Risk Factors for Atonic Postpartum Hemorrhage: A Systematic Review and Meta-analysis

Area of Science:

• Obstetrics and Gynecology
• Maternal Health
• Epidemiology

Background:

• Atonic postpartum hemorrhage (PPH) is a significant cause of maternal morbidity and mortality.
• Identifying accurate risk factors for atonic PPH is crucial for effective prevention and management strategies.
• Current risk assessment tools may not encompass all relevant factors.

Purpose of the Study:

• To systematically identify and quantify risk factors associated with atonic postpartum hemorrhage.
• To evaluate the strength of evidence for known and novel risk factors.

Main Methods:

• A comprehensive literature search was conducted across multiple databases (PubMed, CINAHL, EMBASE, Web of Science, ClinicalTrials.gov).
• Included studies were randomized trials, cohort studies, and case-control studies.
• Risk factors were qualitatively synthesized and, where possible, quantitatively analyzed using meta-analysis.

Main Results:

• Out of 1,239 records, 27 studies were included, identifying 47 potential risk factors.
• Fifteen risk factors were classified as definite or likely, including prior PPH, placenta previa, placental abruption, uterine rupture, and multiple gestation.
• Novel risk factors identified include hypertension, diabetes, and ethnicity; obesity and magnesium were not associated with atonic PPH.

Conclusions:

• Established risk factors for atonic PPH were largely confirmed, with prior PPH posing the greatest risk.
• Hypertension, diabetes, and ethnicity represent new considerations for atonic PPH risk assessment.
• A significant proportion of atonic PPH occurs without recognized risk factors, highlighting the need for continued research.