What You Need to Know About Fetal Testing
November 7, 2014
If you’ve just found out you’re pregnant, odds are you saw the “+” sign on the pregnancy stick. Now, your first item of business will be to schedule an appointment with your OB/GYN to confirm things, establish a due date and begin learning all you can about prenatal diet, health and lifestyle choices that will keep you and your baby healthy.
Fetal testing – or prenatal testing – is one of the topics that will be covered by your doctor. While most of the tests are elective, each of them has a purpose depending on your age, medical history and previous pregnancies. Each test also has its pros and cons so please learn all you can so you can decide what fetal tests you want and which ones you would rather pass on.
What are Fetal Tests and What Will They Tell Me About my Baby?
First, it’s important to know that fetal tests aren’t only about the baby. The information derived from these tests – administered during the first-, second-, or third-trimesters (depending on the test) will also tell us important information about your own health.
For example, the tests can reveal your blood type, your immunity to certain diseases or whether at not you are at risk (or have) gestational diabetes or anemia, both of which are relatively common. They may also reveal that you have a sexually transmitted disease (STD) you were unaware of before or cervical cancer, which will help us to determine which course of treatment will be best.
Of course, as the name implies, these tests are also designed to provide us with lots of information about your baby. We can establish physical characteristics about the baby and/or its position in your uterus, which helps us to prepare for your labor and delivery. The tests may also reveal:
- Potential physical defects or genetic problems
- Possible fetal abnormalities, such as heart defects, which can sometimes be treated inside the womb!
Some of the tests we run are considered screening tests. This means that the test results will show a possibility of a genetic defect but the results are not a 100% guarantee. Other tests provide conclusive evidence regarding your baby’s health.
Prenatal Testing – The First Trimester
- First Trimester Screening. This test is a non-invasive, elective (meaning voluntary) test that uses a blood sample from the mother as well as ultrasounds to pick up potential genetic abnormalities like Down’s Syndrome, Trisomy-18 and Trisomy-21.
- Routine blood tests. Your doctor will also want to run a lab on your blood sample to make sure everything looks healthy. If your blood sugar, iron levels, etc., look a little out of whack, she’ll recommend supplements and specialized diet options and may require further testing.
- Pap Smear. This can help to screen for STDs we need to know about before your baby is born and that you will want to know about as well to prevent passing them to your sexual partner(s).
Prenatal Testing – Second Trimester
- Multiple Marker Test (Triple Screen). This test is usually offered between your 15th an 20th weeks and are performed via a blood sample from your arm. It is used to screen for Down’s Syndrome and neural tube defects. Depending on your age, ethnicity and other factors, your doctor may recommend checking various hormone levels and other markers that can indicate other high-risk pregnancy situations. Do remember that this is a screening, which means the results are not definitive. Comparisons with existing first-trimester screening as well as further testing will be needed if any potential defects are detected.
- Ultrasound. Ultrasounds are not mandatory but are typically offered at least once each trimester, and they should never exceed more than once a month unless there is an abnormality or high-risk situation that has been detected and needs to be monitored. This keeps you and the doctors abreast of the physical condition of your baby and your uterus.
- Glucose Screening. This test can detect the potential for gestational diabetes, which can affect both the health of mother and baby as the pregnancy progresses. A positive screen may require a change in diet and more careful pregnancy monitoring.
- Amniocentesis. For this, your doctor will require a sample of your amniotic fluid. There are potential risks associated with the process involved with extracting amniotic fluid and your doctor should review these with you. The results of the test can indicate Down’s Syndrome, Spina Bifida and other genetic abnormalities. It can also determine Rh factor (blood compatibility) issues and/or whether or not the baby’s lungs are developed enough to induce labor. It is typically recommended for women who are 35-years or older or who have had other abnormal screenings.
- Percutanious Umbilical Blood Sampling (PUBS). This is an invasive test that extracts blood from your baby’s umbilical cord. In addition to testing more concretely for genetic abnormalities, it is also used if the doctor feels your baby may have a platelet or thyroid disorder or is potentially anemic, in which case the doctor can give your baby a blood transfusion in-utero via the umbilical cord. PUBS may be recommended if a fetus is showing signs of distress that are potentially related to a fatal genetic defect.
Prenatal Testing – Third Trimester
Besides an ultra-sound, the third trimester is typically devoid of fetal testing unless something has been detected in previous tests or the doctor wants to test the mother for additional indicated health issues like thyroid abnormalities, blood disorders, and other medical conditions.
Contact the Women’s Health Associates to learn more about prenatal or fetal testing, and whether or not they are necessary for your pregnancy.