In Downs syndrome, 2nd trimester quadruple test includes all EXCEPT:
PAPP REF: Fernando arias 3rd e p. 44-45 The triple test measures the following three levels in the maternal serum: Alpha-fetoprotein (AFP) Human chorionic gonadotropin (hCG) Unconjugated estriol (UE3) The levels may indicate increased risk for ceain conditions: AFP UE3 hCG Associated conditions low low high Down Syndrome low low low trisomy 18 (Edward's syndrome) high n/a n/a neural tube defects like spina bifida associated with increased levels of acetylcholinesterase in aminonic fluid, or omphalocele, or gastroschisis, or multiple gestation like twins or triplets Fuhermore, the triple test may be combined with an ultrasound measurement of nuchal translucency. The Triple test measures serum levels of AFP, estriol, and beta-hCG, with a 70% sensitivity and 5% false-positive rate. It is complemented in some regions of the United States, as the Quad test (adding inhibin A to the panel, resulting in 81% sensitivity and 5% false-positive rate for detecting Down syndrome) Down's syndrome 1st trimester 2nd trimester Screening test Nuchal translucency + beta HCG + PAPP i.e combined test * Triple test (HCG + AFP +UE3) * Quadruple test ( triple test + inhibin A) Diagnostic test CVS Amniocentesis
Alpha fetoprotein
HCG
Inhibin A
PAPP