As clinicians include an immunologic evaluation in their assessment of recurrent fetal loss among otherwise asymptomatic women, the diagnosis of PAPS will be uncovered with greater frequency. Our understanding of the underlying pathophysiology of PAPS is critical if we are to propose safe and rational therapies for these patients. It appears as though prostaglandin metabolites are implicated directly in the processes that culminate in this unique, localized vasculopathy; and research is actively progressing with this focus in mind. For the present, we should look critically at the available treatments to be sure that the rationale for use is consistent with current evidence and that the margin of fetal and maternal safety justifies their use. To date, only low-dose aspirin appears to alter prostaglandin metabolites favorably and is thus, emerging as our safest and most efficacious treatment.