Recent Advancements and Best Practices in Supporting Newborn Feeding: A Narrative Review

INTRODUCTION

Exclusive breastfeeding is recommended for optimal health of infants and their birthing parents. Infants who are not fed human milk are at increased risk of acute and chronic disease. As such, the American Academy of Pediatrics (AAP) and the World Health Organization (WHO) recommend exclusive breastfeeding for 6 months, with continued breastfeeding for at least 2 years.^1,2 The WHO recommends that all birthing hospitals adopt the 10 steps to successful breastfeeding, an evidence-based bundle of practices that promote and support the successful establishment of breastfeeding.³ These steps include provision of no other food or drink to breastfeeding infants unless medically indicated. The health benefits of breastfeeding and skin to skin, guidance on unique or complex newborn feeding questions, response to newborn weight loss, vitamin supplementation, as well as consideration of the social determinants of health (SDoH) in the context of infant feeding are reviewed in detail later.

DISCUSSION

Health Benefits of Breastfeeding

Supporting human milk feeding is an important public health strategy to improve health of infants and postpartum patients as the health benefits of human milk/breast/chest feeding (herein breastfeeding) are numerous.¹ The health benefits of breastfeeding include a reduction in infant mortality⁴ in the immediate neonatal period and through the first year of life⁵ and a reduction in sudden infant death syndrome.⁶ Breastfeeding is also associated with protection against common infections and medical conditions during infancy and early childhood including acute otitis media,⁷ lower respiratory tract infection, severe diarrhea,⁸ allergic rhinitis,⁹ eczema, and asthma.^10,11 Having a personal history of being breastfed is protective against chronic conditions including experiencing obesity as a child¹² and as an adult,¹³ diagnosis of type 1¹⁴ and type 2 diabetes,¹³ inflammatory bowel disease,¹⁵ and acute lymphocytic leukemia.¹⁶ For postpartum patients desiring to breastfeed, the health benefits are arguably more substantial with longer and exclusive breastfeeding reducing risk of the most aggres-sive types of breast^17–19 and ovarian²⁰ cancers, endometrial cancer,²¹ and thyroid cancer.²² Additionally, longer and exclusive breastfeeding reduces risk of cardiovas-cular disease^23,24 and type 2 diabetes, even in postpartum patients with gestational diabetes.²⁵

Contraindications to Breastfeeding

There are very few absolute contraindications to human milk. Human milk is contrain-dicated in classical galactosemia, although the diagnosis may be made after breastfeeding is initiated during the birth hospitalization. In the United States, human T-cell lymphotropic virus type I or type II infection, untreated brucellosis, or suspected or confirmed Ebola virus disease, are contraindications to breastfeeding.¹

Families who choose, or medically need, to use feeding strategies other than breastfeeding should be counseled on safe storage, preparation, and feeding practices with expressed or donor human milk, and/or formula.^26,27

Skin to Skin and Newborn Reflexes

Newborn reflexes serve a critical role in supporting and sustaining infant feeding. Appearing around 28 weeks of gestation, the rooting reflex can be elicited by gentle stroking of the cheek or mouth causing the mouth to open and move toward the object, such as the nipple.²⁸ Triggered by touching the roof of the mouth, the suck/swallow reflex appears around 30 to 35 weeks of gestation and the coordination with respiration is not fully developed until after 36 weeks.²⁸ The immaturity of reflexes required for infant feeding can contribute to challenges of feeding the premature infant. “The Golden Hour”, placing the diapered or naked newborn in skin-to-skin contact (SSC) with the birthing parent’s chest immediately after birth, is critical for both the infant and birthing parent. During SSC, the infant’s heart rate, respiratory rate, glucose level, and temperature are stabilized while breastfeeding reflexes are stimulated.^29,30 SSC immediately after birth reduces neonatal hypoglycemia³¹ and infants allowed to remain in SSC are more likely to successfully breastfeed, and have increased breastfeeding exclusivity and duration, even after a cesarean delivery (CD).^29,30,32 Five weeks of consistent, daily SSC has been shown to increase breastfeeding exclusivity and duration by several months, while reducing maternal anxiety and fatigue.^33,34 Paternal SSC after CD shows similar impact on infant transition to extrauterine life and fathers reported reduced anxiety, depression, and better role attainment.³⁵ Placing the infant skin to skin with their lactating parent stimulates newborn feeding reflexes and enables an infant-led latch, improving latch, and reducing breast problems such as sore nipples.³⁶ Infants placed on the birthing parent’s stomach may crawl toward the nipple, thought to be guided by smell.^37,38 An infant’s ability to participate in SSC and use their newborn reflexes appears critical for successful breastfeeding establishment. Swaddling practices can negatively impact infants’ experience of skin to skin, hindering newborn reflexes and masking feeding cues.³⁹ “Rooming in,”or providing care to the infant and birth parent in the same room during the birth hospitalization, facilitates frequent SSC and feeding.³

