Background and aims It is well interpreted idea that a negative neonatal screening does not exclude transient congenital hypothyroidism and remains the paediatrician competence to diagnose these ‘delayed’ cases. The aim of the study is to establish the significance of all prolonged jaundice patients data.

Methods The study assessed prolonged jaundice (PJ) in infants 3–6 weeks old, with total bilirubin (TB)>2 mg/dL. Were not included congenital hypothyroidism diagnosed at birth, other causes of PJ, other patent pathology. The study parameters were: PJ, pale skin, umbilical hernia (UH), enlarged anterior fontanel (EAF); total and conjugated bilirubin, haemoglobin, blood iron, peripheral blood smear (PBS), thyroid tests (T3, T4, TSH).

Results From 94 cases of prolonged jaundice, 45 were thyroid tested (TT), 49 untested (UT). Anaemia was 100% present in TT and 83,3% in UT. UH was 44,4% in TT and 27% in UT. EAF was noticed in 6,7% in TT and 10,2% in UT. PBS was performed in 26,6% in TT and 12,2% in UT. 6 cases been reported as having abnormal thyroid hormones values, with the following pattern: delayed increase of thyrotropin (9,7 to 17,9 mUI/L), normal values of thyroxin, 7,33 mg/dL mean value of TB, 31,7%, 85,7% mild/moderate anaemia, 57,1% with UH. The incidence of anaemia was highly statistically significant (p 0,00**), conversely to UH and EAF both with no any significance (p 0,39). Only one patient received hormonal substitution treatment, the rest of 5 only recommendation of assessment. The prolonged jaundice and anaemia, too, were linked to delayed hyperthyrotropinemia only in the treated case; in the others, the causes were not been so well formulated (e.g. possible breast milk inhibitors).

Conclusions The transient congenital hypothyroidism can explain some cases of prolonged jaundice, and other associated signs of symptoms (umbilical hernia, enlarged anterior fontanel, anaemia). It is absolutely necessary to assess all such patients, and to treat, by case.