Protein S Deficiency and Retinal Arteriolar Occlusion in Pregnancy

Abstract

Purpose

To report two cases of retinal arteriolar occlusion in pregnant women with transient protein S (PS) deficiency.

Methods

Observational case reports.

Results

Two pregnant women in their 30s presented with a paracentral scotoma in their right and left eye, respectively. In both cases the only risk factor for vascular occlusion was pregnancy. Systemic diseases were excluded. Free and functional PS activity was physiologically reduced in both patients. In Case 1, free PS was 47% and functional PS was 22%. In Case 2, free PS was 43% and functional PS was 25%. These levels of PS seem to be lower than those published for normal pregnancy.

Conclusions

There might be a special relationship between PS deficiency and the development of arterial occlusion in pregnant women. A direct effect may be possible. Although the prevalence and incidence of vasoocclusive disease in these patients are low, PS deficiency should be considered as another risk factor. Further studies are necessary to evaluate changes in PS and to assess its relationship with thromboembolic events during pregnancy.