Intermediate
Technical
IVT
quadruple screen
Second-trimester maternal serum screening test measuring four biochemical markers.
Full Definition
A maternal blood test performed between 15-20 weeks of pregnancy that measures four substances: alpha-fetoprotein (AFP), human chorionic gonadotropin (hCG), unconjugated estriol, and inhibin A. These markers are used to calculate risk for Down syndrome, trisomy 18, and neural tube defects. The test is less accurate than newer screening methods but remains widely used, particularly in areas where advanced screening technologies are not available.
Usage
Usage note: Distinguish from triple screen (older test with three markers).
In Context
- "Quadruple screen results indicated elevated risk requiring genetic counseling." — laboratory report
- "The patient declined quadruple screen testing after discussing limitations." — prenatal visit notes
Also known as
quad screen
maternal serum screen
MSS
Don't confuse with
triple screen
first-trimester screening