Human Chorionic Gonadotropin (hCG) Measured in urine or blood login to view 1 more bullet Produced by login to view 1 more bullet Used to detect pregnancy login to view 1 more bullet Urine Estriol Measured in maternal urine Produced by login to view 3 more bullets Sign of fetal growth login to view 1 more bullet α-Fetoprotein (AFP) Measured in maternal serum ↑ AFP login to view 1 more bullet ↓ AFP login to view 1 more bullet Lecithin/Sphingomyelin (L:S) Ratio Measured in amniotic fluid login to view 2 more bullets L:S ratio > 2 indicates maturity L:S ratio < 2 login to view 4 more bullets First Trimester Screen (10-13 weeks) Serum labs login to view 8 more bullets Imaging login to view 3 more bullets Quadruple Screen (15-22 weeks) Test for aneuploidy login to view 12 more bullets