Antithrombotic prophylaxis in multiparous women with preeclampsia or intrauterine growth retardation in an antecedent pregnancy.

Objective: To determine whether prophylactic low dose aspirin (LDA) alone or in combination with low-molecular-weight-heparin (LMWH) reduces the recurrence of adverse pregnancy outcome (APO).

Study design: In this retrospective cohort study, 84 consecutive multiparous patients with a previous history of severe preeclampsia (sPE) and intrauterine growth restriction (IUGR) (<10%ile) were assigned to receive no treatment, LDA alone, or LDA and LMWH. Odds ratios were calculated from logistic regression models.

Results: Combined LDA and LMWH significantly reduced the risk of developing IUGR in the index pregnancy (OR = 0.16, 95% CI: 0.03-0.98). Among women with antecedent sPE (n=52), combined treatment reduced APO in the index pregnancy (OR = 0.08, CI: 0.01-0.96), IUGR (OR = 0.02, CI: <0.01-0.46), and IUGR with sPE (OR = 0.08, CI: 0.01-0.96).

Conclusion: Combined treatment with LDA and LMWH is strongly protective against the development of APO in a cohort of women with antecedent APO.