Infectious Concerns and Breastfeeding

For postpartum patients living with chronic infectious conditions including human immunodeficiency virus (HIV), hepatitis B (HBV), and hepatitis C (HCV), counseling about infant feeding decisions and the safety of human milk feeding is important. If a pregnant or postpartum patient living with HIV desires to breastfeed, transmission of HIV from mother to infant is less than 1% for those on ART who have achieved viral suppression (<50 copies per mL).⁴⁰ The National Clinician Consultation Center at UCSF (888–448–8765) is available for clinicians desiring peer-to-peer consultation on management of perinatal HIV. For pregnant and postpartum patients living with HBV or HCV, breastfeeding is recommended.^41,42 Human lactoferrin significantly inhibits infectivity of HBV by binding directly to HbsAg, and postnatal administration of hepatitis B vaccine and hepatitis B immunoglobulin effectively eliminates any theoretical risk of transmission via breastmilk.^41–43 HCV is not a contraindication to breastfeeding, but postpartum patients living with HCV are less likely to initiate and continue breastfeeding, compared to patients without hepatitis.^44,45 The AAP does recommend that people living with HCV and who have bleeding or cracked nipples defer directly latching to the injured nipple, underscoring the importance of lactation support for this patient population.⁴³

For hospitalized postpartum patients with active respiratory infections like COVID-19 or influenza, breastfeeding is recommended. In maternal COVID-19 infection, rooming-in and the severity of maternal viral symptoms are not associated with neonatal outcomes. Because of the minimal risk of transmission of infection to the newborn, rooming-in is recommended for infants of patients with COVID-19.^46,47 During active influenza infection, shared decision making is recommended, as the U.S. Centers for Disease Control (CDC) guidance for hospitals recommends continued human milk feeding, but also separation of the postpartum patient and newborn.⁴⁷ Globally, concerns surrounding the orthopoxvirus known as monkeypox (mpox), have been increasing. In August 2024, the WHO declared mpox a public health emergency of international concern.⁴⁸ Evidence regarding breastfeeding safety is lacking and current recommendations call for cessation of direct breastfeeding until mpox lesions are healed.^43,49 If a lactating parent with mpox infection is interested in preserving future breastfeeding, they can be supported to pump and discard their breastmilk during their isolation period.⁴³ Due to risk of severe infection, newborns are not eligible for SSC or rooming-in if their parent has mpox infection.⁴⁹

Medications and Breastfeeding

While most medications during lactation are safe, there are many publicly available tools to help clinicians assess the safety of maternal medications (Table 1). These tools include the Drugs and Lactation Database (LactMed^®) https://www.ncbi.nlm.nih.gov/books/NBK501922/, E-Lactancia https://e-lactancia.org, the Infant Risk Center https://infantrisk.com/, and Hale’s Medications and Mother’s Milk.^50–53

Table 1.

