The July 2018 American College of Obstetricians and Gynecologists' guidelines for aspirin prophylaxis for preeclampsia prevention represent a departure from prior, more stringent guidelines and extend eligibility for aspirin prophylaxis to a large proportion of pregnant women in the United States. However, these latest guidelines are predicated on a complex, risk-factor-based screening algorithm and ignore the reality that, outside of the setting of clinical research, effective implementation of risk-factor-based approaches consistently falls short. Herein we argue for transitioning to universal aspirin prophylaxis for preeclampsia prevention using the concept of libertarian paternalism, knowing that altering the choice architecture from an "opt-in" to an "opt-out" system will greatly increase the number of patients who receive the advantage of this inexpensive, safe, and beneficial preventative intervention.