Ilkovska, B., Trifunova, B. K., Ilkovski, F., Gramatkovski, D., Avramovska, M., Avramovski, P., & Todorovska, L. (2026). Hidden signals in placental biochemistry: PAPP-A MoM as an early indicator of Trisomy 21. Acta Medica Bulgarica, 53(2), 36-43. https://doi.org/10.2478/AMB-2026-0057