Low‐Dose Aspirin Therapy and Placental Pathology in Women With Poor Prior Pregnancy Outcomes

PROBLEM: To determine if low dose aspirin therapy improves placental histology in women with a prior complicated pregnancy demonstrating uterine vascular pathology. METHOD: A retrospective chart review identified patients with a prior complicated pregnancy with placental changes showing uterine vascular pathology (control pregnancy, CP). In the treated pregnancy (TP), 81 mg/day of ASA was started prior to 10 weeks. Placental reports from the CP and TP were reviewed. Pregnancy outcomes and placental histology from the CP were compared to the TP for each patient. RESULTS: Thirteen patients were enrolled. The majority of patients (8/13, 61.5%) exhibited recurrent, histologic evidence of uterine vascular pathology in the TP. The TP was more likely to be uncomplicated (P < 0.05), delivered after 36 weeks (P < 0.05), and result in the delivery of a viable infant (P < 0.05) compared to the CP. CONCLUSIONS: Despite an improvement in outcomes in the aspirin treated pregnancy, histologic evidence of uterine vascular pathology persisted in the majority of women with a prior complicated pregnancy demonstrating similar placental lesions. Abnormal placental histology may be useful in identifying a group of women with poor obstetrical histories who could benefit from low‐dose aspirin therapy. 1995 Munksgaard