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CME Credit Offered
CME Credit Offered
Abstract Award
Abstract Award
Recording available 2/16-5/2
Recording available 2/16-5/2
AIUM Credit
AIUM Credit
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Foundation Awardee
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Abstract Award
Abstract Award
Foundation Awardee
Foundation Awardee

Poster Session 2

Category: Clinical Obstetrics

Poster Session 2

(500) Low Titer O+ Whole Blood in Massive Transfusion of Obstetric Patients: a Retrospective Cohort Study

Wednesday, February 11, 2026
3:30 PM - 5:00 PM  
Objective:
While whole blood is widely used in trauma, it remains underutilized in obstetrics. We evaluated the impact of low-titer O+ whole blood (LTOWB) in massive transfusion protocols (MTP) for obstetric hemorrhage.

Study Design:
We conducted a retrospective cohort study of obstetric patients who received MTP at a tertiary care center from 2016-2024. Patients who received component therapy (2016–2018) were compared to those who received LTOWB after implementation (2020–2024). Cases from the 2019 transition year were excluded. Primary outcome was transfusion volumes. Secondary outcomes included intensive care unit (ICU) admission, hysterectomy, and severe maternal morbidity. Demographics, transfusion volumes, and clinical outcomes were analyzed using t-test, chi-square analysis, and Fisher’s exact test where appropriate.

Results:
Seventy-three patients received component therapy and 56 received LTOWB. Groups were similar in age, body mass index, parity, and Rh status. LTOWB patients had higher rates of diabetes (28% vs. 11%, p=0.04), placenta accreta spectrum (PAS) (62% vs. 38%, p=0.001), and earlier gestational age at delivery (31.7 vs. 34.8 weeks, p=0.005). LTOWB was associated with a significant reduction in total transfusion volume (10.6 vs. 20.8 units, p=0.036), including fewer units of packed red blood cells (2.8 vs. 11, p=0.001), fresh frozen plasma (1.4 vs. 7.6, p=0.006), and platelets (0.51 vs. 1.4, p=0.09). Despite lower transfusion volume, ICU admission (60% vs. 32%, p=0.001) and hysterectomy (71% vs. 41%, p=0.001) were more frequent in the LTOWB group. DIC was less common with LTOWB (18% vs. 36%, p=0.03). No significant differences were observed in maternal death, thromboembolic events, or lactic acid levels.

Conclusion:

Despite a higher baseline risk in the LTOWB group due to increased PAS prevalence, LTOWB was associated with significantly lower total transfusion volumes. Increased ICU and hysterectomy rates likely reflect underlying severe maternal morbidity. LTOWB represents a more efficient transfusion strategy in obstetric hemorrhage.