Five Things to Know About Amniocentesis Testing

From IVF to PGD to 4D ultrasounds, modern technology has improved family building by leaps and bounds in recent years. But one medical procedure has been giving doctors an inside look at a developing pregnancy for decades.

Amniocentesis: Definition

An amniocentesis, or amnio, is a procedure that is normally used to provide a clear picture of potential pregnancy problems that may not be easily addressed any other way.

Amniotic fluid, which surrounds a developing baby during a pregnancy, serves its main purpose by providing protection. But it can also answer many questions about what’s happening in utero.

These are five things to know about amniocentesis testing.

1. The procedure has been done for decades.

In fact, the first amniocentesis was actually performed by a German doctor in the 1880s. While modern lab work wasn’t available, it was originally done to relieve the pressure of excess amniotic fluid. By the 1950s, a more modern version of the technique was developed to use in the prenatal diagnosis of a variety of conditions and infections.

2. There are multiple reasons an amniocentesis might be recommended.

What conditions does an amnio test for? According to the Mayo Clinic, they generally include:

Treatment: The original purpose was for treating polyhydramnios - excess amniotic fluid – which can develop and lead to problems as the pregnancy progresses; an amniocentesis can drain this extra fluid from the uterus.

Fetal lung testing: In order to determine if a baby’s lungs are developed enough for birth, the amniotic fluid can be checked.

Diagnosis of fetal infection: If an infection or other illness is suspected, an amniocentesis can be used to confirm. One of the more common conditions that can be detected this way is Rh sensitization, where a mother’s immune system produces antibodies against a protein on the baby’s blood cell surface. It’s uncommon, but can cause anemia in the unborn baby and lead to other serious complications.

Genetic testing: If prenatal screening tests are abnormal and certain conditions like Down syndrome are suspected, a more accurate form of genetic testing can be completed via amniocentesis.

3. An amniocentesis is typically done midway through the pregnancy.

A genetic amniocentesis is most often completed between 15-20 weeks. A fetal lung maturity amniocentesis, however, is done to prevent complications at birth. Since it’s generally non-emergency, it’s rarely done prior to 32 weeks so as not to cause problems in the duration of the pregnancy.

4. It is your right to have an amniocentesis, but it is not required.

Your physician or specialist may suggest the procedure, but know that it is something you can decline. The idea is that knowledge is power, and having the information prior to birth is helpful for everyone involved; plans can be made, specialists can be contacted, the parents can spend time processing and educating themselves, and, if necessary, a discussion can be had about the risks of continuing the pregnancy.

5. An amniocentesis does come with a risk.

While it can help determine the viability of a pregnancy, the procedure can also jeopardize it. Rarely – as in less than 1% - it can cause miscarriage. According to March of Dimes, 1-2% of women also experience cramping, spotting, or leaking of amniotic fluid, and some infections like HIV or toxoplasmosis can also be passed along to the baby.

In most cases, an amniocentesis is a safe test and the benefit of information outweighs the risk. As with any medical procedure, it should be discussed with the specialist and the pros and cons must be considered so that an informed decision can be made. Check out our blog post for tips on making safe choices during pregnancy, and to learn more about modern family building, please contact us!