A retrospective cohort study examined the association between maternal anemia before delivery and the risk of peripartum blood transfusion and other adverse perinatal outcomes. The study included 18,357 patients who delivered live, nonanomalous neonates at ≥23 weeks’ gestation, excluding those with sickle cell disease or on anticoagulation therapy. The findings revealed that 30% of the patients had anemia before delivery, defined by a mean hemoglobin of 10.0 g/dL, while 70% did not, with a mean hemoglobin of 12.3 g/dL. Anemia was strongly associated with a 5-fold increase in the odds of receiving a blood transfusion during delivery. Additionally, each 1 g/dL increase in predelivery hemoglobin was linked to a 56% reduction in transfusion risk. The optimal hemoglobin threshold for predicting transfusion was identified as 10.6 g/dL, with high sensitivity and specificity.

The study also found that while maternal anemia was linked to higher odds of postpartum readmission, it was not associated with a significant increase in other perinatal morbidities after adjusting for covariates. These results suggest that improving predelivery hemoglobin levels, particularly aiming for ≥10.6 g/dL, could potentially reduce the need for peripartum transfusions and improve maternal outcomes.

Reference: Cozzi GD, Blanchard CT, Edwards JT Jr, Szychowski JM, Subramaniam A, Battarbee AN. Optimal predelivery hemoglobin to reduce transfusion and adverse perinatal outcomes. Am J Obstet Gynecol MFM. 2023 Feb;5(2):100810. doi: 10.1016/j.ajogmf.2022.100810. Epub 2022 Nov 12. PMID: 36379441; PMCID: PMC10559786.