Season of birth and neonatal jaundice

Neonatal jaundice (NJ) is a multifactorial condition specific to the neonatal age. Clinical experience shows that seasons of the year influence the frequency and severity of NJ.
Objective: To investigate the influence of annual seasons on the frequency and severity of NJ.
Material and methods: The study was conducted at the Neonatology Department of University Hospital "Medica Ruse" with 566 full-term newborns. The follow-up of NJ was carried out with transcutaneous bilirubinometry. The newborns are residents of Ruse region, Republic of Bulgaria.
Results: We found a significant difference in bilirubin (BR) levels depending on the season of birth during the early neonatal period. Summer-borns had the highest average levels, followed by spring-borns, and autumn-borns had the lowest. Вorn in the spring had significantly high levels of BR at the end of neonatal period. Climatic factors average and maximum monthly temperature, average monthly rainfall and monthly sunshine duration had a significant influence on the levels of bilirubin on Day 4 (p=0.014), Day 5 (p=0.016) and Day 14 (p=0.004). Prolonged NJ is most commonly observed in summer-borns (p<0.001).
Conclusion: Birth season along with meteorological factors affects the frequency of pathological neonatal jaundice.