Prenatal diagnosis

Prenatal diagnosis includes a set of examinations done during pregnancy focused on detecting congenital abnormalities in the fetus.

Its main goal is to get the information about the current stage and development of the fetus and minimize the risk of a disabled child being born. However, even continuously evolving prenatal diagnostic methods can never guarantee the birth of a completely healthy child with 100% certainty.

Based on the way of performing the examinations are divided into non-invasive and invasive (most often is examination of the amniotic fluid – amniocentesis).

The examination combines the determination of biochemical indicators from mother’s blood (hCG and PAPP-A) and an ultrasound measurement of the fetal features (size, width of the nuchal translucency, presence of nasal bone). The test is focused on screening for the most frequent chromosomal and morphological defects of the fetus in the time period from 11th to 14th week.

The test is effective, the detection rate in the fetus (especially Down syndrome) has a 95% success rate. The calculation divides spontaneous conception and in vitro fertilization and is performed using ASTRAIA programme. 

The calculation of the risk of fetal abnormality combines risks determined by age and weight of the mother, levels of substances in blood and features of the fetus based on the ultrasound.

The result is negative if the risk of fetal abnormality is lower than 1:300 (e.g. the result is 1:5000).

A positive result doesn’t mean that the fetus is actually affected, there is just a higher risk of abnormality. In that case it’s appropriate to follow through with another examination after consultation with your doctor to confirm or rule out the disability. It’s important to realize that even in case of negative results it’s still recommended to attend another examination(especially ultrasound in the 2nd trimester) focused on the presence of development defects in the fetus.

The result of the screening in the 1st trimester is available in less than a week and it’s announced to the patient and explained during the consultation with a doctor. Based on the calculated individual risk we propose the following steps.

This examination, despite being highly effective, is considered above standard in the Czech Republic and it’s not covered by public health insurance. The price is 1 500 CZK and most insurance companies offer complete or partial financial compensation after seeing a proof of payment.

It’s a traditional pregnancy screening in the 2nd trimester covered by public health insurance. The examination includes the determination of biochemical parameters from the mother’s blood (hCG, AFP, and E3) in the 16th to 18th week of pregnancy. Based on the current values we can determine the risk of fetal abnormalities – neural tube defects and Down syndrome.

In comparison with the screening from 1. Trimester the triple test has a low possibility of catching the defect in the fetus(up to 70%). The results of TT can be used to specify the calculation of the individual risk gained during the screening in the 1st trimester (e.g. when the result is unclear)

Integrated screening combines the results of the previous tests (in 1st trimester and TT) and has the highest ability to detect abnormalities in the fetus. To state the risk we use a computer programme(ALPHA 8) which uses the results of biochemistry and an ultrasound gained in 1st and 2nd trimester.

The results are available around the 18th week of pregnancy.

Harmony test is a blood test which evaluates the risk of the most frequent trisomies in the fetus (Down syndrome, Edwards syndrome, Patau syndrome) and assesses the chromosomes X and Y (but it doesn’t identify other abnormalities of the fetus).

The testing is based on direct analysis of genetic equipment of the fetus from a standard blood sampling of the mother. It’s performed from the 10th week of pregnancy. It offers safe and reliable screening which makes it an alternative to invasive examinations.

Reliability of the prenatal test Harmony is high (for Down syndrome more than 99%) and the results can be available at the end of the 1st trimester.

It’s an above standard examination which is not paid by insurance companies. The price is 17 000 CZK.

Attending the ultrasound examinations is really important during the entire pregnancy.

You can read more about ultrasound examinations here.

Invasive examination allows definitive confirmation or exclusion of chromosomal abnormalities in the fetus. 

Is performed between 15th to 24th week of pregnancy in patients with high risk of presence of chromosomal abnormalities, is indicated by a doctor especially based on the results of non-invasive examinations.

It’s an outpatient procedure that doesn’t require general anaesthesia or local numbing. Under ultrasound guidance a thin and long needle is inserted through the abdominal wall into the uterus to take a sample of amniotic fluid (approximately 20 ml). The cells of the fetus gained from the amniotic fluid are examined and then the genetic profile is determined. Biochemical or microbiological examination can also be done from the collected amniotic fluid.

Immediately after the procedure the patient is sent home with a required accompaniment. We recommend a restful regime on the day of the procedure and taking a rest from physical activities for the next 14 days.

Complications of this procedure can be the loss of pregnancy (0,5-1% of all cases).

The results are available in about 14 days.