The most common and widely accepted method of monitoring bilirubin levels in neonates is the use of the laboratory analyzation of serum blood levels. Unfortunately this method is invasive, painful, and can progressively lead to increased blood loss in the neonate. It also requires the use of additional time and resources to coordinate sending the sample to the laboratory and processing the specimen in the lab. There exists a different option for obtaining bilirubin levels in neonates which is the transcutaneous bilirubinometer. This device detects bilirubin levels at the bedside and has been validated for use in infants born at > 35 weeks gestation. There are a limited number of studies evaluating its use in premature infants.

Our aim is to assess the diagnostic accuracy and efficacy of transcutaneous bilirubinometry (TcB) of the Dräger JM-103 by comparing (TcB) readings to total serum bilirubin (TSB) results in neonates born at 23 0/7-34 6/7 weeks gestation.

Design and Project Type In order to allow for appropriate data collection and comparison of TSB versus TcB measurements, this will be a prospective cohort study design. The expected duration will be 2 years. An interim analysis will occur approximately every six months.

Description of Intervention TcB measurements will be obtained within approximately 30 minutes of the TSB being drawn before initiation of phototherapy, approximately 24 hours after the initiation of phototherapy and approximately 24 hours after completion of phototherapy. The TcB measurement will involve lightly pushing three times at each site which will yield an average transcutaneous bilirubin value. This will be calculated for the interscapular, buttock and sternal automatically by the bilirubinometer. While on phototherapy a measurement of the diapered, non-exposed buttock area will be obtained at approximately 24 hours to coincide with the standard of care serum bilirubin measurement.

Instruments The JM-103 is the bilirubinometer that will be utilized in obtaining TcB measurements for this project. This meter is currently used on an as-needed basis within the unit for late preterm or term infants.

Data Collection Basic demographic data such as gestational age, ethnicity and gender will be collected. Relevant laboratory data such as blood type of mom and infant, and Coomb's test results will be collected. In addition, enteral and intravenous nutrition data will be collected including the type and volume of feeds at the same time the TcB is obtained. The results, date, time and location of the TSB and TcB will be collected for analysis.

TcB measurements will be obtained on those infants that are already ordered to have a blood draw for a serum bilirubin level. In the event the enrolled neonate does not require phototherapy during their hospitalization, the initial baseline TSB and TcB measurements will be collected and analyzed. Data will be collected during the first week of life. In the event that a neonate requires a second course of phototherapy and this is initiated during the first week of life, TcB and TSB measurements will be collected through the completion of phototherapy at 24 hours post treatment. If the enrolled neonate does not require phototherapy during their hospitalization, the initial baseline TSB and TcB measurements will be collected and analyzed.

Inclusion Criteria:

• Preterm neonates with gestational age at delivery of 23 0/7 to 34 6/7 weeks

Exclusion Criteria:

• Neonates requiring blood exchange transfusion
• Lethal congenital anomalies
• Hydrops fetalis
• Infants who have received an intrauterine transfusion
• Investigator discretion as to other factors which might impact the study

Infants meeting gestational age criteria specified (23 0/7 up to 34 6/7 weeks gestation) without lethal congenital anomalies or hyperbilirubinemia requiring an exchange transfusion will be recruited for enrollment in this study. The enrolled babies will be divided into two groups based on gestational age as follows: Group A 23 0/7 - 28 6/7 weeks, and Group B 29 0/7 weeks - 34 6/7 weeks. A minimum of 60 infants will be enrolled into each group. As more subjects are likely to be eligible to be enrolled during the anticipated two year duration of the study, up to a maximum of 200 may be enrolled.