Evaluation of the protein C global assay during normal pregnancy and after assisted reproduction

Objective: To prospectively compare the Protein C Global assay results in a cohort of infertile women who conceived after assisted reproductive technology (ART) with results from women who conceived spontaneously. Methods: Sixty-four infertile women who conceived after ART and 47 fertile women who conceived spontaneously were prospectively evaluated. All women in the study and control groups had singleton pregnancies. The Protein C Global assay was performed in the two groups on four occasions: during the first, second, and third trimesters, as well as 6 weeks or later after delivery (baseline). Results: Protein C Global assay results declined gradually during pregnancy in both groups. However, basal as well as first-and second-trimester Protein C Global assay results were significantly lower in the infertile group compared with the fertile group, corresponding to 0.89±0.22 and 1.06±0.33 (P=.025), 0.79±0.15 and 0.87±0.19 (P=.036), and 0.73±0.10 0.79±0.13 (P=.012), respectively. Conclusion: These findings support the notion that infertile women conceiving singleton pregnancies after ART are a priori at an increased hypercoagulation state. Protein C Global assay levels decline gradually during pregnancy in women who conceived naturally, as well as in infertile women who conceived after ART treatment.