A prenatal screening test that is typically performed between weeks 15 and 20 during pregnancy. It is done to measure the levels of four separate substances in the mother’s blood.
These substances include:
- Human chorionic gonadotropin
- Inhibin A
These substances are either hormones made by the placenta or the baby’s liver.
Results of the quad screen indicate a mother’s risk of carrying a baby with developmental or chromosomal conditions.