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Prenatal care

  • Prenatal care is the care you get while you’re pregnant.
  • Regular prenatal care helps keep you and baby healthy.
  • A doctor, midwife or other health provider gives this care.
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Chorionic villus sampling

Chorionic villus sampling (CVS) is a prenatal test. It’s used to diagnose certain birth defects and genetic abnormalities in your baby. Genetic abnormalities are changes in the genes that are passed down to a baby from mom or dad. These genetic changes can cause health problems for a baby.

During CVS, your health care provider takes a small piece of tissue from the placenta. The sample is used to check your baby’s health.

You can get CVS early in pregnancy, between 10 and 12 weeks. CVS isn’t given to all pregnant women because there’s a small chance of miscarriage after the test.

CVS is different from another prenatal test called amniocentesis (also called amnio). Amnio is performed a little later in pregnancy. Talk to your provider about having CVS, amnio or other prenatal tests.

What are some reasons for having CVS?
Your provider should discuss prenatal testing with you and may offer you CVS. And you can ask to have CVS. You may want to have CVS if you’re at risk for having a baby with a genetic abnormality. These risks include:

  • Being 35 or older: The risk of having a baby with certain birth defects or genetic abnormalities, such as Down syndrome, increases as you get older.
  • Having a previous child or pregnancy with a birth defect: If you had a child or a pregnancy with a birth defect in the past, your provider should offer you testing.
  • Abnormal screening test results: If you had abnormal results from a pregnancy screening test, your provider should discuss CVS with you. CVS can provide specific information to confirm if there is an abnormality in the baby. Most babies with abnormal screening test results don’t have problems and are born healthy.
  • Family history of a genetic health problem: If you or your partner has a certain genetic disease (a health condition that gets passed down to a baby from mom or dad), or a close family member with a disease, such as cystic fibrosis or sickle cell anemia, you may want to have CVS.

How is the test done?
The test usually takes 30 to 45 minutes.

A health care provider with expertise in performing CVS takes a tiny piece of tissue from the placenta, which has cells from your baby, to check for problems. The placenta grows with your baby in your uterus (womb). It gives your baby food and oxygen through the umbilical cord.

There are two kinds of CVS:

  1. Testing through the belly (called transabdominal CVS) — Your provider puts a thin needle through your belly into the womb. She then uses the needle to take a small sample of the placenta tissue.
  2. Testing through the cervix (called transcervical CVS) — Your provider places a thin tube through your vagina and cervix (the opening to the uterus that sits at the top of the vagina). The tube gently sucks in a tiny sample of the placenta tissue.

Your provider sends the tissue sample to a lab where it is examined and tested. Test results are usually ready in about 7 days.

Are there any side effects or risks?
Some women find that CVS is painless. Others feel cramping, similar to period cramps, when the sample is taken. Some women who have testing through the cervix say it feels like having a Pap smear.

After CVS, relax for the rest of the day. You may have spotting or cramping for a few hours after the test. Call your health care provider right away if you have heavy bleeding, fever or contractions.

CVS does involve a small risk of miscarriage. The American College of Obstetricians and Gynecologists (ACOG) reports that 1 in 100 (1 percent) women has a miscarriage following testing.

What happens after the test?
In most cases, CVS test results show that a baby is healthy and without birth defects. If the test shows that your baby does have a birth defect, talk to your provider about all of your options. Your baby may be able to be treated with medicines or even surgery before birth. Or there may be treatments or surgery he can have after birth.

Knowing about a birth defect before birth may help you get ready emotionally to care for your baby. You also can plan your baby’s birth with your health care provider. This way, your baby can get any special care she needs right after she is born.

What if you’re not sure about having CVS?
Choosing to have CVS is a personal decision. Talking with genetic counselors, your health care provider, and religious and spiritual leaders can help you make decisions about testing for birth defects during pregnancy.

Ask your provider about other prenatal test options and how you can find a doctor who is trained and experienced in offering specific tests. Learn as much as you can about any prenatal tests your provider recommends to make the right decisions for you and your baby.

Last reviewed August 2011

See also: Your first prenatal checkup, Later prenatal checkups, Birth defects, Amniocentesis, Prenatal tests

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Frequently Asked Questions

What is transabdominal ultrasound?

When you hear about ultrasound during pregnancy, it’s most likely a transabdominal ultrasound. This is a prenatal test that uses sound waves to show a picture of your baby in the uterus (womb). Your health care provider uses it to check your baby’s health. Most women get an ultrasound at 18 to 20 weeks of pregnancy.

During an ultrasound, your provider moves a plastic tool, called a transducer, across your belly. The transducer sends sound waves into your uterus. The waves bounce around to create a picture of your baby on a monitor. To get a better picture, your provider covers your belly with a thin layer of gel. This helps the sound waves move more easily.

Your provider measures your baby’s body throughout the test. Depending on your baby’s position, your provider may point out his hands, legs and other body parts. You should be able to tell if your baby’s a boy or a girl, so be sure to tell your provider if you don’t want to know!

You may need to have a full bladder during the test. This prevents pockets of air in your bladder from affecting the picture. Ultrasound is painless, but having a full bladder may be uncomfortable.

What is first trimester ultrasound?

First-trimester ultrasound (also called early ultrasound) is a prenatal test that uses sound waves to show a picture of your baby in the uterus (womb). Some providers may use this kind of ultrasound to make sure your baby’s organs are growing and developing normally.

Your health care provider uses it to check your baby’s health. A first-trimester ultrasound takes place before 14 weeks of pregnancy.

The kind of first-trimester ultrasound you have depends on the type of information your provider needs. Your provider usually does ultrasound by moving a plastic tool, called a transducer, across your belly. This is called transabdominal ultrasound. You also can have a transvaginal ultrasound, which means it’s done in the vagina (birth canal). Both kinds usually take about 15 to 20 minutes.

