Cytogenetic examination of the fetus is a primary examination for prenatal diagnostics for the pregnancies with higher risk of genetic defects. The main goal of prenatal diagnostics is providing the parents with information that enables them to make a conscious choice regarding their parenting.
The benefits of prenatal diagnostics:
- The exclusion of presence of suspicious genetic defect and the stress related to it lasting till the labour
- Enabling the information to the couples that due to the high risk of having sick children with disabilities would not decide to become pregnant
- Enabling the mental preparation for the parents expecting a sick child
- Planning for the labour and care for the sick child
- Giving a full information to couples deciding to terminate the pregnancy
A vast majority of the couples receive a positive result of the examination of the fetus. Only 2 % has to face with the problem of the decision about the future of the fetus with genetic defect.
The amniotic fluid and chorion samples are taken in the event of an irregular results with Ultrasound, biochemical tests and after the age of 35.
A smaller group consists of patients that had given birth to the child with chromosome aberration before or are burdened with family history of genetic diseases.
The cultivation of amniocyte cells and chorion cells after biopsy takes 2-3 weeks. After that it is terminated and prepared into samples suitable for cytogenetic analysis, like with lymphocytes in the peripheral blood.
There is a possibility of receiving the early result by using the FISH method ( diagnostics of trisomy 13,18,21 and sex chromosomes X, Y) or in the case of chorion the analysis of chromosomes after short-term cultivation of 24-48h.
Early results must always be confirmed with the ultimate results given at the end of long cultivation period for amniocytes and chorion.