Second Trimester Biochemical Markers (HCG and AFP) for Evaluation of Pathological Placentation

into the uterine wall, or both. It encompasses conditions such as placenta accreta (PA) and placenta previa (PP), which are associated with significant maternal and neonatal morbidity. Aim: This study aimed to assess the association between second-trimester levels of serum human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP), measured between 24 and 30+6 weeks of gestation, and the prediction of pathological placentation. Patients and Methods: This prospective case-control study was conducted in Tikrit City from 1st of December 2023, to 1st of september 2024. Ninety pregnant women with singleton gestations who delivered at Tikrit Teaching Hospital and had complete documentation of second-trimester serum screening results were included. Participants underwent maternal serum biochemical screening between the 24 and 30+6 weeks of gestation. The study cohort was divided into two groups: women with pathological placentation (n=60: PA=30, PP=30) and a control group with normal placentation (n=30), matched for gestational age, parity, and history of cesarean sections. Exclusion criteria included multiple gestations, incomplete data, fetal anomalies, and maternal comorbidities. Maternal serum levels of AFP and hCG were measured using time-resolved fluorescence immunoassay. Results: Women with pathological placentation were older (mean age 35.2±5.6 years) compared to the control group (31.7±4.9 years, p = 0.007). Differences were observed in the indications for cesarean delivery, with higher incidences of placenta previa (41.67% vs. 3.33%, p = 0.005) and low-lying placenta (5% vs. 0%, p = 0.041) in the pathological group, while prolonged second-stage labor was more common in the control group (0% vs. 16.67%, p = 0.015). Women with pathological placentation had higher rates of hysterectomy (5% vs. 0%, p = 0.004), blood transfusions (28.33% vs. 3.33%, p