Using Filtered Sunlight to Treat Jaundice in Newborns

Jaundice is the yellowing of a baby’s skin and is a common condition in newborns. The main cause of jaundice is excess bilirubin in the red blood cells (1). Bilirubin is a yellow pigment, and too much of a newborn’s skin and eyes to be tinted yellow. While most cases of jaundice are mild, some do require treatment in order to decrease the concentration of bilirubin within the bloodstream. This condition is known as hyperbilirubinemia. Decreasing levels of this serum is important as it prevents a severe type of brain damage known as kernicterus, which can occur if there is too high a concentration of bilirubin (2) in a newborn's blood cells.

The traditional method of treating jaundice is the use of intensive electric phototherapy (IEPT). This is accomplished by the use of artificial blue light from a lamp directed towards the skin of an infant (3). This light-based treatment lowers the concentration of bilirubin.The length of treatment varies depending on the severity of jaundice. While IEPT has been effective in lowering rates of severe hyperbilirubinemia, and the accompanying health consequences, in high income countries, lower income countries still face high newborn mortality and disability rates due to jaundice as hospitals do not have access to enough effective phototherapy machines or electricity to carry out the required levels of treatment. 

In recent years, filtered sunlight phototherapy (FSPT) has been proposed as an alternative way of treating newborns with jaundice. We are currently working with Dr. Tina Slusher and her team on an adjunct technology for her research, and it is Dr. Slusher who introduced us to FSPT (4). 

This method does not require electricity and instead makes use of natural sunlight to lower bilirubin levels. Initial safety concerns regarding this method included the risk of sunburn from exposure to harmful UV rays, dehydration, body temperature instability, and an inability of a newborn to maintain normothermia during periods of receiving sunlight. To respond to these concerns, studies have been conducted to compare the safety and effectiveness of IEPT and FSPT. One review concluded that the use of filtered sunlight to treat jaundice could be an effective method to use rotationally along with IEPT where there is limited availability, and may be beneficial as a preventative measure for developing jaundice in some newborns. An additional study found no significant discrepancies between the rates of decrease in serum bilirubin concentrations after the use of either FSPT or IEPT, and even suggested that FSPT could be more efficient as dilation of a newborn’s blood capillaries would be greater in FSPT, thus reducing bilirubin levels quickly. This study also noted the ability for increased parental bonding and support for newborn well-being via kangaroo care as another benefit of the use of FSPT. 

Overall, the application of filtered sunlight has been demonstrated to be a safe method of treating high bilirubin levels among near-term or term newborns. Even though sunlight is limited throughout a day, only 4 hours of light is needed to complete a treatment session, a feasible amount of time for most regions of the world. Although more research should be conducted to ensure long-term safety and effectiveness, and clear guidelines must be established to adequately monitor a baby’s temperature during treatment, the research is showing that FSPT holds promise to treat jaundice and reduce cases of severe hyperbilirubinemia, specifically in countries with limited health care resources.

1. https://www.cdc.gov/ncbddd/jaundice/facts.html#:~:text=Kernicterus%20is%20a%20type%20of,sometimes%20can%20cause%20intellectual%20disabilities.
2. https://www.mayoclinic.org/diseases-conditions/infant-jaundice/symptoms-causes/syc-20373865
3. https://my.clevelandclinic.org/health/treatments/24385-phototherapy-light-therapy#:~:text=Phototherapy%20is%20a%20form%20of,common%20treatment%20for%20newborn%20jaundice.
4. https://www.nejm.org/doi/full/10.1056/NEJMoa1501074