Pregnancy: Should I Have Amniocentesis?
You may want to have a say in this decision, or you may simply want to follow your doctor's recommendation. Either way, this information will help you understand what your choices are so that you can talk to your doctor about them.
Pregnancy: Should I Have Amniocentesis?
Get the facts
- Have an amniocentesis test.
- Don't have amniocentesis.
Key points to remember
- Your doctor may recommend amniocentesis if your chances of having a baby with a genetic disorder or birth defect are higher than average.
- Even though amniocentesis can detect certain problems, it can't guarantee that your baby will be born healthy. No test can do that.
- If the test shows that your baby may be born with a serious problem, you and your partner can use the information to plan for the future.
- Amniocentesis is usually very safe. But it does have some risks, including a small chance of causing a miscarriage.
Amniocentesis is a test to look at the amniotic fluid that surrounds your baby. This fluid has cells and other substances in it that can give clues about your baby's health.
During the test, your doctor puts a needle through your belly into your uterus. He or she takes out about 2 Tbsp (30 mL) of amniotic fluid to send to a lab. The cells in the fluid are checked to see if your baby has any signs of a serious health problem.
Amniocentesis is usually done between weeks 15 and 20 of a woman's pregnancy to check for certain health problems. It's not a routine test. But your doctor may recommend it if a fetal ultrasound and blood tests suggest that your chances of having a baby with a genetic disorder or a birth defect are higher than average. Or you may already know that your chances are higher because of your age and family history.
Some women don't want to wait until their second trimester to see if their baby might have a problem. They might decide to have a chorionic villus sampling (CVS) test instead of amniocentesis. CVS can be done between 10 and 12 weeks of pregnancy to look for Down syndrome and other serious health problems. But it can't find certain problems, such as birth defects of the heart, stomach, intestines, or brain and spine (neural tube defect).
Amniocentesis may also be done during the third trimester of pregnancy to see if your baby's lungs are fully formed. This test may be recommended if you need to deliver early because of a problem with your pregnancy. The test may also be done to check the amniotic fluid for infection.
Amniocentesis can tell you if your baby is at risk for:
- Genetic disorders or birth defects, such as Down syndrome and neural tube defects.
- Certain diseases that run in families, such as cystic fibrosis, sickle cell disease, and Huntington's disease.
When amniocentesis is done during your third trimester, it can tell you if your baby's lungs are fully formed. The test can also show whether there is an infection in the amniotic fluid.
Even if the results from your amniocentesis are normal, it doesn't guarantee that your baby will be born healthy. For example, this test can't find many common birth defects, such as cleft lip, cleft palate, and heart problems. No single test can find all problems.
This test can tell you if your baby may be born with a serious health problem. Many parents are not prepared to care for a baby who is sick or has a birth defect. Information that you get from this test can help you and your partner plan for the future.
If the test finds that your baby has a genetic disorder or a birth defect, you and your partner may be faced with a tough decision about whether to continue the pregnancy. You may find it helpful to talk with your doctor and a genetic counselor. They can help you understand your baby's health problem and what to expect when he or she is born.
Results from the test can also help you decide where to have your baby. If your baby will need surgery or special care, you can plan to have your baby in a hospital that has special services for newborns, such as a neonatal intensive care unit.
Amniocentesis is usually very safe. But the test does have some risks. You'll have to weigh the risks against the benefits of knowing if something might be wrong with your baby.
There is a chance that the test may cause you to have a miscarriage. This means that you could lose your baby after you have the test. But when the test is done by highly trained doctors, the risk of having a miscarriage is small.
- In one study of women who had amniocentesis performed by a highly trained doctor, about 1 out of 400 women had a miscarriage after the test. This means that 399 did not.1
- Another study showed that 2 to 4 out of 400 women had a miscarriage after the test. This means that 396 to 398 did not. This greater risk may be more likely in medical centers whose doctors have less experience in doing the test.2
Other risks include:
- Infection. There is a very small chance that the amniotic fluid may get infected.3
- Injury. There is a chance that your baby may be poked by the needle during the test. But this is rare when ultrasound is used to guide the needle. The most common injury is a tear in the placenta. This usually heals without a problem.
