PB0487 - Early correction of hemostatic disorders improves pregnancy outcomes in women with a bad obstetric history

Background: Women with a bad obstetric history (BOH) often have hemostatic disorders underlying obstetric complications. However, it remains uncertain whether the early prescription of antithrombotic medications beginning in the preconception period would improve pregnancy outcomes for women with a history of previous pregnancy issues.

Aims: To justify the early prescription of enoxaparin and aspirin from the preconception period throughout pregnancy in women with BOH.

Methods: The study was approved by the Ethical Committee of Kazan Federal University with written consent obtained. 115 women with BOH and 33 parous women without past obstetric complications were enrolled. Obstetric complications included early (before 10 weeks) and late (10-22 weeks) miscarriages, as well as premature births at 22-34 weeks of gestation. Antiphospholipid syndrome was excluded, and the groups did not differ in the incidence of congenital thrombophilia. Before and during pregnancy (3-11 times overall), hemostasis was assessed using the thrombodynamics assay, D-dimer, and routine hemostatic tests to control and adjust enoxaparin dosage. Platelet functionality was monitored with the blood clot contraction assay and flow cytometry before and after activation with the TRAP peptide. All patients with BOH received enoxaparin and aspirin according to the schematic shown in the figure.

Results: In the preconception period, patients with BOH had impaired blood clot contraction and reactivity due to platelet dysfunction (exhaustion) associated with chronic background platelet activation caused by hypercoagulability. Throughout pregnancy, hemostatic parameters and platelet function in patients with BOH gradually improved and, beginning in the second trimester, did not differ from those in the control group. Most importantly, the outcomes of current pregnancies were significantly better than those of previous pregnancies (Table).

Conclusion(s): We attribute the much better clinical outcomes to the normalization of hemostasis resulting from the prescription of LMW heparin (enoxaparin) and aspirin in the preconception period and throughout pregnancy.