Fetal DNA that is shed from the pregnancy and can be detected in the mother’s blood during pregnancy.
Use in clinical context
Cell-free fetal DNA can be used to test for some genetic conditions affecting the fetus. This method of obtaining fetal DNA is advantageous compared to other methods because it is not invasive to the pregnancy, and so does not increase the risk of miscarriage.
Some of the tests performed using cell-free fetal DNA are diagnostic, for example, they can confirm the presence of a particular variant that results in a condition, such as spinal muscular atrophy. Other tests using cell-free fetal DNA are part of the screening pathway. Diagnostic tests typically look for genetic variants not present in the mother’s genome to identify variants that have come from the fetus. Screening tests can be used to determine whether the fetus has a higher chance of being affected by a particular condition, such as Down syndrome, but further, more invasive, testing is required to confirm the diagnosis.