- Bleeding. There is a small chance that you could bleed during the test. If this happens, your blood may mix with your baby's blood. This is only a problem if your blood is Rh-negative and your baby's is Rh-positive, because you could have an immune system response called Rh sensitization. If you're at risk for Rh sensitization, you'll be given a vaccine to prevent it.
- Foot defect. There is an increased risk that your baby may be born with a clubfoot when amniocentesis is done before 15 weeks of pregnancy.
All patient decisions are personal. You might think about:
- Your chance of passing on a family disease to your baby.
- Your age. As you get older, you have a greater chance of having a baby with a birth defect. Many doctors use 35 and older as the age for higher risk.
- Your need to know about any problems with your baby.
- What you might do if the test shows a problem.
- Whether you can afford to pay for the test. Amniocentesis can cost a lot. Most insurance companies will cover the cost of the test if you have certain risk factors that may increase your baby's chance of having a serious health problem. A risk factor is somethingâ€”such as your age or family historyâ€”that raises your risk of having a certain health problem.
Your doctor may advise you to have amniocentesis if:
- Other tests suggest that your chance of having a baby with a genetic disorder or birth defect is higher than average.
- You or your partner has a family history of birth defects.
- You or your partner carries an abnormal gene that is known to cause a certain disease.
- You want to know if your baby has a serious health problem so you can decide early whether you want to continue your pregnancy or make plans to care for a sick child.
Compare your options
What is usually involved?
What are the benefits?
What are the risks and side effects?
- You lie on your back while your doctor puts a long needle into your belly.
- You may feel some discomfort, but the test only takes a few minutes.
- You go home after the test.
- You find out early in your pregnancy if your baby has a genetic disorder or birth defect.
- Information from the test can help you to:
- Decide if you want to continue your pregnancy.
- Make plans to care for a baby who is sick or has a birth defect.
- Choose a hospital that specializes in caring for newborns with serious health problems.
- Possible risks
- A miscarriage.
- An infection.
- A needle injury to your baby.
- A foot defect.
- You have regular prenatal exams and blood tests to check for any signs of problems.
- You avoid the cost of amniocentesis.
- You avoid the risks of having amniocentesis.
- You won't know if your baby has a severe birth defect until after he or she is born.
- Birth could be harder on you or your baby if the doctor doesn't know ahead of time that there is a problem.
Personal stories about considering amniocentesis
These stories are based on information gathered from health professionals and consumers. They may be helpful as you make important health decisions.
I have a friend whose child was born with Down syndrome. She didn't know about her baby's Down syndrome until after he was born, and it was emotionally difficult for her to deal with the diagnosis. I remember how hard it was for her and her family to adjust to a new life with a special-needs child. I want to know before giving birth if I am going to have a child with a disability. This will give me time to prepare emotionally as well as time to prepare to have my baby at a hospital that is equipped to care for sick babies.
Darla, age 35
I am prepared to accept my child, regardless of whether he or she has a birth defect, even a severe birth defect. Even though I am at a higher risk of having a child with a birth defect because of my age, I will continue the pregnancy regardless of the results of an amniocentesis. My doctor and hospital are well equipped to handle my pregnancy and delivery, so I feel that I have made the best decision for my family and me.
Sarah, age 39
I have no family history of birth defects. But I am 42 years old, which puts me at higher risk for having a baby with a birth defect. I have two children already, and I feel that my time, energy, and financial resources are at a premium. I can't afford, financially or emotionally, to have a child with a serious birth defect. I am choosing to have an amniocentesis to help detect a birth defect. If the results are abnormal, I feel it is in my best interest (and my family's) to end this pregnancy.
