Finding out you’re pregnant and expecting a baby can be an exciting time for you and your family.
However, pregnancy can also cause a lot of worries about whether your baby will arrive healthy and safely. It can be difficult to know what to expect, especially if this is your first pregnancy.
Prenatal tests may give you valuable insight into how the baby is doing during your pregnancy. These tests can check gender, as well as alleviate fears and put an expectant mother’s mind at ease that baby is growing adequately.
If complications are identified during pregnancy, prenatal tests allow doctors and specialists to diagnose conditions quickly and give mothers and their infants the best possible care.
Prenatal tests check for a number of potential health issues
Some prenatal tests are routine and performed in most pregnancies. Urine and blood pressure checks, for example, are done regularly during doctor visits.
However, other tests are done only if a pregnancy is deemed high-risk, whether because of a known factor, such as mother’s age or medical history, or if another prenatal test, such as a blood draw or ultrasound, flags a potential issue.
Some are screening tools that determine how likely it is for your baby to have a specific condition, whereas others diagnose these problems.
Prenatal tests look at these health issues:
- Birth defects
- Genetic or chromosomal conditions
- Risk of premature labor
- Overall health of mom and baby
The Ohio State University Wexner Medical Center’s obstetric team can help you expect the unexpected.
And if something unexpected does happen, the maternal fetal specialists at the Ohio State Wexner Medical Center are specially trained to handle the most complex cases and devote special attention to ensure families dealing with prenatal issues receive proper care and support to get baby here safely.
What routine prenatal tests can I expect during my pregnancy?
Throughout your pregnancy, you’ll most likely be offered these routine prenatal tests:
- Ultrasounds – This is an imaging technique that uses sound waves to produce images of the baby inside the uterus. Ultrasounds will be performed several times throughout the nine months for a variety of reasons, including dating the pregnancy, determining number of babies and checking the baby's anatomy and growth. For example, they'll count fingers and toes and chambers of the heart, as well as measure the head and certain bones. This also encompasses an anatomy scan, or anatomy ultrasound, which is performed at the halfway mark of your pregnancy.
- Glucose test – Around the 6- or 7-month mark, a glucose challenge test is ordered to check whether you have gestational diabetes, which can affect the baby. The test consists of drinking a sugary drink provided by your doctor and having a blood test an hour later to check your blood sugar.
- Nonstress test – Usually ordered in the third trimester, an NST monitors the baby’s heart rate for about 30 minutes and how the baby responds to its own movements and any contractions happening.
- Group B strep test – A woman is screened during her 36th or 37th week of pregnancy for Group B strep. Her provider will swab the vagina and rectum for a sample and if it is positive, the woman will receive IV antibiotics during labor to prevent infection for the baby.
- Fetal kick counts – During this test, you or your provider will count how long it takes for your baby to make eight to 10 movements during the later months in pregnancy. Generally, this should take less than two hours. If your baby isn’t moving that much, it might be worth further testing. This can be done at home, too.
When is a pregnancy considered high-risk?
A number of factors can lead to a potentially high-risk pregnancy even prior to receiving prenatal testing results. These might include:
- Age
- Multiple pregnancies, such as twins or triplets
- Preexisting medical conditions in mom, such as diabetes or high blood pressure
- History of pregnancy complications
However, a pregnancy might also be deemed high-risk if some of the routine tests listed above identify potential issues with you or the baby.
If your provider thinks your pregnancy might have complications, you could be referred to a high-risk pregnancy expert like the Maternal Fetal Medicine specialists at the Ohio State Wexner Medical Center. Here you will have access to genetic counselors, the latest testing resources and the most advanced technologies to treat any conditions these tests might identify.
Also, there are a number of additional prenatal tests that might be performed if your pregnancy is potentially high-risk that will allow our providers to best serve both mother and baby.
Prenatal tests for high-risk pregnancies
These tests can be screenings, which require further investigation to confirm a diagnosis, or diagnostic and offer a definitive diagnosis.
Screening tests include:
- Quad screening – This blood test administered at 15-22 weeks screens for open neural tube defects, such as spina bifida and anencephaly, abdominal wall defects and chromosome changes.
- Nuchal translucency – This ultrasound examination can be performed between 11 and 13 weeks and it measures the collection of fluid under the baby’s skin at the back of the neck. An abnormal finding helps detect chromosomal abnormalities, heart defects and other genetic syndromes.
- Cell-free DNA test – Also referred to as a noninvasive prenatal test (NIPT), this blood test is done after nine weeks of pregnancy to check if a baby has a higher risk for Down syndrome and other genetic chromosomal disorders. Further testing will need to be done to determine definitively if the baby does have one of these conditions.
Diagnostic tests include:
- Chorionic villus sampling – This diagnostic test, done at 10-12 weeks, takes a sample of the developing placenta for laboratory analysis to identify or rule out chromosome abnormalities, such as Down syndrome and certain genetic disorders, such as cystic fibrosis.
- Amniocentesis – Done around week 16, this tests for certain genetic conditions by examining the amniotic fluid that surrounds baby. It can also tell the baby’s sex, help find certain neural tube defects and identify an infection in the amniotic fluid.
Other ultrasounds include:
- Fetal echocardiogram – A special ultrasound of your baby’s heart, which allows specialists to diagnose certain heart defects.
- Biophysical profile – This examination uses ultrasound to provide more information about a baby’s health. Generally done in the third trimester if there are concerns, this test looks at baby’s movements, breathing and amniotic fluid.
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Small pieces of genetic material (DNA) from the pregnancy are in a mother’s blood and are tested to check if a baby is at higher risk for Down syndrome and other genetic chromosomal conditions. This is a screening test and does not give a definite answer. Further testing may be done if cell‐free DNA screening indicates a pregnancy is at high risk.
This ultrasound is provided in partnership with Nationwide Children’s Hospital. It’s performed here are Ohio State and read by a pediatric cardiologist. If a heart defect is found, the pediatric cardiologist will determine its significance and whether the defect will affect your baby prior to birth, will require immediate transfer after birth to Nationwide Children’s or will require heart surgery after birth.
During this test, you’ll count how long it takes your baby to make eight to 10 movements – a kick, flutter, burp, included – in the third trimester. Generally, this should take about an hour. If your baby isn’t moving this much, it might be worth further testing.
You’ll be screened for this during the 36thor 37th week of pregnancy. This test involves swabbing the vagina and rectum and if you test positive, you’ll receive IV antibiotics during labor to prevent infection for the baby.
An abnormal finding during the first trimester can help detect chromosomal abnormalities, heart defects and other genetic syndromes.
Administered during 15 and 22 weeks of pregnancy, this will screen for conditions such as spina bifida, anencephaly, abdominal wall defects and chromosome changes. If results indicate a high risk of these disorders further tests will be performed.