Women with preeclampsia were found to be at the highest risk for transfusion reactions when receiving a blood transfusion post partum, according to results from a retrospective study.
Additionally, all women who received a transfusion postpartum were twice as likely to experience a procedure-related complication, compared with nonpregnant controls who received identical care.
“The objective of our study was to assess the incidence and risk factors for postpartum [transfusion reactions] in women transfused with red blood cells, plasma, or platelets post partum,” wrote Lars Thurn, PhD, of the Karolinska Institute in Stockholm and colleagues. The findings were reported in Blood Advances.
The researchers conducted a population-based cohort study that included a total of 517,854 women who gave birth in Stockholm County over a period of 21 years. Of those included, 12,183 (2.4%) received a blood transfusion postpartum.
Data was obtained from the Swedish National Birth Registry and was linked to the Stockholm Transfusion Database in order to evaluate the risk of transfusion reactions in pregnant women versus nonpregnant controls.
The researchers identified a total of 96 transfusion reactions postpartum for a prevalence of 79 per 10,000, compared with 40 per 10,000 among nonpregnant controls (odds ratio, 2.0; 95% confidence interval, 1.6-2.5).
The risk of transfusion-related reactions was more than double in pregnant women with preeclampsia versus pregnant women without the condition (OR, 2.1; 95% CI, 1.7-2.6).
“Preeclampsia, induced labor, and preterm delivery were significant risk factors for [transfusion reactions], but we found no differences due to parity, donor gender, or blood group,” the researchers wrote.
The large sample size was a major strength of the study, while a key limitation was the retrospective design.
“Our findings suggest heightened attention be paid when patients with preeclampsia are being evaluated for blood transfusions post partum,” the researchers concluded.
The study was partially funded by Södra Sjukvårdsregionen. The researchers reported having no conflicts of interest.
SOURCE: Thurn L et al. Blood Adv. 2019 Jul 31. doi: 10.1182/bloodadvances.2019000074.