Dai_2017_Ann.Clin.Biochem__4563217738801

AIMS: Physiological changes that occur during pregnancy can influence biochemical parameters. Therefore, using reference intervals based on specimens from non-pregnant women to interpret laboratory results during pregnancy may be inappropriate. This study aimed to establish essential to establish reference intervals for a range of analytes during pregnancy.
METHODS: The cross-sectional study was performed in 13656 healthy pregnant and 2634 non-pregnant women. Fifteen biochemical measurands relating to renal and hepatic function were analyzed using an Olympus AU5400 analyzer (Olympus, Tokyo, Japan). All the laboratory results were checked for outliers using Dixon's test. Reference intervals were established using a non-parametric method.
RESULTS: Alanine aminotransferase, aspartate aminotransferase, albumin, cholinesterase, creatinine, direct bilirubin, gamma-glutamyl transpeptidase, total bilirubin, total bile acid, and total protein showed a decrease during the whole gestational period, while alkaline phosphatase and uric acid increased. Urea nitrogen, beta2-microglobulin, and cystatin-C fell significantly during the first trimestersand then remained relatively stable until third trimester. Reference intervals of all the measurands during normal pregnancy have been established.
CONCLUSIONS: The reference intervals established here can be adopted in other clinical laboratories after appropriate validation. We verified the importance, for some measurands, of partitioning by gestational age when establishing reference intervals during pregnancy.