Your provider can use first-trimester ultrasound to:

See also: Ultrasound

What is 4-D ultrasound?

4-D ultrasound is a prenatal test that uses sound waves to show a three-dimensional picture of your baby in the uterus (womb) and shows your baby’s movement. 3-D images are almost as clear as a photograph, and 4-D is a moving-picture version or video. Some providers may use this kind of ultrasound to make sure your baby’s organs are growing and developing normally.

You may know of some places, like stores in a mall, that aren’t run by doctors or other medical professionals that offer “keepsake” 3-D or 4-D ultrasound pictures or videos for parents. The American College of Obstetricians and Gynecologists, the Food and Drug Administration and the American Institute of Ultrasound in Medicine do not recommend these non-medical ultrasounds. The people doing them may not have medical training and may give you wrong or even harmful information.

What is 3-D ultrasound?

3-D ultrasound is a prenatal test that uses sound waves to show a three-dimensional picture of your baby in the uterus (womb). Some providers may use this kind of ultrasound to make sure your baby’s organs are growing and developing normally.

The 3-D ultrasound is almost as clear as a photograph. A moving-picture version is called 4-D ultrasound.

You may know of some places, like stores in a mall, that aren’t run by doctors or other medical professionals that offer “keepsake” 3-D or 4-D ultrasound pictures or videos for parents. The American College of Obstetricians and Gynecologists, the Food and Drug Administration and the American Institute of Ultrasound in Medicine do not recommend these non-medical ultrasounds. The people doing them may not have medical training and may give you wrong or even harmful information.

See also: Ultrasound

What is Doppler ultrasound

Doppler ultrasound is a kind of prenatal test that can be used to check a baby’s health in high-risk pregnancies. Providers usually use Doppler ultrasound during the last trimester, but it may be done earlier.

During Doppler ultrasound, your provider uses a plastic tool called a transducer to measure the blood flow in the umbilical cord and some of your baby’s blood vessels. This test shows if your baby is getting enough oxygen. Your provider also can listen to your baby’s heartbeat using Doppler ultrasound.

Some providers use Doppler ultrasound to check mothers with Rh disease. This is a condition where a difference between the mother’s blood and baby’s blood can cause a dangerous kind of anemia in the baby. Anemia is when the body doesn’t have enough red blood cells or the red blood cells are too small. When the condition is found early and treated, most affected babies survive.

What is transvaginal ultrasound?

Transvaginal ultrasound is a prenatal test that uses sound waves to show a picture of your baby in the uterus (womb). Your health care provider uses transvaginal ultrasound to check your baby’s health. It’s often used for early ultrasound in the first trimester.

During the test, your provider moves a thin, wand-like transducer into the vagina. You lay on your back with your feet in stirrups during the exam. You may feel some pressure from the transducer, but it shouldn’t cause pain.

Transvaginal ultrasound can be used throughout pregnancy to check for problems with the cervix (opening to the uterus) and lower uterus.

See also: Ultrasound

How is blood pressure measured?

Blood pressure is the force of blood that pushes against the walls of your arteries. Arteries are blood vessels that carry blood away from your heart to other parts of the body. If the pressure in your arteries becomes too high, you have high blood pressure. High blood pressure is also called hypertension.

At each prenantal care visit, your health care provider checks your blood pressure. To do this, she wraps an inflatable cuff around your upper arm. She pumps air into the cuff to measure the pressure in your arteries when the heart contracts (gets tight) and then relaxes.

Your blood pressure reading is given as two numbers: the top (first) number is the pressure when your heart contracts and the bottom (second) number is the pressure when your heart relaxes. A healthy blood pressure is 110/80. High blood pressure happens when the top number is 140 or greater, or when the bottom number is 90 or greater

Your blood pressure can go up or down during the day. Your provider can re-check a high reading to find out if you have high blood pressure during pregnancy.

Last reviewed March 2012

See also: High blood pressure during pregnancy, Preeclampsia, HELLP syndrome

Can a rubella shot hurt my baby during pregnancy?

If you got your rubella shot around the time you got pregnant, it's unlikely that your baby will be harmed by the vaccine. However, it's best to wait to get pregnant for 28 days after vaccination because there is a very small risk of potentially hurting the baby. To date, there hasn't been any birth defects reported that are attributed to the rubella vaccine. In any case, the risk of harming your baby by getting the vaccine at the time you got pregnant is much lower than the risk of harming your baby if you caught rubella during pregnancy.

I couldn't see my baby at my 7 week ultrasound. Why?

At the 7th week of pregnancy, your baby is about ½ an inch long or the size of a blueberry. He's very small. When a transabdominal ultrasound (done on your belly) is done at such an early stage, it's possible that the baby can't be seen. It could be because it's too early in the pregnancy or because you conceived a little later than what you thought. Your health care provider might recommend a transvaginal ultrasound (done inside the vagina) to help see the baby more clearly.

What are choroid plexus cysts?

The choroid plexus is the area of the brain that produces the fluid that surrounds the brain and spinal cord. This is not an area of the brain that involves learning or thinking. Occasionally, one or more cysts can form in the choroid plexus. These cysts are made of blood vessels and tissue. They do not cause intellectual disabilities or learning problems. Using ultrasound, a health care provider can see these cysts in about 1 in 120 pregnancies at 15 to 20 weeks gestation. Most disappear during pregnancy or within several months after birth and are no risk to the baby. They aren't a problem by themselves. But if screening tests show other signs of risk, they may indicate a possible genetic defect. In this case, testing with higher-level ultrasound and/or amniocentesis may be recommended to confirm or rule out serious problems.

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