What Are the Pros and Cons of Amniocentesis Testing?

Amniocentesis testing can offer families and their health care providers important information about the well-being of a developing baby. It can help the physician to diagnose genetic disorders, and assess whether a fetus is mature enough to survive outside of the womb. This procedure is not without risks, however. Complications of amniocentesis can include infection, bleeding, leakage of amniotic fluid, miscarriage, and injury to the fetus. In some cases the procedure fails to provide accurate information about the fetus.

The biggest pro of amniocentesis testing is that it provides a sample of the genetic material of the developing fetus. This information is critical for making a more definitive prenatal diagnosis of genetic syndromes. Although ultrasounds and tests done on the maternal blood can suggest conditions such as Down Syndrome, amniocentesis provides a more accurate diagnosis.

Amniocentesis testing is also important in evaluating women at risk for preterm delivery. The sample obtained from the procedure can be tested to assess how mature the fetus’s lungs are. Immature lungs might suggest that the woman should try to hold on to the pregnancy as long as possible in order to give her baby the best chance for survival after birth. In contrast, having a test that suggests mature lungs might shift the balance in favor of delivering the preterm baby.

Unfortunately, there are a number of risks of amniocentesis testing. Some of the risks are associated with the fact that amniocentesis is an invasive procedure. There is always a chance of infection, either of the mother’s skin or of the amniotic fluid surrounding the developing fetus. Women could bleed excessively as a result of the procedure. Some women experience a persistent leakage of amniotic fluid from the site of needle entry.

Having a miscarriage after amniocentesis is another con of the procedure. Different researchers have estimated different rates of fetal loss after amniocentesis. In general, the post-procedure risk of miscarriage is estimated to be 1.1 to 2.2%. This is an increase from a rate of 0.7 to 1.5% in comparable women who did not undergo an amniocentesis. In other words, the risk of miscarriage associated with the procedure ranges from one in 300 to one in 500.

Other risks of amniocentesis testing can be seen as downsides to the procedure. The needle can injure the developing fetus, although this risk is rare as it has become common practice to use ultrasound to guide the needle. Sometimes the cells obtained in the amniocentesis fluid are not representative of the genetic makeup of the developing fetus, and the genetic diagnoses obtained from analyzing these cells could be incorrect. The procedure is also not always successful, meaning that occasionally an insufficient amount of fluid is collected for full analysis.