At its most basic form, prenatal testing is any kind of test you get while you’re pregnant (thankfully, not the multiple choice kind). This could include ultrasounds, taking your blood pressure, or testing your urine. However, there are other prenatal testing types available throughout your pregnancy that can confirm your baby’s gender or test for abnormalities in your baby’s growth and development.
An ultrasound test can be one of the most exciting tests you’ll do while pregnant. Another name for it is a sonogram. That’s because an ultrasound allows you to see your baby, and allows your obstetrician to track your baby’s growth and development. The technology uses sound waves to re-create an image of your baby on a computer screen. Some doctors perform this test twice: in your first trimester and around 20 weeks of pregnancy. Others provide the test more frequently to monitor your baby’s growth and levels of amniotic fluid.
In your second trimester, somewhere between 24 and 28 weeks’ gestation, your obstetrician will have you complete a glucose screening test. Most commonly, you’ll drink a glucose-containing drink (like a Sprite, but with more sugar), and test your blood to see how well your body processes the sugar. The test is to determine if you could have gestational diabetes, a condition that affects your blood sugar in pregnancy.
Your doctor will draw a sample of your blood for testing for certain conditions that could affect you and your baby. Examples include HIV, anemia, hepatitis B, and your blood type. Your blood type is especially relevant if you have a “negative” blood type, like B-negative and your partner has a positive blood type. This is known as Rh incompatibility and may require the administration of a special medication known as RhoGAM that can reduce the risks for adverse effects to your baby.
Not all expectant moms need (or want) genetic testing, but it is available. Some are known as screening tests that will test for potential risks for a baby to experience a condition, such as cystic fibrosis or Down’s syndrome. Other tests are diagnostic and can more definitively say if your baby has a certain medical condition. There are some instances where a doctor may recommend these tests. This includes if you are older than age 35, have had a premature baby in the past, or are a known carrier for certain genetic conditions.
An amniocentesis is a test that involves taking a sample of the amniotic fluid in your uterus to test for abnormalities. This involves inserting a thin needle into your belly, so it is associated with some risks. The test is usually performed between 14 and 20 weeks into your pregnancy. Doctors don’t usually recommend amniocentesis unless you have had an abnormal blood test or ultrasound that may indicate the potential presence of an abnormal condition in your baby. An example could be if your baby has fetal anemia and may require a blood transfusion.