Center for Medical Genetics Ltd – Specialized Center for Prenatal Diagnosis
Karel Čutka, MD, David Čutka, MD, Novohradská 68/1806, České Budějovice

Chromosomal (cytogenetic) testing of amniotic fluid

Retrieved amniotic fluid is examined in our cytogenetic laboratory. After centrifugation fetal cells are put in two cultivation containers with nutrient solutions at human body temperature of 37 degrees Celsius.

Usually after 12 - 16 days newly grown tissue cultures are processed and microscopical preparations are provided. After they are 1000-times magnified they enable us to determine a human karyotype – the number of human chromosomes. The result is obtained from two independent tissue cultures.

At present we offer patients with a higher genetic risk a quicker result – the result for testing of the most common chromosomal anomalies is available in 2-3 days (testing of chromosomes 13,18,21,X,Y using the QF PCR or FISH method).

The normal number of human chromosomes is 46, XX in a female and 46, XY in a male. An aberration of a number of the whole or a part of a chromosome, which is made of hereditary DNA material, is always linked to multiple defects and mental retardation. In such case it is possible to terminate pregnancy up to 24 weeks gestation for genetic reasons.

The vast majority of patients have a normal result so we can recommend continuation of their pregnancy.