Amniocentesis is an amniocentesis procedure used to examine the fetal (child) cells present in the amniotic fluid. It is offered in the 15th-18th week of pregnancy to detect possible chromosomal abnormalities by chromosomal analysis. Regarding trisomy 21 screening, for example, the test accuracy of amniocentesis is 99-99.95%.Amniocentesis can also be performed at a later time if blood group incompatibility between mother and child is suspected, or to detect infectious agents.
Indications (areas of application)
This test is important for pregnant women with the following risks:
- Age over 35 years
- Previous birth of a child suffering from a genetic defect or metabolic disease
- Hereditary diseases in the family
- Hereditary metabolic diseases
- Congenital infections, i.e. infections acquired during pregnancy.
- Indication of child development disorders or malformations
- Suspicion of blood group incompatibility between mother and child.
- Lung maturity determination in the case of threatened premature birth.
The method
During amniocentesis, the amniotic cavity (amniotic cavity) is punctured with a thin needle (0.7 mm in diameter) under sonographic control (ultrasound) and little amniotic fluid (12-15 ml) is withdrawn through the puncture needle. The amniotic fluid is then examined in the laboratory. The findings are only available after two to three weeks, as the cells from the amniotic fluid have to be cultivated (grown). Other applications of amniocentesis are: Diagnosis of open neural tube defects as well as genetic diagnostics and biochemical diagnostics.
Potential complications
The intervention-related loss rate for amniocentesis is reported to be 0.3-1.5%.
The rate of complications such as abortion (miscarriage) or premature rupture of membranes is 0.4-1%.