Ascending infection is the leading cause of antepartum hemorrhage: A case-control study

Placental abruption is a significant obstetric complication characterized by the premature separation of the placenta from the uterine wall, affecting 2-3 per 100 pregnancies. This condition presents a dual diagnostic challenge: obstetricians rely on clinical signs such as antepartum hemorrhage, abdominal pain, and ultrasound findings to suspect abruption, often leading to emergency cesarean delivery. Conversely, pathologists diagnose abruption through macroscopic and microscopic examination of placental tissue, identifying hematomas and signs of maternal vascular malperfusion. Notably, there is often a poor correlation between clinical diagnosis and pathological findings, with sensitivity reported as low as 30.2%. This study seeks to elucidate placental conditions associated with antepartum hemorrhage that may indicate abruption and emphasizes the importance of histopathological referral in understanding recurrence risks in subsequent pregnancies. By enhancing diagnostic accuracy, we aim to improve clinical outcomes for affected patients. Our objective is to evaluate placental conditions associated with antepartum hemorrhage and assess the correlation between clinical diagnoses and histopathological findings.

A retrospective analysis of 285 placental histopathology reports from Sheffield Children NHS FT (January-December 2021) was conducted. This included 181 cases with clinical diagnoses of antepartum hemorrhage/abruption and 104 controls with well-controlled gestational diabetes mellitus. Histopathological findings were compared between groups.

Significant placental findings associated with clinical antepartum hemorrhage/abruption included adherent blood clots (OR = 3.89, 95% CI: 1.88-8.04), umbilical cord hypercoiling (OR = 0.56, 95% CI: 0.33-0.96), and ascending infection/chorioamnionitis (OR = 3.08, 95% CI: 1.38-6.91). Histological abruption and chorioamnionitis were independently associated with antepartum hemorrhage (OR = 3.15, 95% CI: 1.21-9.87 and 3.13, 95% CI: 1.42-7.65 respectively), but there was no significant association with maternal vascular malperfusion (OR = 1.46, 95% CI: 0.65-3.30). Gestational age was lower in the antepartum hemorrhage group (33 weeks) versus controls (39 weeks).

The most frequent placental conditions presenting as antepartum hemorrhage are ascending infection (leading to acute deciduitis) and histological abruption, suggesting a multifactorial spectrum. This is most relevant to the clinical implications involved, such as outcome and recurrence risk.