A Broad Look at Prenatal Testing
A Broad Look at Prenatal Testing
When you find out you are pregnant, sometimes its hard not to worry. You might find yourself asking questions like: What if something goes wrong with my baby? What if my body isn’t good at being pregnant? One of the reasons early prenatal care is so important is because in many instances, complications during pregnancy can be detected and treated to give you and your baby the best possible outcome. To detect any complications, there are dozens of prenatal tests available. Although healthcare providers will recommend certain prenatal tests, pregnant women can ultimately make the decision to have these tests or not.
Screening Tests vs. Diagnostic Tests
There are two types of prenatal tests. Screening tests check if you or your baby have a chance of developing some type of health condition, but they don’t confirm a diagnosis. Diagnostic tests are usually more invasive than screening tests and are fairly effective at diagnosing specific health problems. With treatment, many conditions can be managed throughout pregnancy and reduce the chances of premature birth. Some prenatal tests – such as blood and urine tests and checking blood pressure – are performed routinely to all pregnant women, while others are only recommended if certain symptoms or medical history indicate it could be beneficial to undergo those tests. Mother’s age can also be a factor in some instances, as getting pregnant after the age of 35 can increase the likelihood of certain complications.
Prenatal tests during the first trimester
There are some prenatal tests that can only be performed at certain times during your pregnancy. In the first trimester, genetic screening can begin if you or your partner have health conditions that run in your family. These screenings check for the possibility of your baby having birth defects or genetic conditions such as down syndrome, heart defects, or cystic fibrosis. These tests include:
- Carrier screening (for genetic conditions)
- Cell-free DNA testing
- Chorionic Villus Sampling (CVS) – Used as a diagnostic test, CVS is performed to detect genetic abnormalities in the baby. A small sample of tissue is taken from the placenta – which contains cells from your baby – for testing.
- Ultrasound – First trimester ultrasounds are sometimes used to confirm you are really pregnant and how far along you are in your pregnancy.
Second trimester prenatal tests
During weeks 4-6 of pregnancy, you can have the following prenatal tests:
- Maternal blood test – These tests check for protein, iron, and Rh factor in your blood. This can determine if you are at risk for preeclampsia, anemia, neural tube defects, and other health problems.
- Glucose test – Around 18 weeks, you will have a blood sugar test to screen for gestational diabetes. To assess your body’s ability to process glucose (sugar), you are given a syrupy drink in your doctor’s office or clinic. After one hour, your blood is drawn.
- Amniocentesis – Also called an amnio, this diagnostic test is done by withdrawing the amniotic fluid that surrounds your baby in the sac and can assess lung development, birth defects, or infection.
- Ultrasound – In the second trimester, most women receive an ultrasound to measure the baby’s limbs, head, and overall growth. This is also the time when you can see the gender of your baby if you choose.
- Fetal blood sampling – Used to get quick results as to the health of the baby, fetal blood sampling could be recommended if amniocentesis results have been inconclusive, if your baby has an infection, or Rh incompatibility.
Third trimester prenatal tests
By the third trimester, the only routine prenatal test given is for group B strep (GBS). This is an infection that can pass from mother to baby during birth. For a GBS exam, your doctor or midwife will obtain a fluid sample from your cervix (at the top of the vagina) for testing. If you have any other symptoms that point to a possible complication or a high-risk pregnancy, additional prenatal testing – such as a nonstress test or fetal distress monitoring – may be offered.
Prenatal tests can take some of the stress out of pregnancy for many women by ruling out possible disease in the baby. For others, knowing about a deformity or birth defect in the baby that can’t be changed is not worth having prenatal tests done. It’s important to talk with your partner and doctor, then decide what you prefer.
Do you think prenatal tests are worthwhile? Share your opinion with us in the comments!