What fetal defects can be detected from amniotic fluid?

Amniocentesis is a prenatal test that involves taking a sample of amniotic fluid from the amniotic sac surrounding the developing fetus. This test can detect various fetal defects and chromosomal abnormalities. Some of the fetal defects that can be detected from amniotic fluid include:

1. Neural Tube Defects (NTDs): Amniocentesis can detect NTDs such as spina bifida and anencephaly. These defects occur due to the incomplete closure of the neural tube during fetal development.

2. Chromosomal Abnormalities: Amniocentesis can identify chromosomal abnormalities, such as Down syndrome (Trisomy 21), Trisomy 18, and Trisomy 13. These conditions are caused by the presence of extra or missing chromosomes.

3. Genetic Disorders: Amniocentesis can be used to diagnose specific genetic disorders, such as cystic fibrosis, sickle cell anemia, and Tay-Sachs disease. These disorders are caused by mutations or alterations in specific genes.

4. Fetal Infections: Amniocentesis can detect certain fetal infections, such as cytomegalovirus (CMV), toxoplasmosis, and rubella. These infections can have severe consequences for the developing fetus.

5. Lung Maturity: Amniocentesis can assess fetal lung maturity by measuring the levels of specific compounds, such as lecithin and sphingomyelin, in the amniotic fluid. This information is important when considering preterm delivery.

6. Rh Incompatibility: Amniocentesis can be used to monitor pregnancies where the mother is Rh-negative and the father is Rh-positive. This test can help detect Rh incompatibility, where the fetus is Rh-positive and at risk of developing hemolytic anemia.

It's important to note that amniocentesis is typically performed between 15 and 20 weeks of pregnancy. It is a relatively safe procedure, but it carries a small risk of complications, including leakage of amniotic fluid and infection. Therefore, it is essential to discuss the risks and benefits of amniocentesis with a healthcare provider before making a decision regarding the test.