Prenatal testing during pregnancy ensures that both mother and baby are progressing through the pregnancy smoothly.
There are many types of prenatal screenings available, and each one is designed to assess or evaluate your baby’s health. Some tests monitor growth and development, while others detect the risks for having certain genetic conditions, such as spina bifida.
Our team of board-certified specialists at OBGYN Westside PLLC, on the Upper West Side of New York City, offer prenatal tests to expectant mothers through all stages of pregnancy.
Here’s what you need to know about prenatal testing.
Two types of prenatal testing
Prenatal testing falls into two categories:
- Screening tests, which highlight if your baby carries an increased risk of developing a certain condition
- Diagnostic tests, which confirm if your baby has (or doesn’t have) a certain condition
Prenatal tests are important because the results either confirm your pregnancy is progressing without incident or it opens the door to receiving treatments or interventions in a timely manner.
Which tests do you need?
Your age, how far along you are in your pregnancy, and your health history help shape your prenatal testing plan. Here’s a look at which tests are available during each trimester:
First trimester screening tests
You can expect to receive several ultrasounds during your first trimester, including an initial ultrasound at your first visit. This test confirms pregnancy, checks for potential red flags, and helps date your pregnancy. Blood tests also screen for any red flags, such as low hormones or low iron.
We also offer 2 prenatal tests that screen for Down Syndrome and will recommend that you do both. The NIPT is a blood test that assesses fetal DNA in your bloodstream. This test screens for increased risk of chromosomal problems, and as a bonus, this test also reveals your baby’s gender! (You do not have to have the gender revealed if you do not want to!)
The second test is the nuchal translucency, which is an ultrasound of your baby. During the ultrasound, the nuchal fold thickness near your baby's neck (nuchal translucency) is measured. This space can appear abnormally large in babies born with Down Syndrome, so the test can indicate an increased risk for Down Syndrome, trisomy 13, trisomy 18, and other genetic disorders.
This test won’t confirm if your baby has one of these genetic conditions, but it can help determine if you need more invasive diagnostic testing, such as a CVS or amniocentesis.
Second trimester screening tests
The maternal serum AFP test is a blood test done anytime between 15-20 weeks of pregnancy. This is a blood test that screens for open neural tube defects, which are malformations of the central nervous system.
We will also recommend that you have anatomy ultrasounds at about 16 and 20+ weeks of your pregnancy. These ultrasounds look at the different parts of the baby’s anatomy including the heart, spine, kidneys, etc., and are generally very fun to go to!
Between 24-28 weeks we will also do a Glucose Challenge Test to screen for diabetes.
Third trimester screening tests
There are a few prenatal tests done during your final few weeks. Examples of third trimester testing include:
- Group B strep test
- Ultrasounds, including a biophysical profile
- Non-stress tests, which may be scheduled more regularly for high-risk pregnancies
Most women don’t realize if they have a group B strep infection, but in rare circumstances, newborns can be affected by this bacteria. This screening is important because our team then knows to administer IV antibiotics during labor. Third trimester ultrasounds can assess growth, to ensure that your baby is in the ideal position for birth and that there is enough amniotic fluid.
At all prenatal appointments, regardless of trimester, we check your blood pressure and screen your urine for signs of sugar or protein (to help catch dangerous conditions such as preeclampsia).
If you have questions about prenatal tests or need to schedule your next prenatal appointment, call our office or book an appointment online today.