Low‐dose‐aspirin usage among women with an increased preeclampsia risk: A prospective cohort study

INTRODUCTION: Low‐dose aspirin (LDA) prophylaxis has been shown to reduce women’s preeclampsia risk. Evidence regarding LDA adherence rates of pregnant women is based almost exclusively on clinical trials, giving a potentially biased picture. Moreover, these studies do not report on determinants of adherence. Since 2017, obstetric healthcare professionals in a Dutch region have assessed women’s preeclampsia risk by means of a prediction tool and counseled those with an above‐population average risk on LDA as a prophylactic measure. MATERIAL AND METHODS: From 2017 to 2018, 865 women were recruited in multiple centers and prospectively followed using web‐based surveys (Expect Study II). Rates and determinants of LDA usage among women with an increased preeclampsia risk in daily practice were assessed. Results were compared with findings in a similar cohort from a care‐as‐usual setting lacking risk‐based counseling (Expect Study I, n = 2614). Netherlands Trial Register NTR4143. RESULTS: In total, 306 women had a predicted increased preeclampsia risk. LDA usage was higher for women receiving risk‐based care than care‐as‐usual (29.4% vs 1.5%, odds ratio 19.1, 95% confidence interval 11.2‐32.5). Daily LDA usage was positively correlated with both predicted risk and women’s concerns regarding preeclampsia. Most reported reasons for non‐ or incomplete use were unawareness of LDA as a preventive intervention, concerns about potential adverse effects and doubts regarding the benefits. CONCLUSIONS: Risk‐based counseling was associated with a higher prevalence of LDA usage, but general usage rates were low. Future research regarding potential factors improving the usage of LDA during pregnancy is necessary.