Vitamin K Antagonists for Pregnant Women With Antiphospholipid Antibodies: A Scoping Review

To describe characteristics of published research on the safety and efficacy of vitamin K antagonists (VKA) for pregnant patients with antiphospholipid antibodies (aPL), including their methodological characteristics and knowledge gaps.

This study followed the Joanna Briggs Institute methodology for scoping reviews and used the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews protocol system. Studies were primarily identified through searching electronic databases including MEDLINE, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials. Study characteristics and outcomes were reported and described using customized charting tables.

Of 1528 publications, 17 remained in the final analysis. These reported up to 190 VKA-treated aPL-positive pregnancies diagnosed as antiphospholipid syndrome (APS); pregnancy cases were likely overlapping in some publications. In the 17 reports, there were 723 individuals in comparison groups, including healthy pretreatment pregnancies and women with APS treated with standard therapies without VKA. However, only 4 (23.5%) of the 17 publications stated a study objective focusing on VKA use, of which only one was a full-length article. In addition, information on VKA doses, disease diagnostic criteria, and the long-term outcomes of offspring were largely absent.

The current evidence is insufficient to assess VKA efficacy and safety profiles in aPL-positive pregnant patients. Studies with a defined focus on VKA use in this population are lacking, and reporting of key information is not consistent. The relative lack of knowledge of VKA use in pregnant women with APS is concerning, and efficacy and safety questions remain.