The purpose of this study is to evaluate if adding a noninvasive testing of End Tidal Carbon Monoxide with a FDA approved device will help improve management of jaundice in the Neonates by reducing the number of lab draws, Coombs tests and optimizing the number of phototherapy hours in Neonates who need it.

Eligible subjects will be Term and healthy late preterm newborns born at Cedars-Sinai Medical Center and admitted to well baby nursery from November 2020 onwards.

The primary procedure of measuring an End-Tidal Carbon monoxide in a Newborn is going to be with a soft cannula applied to the Newborn's nose for a few minutes. The whole procedure will take about 15+ 5 minutes.

Subject participation will last approximately 6 months and all subjects will be followed up with one phone call at about 2-4 weeks of age.

Adding ETCO testing to current standard of care might reduce the number of lab draws in a newborn and potentially reduce costs by optimizing the number of phototherapy hours in a Newborn who needs it. Cedars- Sinai Medical Center will not be billing the patients for the End-Tidal Carbon Monoxide measurement for this study.

The purpose the research is:

• Whether near simultaneous measurements of Total Serum bilirubin (Tsb) & End-Tidal Carbon Monoxide (End-Tidal Carbon monoxide as a function of bilirubin) will help identify hyperbilirubinemia accurately and easily This has been shown in a single center study.
• Whether near simultaneous measurement of Total serum bilirubin & End Tidal Carbon Monoxide is more accurate and less costly in overall management of Neonatal Hyperbilirubinemia Eligible infants would be male or female with GA > 35 weeks and BW > 2000, post natal age 6 hours to < 6 days of age and meets any one of the following criteria
• Due for an early discharge
• Has a Transcutaneous bilirubin or a Total serum bilirubin on or > the 75th % of Bhutani hyperbilirubinemia nomogram
• Has 2 or more risk factors for neonatal jaundice as specified in the protocol
• The study includes 388 patients in each arm - ~ 776 total newborn admissions
• The total study duration is: 6 months Methods: a retrospective group (Standard of Care) will be compared with a prospective Group (Standard of care + End-Tidal Carbon monoxide). Informed Consent will be obtained before the subject is recruited in the prospective group.

A phone call will be made to each subject in the prospective group at 2-4 weeks of age post birth hospitalization. This is a minimally risk study.

Inclusion Criteria:

• male or female with GA > 35 weeks and BW > 2000, post natal age 6 hours to < 6 days of age and meets any one of the following criteria

  • Due for an early discharge
  • Has a TcB or Tsb on or > the 75th % of Bhutani hyperbilirubinemia nomogram
  • Has 2 or more risk factors for neonatal jaundice as specified in the protocol

Exclusion Criteria:

• babies requiring any kind of respiratory support (O2, CPAP or assisted ventilation) has severe or life threatening congenital anomalies, weighed less than 2000 gms and if their mother has a known history of smoking during 3rd trimester of pregnancy. Also in addition nasal mucosal abrasion or nasal mucosal abnormalities will be excluded.