Factors associated with postcesarean blood transfusion: a case control study.

Objective: Cesarean delivery (CD) is a known risk factor for postpartum hemorrhage. However, the characteristics associated with post-CD transfusion are not well-established. We aimed to assess blood transfusion rates and associated factors following CD.

Methods: A retrospective case-control study of women who underwent CD at a university hospital. The study group comprised all women who received blood transfusion following surgery. A control group of women who did not receive postoperative blood transfusion was assigned in a two-to-one ratio.

Results: During study period, the overall post-CD blood transfusion rate was 4.7%. The study group comprised 170 women, and the control group 340. Maternal age (aOR [95% CI]: 1.07 (1.03, 1.11),  = .001), parity (aOR [95% CI]: 1.26 (1.09, 1.47),  = .002), gestational hypertensive disorders (aOR [95% CI]: 4.07 (1.52, 10.91),  = .005), maternal comorbidities (aOR [95% CI]: 4.16 (1.88, 9.1),  < .001), lower predelivery hemoglobin level (aOR [95% CI]: 0.43 (0.34, 0.54),  < .001), and major placental abnormalities (aOR [95% CI]: 2.74 (1.04, 7.18),  = .04) were independently associated with blood transfusion requirement. Intrapartum characteristics associated with blood transfusion requirement included nonelective procedure (aOR [95% CI]: 3.21 (1.72, 5.99),  < .001), prolonged second stage of labor (aOR [95% CI]: 5.50 (2.57, 11.78),  < .001), longer duration of surgery (aOR [95% CI]: 1.03 (1.02, 1.04),  < .001), general anesthesia (aOR [95% CI]: 2.11 (1.14, 3.91),  = .02), and greater estimated operative blood loss (aOR [95% CI]: 5.72 (3.15, 10.36),  < .001).

Conclusions: Among women who underwent CD, we identified 11 factors associated with blood transfusion following surgery. Prospective studies are warranted to assess the implementations of prophylactic interventions to reduce transfusion rates among those deemed at high risk for CD-related bleeding.