Reference intervals for serum cystatin C in the second and third trimester of Thai pregnant women

Abstract

Background: Cystatin C is a specific protein which is used to evaluate renal function. Few obstetrics conditions involve in its high level during pregnancy. Objective: To determine reference values for serum cystatin C in the second and third trimester of pregnancy. Materials and Methods: The Thai singleton uncomplicated pregnant women who had antenatal care at HRH Maha Chakri Sirindhorn Medical Center during August 2016 to July 2017 were included. The participants were allocated in two groups by their gestational age. Demographic data, antenatal care, and obstetrics outcomes were collected. Venous blood was collected additionally from routine antenatal blood test. The frozen-thawed serum was measured for cystatin C by particle-enhanced turbidimetric immunoassay (PETIA) with ARCHITECT c Systems® automate machine (ABBOTT, Germany). Results: A total of 132 pregnant women were eligible for the study. The reference intervals for serum cystatin C in second and third trimester of normal individual pregnant women were 0.41 to 0.94 mg/L and 0.43 to 1.33 mg/L respectively. The mean and standard deviation of serum cystatin C in second and third trimester were 0.62+0.13 mg/L and 0.80+0.18 mg/L respectively. There was no significant correlation between serum cystatin C and creatinine level (r = 0.04, p-value = 0.61). Conclusion: The reference value of serum cystatin C in the second and third trimester was established for Thai pregnant women. © JOURNAL OF THE MEDICAL ASSOCIATION OF THAILAND| 2019.