The purpose of this study is to find out the diagnostic significance of serum bile acid on total parenteral nutrition induced cholestasis in premature infants.

Infants without cholestasis were classified into postnatal days and each change of serum bile acid was measured and analyzed. Also, the serum direct bilirubin, serum bile acid, γ-glutamic acid transferase, and alkaline phosphatase of premature infants with total parenteral nutrition induced cholestasis were measured for comparison and analysis of their correlation.

Changes of serum bile acid analysis after birth showed no significant difference between boys and girls, between premature infants and term infants without cholestasis. Serum bile acid levels are constant after two weeks after birth in neonates without cholestasis. In premature infants with total parenteral nutrition induced cholestasis, the increase of serum direct bilirubin over 2 mg/dL was 34.9±18.3 days after birth, and the increase of serum bile acid was 28.1±18.3 days. Its increase was about 1 week faster than serum direct bilirubin, however, there was no statistical significance( P =0.114). Comparing analysis of serum bile acid, γ-glutamic acid transferase, and alkaline phosphatase, serum bile acid showed the highest correlation to serum direct bilirubin(r=0.487, P =0.000).

Serum bile acid is an important parameter of total parenteral nutrition induced cholestasis in premature infants and will be useful for early diagnosis and treatment.