Table of contents:
1- What does it consist of?
2- Why is it performed?
3- Preparing for amniocentesis
4- What does it feel like during the test?
5- Risks of amniocentesis
6- Meaning of abnormal results
Amniocentesis or amniotic fluid analysis is a test performed between 15 and 20 weeks of pregnancy to diagnose genetic disorders, birth defects and other pathologies in a fetus.
It is a test that serves to determine if there is any specific health problem, that is, it differs from prenatal screening tests because these do not diagnose, but show if the baby could have any pathology, from which the professional can indicate the need for an amniocentesis.
What does it consist of?
It consists of performing a puncture in the womb to obtain a small amount of amniotic fluid, which is the sac that surrounds and protects the fetus. Subsequently, an analysis of this fluid is performed in order to rule out genetic and chromosomal problems in the baby, such as anencephaly, Down syndrome, spina bifida, Rh incompatibility, infections and rare metabolic disorders that are transmitted from parent to child.
Why is it performed?
Amniocentesis is not a mandatory test. It is usually indicated for women at higher risk of having a child with congenital anomalies, usually because of a family history of genetic disorders or because they are older than 35 years.
This type of analysis can be indicated for different reasons:
– Genetic analysis: a sample of amniotic fluid is taken to detect pathologies such as Down syndrome.
– Fetal lung analysis: seeks to establish whether a baby’s lungs are mature enough for birth.
– Diagnosis of fetal infection.
– DNA analysis: DNA collected during amniocentesis can be compared with the DNA of the potential father.
– Amniocentesis is also performed as a treatment in cases where there is excess amniotic fluid in the uterus.
Amniocentesis is indicated when there is a risk of genetic
risk of genetic abnormalities
Preparation for amniocentesis
The bladder must be full at the time of the ultrasound. Sometimes a blood sample is taken before the test to determine blood type and Rh factor. If the pregnant woman is Rh negative, she may be given an injection of a drug known as Rho immune globulin (D). On the day of the test it is not essential to fast, although it is advisable to have a bowel movement. It is recommended to be accompanied.
What does the test feel like?
It is not a painful test, in fact it is usually performed without anesthesia. The only pain is the prick of the needle. It is advisable to be relaxed to avoid muscle contraction and pain. In some centers, local anesthesia is injected in the area where the puncture is performed.
Risks of amniocentesis
This test may cause cramping in the area, leakage of amniotic fluid or vaginal bleeding. More serious risks such as infection or injury to the baby and miscarriage may occur in less than 1% of cases.
Significance of abnormal results
Abnormal results may indicate that the baby has a genetic or chromosomal problem, such as Down syndrome, or birth defects involving the baby’s spine or brain.
In the case of amniocentesis, which is performed to test the baby’s lung maturity, this test may result in the decision to give birth prematurely or not.