Does adherence modify low-dose aspirin effects in pregnancy? Post hoc analysis from a multi-centre trial

Authors

• Musaku Mwenechanya, University Teaching Hospital, Zambia
• Abigail Mwapule Tembo, University Teaching Hospital, Zambia
• Elwyn Chomba, University Teaching Hospital, Zambia
• Matthew K Hoffman, Christiana Care Newark, USA
• Shivaprasad S Goudar, KLE Academy of Higher Education and Research, India
• Janet L Moore, Research Triangle Park, USA
• Mrityunjay C Metgud, KLE Academy of Higher Education and Research, India
• Manjunath S Somannavar, KLE Academy of Higher Education and Research, India
• Jean Okitawutshu, Kinshasa School of Public Health, The Congo
• Saleem Jessani, Aga Khan UniversityFollow
• Sarah Saleem, Aga Khan UniversityFollow

Document Type

Article

Department

Community Health Sciences

Abstract

Objective: To evaluate if the effect of low-dose aspirin (LDA) commenced between 6 and 13 weeks of gestational age (GA) on preterm delivery (PTD) is modified by total exposure.
Design: Post hoc analysis of a randomized controlled trial.
Setting: Hospitals in low-resource settings in Africa, Asia and Latin America.
Population: Outcomes were obtained for 11 908/11943 women at 6 0/7 to 13 6/7 weeks' GA randomized.
Methods: Women received prepackaged two-week medication allotments. Adherence was assessed by pill counts every 2 weeks. Estimated relative risk and 95% confidence interval data for each outcome at each GA of treatment initiation weeks were obtained by fitting a Poisson model to each outcome, adjusting for site, treatment arm and GA at treatment initiation.
Main outcomes measures: The primary outcome was PTD. Secondary outcomes included PTD < 34 weeks and perinatal mortality including analysis by region.
Results: The median gestational age at treatment initiation was 10.1 weeks (IQR 8.6, 12.0). 85.5% of the mothers had over 90% adherence to treatment. For each 1 week increase of GA at treatment initiation, the treatment risk ratio did not change for PTD [RR 0.97 (95% CI, 0.93, 1.02)], PTD < 34 weeks [< 0.98 (0.89, 1.07)] or perinatal mortality [1.04 (0.96, 1.12)], with no evidence of effect modification. For each 5% increase in adherence, the treatment risk ratio did not change for PTD [1.01 (0.99, 1.04)], PTD < 34 weeks [< 0.99 (0.95, 1.03)] or perinatal mortality [1.02 (0.98, 1.06)], indicating no meaningful interaction with adherence. There was no effect modification by region.
Conclusions: This analysis shows that the results of PTD, PTD < 34 weeks and perinatal mortality were not dependent on the timing of the initiation or adherence to treatment

Comments

Pagination, volume and issue no are not provided by author/publisher

Publication (Name of Journal)

BJOG : an international journal of obstetrics and gynaecology

DOI

doi: 10.1111/1471-0528.70244

Recommended Citation

Mwenechanya, M., Tembo, A., Chomba, E., Hoffman, M., Goudar, S., Moore, J., Metgud, M., Somannavar, M., Okitawutshu, J., Jessani, S., Saleem, S. (2026). Does adherence modify low-dose aspirin effects in pregnancy? Post hoc analysis from a multi-centre trial. BJOG : an international journal of obstetrics and gynaecology.
Available at: https://ecommons.aku.edu/pakistan_fhs_mc_chs_chs/1299