D-Dimer Assay May Guide LMWH Treatment in Repeated Biochemical Pregnancy Losses in Women with Positive Antiphospholipid Antibody

Abstract

Background: Do D-dimer levels influence the pregnancy outcomes after treatment with low molecular weight heparin (LMWH) in women of recurrent miscarriage (RM), repeated biochemical pregnancy losses (BPL), and a positive test for antiphospholipid antibodies (aPLs)?

Methods: This study was a retrospective chart review of 569 RM patients who were identified as having a history of BPL and a positive aPL. These patients were grouped into three groups according to their treatment plan including those who received low dose aspirin (LDA) alone (group A), LDA plus LMWH after ovulation therapy (group B), and LDA plus LMWH after pregnancy confirmation (group C). We hypothesized that the administration of LMWH after ovulation increased the rates of live birth. D-dimer may predict the pregnancy outcome after treatment.

Results: The live birth rate of group B and group C is significantly higher than group A (86.96% and 66.80% vs. 52.89%, p < 0.0001, respectively). The live birth rate in group A, B, and C with elevated D-dimer is 36.92%, 90.52%, and 61.60% respectively. However, there is no significant difference in live birth rate among those who had normal baseline D-dimer.

Conclusions: These results suggest that LMWH therapy is more effective in improving the live birth rate when given after ovulation than after pregnancy confirmation. The plasma D-dimer assay can possibly guide LMWH treatment appropriately.