Endogenous Creatinine and Blood Urea Nitrogen Clearances in Normal Pregnancy

Endogenous creatinine and BUN clearances were determined during the first trimester (n=11), second trimester (n=17) and the third trimester (n=27) of healthy pregnant women. Both of the clearances increased significantly during the first trimester and sustained a high level till term, relatively decreasing below the first trimester values towards the end pregnancy. The increments observed in the corrected creatinine and corrected BUN clearances were determined to be higher. Being an expected result of these findings, plasma creatinine and BUN levels in pregnant women decreased significantly from their nonpregnant controls.