Chorioamnionitis and Postpartum Hemorrhage: Risk Assessment and Management
Yes, chorioamnionitis is a documented risk factor for postpartum hemorrhage, and when present, requires heightened vigilance for hemorrhagic complications and prompt antibiotic therapy to reduce maternal morbidity and mortality.
Evidence for the Association
The relationship between chorioamnionitis and postpartum hemorrhage is well-established in the literature:
Chorioamnionitis directly increases PPH risk through multiple mechanisms including abnormal uterine contractility, impaired response to uterotonics, and systemic inflammatory effects that compromise hemostasis 1.
In the context of previable and periviable preterm prelabor rupture of membranes with expectant management, postpartum hemorrhage occurred in 23.1% of cases with intraamniotic infection, compared to 11.0% with immediate intervention 2.
The Society for Maternal-Fetal Medicine reports that while postpartum hemorrhage rates did not differ significantly in some cohorts (14.9% vs 20%; P=0.56), antepartum hemorrhage or abruption were significantly more common with expectant management in the setting of chorioamnionitis (41.9% vs 19%; P=0.02) 3.
Chorioamnionitis ranks among the documented causes of uterine atony, accounting for 5.2% of atony cases in one audit, making it a direct contributor to the most common cause of PPH 4.
Clinical Presentation and Risk Stratification
When chorioamnionitis is present, assess for these compounding risk factors:
Preterm delivery <32 weeks with chorioamnionitis carries a 3.8-fold increased odds of postpartum infection (95% CI: 1.07-13.7), which itself increases hemorrhage risk 5.
Grand multiparity, prolonged or augmented labor, and instrumental delivery are additional risk factors that frequently coexist with chorioamnionitis and independently increase PPH risk 4.
Epidural use is associated with an 8-fold increased risk of clinical chorioamnionitis (unadjusted OR: 8.3; 95% CI: 2.63-26.40), though this may reflect confounding by labor duration 6.
Management Algorithm for Chorioamnionitis with Hemorrhage Risk
Intrapartum Management
Antibiotic therapy must be initiated immediately when chorioamnionitis is diagnosed, as this is the cornerstone of reducing maternal morbidity including hemorrhagic complications 7, 1.
Administer broad-spectrum intravenous antibiotics intrapartum (typically ampicillin plus gentamicin, with clindamycin or metronidazole added for cesarean delivery) 7.
Active management of third stage of labor is mandatory: administer prophylactic uterotonics immediately after delivery of the anterior shoulder 4.
Perform controlled cord traction and uterine massage to ensure complete placental delivery 4.
Immediate Postpartum Assessment
When hemorrhage occurs in the setting of chorioamnionitis, use this systematic approach:
Assess uterine tone first: A soft, boggy uterus indicates atony (70-80% of PPH cases), requiring immediate bimanual massage and additional uterotonics 8.
If the uterus is firm, systematically inspect for genital tract lacerations under adequate lighting, as trauma becomes the leading cause when atony is excluded 8.
Verify complete placental delivery: Retained placental fragments complicate approximately 1% of deliveries and represent the second most common PPH etiology after atony 8.
Assess for coagulopathy if bleeding persists despite addressing the above: obtain PT/PTT, fibrinogen, and platelet count, as chorioamnionitis can trigger systemic inflammatory responses that impair coagulation 8, 1.
Postpartum Antibiotic Continuation
The decision to continue postpartum antibiotics after vaginal delivery depends on specific risk factors:
For spontaneous vaginal delivery with chorioamnionitis, postpartum infections occur in approximately 1 in 15 women (6.6%) 5.
Delivery before 32 weeks is the strongest predictor requiring extended postpartum antibiotic coverage 5.
Standard practice reserves postpartum antibiotics for high-risk women, though intrapartum coverage should always be completed 5.
Critical Pitfalls to Avoid
Do not assume the uterus is adequately contracted based on initial assessment alone when chorioamnionitis is present, as the inflammatory process impairs myometrial contractility and response to oxytocin 1.
Rapid clinical deterioration is characteristic of chorioamnionitis-related complications: the median time from infection identification to maternal death is only 18 hours in severe cases, demanding aggressive early intervention 3, 2.
Examination under anesthesia should be considered early if adequate inspection of the genital tract cannot be performed, as missed lacerations are a common cause of ongoing hemorrhage with a firm uterus 8.
Special Considerations
Women on therapeutic anticoagulation (e.g., LMWH) have baseline PPH rates of 29.6% after vaginal delivery, and chorioamnionitis compounds this risk substantially 9.
Coagulopathy may be inherited or acute (amniotic fluid embolism, abruption, severe preeclampsia/HELLP), and chorioamnionitis can trigger or worsen these conditions 9.
Maternal morbidity with expectant management of previable PPROM complicated by chorioamnionitis reaches 60%, with infection being the most common complication (38.0%) followed by hemorrhage 2.