Assessment of adherence to aspirin for preeclampsia prophylaxis and reasons for nonadherence

Preeclampsia is a hypertensive disease unique to pregnancy and has a significant impact on maternal and neonatal morbidity and mortality. Daily aspirin has been demonstrated to reduce the risk of preeclampsia. The American College of Obstetricians and Gynecologists recommends daily low-dose aspirin, ideally before 16 weeks' gestation, in at-risk patients for preeclampsia risk reduction. This study examined whether patients at-risk for preeclampsia by the American College of Obstetricians and Gynecologists criteria recalled aspirin recommendation and factors associated with treatment adherence.

This study examined whether patients at-risk for preeclampsia by the American College of Obstetricians and Gynecologists criteria recalled aspirin recommendation and factors associated with treatment adherence.

This study used an anonymous written survey. Pregnant patients were asked to record self-reported risk factors and to recall recommendation to take aspirin for preeclampsia prophylaxis. Participants were then determined to be high-, moderate-, or low-risk on the basis of the American College of Obstetricians and Gynecologists guidelines. Self-reported adherence to recommendations and factors contributing to the patients' decisions to take or decline aspirin were assessed. Secondary outcomes included demographic characteristics of adherent patients and patients who did not recall aspirin recommendation.

A total of 544 surveys were distributed and 500 were returned (91.9% response rate). Of the 104 high-risk pregnancies identified, aspirin was recommended in 60 (57.7%; 95% confidence interval, 0.48-0.67). Of the 269 patients with 2 or more moderate-risk factors, aspirin was recommended for 13 (4.8%; 95% confidence interval, 0.03-0.08). Among the participants who recalled aspirin recommendation, adherence was similar between high-risk (81.7%) and moderate-risk (76.9%) groups (P=.69). Patients with chronic hypertension, a history of preeclampsia or gestational hypertension in a previous pregnancy, and pregestational diabetes mellitus were most likely to report receiving aspirin recommendation (78.8%, 76.5%, 63.8%, and 53.3%, respectively). No high-risk factor was associated with a decreased likelihood of adherence. Nonadherent patients rarely discussed their decision with their medical provider (5.9%). In the 42.3% of high-risk participants who did not recall aspirin recommendation, autoimmune disease, multiple gestation, and kidney disease were the most prevalent risk factors (42.9%, 35.7%, and 25.0%, respectively).

In the population studied, many at-risk patients, as defined by the American College of Obstetricians and Gynecologists criteria, did not recall recommendations to take aspirin for preeclampsia prophylaxis. This raises concerns for absent or ineffective counseling. Of the patients who recalled aspirin recommendation, most reported adherence, and a history of hypertensive disorders or preeclampsia, autoimmune disease, and pregestational diabetes mellitus were most often associated with adherence. There was no single factor most strongly associated with intentional nonadherence.