Calcium Aspirin Preeclampsia Early Prevention and Response (CASPER) Trial in Blantyre, Malawi: A Double-Blinded Cluster Randomized Trial

BACKGROUND: Preeclampsia remains one of the major causes of maternal and neonatal mortality and morbidity, and yet it is uncertain whether aspirin combined with calcium would reduce the burden of preeclampsia in Malawian women, as elsewhere. This study assessed the efficacy of early low-dose aspirin in preventing in women given calcium to prevent preeclampsia/eclampsia in Blantyre, Malawi. METHODS: This was a pragmatic, double-blind, cluster randomized controlled trial conducted in 4 urban health centers and Queen Elizabeth Central Hospital in Blantyre. A total of 306 women at high risk of preeclampsia were assigned to low-dose aspirin (150 mg/day) or placebo from 12 to 16 weeks until 34 weeks of gestation in clusters. All women were given calcium 1 g/day. The intention-to-treat analysis and adherence analysis were conducted with the primary end point of preeclampsia. RESULTS: A total of 39 women were lost to follow-up, and 1 withdrew consent. Data for 266 women were available for analysis. Overall, preeclampsia occurred in 15.8% (42/266) and eclampsia in 2.3% (6/266) of all women. There was no statistically significant difference in the rate of preeclampsia between the low-dose aspirin group 19.3% (26/135) and placebo group (12.2% 16/131; adjusted odds ratio, 1.16 [95% CI, 0.41–3.41]; P =0.781). No statistically significant difference was observed in the secondary maternal and neonatal outcomes. The overall adherence was 69%. CONCLUSIONS: In high-risk women treated with calcium, additional low-dose aspirin resulted in no difference in the rate of preeclampsia, cesarean section rates, or important neonatal outcomes in Malawi.