Valuable resources for the newborn clinician

Resources	Available From
Breastfeeding in Substance Use or Substance Use Disorder
Academy of Breastfeeding Medicine Clinical Protocol #21: Breastfeeding in the Setting of Substance Use and Substance Use Disorder (Revised 2023)	Harris M, Schiff DM, Saia K, Muftu S, Standish KR, Wachman EM. Academy of Breastfeeding Medicine Clinical Protocol #21: Breastfeeding in the Setting of Substance Use and Substance Use Disorder (Revised 2023). Breastfeed Med. 2023;18(10):715–733. https://doi.org/10.1089/bfm.2023.29256.abm
Committee Opinion No. 711: Opioid Use and Opioid Use Disorder in Pregnancy. Obstetrics & Gynecology	Committee Opinion No. 711: Opioid Use and Opioid Use Disorder in Pregnancy. Obstet Gynecol. 2017 Aug;130(2):e81-e94. https://doi.org/10.1097/AOG.0000000000002235
Health Benefits of Breastfeeding
American Acadcmy of Pediatrics Breastfeeding and the Use of Human Milk	Meek JY, Noble L; Section on Breastfeeding. Policy Statement: Breastfeeding and the Use of Human Milk. Pediatrics. 2022 Jul 1;150(1):e2022057988. https://doi.org/10.1542/peds.2022-057988. PMID: 35921640.
Ten Steps to Successful Breastfeeding	https://www.who.int/teams/nutrition-and-food-safety/food-and-nutrition-actions-in-health-systems/ten-steps-to-successfulbreastfeeding
World Health Organization recommendations	https://www.who.int/health-topics/breastfeeding#tab=tab_1
Infectious Concerns while Breastfeeding
American Academy of Pediatrics. Kimberlin et all. Red Book: 2024 Report of the Committee on Infectious Diseases; American Academy of Pediatrics, 2024.	Hepatitis B, page 138 & 450 Hepatitis C, page 138 Human Immunodeficiency virus, page 139 MPOX, page 140 SARS-COV-2 (COVID-19), page 140
National Clinician Consultation Center at UCSF	888-448-8765
Late Preterm Infant in Newborn Nursery
ABM Clinical Protocol #10: Breastfeeding the Late Preterm (34–36 6/7 wk of Gestation) and Early Term Infants (37–38 6/7 wk of Gestation), Second Revision 2016.	Boies EG, Vaucher YE. ABM Clinical Protocol #10: Breastfeeding the Late Preterm (34–36 6/7 wk of Gestation) and Early Term infants (37–38 6/7 wk of Gestation), Second Revision, 2016. Breastfeed Med. 2016 Dec,11:494–500. https://doi.org/10.1089/bfm.2016.29031.egb. Epub 2016 Nov 10. PMID: 27830934.
Updates on an At-Risk Population: Late-Preterm and Early-Term Infants	Dan L. Stewart, Wanda D. Barfield, COMMITTEE ON FETUS AND NEWBORN, James J. Cummings, Ira S. Adams-Chapman, Susan Wright Aucott, Jay P. Goldsmith, Ivan L. Hand, Sandra E. Juul, Brenda Bradley Poindexter, Karen Marie Puopolo; Updates on an At-Risk Population: Late-Preterm and Early-Term Infants. Pediatrics November 2019; 144 (5): e20192760. 10.1542/peds.2019-2760
Medication Safety while Breastfeeding
Academy of Breastfeeding Medicine Clinical Protocol #15:Analgesia and Anesthesia for the Breastfeeding Mother (Revised 2017)	Reece-Stremtan S, Campos M, Kokajko L; Academy of Breastfeeding Medicine. ABM Clinical Protocol #15: Analgesia and Anesthesia for the Breastfeeding Mother, Revised 2017. Breastfeed Med. 2017 Nov;12(9):500–506. PMID: 29624435. https://doi.org/10.1089/bfm.2017.29054.srt
Drugs and Lactation Database (LactMed®) [Internet]. Bethesda (MD): National Institute of Child Health and Human Development; 2006.	https://www.ncbi.nlm.nih.gov/books/NBK501922/
E-lactancia	https://e-lactancia.org/
Infant Risk Center at Texas University Health Sciences Center	https://infantrisk.com/
Newborn Weight Loss
Newborn Weight Loss Tool (NEWT)	https://newbornweight.org/
Social Determinants of Health
Housing Instability Vital Sign™	Sandel M, Sheward R, Ettinger de Cuba S, Coleman SM, Frank DA, Chilton M, Black M, Heeren T, Pasquariello J, Casey P, Ochoa E, Cutts D. Unstable Housing and Caregiver and Child Health in Renter Families. Pediatrics. 2018 Feb;141(2):e20172199. https://doi.org/10.1542/peds.2017-2199. Epub 2018 Jan 22. PMID: 29358482.
Hunger Vital Sign™	https://childrenshealthwatch.org/public-policy/hunger-vital-sign/

