Vol. 7, Issue 2, Part A (2025)

Background: Abnormally Invasive Placenta (AIP), encompassing placenta accreta, increta, and percreta, results from excessive trophoblastic invasion beyond the decidual barrier. This pathological process is associated with disrupted angiogenesis, elevated vascular endothelial growth factors, and altered immune responses. While multiple biomarkers have been investigated for predicting AIP, their diagnostic accuracy remains controversial. Recent evidence suggests a potential role for thyroid function markers including Thyroid Stimulating Hormone (TSH) and thyroglobulin antibodies (TgAb) in modulating placental invasion and vascular remodeling.
Objective: To investigate the relationship between maternal thyroid function specifically serum levels of TSH and TgAb and the incidence and severity of AIP in pregnant women.
Methods: This prospective case-control study included 105 third-trimester pregnant women at Tikrit Teaching Hospital, Iraq (November 2024 to June 2025). Participants were divided into three equal groups (N=35 each): AIP group (confirmed intraoperatively and histologically), placenta previa totalis (PPT) group without invasion, and healthy controls. Exclusion criteria included thyroid disease, autoimmune disorders, and other confounding obstetric or medical conditions. Thyroid markers (TSH, T₃, T₄, TgAb, TPOAb) were assessed via electrochemiluminescence. Diagnostic accuracy was evaluated using ROC analysis. Obstetric and neonatal outcomes were compared across biomarker levels.
Results: Women with AIP had significantly lower TSH and higher T₄ levels compared to PPT and controls (p<0.05). ROC analysis identified a TSH cutoff of 2.25 mIU/L with 74.29% sensitivity and 70.00% specificity (AUC=0.831, p<0.001) for predicting AIP. Logistic regression showed TSH (OR=0.36, P=0.03) and TgAb (OR=0.68, P=0.04) as significant predictors. Lower TSH and higher TgAb levels were associated with reduced risks of cesarean hysterectomy and massive transfusion. High TSH was linked to adverse neonatal outcomes including preterm birth (62.86%) and NICU admission (51.43%).
Conclusion: Maternal thyroid function-particularly elevated TSH and low TgAb levels is associated with increased risk and severity of AIP and poorer maternal-neonatal outcomes. TSH and TgAb may serve as useful biomarkers in the early identification and risk stratification of AIP in pregnant women. Further large-scale studies are warranted to validate these findings and explore underlying mechanisms.