Neonatal jaundice in Chinese newborns

Effects of Season of Birth and Meteorological Parameters on Serum Bilirubin Levels during the Early Neonatal Period: A Retrospective Chart Review

To establish whether serum bilirubin levels vary in healthy term neonates according to seasonal variations and meteorological factors, we retrospectively studied 3344 healthy term neonates born between 2013 and 2018. Total serum bilirubin (TSB) levels were measured on the fourth day after birth. The monthly and seasonal variations in TSB levels and clinical and meteorological effects on TSB levels were assessed. In the enrolled neonates, the median TSB level was 195 µmol/L. The TSB level peaked in December and was the lowest in July, but the variation was not statistically significant. The TSB level was significantly higher in the cold (October to March) than in the warm season (April to September; p = 0.01). The comparison between seasonal differences according to sex showed TSB levels were significantly higher in the cold than in the warm season in male infants (p = 0.001), whereas no significant difference was observed in female infants. A weakly negative but significant association existed between TSB levels and the mean daily air temperature (r = -0.07, p = 0.007) in only the male population; the female population showed no significant correlation between TSB levels and meteorological parameters. The season of birth is an etiological factor in neonatal jaundice, with an additional influence from sex.

Severe neonatal jaundice associated with glucose-6-phosphate dehydrogenase deficiency: pathogenesis and global epidemiology

The association of glucose-6-phosphate dehydrogenase deficiency (G6PD def) with severe neonatal jaundice (NJ) and Kernicterus was described just over 30 years ago in reports from Sardinia (1-4) Singapore (5,6) and Greece (7,8). In this review we will examine the progress made since that time in our understanding of the pathophysiology of severe NJ associated with G6PD def, its global epidemiology, and its role in the balanced polymorphism of the G6PD def gene (Gd). Including this review in the Festschrift to Spyros Doxiadis should highlight his contribution to the field. In Greece the search for a new cause of severe NJ and Kernicterus was triggered by his realization that the recognized at the time, causes of severe NJ were absent in a large proportion of the neonates treated at the "Alexandra" Maternity Hospital in Athens (9).

Neonatal jaundice in Asia

Neonatal jaundice is a major clinical problem globally, especially in the Asian and south-east Asian regions. There is no universal definition of hyperbilirubinaemia, and comparisons of management and control of hyperbilirubinaemia in infants at different centres are difficult. G6PD deficiency, ABO incompatibility, low birth weight and sepsis are the common causes of neonatal jaundice, but there is a group of babies whose cause of neonatal jaundice has yet to be found. Genetic factors may be responsible for ethnic differences in the ability to eliminate bilirubin, while unidentified environmental factors may also play a role in the prevalence of neonatal jaundice. As a result of a surveillance programme for neonatal jaundice in Singapore, involving health education of doctors, nurses and the lay public, screening of the newborn and the early treatment of jaundice, we have not seen a single case of kernicterus in Singapore for more than 10 years.