Livrinova, V.; Petrov, I.; Samardziski, I.; Jovanovska, V.; Boshku, A. A.; Todorovska, I.; Dabeski, D.; Shabani, A. Clinical Importance of Low Level of PAPP-A in First Trimester of Pregnancy - An Obstetrical Dilemma in Chromosomally Normal Fetus. Open Access Maced J Med Sci 2019, 7, 1475-1479.