Ana, age 42
I was 35 when I became pregnant with my first child. I was nervous about pregnancy anyway and especially worried that there might be something wrong with the baby. I decided to have chorionic villus sampling instead of waiting for an amniocentesis because it allowed me to find out in the first trimester if the baby had genetic problems. If the answer had been yes, I would have terminated the pregnancy. In my case, the answer was negative, and I was able to go through the rest of my pregnancy feeling more at ease.
Liza, age 45
What matters most to you?
Your personal feelings are just as important as the medical facts. Think about what matters most to you in this decision, and show how you feel about the following statements.
Reasons to have amniocentesis
Reasons not to have amniocentesis
I'm worried that something might be wrong with my baby.
I'm not worried that something might be wrong with my baby.
I want to know if my baby has a birth defect so I have time to prepare to care for a child with special needs.
Knowing that my baby has a birth defect won't change the way I plan to care for my child.
I want to know if my baby has a birth defect so I have time to decide if I want to continue my pregnancy.
Knowing that my baby has a birth defect won't change my plans to carry my baby to term.
I'm not afraid of the needle that is used to do the test.
I don't like needles.
I'm not worried about how much the test costs.
I don't have insurance, and I can't afford to pay for the test myself.
My other important reasons:
My other important reasons:
Where are you leaning now?
Now that you've thought about the facts and your feelings, you may have a general idea of where you stand on this decision. Show which way you are leaning right now.
NOT having amniocentesis
What else do you need to make your decision?
Check the facts
Can an amniocentesis test guarantee that your baby will be born healthy?
- YesSorry, that's not right. Even though amniocentesis can detect certain problems, it can't guarantee that your baby will be born healthy. No test can do that.
- NoThat's right. Even though amniocentesis can detect certain problems, it can't guarantee that your baby will be born healthy. No test can do that.
- I'm not sureIt may help to go back and read "Get the Facts." Even though amniocentesis can detect certain problems, it can't guarantee that your baby will be born healthy. No test can do that.
Does amniocentesis have some risks?
- YesThat's right. Amniocentesis is usually very safe. But it does have some risks, including a small chance of causing a miscarriage.
- NoSorry, that's not right. Amniocentesis is usually very safe. But it does have some risks, including a small chance of causing a miscarriage.
- I'm not sureIt may help to go back and read "Get the Facts." Amniocentesis is usually very safe. But it does have some risks, including a small chance of causing a miscarriage.
Should all pregnant women have amniocentesis?
- YesSorry, that's not right. Your doctor may recommend amniocentesis if your chances of having a baby with a genetic disorder or birth defect are higher than average.
- NoThat's right. Your doctor may recommend amniocentesis if your chances of having a baby with a genetic disorder or birth defect are higher than average.
- I'm not sureIt may help to go back and read "Get the Facts." Your doctor may recommend amniocentesis if your chances of having a baby with a genetic disorder or birth defect are higher than average.
Decide what's next
Do you understand the options available to you?
Are you clear about which benefits and side effects matter most to you?
Do you have enough support and advice from others to make a choice?
How sure do you feel right now about your decision?
Use the following space to list questions, concerns, and next steps.
Here's a record of your answers. You can use it to talk with your doctor or loved ones about your decision.
|Primary Medical Reviewer||Sarah Marshall, MD - Family Medicine|
|Specialist Medical Reviewer||Siobhan M. Dolan, MD, MPH - Reproductive Genetics|
- Caughey AB, et al. (2006). Chorionic villus sampling compared with amniocentesis and the difference in the rate of pregnancy loss. Obstetrics and Gynecology, 108(3): 612â€“616.
- Seeds JW (2004). Diagnostic mid trimester amniocentesis: How safe? American Journal of Obstetrics and Gynecology, 191: 608â€“616.
- Cunningham FG, et al. (2010). Prenatal diagnosis and fetal therapy. In Williams Obstetrics, 23rd ed., pp. 287â€“311. New York: McGraw-Hill Medical.