Trimester-specific reference intervals for cystatin C and neutrophil gelatinase-associated lipocalin during pregnancy.

Background: During normal pregnancy, the glomerular filtration rate (GFR) increases dramatically. Failure to obtain this physiological increase is an important risk factor for morbidity and mortality for both mother and child. The estimated GFR (eGFR) using serum creatinine levels is unsuitable for accurate measurement of renal function during pregnancy.