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Jaundice in Breastfed Neonates
Jaundice is an extremely common clinical assessment finding in newborn infants, particularly those who are breastfed. Because of the contribution of breastfeeding or breast milk to jaundice in the neonate, the pattern and course of jaundice in breastfed infants can differ from that of their formula-fed counterparts. In the clinical setting, it is important to understand these patterns to be able to provide anticipatory guidance to anxious and concerned parents, as well as to be able to intervene, if necessary, when jaundice deviates from its typical course. In the breastfed infant, this course is sometimes prolonged, leaving both clinicians and parents wondering whether to worry about jaundice in the otherwise healthy, thriving neonate.
To learn more about the natural history of jaundice in the healthy breastfed infant and determine the prevalence of prolonged hyperbilirubinemia in a US population of infants, Maisels and colleagues measured transcutaneous bilirubin (TcB) levels in a convenience sample of 1044 near-term and term neonates (≥ 35 weeks' gestation) who were seen in pediatric clinics for follow-up after discharge from their birth hospitalization. A third objective was to evaluate the clinician's assessment of jaundice in healthy breastfed infants and whether the Kramer rule for visual assessment of jaundice[1] is useful in this group.
With the Dräger Air Shields JM-103 transcutaneous jaundice meter (Draeger Medical; Telford, Pennsylvania), 3 midsternum measurements were obtained and averaged. All infants were "predominantly breastfed," defined as receiving no more than 1 formula feeding in 24 hours. Measurements of TcB took place in the hospital during the first 2 days of life, and thereafter in outpatient settings during routine follow-up visits.
Staff in the outpatient settings also assessed jaundice visually using the Kramer rule,[1] which divides the body into 5 "jaundice zones" that correspond roughly to increasing serum bilirubin levels as jaundice moves from the head to the extremities. For example, jaundice of the head or face only receives a score of 1, whereas jaundice reaching the toes and fingers receives a score of 5. TcB levels were not known to staff who assigned the visual jaundice zone score (JZS).
Prolonged jaundice and bilirubinemia were documented in many breastfed infants in this cohort, as demonstrated by visible jaundice and TcB levels at 3 and even 4 weeks of age (Table).
| Measurement | Patients (%) | |
|---|---|---|
| 21 Days | 28 Days | |
| Jaundice zone score > 1 | 34% | 21% |
| TcB > 5 mg/dL (85 μmol/L) | 44% | 34% |
There was a strong correlation between the mean TcB level and the JZS (r = 0.722; P = .0000), which remained strong at 14, 21, and 28 days. However, a wide range of TcB levels was associated with each JZS. For example, among 525 infants assessed by clinicians as having a JZS of zero (no jaundice), actual TcB levels ranged from zero to 15.5 mg/dL (264 µmol/L), although only 4 of these 525 infants had TcB levels > 12.9 mg/dL (219 µmol/L). Infants assessed as having a JZS of 2 (typically, face, neck, and upper trunk/above the umbilicus jaundice) had TcB levels up to 18 mg/dL (306 µmol/L).
This study provides the first data on the natural history of jaundice and bilirubinemia in a healthy, breastfed, predominantly white population of infants up to 4 weeks of age. Maisels and colleagues concluded that although the JZS is considered unreliable for the assessment of bilirubinemia in the first few days of life, a JZS ≥ 2 should prompt a TcB or total serum bilirubin (TSB) measurement, regardless of infant age.
Citation: Maisels MJ, Clune S, Coleman K, et al. The Natural History of Jaundice in Predominantly Breastfed Infants. Pediatrics. 2014;134:e340-e345.
Viewpoint
It is well known that jaundice peaks between days 3 and 5 of life in most newborns, and gradually declines thereafter. In breastfed infants, however, we know less about the definition of "gradually declines" or how long "thereafter" is expected to last. The data provided by this study go a long way toward answering those questions, and should prove useful in pediatric outpatient settings.
Two patterns of jaundice are believed to be associated with breastfeeding. The first is an early increase in serum bilirubin that is a primarily a consequence of low intake in the breastfeeding infant. Insufficient intake of mother's milk can be caused by difficulty in establishing lactation or a delay in milk production.
Low intake, combined with slow elimination of meconium, contribute to a rise in serum bilirubin. This situation is more accurately characterized as "lack of breastfeeding jaundice," because it is not the intake of breast milk that is causing jaundice, but a relative deficiency of breast milk. A lactation consult can go a long way in preventing this problem.
