Relationship between risk factor profile and prescription of low-dose aspirin for preeclampsia prevention

The purpose of this study was to assess obstetrician-gynecologist utilization of low-dose aspirin for women at increased risk for hypertensive disorders of pregnancy using guidelines developed by the American College of Obstetricians and Gynecologists and supported by the United States Preventive Services Task Force. Further, the study evaluated prescribing practices in relation to specific risk factor profiles to identify which women are at highest risk of not receiving recommended therapy.

This was a retrospective cohort study reviewed and approved by the local Institutional Review Board. Electronic health records of women with singleton pregnancies who delivered between February and August 2020 were reviewed to identify risk factors for preeclampsia. Women were eligible for aspirin prophylaxis if they had at least one "high" risk factor or multiple "moderate" risk factors, as defined by the United States Preventive Services Task Force guidelines. Associations of interest were addressed using Pearson Chi-squared tests and multinomial logistic regression.

970 patients were included and 301 pregnant persons (31%) met criteria for low-dose aspirin prophylaxis; of these, 92 (31%) were given this recommendation. Those eligible for prophylaxis by presence of multiple "moderate" risk factors alone are least likely (0-6%) to receive indicated aspirin prophylaxis.

Low-dose aspirin is an underutilized tool for preventing preeclampsia. Women with a combination of "moderate" risk factors are most likely to not receive indicated aspirin prophylaxis. Efforts should be made to encourage broader uptake of the recommendations for aspirin prophylaxis among obstetrician-gynecologists.

What is already known on this subject? Low-dose aspirin has been shown to reduce preeclampsia risk in pregnant persons. This preventive measure has been recommended by most national and international organizations including the American College of Obstetricians and Gynecologists and the United States Preventive Services Task Force. Yet despite widespread support of this recommendation, uptake is not universal among obstetric care providers. What this study adds? This study identifies those who are most likely to experience a missed opportunity for aspirin prophylaxis, thus providing a suggestion for where provider education or other efforts to increase adherence to this guideline may be most impactful.