The following is a summary of “Low-dose aspirin for the prevention of superimposed preeclampsia in women with chronic hypertension: a systematic review and meta-analysis,” published in the APRIL 2023 issue of Obstetrics and Gynecology by Richards, et al.

For a systematic review and meta-analysis, researchers sought to assess the effect of low-dose aspirin use during pregnancy in women with chronic hypertension on the odds of superimposed preeclampsia and perinatal outcomes.

A comprehensive search was conducted in September 2021 across Embase, MEDLINE, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, and the EU Clinical Trials Register. No restrictions were applied to language or time. Included studies were cohort, case-control, and randomized controlled trials reporting on pregnant women with chronic hypertension and singleton pregnancy. The studies compared the use of low-dose aspirin during pregnancy with a control group. The risk of bias was evaluated using the RoB 2 and ROBINS-I tools.

Meta-analysis was performed using a random-effects model, calculating odds ratios with corresponding 95% CI and prediction intervals. The quality of evidence was assessed using the GRADE approach. Heterogeneity was explored based on study methodology, aspirin initiation timing, and the preterm preeclampsia outcome.

A total of 9 studies (3 retrospective cohort studies and 6 randomized trials) involving 2,150 women with chronic hypertension were included. The meta-analysis indicated that low-dose aspirin did not significantly reduce the odds of superimposed preeclampsia in both randomized controlled trials (odds ratio: 0.83; 95% CI: 0.55-1.25; prediction interval: 0.27-2.56; low-quality evidence) and observational studies (odds ratio: 1.21; 95% CI: 0.78-1.87; prediction interval: 0.07-20.80; very low-quality evidence). There was no significant reduction in the odds of preterm preeclampsia with low-dose aspirin (odds ratio: 1.17; 95% CI: 0.74-1.86), and the timing of aspirin initiation did not have a significant impact. Low-dose aspirin did not significantly affect the rates of small-for-gestational-age neonates or perinatal mortality. However, there was a significant reduction in the odds of preterm birth (odds ratio: 0.63; 95% CI: 0.45-0.89; moderate-quality evidence). The quality of evidence was limited due to heterogeneity and the potential risk of bias.

The meta-analysis found no significant change in the odds of superimposed preeclampsia, small-for-gestational-age infants, or perinatal mortality using low-dose aspirin in women with chronic hypertension. However, there was a significant reduction in the odds of preterm birth, which supports the continued use of aspirin prophylaxis in the population.

Source: ajog.org/article/S0002-9378(22)00803-1/fulltext