Abstract:
Background: Low dose aspirin (LDA) is an efective strategy to reduce preterm birth. However, LDA might have dif‑
ferential efects globally, based on the etiology of preterm birth. In some regions, malaria in pregnancy could be an
important modifer of LDA on birth outcomes and anemia.
Methods: This is a sub‑study of the ASPIRIN trial, a multi‑national, randomized, placebo controlled trial evaluating
LDA efect on preterm birth. We enrolled a convenience sample of women in the ASPIRIN trial from the Democratic
Republic of Congo (DRC), Kenya and Zambia. We used quantitative polymerase chain reaction to detect malaria. We
calculated crude prevalence proportion ratios (PRs) for LDA by malaria for outcomes, and regression modelling to
evaluate efect measure modifcation. We evaluated hemoglobin in late pregnancy based on malaria infection in early
pregnancy.
Results: One thousand four hundred forty‑six women were analyzed, with a malaria prevalence of 63% in the DRC
site, 38% in the Kenya site, and 6% in the Zambia site. Preterm birth occurred in 83 (LDA) and 90 (placebo) women,
(PR 0.92, 95% CI 0.70, 1.22), without interaction between LDA and malaria (p= 0.75). Perinatal mortality occurred in
41 (LDA) and 43 (placebo) pregnancies, (PR 0.95, 95% CI 0.63, 1.44), with an interaction between malaria and LDA
(p= 0.014). Hemoglobin was similar by malaria and LDA status.
Conclusions: Malaria in early pregnancy did not modify the efects of LDA on preterm birth, but modifed the efect
of LDA on perinatal mortality. This efect measure modifcation deserves continued study as LDA is used in malaria
endemic regions.
