Reducing admissions for neonatal jaundice are needed to maximise benefits of breastfeeding promotion

Hong Kong had one of the lowest global breastfeeding rates in the 1990s,1 but the Government, and non-governmental organisations, have vigorously promoted breastfeeding since then. This included stopping hospitals from accepting free infant formula in 2006. Since 2013, all local public birthing hospitals have achieved, or are working towards, Baby Friendly Hospital accreditation. Breastfeeding plays a key role in the development of breastfeeding jaundice in the first few weeks of life and prolonged breastmilk jaundice beyond 14 days.2 Breastfeeding jaundice is when breastfeeding problems lead to reduced fluid and calorie intake and greater enterohepatic circulation. This increases the concentration of bilirubin and exacerbates physiological jaundice. This type of jaundice has also been called ‘sub-optimal intake jaundice’ or ‘insufficient breastmilk jaundice’ to reflect the underlying cause. In contrast, breastmilk jaundice is prolonged, unconjugated hyperbilirubinemia from 3 weeks to 3 months of age in healthy infants who are optimally breastfed. It is a normal, harmless developmental phenomenon, observed in exclusively breastfed infants who are thriving. A local birth cohort in the 1990s found that more breastfed infants were being admitted to hospital for neonatal jaundice (NNJ) than those who were not breastfed.3 The question that prompted this study is does successfully promoting breastfeeding increase the healthcare burden for treating NNJ? We carried out a retrospective study using anonymous data on time trends of birth rates, breastfeeding rates and hospitalisations for NNJ in Hong Kong and their implications for breastfeeding promotion. The Hong Kong Census and Statistics Department data showed the annual number of births in Hong Kong decreased from around 90 000 in 2010–12 to 50–60 000 in 2013–19. (Figure 1) Births dropped significantly in 2013 because women from mainland China could only deliver in Hong Kong if their husbands were residents. The Hong Kong College of Obstetricians and Gynaecologists reported first-time mothers increased from 49% in 2009 to 56% in 2014. Any and exclusive breastfeeding rates increased during 2010–19. Hong Kong biannual breastfeeding surveys reported ever breastfeeding rates at discharge increased from 74% in 2008 to 88% in 2018. The percentages of infants exclusively breastfed also increased during 2012–2018 from 22% to 33% at 1 month and from 19% to 29% at 4 months. The aggregated territory-wide inpatient discharge data from the Hong Kong Hospital Authority showed there were 17 000–21 000 admissions/year in public hospitals in 2010–2019 for infants up to 3 months of age with NNJ (identified by principal diagnosis as ICD-9-CM of 774). While the number of admissions for NNJ before 6 days of age (which contributed about 60% of total) decreased in this period, admissions for NNJ during 31–90 days increased, (Figure 1) resulting in an increase in its rates per 100 000 births during 2010–2019. The increases in hospital admissions rates for NNJ at 1–3 months of age in the past decade increased the healthcare burden and coincided with increased exclusive breastfeeding rates. This may suggest that NNJ, especially prolonged breastmilk jaundice, is an unintended consequence of successfully promoting breastfeeding in Hong Kong. Large efforts to promote breastfeeding, by the Government and non-government organisations, were reflected in higher breastfeeding rates at discharge, from 74% in 2008 to 88% in 2018. Breastfeeding jaundice and breastmilk jaundice increased with higher breastfeeding rates. On the contrary, only around 33% of one-month-old infants were exclusively breastfed, highlighting the need for breastfeeding support during the first month of life, especially if infants have jaundice. Our theories are based on aggregated data and may suffer from ecological fallacies, which are logical errors that occur when the characteristics of a group are attributed to an individual. We need to study individual data to confirm our findings. Nevertheless, it is useful to revisit the admission policy for NNJ in Hong Kong, where adherence to phototherapy guidelines vary by hospital, with a tendency to be overcautious in some units. These approaches separate mothers and babies and create barriers to breastfeeding.4 Although sub-threshold phototherapy may have benefits, unnecessary hospitalisation for NNJ should be avoided. Further studies on admission policies will identify any required improvements. These include the hospital-specific total serum bilirubin concentrations that lead to admissions, the number of admissions for NNJ and the extent that mothers and babies are separated due to admitting infants for phototherapy. Any change in admission policies needs to consider possible changes in the incidence of kernicterus, which has been close to 0% in Hong Kong since the 1990s. An increase in the healthcare burden of NNJ is a likely, but preventable, consequence of successful breastfeeding promotion. This is particularly true in South-East Asian communities with higher rates due to a genetic predisposition to glucose-6-phosphate dehydrogenase deficiency. Strengthening breastfeeding support to prevent breastfeeding jaundice,5 and optimising NNJ management, will maximise the benefits of breastfeeding promotion. Lai Ling Hui: Conceptualization; data curation; funding acquisition; investigation; methodology; writing – original draft. Emily Liao: Formal analysis; visualization. Karene Hoi Ting Yeung: Project administration; writing – review and editing. Patricia Lai Sheung Ip: Investigation; writing – review and editing. Hugh Simon Lam: Investigation; methodology; writing – review and editing. Edmund Anthony S. Nelson: Conceptualization; data curation; funding acquisition; methodology; project administration; supervision; writing – review and editing. We are grateful to the hospital admission data provided by the Central Panel on Administrative Assessment of External Data Requests, Hospital Authority. The authors wish to express their deepest gratitude to the late Dr Patricia Lai Sheung IP. Patricia was a founding member of Baby Friendly Hospital Initiative Hong Kong Association and a tireless advocate for breastfeeding. Her leadership, dedication and wisdom will be sorely missed. This investigation utilised data for a study supported by the Health and Medical Research Fund, Hong Kong (#07181226).