagnostic testing. We encourage you to discuss your concerns and questions openly with your TopLine MD Alliance Network provider so you can make a well-informed decision. Again, our team is here to support you through every step of your pregnancy journey.

Find a provider today

TopLine MD Alliance was created by physicians who came together to make healthcare experiences better for patients. We help patients navigate the healthcare system, connecting them with top-tier providers, practices, diagnostic centers, and imaging centers we trust.

In addition to obstetrics and maternal fetal medicine, TopLine MD Alliance offers gynecology, urogynecology, gynecologic oncology, female pelvic medicine and reconstructive surgery, breast surgery, and many other women’s health specialties.

To learn more, visit us online and find a provider today.