Using Placental Pathology to Prevent Recurrent Adverse Pregnancy Outcomes: A Pilot Project

In this clinical trial, participants will undergo consent, blood samples will be collected, and participants will be randomized in a 1:1 ratio to the enoxaparin or control groups at their first study visit. * Participants will return for a study visit within 1 week following randomization. * If assigned to the enoxaparin, the participant will be asked to take a dose of the enoxaparin once a day (40 mg daily) daily from 12 0/7 weeks and/or the start of enrollment (whichever is later) and continue until 36 weeks gestational age, after which enoxaparin will be discontinued. * Participants in the control group will have care as usual, with no additional medications. * During this study, a study team member will collect a blood sample from all participants at 20-24 weeks, 32-34 weeks, and at delivery. * Participants in the enoxaparin group will have their blood work checked a week after starting medication to ensure that they have no unanticipated side effects. Researchers will compare the enoxaparin group to the control group to see if enoxaparin prevents or reduces the occurrence or severity of maternal vascular malperfusion (MVM) among patients with a prior adverse pregnancy outcome.