When are bilirubin (bilirubin) levels measured in a newborn and how often are they taken?

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From the Guidelines

Bilirubin levels in newborns should be first measured within the first 24 hours after birth, and the need for and timing of repeat measurements depend on the initial results, the baby's risk factors, and the evolution of hyperbilirubinemia, as recommended by the most recent guidelines 1. The frequency of subsequent measurements depends on the initial levels and how quickly they're rising.

  • For babies with elevated levels, testing might be needed every 6-12 hours,
  • while those with borderline levels might be tested daily or every other day. Testing continues until bilirubin levels stabilize or decrease, usually within the first week of life. Bilirubin testing is crucial because newborns naturally produce higher levels as their bodies break down excess red blood cells from fetal life, and their immature livers cannot efficiently process bilirubin. Elevated levels can lead to jaundice and, if extremely high, may cause kernicterus, a form of brain damage. The most recent guidelines recommend using total serum bilirubin (TSB) as the definitive diagnostic test to guide all interventions, and transcutaneous bilirubin (TcB) measurements can be used to screen for hyperbilirubinemia, but TSB should be measured if the TcB reading is within 3.0 mg/dL of the phototherapy treatment threshold, if the TcB exceeds the phototherapy treatment threshold, or if the TcB is ≥15 mg/dL 1. The American Academy of Pediatrics (AAP) recommends promoting and supporting successful breastfeeding, performing a systematic assessment before discharge for the risk of severe hyperbilirubinemia, providing early and focused follow-up based on the risk assessment, and treating newborns with phototherapy or exchange transfusion when indicated to prevent the development of severe hyperbilirubinemia and, possibly, bilirubin encephalopathy (kernicterus) 1. However, the most recent guidelines from 2024 should be followed, which provide more specific recommendations for the management of hyperbilirubinemia in newborns, including the use of phototherapy and exchange transfusion 1.

From the Research

Bilirubin Levels in Newborns

  • Bilirubin levels are typically taken for newborns to check for jaundice, which can be a common condition in the neonatal period 2, 3.
  • The frequency of taking bilirubin levels for a newborn depends on various factors, including the baby's age, weight, and overall health 4.
  • In general, bilirubin levels are usually checked within the first few days of life, and may be repeated at regular intervals to monitor for any changes or potential complications 5, 6.

Timing of Bilirubin Level Checks

  • For term infants, bilirubin levels are typically checked at 24-48 hours of age, and again at 3-5 days of age if the initial level is elevated 4.
  • For preterm infants, bilirubin levels may be checked more frequently, such as every 12-24 hours, due to their increased risk of developing hyperbilirubinemia 3, 5.

Methods for Checking Bilirubin Levels

  • Bilirubin levels can be checked using a non-invasive transcutaneous bilirubinometer, or through a blood test 2, 6.
  • The choice of method depends on the baby's age, weight, and overall health, as well as the availability of equipment and personnel 4.

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Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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