Prenatal genetic diagnostics
AMC – sampling of amniotic fluid
We perform amniocentesis or sampling of amniotic fluid from the start of the 16th week of pregnancy.
We also perform amniocentesis at later stages of pregnancy, however, most often up to the 24th week of pregnancy due to generally valid legislation for the possibility of terminating a pregnancy.
Amniotic fluid is examined mainly for chromosomal abnormalities. With the QF-PCR examination method the result, most often chromosomal aberrations, including Down Syndrome, is known within 24-48 hours of sampling. The result of a complete chromosomal examination by the microarray method, which is significantly more sensitive than the classic “karyotyping” should be known in approximately 8 to 10 days.
For the sampling we use a very thin needle, through which we take a sample of about 15-30 ml of amniotic fluid through the abdomen wall under continuous ultrasound control (this volume is again refilled within several hours).
Patients indicate periodic pain as with a blood sample or with injection into the rump muscle.
The risk of complication and possible loss of pregnancy during amniocentesis is perhaps 0.5 to 1%.
At CFGD we never do amniocentesis only on the basis of age risk or risk of chromosomal aberration from the triple test (from biochemical screenings).
In the case of not undergoing the first-trimester screening (the combined test) we do not recommend amniocentesis without first undergoing morphological ultrasound explicitly (this process is from the viewpoint of maternal-foetal management highly dangerous and counterproductive for the patient).