Cell-free fetal DNA is an extension of prenatal testing in a safe and non-invasive method. Prenatal tests are used to find any irregularities in a fetus. The two predominant prenatal tests are chorionic villus sampling (CVS) and amniocentesis, both are invasive and could possess harm to the developing fetus, in some cases it can cause miscarriage. Cell-free fetal DNA is a new alternative of prenatal tests. Fetal DNA is found in mother’s blood stream, cell-free fetal DNA enters into the blood stream through the placenta, placenta is a flattened organ in the uterus where maternal blood and fetal blood. The fetal DNA can be split into very acute fragments, less than 200 base pairs on an average. Maternal DNA fragments are also present in the blood. Fetal DNA is first noticed after 22-25 days of fertilization and its concentrations increase as the time period of pregnancy increases. Diagnostic tests for pregnancy using fetal DNA is possible in seventh week of pregnancy.
