Alpha-Fetoprotein as a Biomarker in Pregnancy: From Genetic Disorders to Obstetric Complications

Alpha-fetoprotein (AFP) is a glycoprotein primarily produced by the fetal liver and yolk sac during development. It is a multifaceted biomarker with significant applications in the prenatal screening of congenital abnormalities, cancer, and other disorders. The level of AFP in maternal blood may indicate several obstetric concerns and complications during pregnancy. Atypical AFP levels are commonly utilized as a biomarker for detecting fetal anomalies, placental complications, and other pregnancy-related issues. These findings raise concerns regarding the effectiveness of screening maternal serum alpha-fetoprotein (MS-AFP) as a primary indicator of pregnancy problems and underscore the need for further investigation into the functional role of AFP throughout pregnancy. The measurement of MS-AFP has been utilized for the past four decades. It is anticipated that MS-AFP measurement will continue to be utilized as a component of integrated or sequential tests for chromosomal abnormalities and may serve as a prognostic indicator for adverse obstetric outcomes. Critically, whether AFP functions solely as a passive marker or plays active biological roles in pregnancy physiology and pathology remains unresolved, necessitating additional mechanistic investigation and discourse. This review consolidates critical data from numerous studies on AFP, focusing specifically on its diagnostic and prognostic applications for congenital abnormalities and problems during pregnancy. This review also identifies key research gaps regarding the functional biology of AFP, particularly whether AFP functions as a passive biomarker or an active participant in the pathophysiology of adverse pregnancy outcomes.