Climatic factors and prolonged neonatal jaundice

Prolonged neonatal jaundice (PrNJ) in full-term newborns(NB) is defined if it persists beyond the 14th day after birth. Clinical experience shows that seasons of the year influence the frequency and severity of neonatal jaundice (NJ).
Objective: To establish the role of climatic factors on PrNJ expression in term neonates.
Material and methods: The study was conducted at the Neonatology Department of University Hospital "Medica Ruse" with 92 full-term newborns who were with PrNJ. The follow-up of NJ was carried out with transcutaneous bilirubinometry. The NBs are residents of Ruse region, Republic of Bulgaria.
Results: We found that air temperature directly affects the levels of bilirubin(BR) for the entire neonatal period and the duration of PrNJ. The amount of rainfall during the first two weeks after birth directly correlated with bilirubinemia at end of neonatal period and the duration of PrNJ. A higher level of atmospheric pressure during the early neonatal period was associated with lower BR levels at the same and a shorter duration of PrNJ. The degree of cloudiness after postnatal day 14 is inversely related to the levels of BR and the duration of the PrNJ. Sunshine during the first two weeks affects the levels of BR on the end of neonatal perod and the prolongation of PrNJ.
Conclusion: According to our data climatic factors: air temperature, amount of rainfaull, atmospheric pressure, degree of cloudiness, duration of sunshine affect the degree of manifestation and duration of PrNJ.