Amniocentesis is known as an exam that can be done during pregnancy, this exam consists in finding problems in the developing baby. We know you might be wondering “is this possible?”, and yes, It is possible to tell from the fluid if the fetus has certain birth defects, such as chromosome abnormalities.
Let us explain, the fluid contains cells from the fetus, which can be grown in a laboratory to be examined and counted after a careful process. The amniocentesis must be performed by a specialist, and it is generally used frequently during the second trimester of pregnancy to diagnose or discard the presence of chromosomal and genetic defects.
How is the amniocentesis performed?
Amniocentesis is a diagnostic technique for withdrawing amniotic fluid from the uterine cavity using a needle via a transabdominal approach, “the specialist will use an ultrasound as a guide to determine a safe location for the needle to enter the amniotic sac. This way the fluid may be safely removed”. The amniotic fluid is the one that contains cells shed by the fetus, that is to say amniotic fluid is the protective liquid contained by the amniotic sac.
Once the procedure is done, the amniotic fluid is sent to the laboratory for analysis, after that, the results may be delivered in a few days or a couple of weeks.
In some cases, amniocentesis is also used later in pregnancy to; diagnosing an infection, check if the baby’s lungs are developed and ready for delivery. In other cases, amniocentesis is used to remove excess amniotic fluid when it is produced excessively and abnormally, which could lead to complications during pregnancy.
It is important to know that amniocentesis is usually performed in cases of a higher than normal chance of birth defects in the fetus. Therefore, there are some less invasive tests like combined structural ultrasound and blood tests that are recommended before amniocentesis. In case of these showing a higher risk of down syndrome or other abnormalities, you can have amniocentesis.
Does amniocentesis have risks?
Like other invasive procedures, amniocentesis has some risks, which include:
– Miscarriage: Some researches suggest that amniocentesis done before 15 weeks of pregnancy carries the risks of miscarriage.
– Infection or infection transmission: This is considered as a rare risk, however, in some cases amniocentesis can develop uterine infection or in case of having hepatitis or toxoplasmosis the infection might be transferred to the body during the procedure.
– Needle injury: This means that maybe during amniocentesis, the baby might move a leg or arm into the path of the needle, however, it is not a big deal.
– Rh sensitization: In case of having Rh negative blood and haven’t developed antibodies to Rh positive blood, you’ll be given an injection of a blood product called Rh immune globulin after amniocentesis. This way you will prevent your body from producing Rh antibodies that can cross the placenta and damage your baby’s red blood cells.
Remember, these risks are generally rare. So it is nothing to worry because the specialist mentions them, however it is important to consult one before the procedure, since there are other procedures that can be done before an amniocentesis.
We thank Dr. Elsa Díaz Lopez, obstetrician-gynecologist, who reviewed and verified this article. She studied Obstetrics-Gynecology at Anahuac University. She has 28 years of medical experience and specializes in Colposcopy, Laparoscopic Surgery, HPV, Vaccination, Sexually Transmitted Infections, Laser Surgery, and Bioethics.