A pilot study of changes in urinary podocalyxin levels during normal pregnancy and labor.

Introduction: Increased urinary podocalyxin, a surrogate marker of podocyte detachment, has been shown in preeclampsia and eclampsia, but there is a paucity of data of the effect of normal pregnancy on its urinary excretion. We aimed to describe these changes in this pilot study. Methods: Urine podocalyxin levels were measured in 115 pregnant women. Of these, 12 women were in the second trimester of gestation, 57 in the third trimester and 46 women were in labor. Results: The median [IQR] urinary podocalyxin levels were 0.81 [0.27, 3.68], 0.92 [0.44, 5.49] and 64.7 [30.5, 106.3] ng/mg creatinine in the second trimester, third trimester, and during labor, respectively (p<0.0001). Patients with hematuria during labor had higher levels of urinary podocalyxin (128.6 [79.8, 169.6] ng/mg creatinine. There was a moderate correlation between gestational age and urinary podocalyxin levels (r=0.63, p<0.0001). Conclusion: Urinary podocalyxin levels were low in normal pregnancies and increased significantly during labor and with hematuria.