The timing of discontinuation of low-dose aspirin and postpartum hemorrhage risk

Objectives

To evaluate associations of the timing of low-dose aspirin (LDA) discontinuation, with postpartum hemorrhage (PPH) and bleeding-related complications.

Study design

A retrospective cohort study was conducted at a tertiary medical center, of pregnant women who received LDA and delivered beyond 23 weeks of gestation. The women were categorized as having discontinued LDA ≤7 days or >7 days before delivery. Exclusion criteria were: severe fetal malformations, intrauterine fetal death, multiple pregnancy, pre-conceptional use of LDA, and missing data on the timing of LDA discontinuation.

Main outcome measures

The primary outcome was a composite bleeding outcome that included at least one of the following: PPH, blood loss greater than 1000 ml, the need for blood product transfusions, and a drop in hemoglobin of ≥4 g/dL after delivery.

Results

Among 763 women, 192 (25.2 %) discontinued LDA ≤7 days of delivery, while 571 (74.8 %) discontinued >7 days before delivery. Comparing these groups, PPH rates, severe blood loss, and transfusion requirements did not differ significantly, nor did the composite bleeding outcome (9.9 % vs. 8.6 %, p = 0.661). Placental abruption occurred more frequently among women who discontinued LDA ≤7 days compared to >7 days before delivery (5.2 % vs. 1.1 %, p = 0.002). However, in multivariate analysis, the timing of LDA discontinuation was not independently associated with an increased risk of placental abruption.

Conclusion

The timing of LDA discontinuation was not associated with increased PPH or major bleeding complications.