Amniocentesis
Invasive prenatal diagnostic testing
Invasive prenatal diagnostic testing includes methods used to perform fetal chromosome analysis. Such an analysis proves or excludes chromosomal anomalies, congenital metabolic disorders and hereditary conditions linked to the X-chromosome.
Congenital anomalies occur in 3-5% of all newborns, and arise as a result of chromosomal abnormalities, complications during pregnancy (intrauterine infection) or for unknown reasons. Invasive prenatal procedures (amniocentesis and chorionic villus sampling - CVS) are the only way to reliably confirm or exclude the diagnosis of Down syndrome or some other chromosomal abnormality.
Quick preliminary results in 24 hours
Amniocentesis is a prenatal test that takes amniotic fluid from the uterus, which is performed from week 15 of pregnancy by inserting a thin needle through the abdominal wall using the ultrasound image. Amniotic fluid samples have the same karyotype (number, shape and size of chromosomes) as fetuses, which allows detailed analysis of the chromosomal status of the fetus. However, every invasive testing procedure carries the risk of miscarriage, regardless of whether the fetus is healthy or sick, and with amniocentesis the risk is between 0.5 and 1%.
When do we offer an invasive procedure?
- If there is a high risk after NIPT testing (NIFTY, Panorama, Qualified, myPrenatal)
- If there is a risk higher than 1:250 based on the result of a combined screening test
- In case of chromosomal condition in medical or family history
- If previously children were born with multiple malformations
- In case of unusual ultrasound findings
- In case of psychological factors
The decision on invasive diagnostics is exclusively personal. It is made by the parents after non-invasive screening methods and genetic counseling have been carried out.
Invasive procedures are performed by an experienced doctor using the ultrasound image, and after the procedure, the patient rests for several hours in the hospital suite.
Chromosome analyses are performed by a geneticist in the cytogenetic laboratory of the cooperating institution.
After amniocentesis, a small amount of the amniotic fluid is sent to a specialized laboratory for PCR molecular analysis. After 24-48 hours, we get a result that reliably confirms or excludes the 7 most common chromosomal errors: trisomy 21, 13, 18, 45 X0, 47 XXY, 47 XXX. The final result of the karyogram, which requires a cell culture, is obtained after 2 weeks. Depending on the result of the karyogram, we provide parents with genetic counseling and help and support in making further decisions.
