Risk factors for peripartum blood transfusion in South Africa: a case-control study

Obstetric hemorrhage (OH) and access to peripartum blood transfusion remains a global health challenge. The rates of peripartum transfusion in South Africa exceed those in high-income countries despite comparable rates of OH. We sought to evaluate factors associated with peripartum transfusion.

A case-control study was conducted at four large South African hospitals. Transfused peripartum women (cases) and nontransfused controls were stratum matched 1:2 by hospital and delivery date. Data on obstetric, transfusion, and human immunodeficiency virus (HIV) history were abstracted from medical records. Blood was obtained for laboratory evaluation. We calculated unadjusted and adjusted odds ratios (ORs) for transfusion using logistic regression.

A total of 1200 transfused cases and 2434 controls were evaluated. Antepartum hemorrhage (OR, 197.95; 95% confidence interval [CI], 104.27-375.78), hemorrhage with vaginal delivery (OR, 136.46; 95% CI, 75.87-245.18), prenatal anemia (OR, 22.76; 95% CI, 12.34-41.93 for prenatal hemoglobin level < 7 g/dL), and failed access to prenatal care (OR, 6.71; 95% CI, 4.32-10.42) were the major risk factors for transfusion. Platelet (PLT) count (ORs, 4.10, 2.66, and 1.77 for ≤50 × 10⁹ , 51 × 10⁹ -100 × 10⁹ , and 101 × 10⁹ -150 × 10⁹ cells/L, respectively), HIV infection (OR, 1.29; 95% CI, 1.02-1.62), and admitting hospital (twofold variation) were also associated with transfusion. Mode of delivery, race, age category, gravidity, parity, gestational age, and birthweight were not independently associated with transfusion.

Major risk factors of peripartum transfusion in South Africa, namely, prenatal anemia and access to prenatal care, may be amenable to intervention. HIV infection and moderately low PLT count are novel risk factors that merit further investigation.