What is an early sex blood test?
Prenatal genetic tests may provide information to would-be parents about the chances of their fetus having genetic abnormalities. There are two main kinds of prenatal genetic testing:
Prenatal screening testing may identify the likelihood of your baby having defects at birth (many among these are genetic abnormalities). These tests are:
- Blood tests
- Prenatal screening for cell-free DNA
- A specific type of ultrasound
Health care providers usually perform a prenatal screening test during the first or second trimester. Screening tests don’t definitively diagnose birth defects — if the results of the test indicate an increased risk of a genetic disorder, additional diagnostic tests may be needed to confirm a diagnosis.
An early sex blood test is a non-invasive prenatal test (NIPT) during which a health care provider takes a blood sample to identify the sex of the fetus. This method analyzes the cell-free fetal DNA present in the blood during early pregnancy.
Cell-free fetal DNA is the small quantity of DNA the placenta releases into the maternal bloodstream during pregnancy. The doctor may screen the cell-free fetal DNA for a wide variety of genetic disorders, including Down syndrome, Edwards syndrome, Patau syndrome, trisomy 13, and problems related to the number of sex chromosomes. An early sex blood test is usually done at the beginning of week 10 of pregnancy. It may take about one week for the results to come back. Your doctor will recommend a diagnostic test such as chorionic villus sampling (CVS) or amniocentesis if your cell-free fetal DNA test comes back positive for a genetic abnormality.