Aim: The aim of this study was to determine the levels of cystatin C, creatinine and creatinine clearance in different trimesters of uncomplicated pregnancy in women with normal kidney function.
Subjects and methods: A total of 109 pregnant women were included: group 1 - 38 women (average age 29.63 ± 4.3 y) in the first trimester, Group 2 - 32 women (average age 33.56 ± 5.95 y) in the second trimester and Group 3 - 39 pregnant women (average age 30.1 ± 6.95 y) in the third trimester. Serum cystatin C was determined by the PENIA method (Particle-Enhanced Nephelometric Immuno-Assay), using Behring tests (Behring Diagnostics GmbH, Marburg, Germany). Results were statistically analyzed using the ANOVA.
Results: A statistically significant increase in serum cystatin C level was found in the third trimester of pregnancy (0.69 ± 0.16 mg/l vs. 0.78 ± 0.26 mg/l vs. 1.21 ± 0.30 mg/l).
Conclusion: It appears that cystatin C is not a reliable marker of kidney function in pregnancy and that its increase is connected with a combination of several factors, including endotheliasis, hormonal influence and glomerular filtration rate (GFR) alterations.