Maternal Serum Alpha-fetoprotein: A Predictive Biomarker of Preterm Delivery

and its outcomes.Among these, maternal serum alpha-fetoprotein (MSAFP) has emerged as one of the most essential and validated second-trimester biomarkers.Alpha-fetoprotein (AFP), a 591 amino acid glycoprotein, serves as a transport protein.9 AFP is first detectable around the gestational age of 10 weeks with a concentration as low as 5 µg/L.Levels rise by about 15% per week, peaking around 180 µg/L near 25 weeks.After birth, MSAFP rapidly decreases to <2 µg/L.10 It is the most abundant plasma protein in the human fetus and is considered by some researchers to be a fetal analog of serum IntroductIonGlobally, preterm delivery is a significant contributor to perinatal morbidity and mortality, 1-3 approximately 70% leading to neonatal deaths, and about half of them suffer from long-term neurocognitive/neurofunctional impairments.1,2 Preterm is defined as the birth of a baby before 37 completed weeks of pregnancy, compared to the normal term of around 40 weeks.Since birth weight is often easier to assess than gestation, the World Health Organization also tracks the incidence of low-birth weight (<2500 gm), approximately one third of which results from preterm delivery.Early neonatal mortality rate (within the first 7 days of life), unrelated to congenital malformations, approximately 28% is attributable to preterm birth.4 The global incidence of preterm births has risen steadily from the 1990s to the 2010s.5 The chances of neonatal survival improve with gestational age.At 22 weeks, it is around 6%; at 23 weeks rises to 26%; at 24 weeks, approximately 55%; and at 25 weeks, it significantly increases to 72%. 6 However, even among survivors, chronic sequelae such as developmental delay, cerebral palsy, hearing, or visual impairments are common.These complications often persist into later life, imposing substantial physical, psychological, and socioeconomic burdens on affected families and healthcare systems.7,8 Screening for preterm birth during pregnancy involves assessing women using specific clinical and biochemical markers to recognize women who are at higher risk of preterm delivery.Early identification enables timely interventions to minimize complications for both mother and fetus.Several biochemical markers, present in amniotic fluid, fetal circulation, and maternal serum, have been studied for their association with preterm labor