OBJECTIVE Hypothyroid can aggravate bile stasis due to delayed biliary flow towards duodenum. Examining thyroid function in cholestasis infant hasn’t routinely done yet. The objective of this study as to evaluate risk factors of central hypothyroid in infants with cholestasis 
METHOD This case-control study involved infants with cholestasis (direct bilirubin more than 20% of the total bilirubin), during January-March 2019, in Hepatology outpatient clinic Dr.Soetomo Academic Hospital. Subject was grouped into central hypothyroid as cases (n=17) and normal thyroid function as control (n=27). Central hypothyroid was defined as low free thyroxine (FT4) and low/normal thyroid stimulating hormone (TSH) level by age. Risk factors consist of gestational age (term infant or preterm infant), birth weight (normal birth weight or low birth weight), head circumference (normal or microcephaly), anti cytomegalovirus (CMV) immunoglobulin (Ig) M, and liver biopsy result which classified as extrahepatic cholestasis or intrahepatic cholestasis. Chi-Square and logistic regression test was used to analyze with P value<0.05 regarded as significant.
RESULT Total 44 infants with median age 4 month-old included in study. Risk factor associated with central hypothyroid were microcephaly (13/17 vs 3/27; OR 26; 95%CI 5.03 to 134.31; P<0.0001) and positive anti CMV IgM  (11/17 vs 4/27; OR 10.54; 95%CI 2.46 to 45.16; P=0.001). Preterm infant (10/17 vs 8/27; OR 3.4; 95%CI 0.95 to 12.13; P = 0.055), low birth weight (11/17 vs 10/27; OR 3.117; 95%CI 0.88 to 11.04 ; P=0.074), and extrahepatic cholestasis (6/17 vs 9/27; OR 1.11; 95%CI 0.30 to 3.91; P=0.894) were not significantly associated with central hypothyroid.
CONCLUSION Thyroid function test should be considered in cholestasis infants with microcephaly or positive test for anti CMV IgM.