Objective Evaluate the feasibility and acceptability of routine aspirin in low-risk women, compared with screening-test indicated aspirin for the prevention of pre-eclampsia and fetal growth restriction.
Design Multicentre open-label feasibility randomised controlled trial.
Setting Two tertiary maternity hospitals in Dublin, Ireland.
Participants 546 low-risk nulliparous women completed the study.
Interventions Women underwent computerised randomisation to: Group 1—routine aspirin 75 mg from 11 until 36 weeks; Group 2—no aspirin and; Group 3—aspirin based on the Fetal Medicine Foundation screening test.
Primary and secondary outcome measures (1) Proportion agreeing to participate; (2) compliance with protocol; (3) proportion where first trimester uterine artery Doppler was obtainable and; (4) time taken to issue a screening result. Secondary outcomes included rates of pre-eclampsia and small-for-gestational-age fetuses.
Results 546 were included in the routine aspirin (n=179), no aspirin (n=183) and screen and treat (n=184) groups. 546 of 1054 were approached (51.8%) and enrolled. Average aspirin adherence was 90%. The uterine artery Doppler was obtained in 98.4% (181/184) and the average time to obtain a screening result was 7.6 (0–26) days. Of those taking aspirin, vaginal spotting was greater; n=29 (15.1%), non-aspirin n=28 (7.9%), OR 2.1 (95% CI 1.2 to 3.6). Postpartum haemorrhage >500 mL was also greater; aspirin n=26 (13.5%), no aspirin n=20 (5.6%), OR 2.6 (95% CI 1.4 to 4.8).
Conclusion Low-risk nulliparous women are open to taking aspirin in pregnancy and had high levels of adherence. Aspirin use was associated with greater rates of vaginal bleeding. An appropriately powered randomised controlled trial is now required to address the efficacy and safety of universal low-dose aspirin in low-risk pregnancy compared with a screening approach.
Trial registration number ISRCTN (15191778); Post-results.
- low risk
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Contributors Conceived and designed the experiments: FM, CM, PMP, FB, PDo, DMC, MC, AS, FC, JM, SD, JH, AC, ECT, PDi, ZA, FDM, FMA. Performed the experiments: FM, CM, FC. Analysed the data: FM, PD, ZA, FMA. Contributed reagents/materials/analysis/tools: PMP, FB, PDo, DMC, MC, AS, JM, SD, JH, AC, AH, ECT, PDi, ZA, FDM, FMA. Wrote the paper: FM, CM, PMP, FB, PDo, DMC, MC, AS, FC, JM, SD, JH, AC, AH, ECT, PDi, ZA, FDM, FMA. All coauthors approved changes to the manuscript following reviewer comments.
Funding This work was supported by Perinatal Ireland HRB and HRB Mother and Baby Clinical Trials Network.
Competing interests None declared.
Patient consent Not required.
Ethics approval National Maternity Hospital Central Ethics Committee.
Provenance and peer review Not commissioned; externally peer reviewed.
Data sharing statement Dataset available from corresponding author on request.
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