The amniocentesis debate

This test, performed during pregnancy, may not be for everyone

By Julia K. Agresto

For many pregnant women, the debates surrounding the risks and benefits of what to do, and what not to do, while pregnant can be overwhelming. What should and shouldn’t you eat? Which vitamins should and shouldn’t you take? Which medical tests should you get done or not get done?

One such debate centers around whether pregnant women should undergo a test called amniocentesis during pregnancy. Amniocentesis, also referred to as an amniotic fluid test or AFT, is a medical procedure used in prenatal diagnosis of chromosomal abnormalities and fetal infections that can cause a variety of problems and disorders in a developing fetus – the most common one being Down syndrome.

According to Denise Poulin, MD, FACOG; who works with the practice of OB/GYN Associates of Southern NH associated with St. Joseph Hospital and is board-certified in Obstetrics and Gynecology, amniocentesis is a procedure in which amniotic fluid is removed from the pregnancy sac through a small needle passed through the mother's abdomen. It is commonly done at 16 to 20 weeks to test for chromosomal abnormalities indicated by a woman's age, family history or prior pregnancy history.

While this test used to be commonplace years ago, the potential risks have been more emphasized in recent years, resulting in a debate as to whether the test is safe or even necessary, despite its advantages of high reliability and specificity, Poulin said.

“Amniocentesis is done less often today because of alternative blood testing available at 13 to 20 weeks, which may offer reassurance to women without the discomfort of this procedure, and without the risk of pregnancy loss, which is about one percent or less with amniocentesis,” she said. “Level II ultrasound and late first-trimester ultrasound assessment have also contributed to the decreased use of this diagnostic test.”

Some pregnant women, however, do still opt to have the test done – or it becomes necessary due to circumstances in their pregnancy.

Ashley Forsberg, 23, of Moultonborough, had an amniocentesis performed when she was 32 weeks pregnant because doctors thought she had gone into preterm labor, believed to be a result of an infection in her amniotic fluid, and thought they may have to deliver her son, Beckett immediately. This option was presented to Forsberg as a definitive way to rule out the possibility of an infection in her amniotic fluid called chorioamnionitis. She had been transported from Concord Hospital, where she was supposed to deliver, to Elliot and admitted immediately into the Neonatal Intensive Care Unit, or NICU.

“I am amazingly grateful for the test and the doctor that did it, because it was the only thing that would solidly prove whether or not I had the infection,” Forsberg said. “And its results led doctors to be able to look elsewhere for the cause of preterm labor, so I was able to carry my son until he was ready to come.”

According to Erica Stelmach, MS CGC, certified genetic counselor for the Prenatal Diagnosis Program at Dartmouth-Hitchcock Manchester, amniocentesis, although an invasive procedure with risks, does have its benefits.

“Amniocentesis testing can be very reassuring when results are normal,” says Stelmach, who explained that the number of women who have the test varies greatly by many factors.

“For families at risk for certain genetic conditions, amniocentesis can provide the comfort of knowing that the unborn baby will not be affected.  For couples whose amniocentesis results show that the baby has a problem, it can be helpful to be able to plan for the remainder of the pregnancy.  Some couples say that being uncertain about the health of the baby was harder than learning that the baby did have a problem.  For some conditions diagnosed by amniocentesis, it may be possible to provide treatment prenatally or at birth.”

But for many women, the potential positives of having an amniocentesis procedure done are not enough to convince them to go through with the procedure.

Abbey Martino Devens, 25, of Groton, Mass., was someone who chose not to have any testing done during her pregnancy. She made this decision despite finding out in her first ultrasound that her baby had an “ugly kidney.” Also three days before going in for her scheduled C-section, the doctor told her the baby was at high risk of having Down syndrome or some other type of syndrome. This did not end up being the case.

Martino Devens said the experiences of others close to her contributed largely to her decision not to have any testing done, as they were not given accurate results.

“In my mind, I didn't think I would do anything if something did show up on a test,” she said.

Poulin says the choice to have amniocentesis or other tests done is not for everyone and is a personal and situational decision.

“Not every woman with abnormal testing or specific risks, such as maternal age, will decide to proceed with amniocentesis,” Poulin said. “Only a pregnant woman can make the best decision for herself. We provide information, but don't make the recommendation for or against any testing. Women of any age can choose or decline blood or ultrasound screening.”

Forsberg agreed every woman should make the best decision for herself and her own situation, whatever that may be.

“My personal advice to other pregnant women would be to trust themselves and the doctors they are working with to make a decision that is best for them,” Forsberg said. “I was very fortunate to have not only an amazing set of doctors and nurses, but an amazing practice that I saw throughout my pregnancy. Combined, they answered millions of my questions in nine months and gave me relevant information so we could make the best decisions for myself and my son, which I think is invaluable, especially when considering any type of procedure.”

Thinking about getting amniocentesis done? Consider this…

Denise Poulin, MD, FACOG, cautions that amniocentesis is only recommended for pregnant women with specific risks for genetic problems, and is not recommended to simply offer "peace of mind.” The risks of testing by blood tests or ultrasound are primarily the risk of falsely worrying a woman who has an abnormal test but her baby is not affected, Poulin says, and this varies from three to five percent. This is called "false positive" testing. Amniocentesis has a less than one percent false positive testing rate, but carries a risk of pregnancy loss – although small – and this is its primary disadvantage or risk. Amniocentesis results will tell whether a baby is or is not affected with a chromosomal condition with a high degree of reliability. The blood and ultrasound testing will be reported as an odds probability, such as 1/200 or 1/50, and is intended to be reassuring or alternatively to raise suspicion, but is not definitive.

Erica Stelmach, MS CGC, also points out it is not possible to use an amniocentesis sample to test an unborn baby for every potential chromosome condition, genetic disorder or infection.  The testing done on an amniocentesis sample is targeted based on factors specific to the pregnancy. She also added it is important to note not all health insurance plans will cover amniocentesis and those that do may not cover the procedure for every woman. It is important for women considering amniocentesis to contact their health insurance provider to educate themselves about their coverage and options. Lastly, there are many issues to think about when considering an amniocentesis. Women considering this procedure should discuss it with their physician and/or a prenatal genetic counselor.