Trimester-Specific Patterns of Maternal Serum Alpha-Fetoprotein Among Pregnant Women Attending a Tertiary Hospital in Southeast Nigeria Serum Alpha-Fetoprotein Among Pregnant Women

Abstract

Alpha-fetoprotein (AFP) is a fetal-derived glycoprotein widely utilized in prenatal screening and increasingly recognized as a biomarker of placental integrity and fetal well-being. Despite its established clinical value, locally derived trimester-specific reference data remain limited in Nigeria. This study evaluated maternal serum AFP concentrations across different trimesters among pregnant women attending antenatal care at a tertiary hospital. A hospital-based cross-sectional study design was employed, involving 50 healthy pregnant women and 40 healthy non-pregnant women of reproductive age. Venous blood samples were collected, and serum AFP concentrations were measured using a standard immunoassay method. Gestational trimester was determined clinically using ultrasound scanning, and pregnant women were categorized into first, second, and third trimesters. AFP values were compared using one-way ANOVA with a significance threshold of p < 0.05. Serum AFP levels were markedly higher in pregnant women than in non-pregnant controls across all age categories (p < 0.05), while AFP values in controls remained low and relatively uniform. The concentrations of AFP increased gradually across the trimesters (28.90 ± 5.62 ng/mL in the first trimester, to 98.80 ± 7.31 ng/mL in the second trimester, and rose to 112.60 ± 11.31 ng/mL in the third trimester, (p < 0.05). The AFP levels in this study rose significantly with gestational age and are substantially elevated in pregnancy compared with non-pregnant women. These findings provide baseline trimester-specific AFP data for pregnant women at various trimesters and support the potential use of AFP as a locally interpretable biochemical marker for risk-stratification and screening during antenatal visits.