Fetal Cell DNA Analyses (cfDNA =hdDNA)
Routine screening tests in pregnant women; These are the first and second trimester screening tests performed considering hormonal blood tests and USG data. In these tests, amniocentesis is the most frequently used method for determining whether there are chromosomal abnormalities in the babies of high-risk mothers. In this process, a sample is taken from the amniotic fluid the baby is in. In this example, baby cells are reproduced in culture medium and analyzed for possible numerical and structural disorders in chromosomes. Amniocentesis is an interventional procedure. Just like amniocentesis, chorionic villus biopsy (CVS) and cordocentesis are interventional and carry a low risk of certain rates. In order to eliminate this risk, it has become necessary to develop non-invasive alternative diagnostic tests in risky pregnancies. This requirement led to the application of free fetal DNA tests.
What is the Free Fetal DNA test?
Some of the baby's cells circulate throughout the pregnancy in the blood of the expectant mother. "Fetal DNA", which is the genetic material of the baby, can be separated from the cells with certain technologies and its relative amount can be analyzed. DNA analyzed in this state is called "free fetal DNA".
Free fetal DNA tests can be a guide for detecting aneuploidy conditions characterized by the presence of abnormal number of chromosomes in cells. However, it should be noted that this test is not a definitive diagnostic test. Rather, it should be considered as a highly reliable screening test.
Who Should get Free Fetal DNA test?
Taking free fetal DNA tests is optional, it may be an option for families who do not want to risk the loss of the baby due to the amniocentesis procedure. Free fetal DNA analysis can be done in both single and twin pregnancies. As it is expensive and new, it is now available to expectant mothers as an alternative to amniocentesis rather than a diagnostic test.
Candidate mothers recommended by the U.S. Obstetric and Gynecology Association to conduct this test:
- Being 35 years or older at the time of birth
- Increased risk of aneuploidy detected by fetal USG
- Having a baby with trisomy before
- Increased risk for aneuploidy in standard screening tests
How and when Free Fetal DNA test can be done?
The test can be done after the 10th week of pregnancy by taking blood from the expectant mother.
When I can Get the Results?
The free fetal DNA ratio adequacy is usually reported to the patient within 3 days, and in case of sufficient rate, the study can be started and the result can be achieved within two weeks.