Aspirin use during pregnancy and hypoxia-related placental pathology

Aspirin has been shown to prevent preeclampsia. But the mechanisms remain unclear despite that improved placental circulation is considered as an underlying contributor. Our aim was to examine the hypoxia-related morphological and histopathological placental measures in relation to aspirin use during pregnancy.

We used the Collaborative Perinatal Project (CPP) data, which is a cohort study conducted in the U.S. from 1959 to 1976. A total of 23, 604 women who had information on placental pathology and aspirin intake during pregnancy were included in the analysis. Among them, 1474 women had a history of hypertension or preeclampsia/eclampsia and were classified as a high-risk population; the rest were considered as a low-risk population. 47 placenta measures considered to be relevant to hypoxia were selected to build a composite hypoxia- related placenta index. The generalized linear mixed model was used to fit the relationship between aspirin and placental pathology.

Hypoxia-related placental pathology.

Aspirin use during pregnancy was associated with a reduced risk of hypoxia-related placental pathology in the high-risk population [the adjusted odds ratio and 95% confidence interval in the 1st, 2nd, and 3rd trimesters: 0.55 (0.31, 1.00), 0.76 (0.49, 1.17), and 0.53 (0.29, 0.94), respectively]. Longer duration of aspirin use in pregnancy tended to have a lower risk of hypoxia-related placental pathologies in the high-risk population.

Aspirin use during pregnancy reduced risks of hypoxia-related placental pathologies in the high-risk women for preeclampsia. The duration of aspirin use determined its effects.