In its severest form, hyperbilirubinemia persists and even worsens as the newborn becomes progressively more dehydrated and hypernatremic, often losing an excessive amount of weight. The feeding history, clinical assessment, laboratory studies, and measurement of body weight can point to insufficient breast milk intake as the cause of hyperbilirubinemia in these infants.
The second pattern of jaundice associated with breastfeeding is generally called "breast milk jaundice," because the source of bilirubinemia is either a component of breast milk itself, or an interaction between breast milk and the infant's innate ability to metabolize or eliminate bilirubin. Breast milk jaundice is typically milder and lasts longer than many other causes of neonatal jaundice.
In the future, genetic testing may be able to tell us which infants are prone to breast milk jaundice, and when it can safely be ignored. If more infants were exclusively breastfed, we would probably see a lot more breast milk jaundice, and we might even stop considering the nonicteric formula-fed neonate to be the norm.
When faced with a jaundiced infant, the healthcare professional must decide whether to intervene to lower the bilirubin level, or take a wait-and-see approach to the infant's bilirubinemia. Along with feeding and elimination history and the clinical assessment, the age of the infant is a critical factor in this decision. If the bilirubin level is still peaking in the first week of life, current guidelines recommend an objective measure of bilirubin -- either laboratory-measured bilirubin or a transcutaneous bilirubinometer -- to guide decisions about treatment or monitoring.
Moreover, there are other causes of persistent jaundice in the neonate, and just because an infant is breastfed, this doesn't mean that the jaundice doesn't have a more serious pathogenesis, such as glucose-6-phosphate dehydrogenase deficiency. An important clue provided by this study is that although prolonged, jaundice and TcB levels in healthy breastfed infants gradually and predictably decline over time.
Can We Rely on the Eye?
Clinicians (and parents) may continue to waver on the need to check TSB in the 3-week-old neonate who presents with persistent visible jaundice. A TcB device is an excellent compromise, because clinicians can noninvasively measure the level of jaundice within a couple of minutes, and reassure parents that it is indeed gradually coming down.
In the absence of a TcB device, visual assessment is typically used to decide on the need for a TSB. Jaundice is known to have a cephalocaudal progression in onset, at least after birth, and Maisels and colleagues evaluated the use of a visual assessment method that takes advantage of this phenomenon, finding that it had some limited practicality. A JZS of zero was highly predictive of a TcB ≤ 12.9 mg/dL (219 µmol/L), and at the other end of the scale, a JZS ≥ 4 usually predicts a TcB > 10 mg/dL (170 µmol/L).
The investigators do, however, acknowledge the inconsistency in the clinician's ability to estimate bilirubin level from the visual assessment of jaundice, a finding that has been reported previously.[2-5] I have always wondered about the reason for so much variation in the ability of the human eye to perceive jaundice in the neonate. Some of this might be the result of the clinician's experience level and technique, and some might be related to differences in infant skin tones. But the most important factor might well be the level and type of ambient light used for the assessment of jaundice.
Jaundice is best assessed in good, natural light. The low lights of a postpartum mother's room, and even the artificial lights of a hospital nursery or clinic examination room, can influence the perception of jaundice. It may be inconvenient to take infants outdoors to assess jaundice, so the next best thing is to do so in the natural light from a window.
And this useful and critical point about jaundice assessment was made by Maisels and colleagues: If the sclera are yellow, get a serum bilirubin level. Yellowed sclera are not merely "facial jaundice," and almost always indicate significant hyperbilirubinemia.
References
1.Kramer LI. Am J Dis Child. 1969;118:454-458.
2.Keren R, Tremont K, Luan X, Cnaan A. Arch Dis Child Fetal Neonatal Ed. 2009;94:F317-F322.
3.De Luca D, Zecca E, Zuppa AA, Romagnoli C. Turk J Pediatr. 2008;50:456-461.
4.Riskin A, Tamir A, Kugelman A, Hemo M, Bader D. J Pediatr. 2008;152:782-787.
5.Moyer VA, Ahn C, Sneed S. Arch Pediatr Adolesc Med. 2000;154:391-394.
(Ref. Laura A. Stokowski. Still Jaundiced After All These Weeks: The Breastfed Neonate. Medscape. Aug 19, 2014.)