(1049) Aspirin-triggered lipoxins in high-risk pregnancy: A dose-effect comparison

Aspirin (ASA) appears to alter [lipoxin] in pregnancy when compared with controls. Our objective was to identify [lipoxin] differences in high-risk women based on ASA dose.

Study Design:

This open-label randomized trial recruited participants defined as high risk for pre-eclampsia by the United States Preventative Services Task Force (USPSTF) major criteria. Based on BMI < 30 vs. ≥30 kg/m2, participants were independently randomized to 81mg or 162mg ASA for daily prophylaxis. A separate cohort study recruited low risk participants to serve as controls. Participants were assessed in each trimester. Maternal serum samples were obtained at 11-16 and 28-32 weeks to measure lipoxins (LXA₄) using Lipoxin A₄ ELISA. T-tests, Paired t-tests and ANOVA were utilized where appropriate.

Results:

160 participants were enrolled (56 low-risk; 104 high risk prescribed to ASA prophylaxis). Of the high-risk participants, 47 were assigned to 81mg (n=30-BMI ≥30) and 57 were assigned to 162mg (n=37-BMI ≥30). There was no significant difference in [LXA₄] between ASA dose groups at enrollment (baseline) or third trimester (P=.67 & P=.38, respectively).

The change in LXA₄ over the pregnancy (delta) was significantly different between ASA subgroups based on exposure (P=.02) (Figure 1); however, between 81mg and 162 mg, a significant difference was not observed (P=.63). When comparing change over time in non-obese and obese subpopulations, a greater reduction in LXA₄ was seen in controls versus high-risk patients exposed to ASA (Table 1), which was statistically significant when the dose groups were combined for all exposed (p=0.04 and 0.03, non-obese and obese). While nearly all the participant subgroups had reduced LXA₄ over time, only non-obese participants on 162mg ASA had non-significant increase in [LXA₄] potentially suggesting a dose effect.

Conclusion: While a statistically significant change in [LXA₄] was not observed when comparing 81 mg to 162 mg, our sample size was small. Our subpopulations may demonstrate an ASA dose effect with a larger sample size. BMI appears to influence the potential for this observation.