Weight Loss/Weight Testing

Newborns normally experience weight loss in the first days after birth, yet results are mixed on the threshold for “excessive” weight loss, especially for exclusively breastfed newborns.⁵⁴ Limited data show weight loss greater than 10% may be associated with hyperbilirubinemia and hypernatremia dehydration.⁵⁵ Routine monitoring of newborn weight during the birth hospitalization is a best practice to identify newborn hydration status and rapid weight loss, although there is limited evidence that daily weighing improves outcomes compared to less frequent hospital weighing policies.⁵⁶ The Newborn Weight Loss Tool (NEWT, www.newbornweight.org) was developed using data from more than 100,000 exclusively breastfed healthy newborns of 36 weeks or greater gestational age at birth⁵⁷ and can be integrated into nursery clinical practice to guide infant evaluation and potential feeding changes. In-hospital weight loss percentile at 24 hours relative to NEWT 90th percentile or greater for vaginal births and relative to 75th percentile or greater for Cesarean-section births is associated with indicators of breastfeeding difficulties at home by the fourth day of life.⁵⁸ Recent evidence suggests the NEWT may also be applicable in low and middle-income countries.⁵⁹ Pediatric clinicians should evaluate potential causes of newborn weight loss among breastfeeding newborns in the first few days of life to determine the best intervention, which may or may not include donor breastmilk or formula supplementation.⁶⁰ Evaluation should consider maternal factors related to human milk production and transfer as well as the maternal–newborn interaction.⁶¹ Some exclusively breastfed newborns receive insufficient human milk due to suboptimal breastfeeding positioning or latch or inadequate maternal milk production.⁶² Maternal risk factors for potential delayed lactogenesis and insufficient breastmilk production include older age, primiparity, thyroid dysfunction, obesity, gestational diabetes, and CD.⁶³ Provider concern about newborn weight loss coupled with maternal anxiety about milk supply or perceived insufficient milk supply can contribute to early interruption of exclusive breastfeeding with formula supplementation and decreased breastfeeding duration.^64,65 Additionally, newborn feeding disparities remain with greater prevalence of formula supplementation among minoritized populations, Medicaid public insurance recipients, patients with less than a high school degree, and postpartum patients who smoke.⁶⁶ Consideration for newborn current and potential future weight loss with utilization of clinical tools such as NEWT, identification of maternal risk factors for insufficient human milk production, and culturally sensitive communication between members of the interdisciplinary care team and caregivers about newborn weight loss and feeding practice can inform targeted, enhanced in-hospital breastfeeding and lactation support interventions.⁶⁷ Such interventions must include culturally sensitive education and counseling for caregivers about donor human milk as a medical supplementation source and equitable access to pasteurized banked donor human milk.⁶⁸ Pediatric clinicians can also develop nursery discharge checklists that include clinician and care team support for equitable access to and utilization of enhanced home lactation resources and close outpatient pediatric follow-up for newborn weight check.

Vitamins

Newborns fed human milk produced from a well-nourished caregiver will take in sufficient quantities of vitamin D, E, and the B vitamins. For lactating people who follow restricted diets (ie, vegan diet with limited B12 vitamin sources), vitamin supplementation may be beneficial.⁶⁹ In addition, due to limited direct exposure to the sun and high levels of vitamin D deficiency among US adults, newborns are at greater risk for vitamin D deficiency and sequelae such as stunted growth, rickets, skeletal issues, and immune system issues.^70,71 Newborns receiving exclusive human milk are recommended by the CDC and the AAP to supplement with 400 IU of vitamin D daily starting in the newborn period, up until 12 months of age.⁷¹ Although US-made standard term formula is fortified with 400 IU of vitamin D per liter, exclusively or mostly formula fed newborns in the first few weeks or months of life are not consuming a liter of formula per day. A 2022 study by Gallo and colleagues⁷² determined that the majority of a national sample of low-income infants enrolled in the Supplemental Nutrition Program for Women, Infants, and Children (WIC) who were exclusively formula-feeding were not consuming the recommended quantity of vitamin D between 1 and 13 months of age and only 19% of exclusively breastfeeding newborns received supplemental vitamin D at 1 month of age. Pediatric clinicians should deliver sufficient in-hospital education to caregivers on the importance of vitamin D oral supplementation for all newborns in the first months, irrespective of feeding practice.⁷² While oral vitamin D supplementation for infants is available over-the-counter (OTC), the cost may be pro-hibitive to families with limited financial resources. Clinicians should ensure financial hardship is not a barrier to newborn access to supplementation by providing a pre-scription to families enrolled in Medicaid for this medication, to enable coverage bystate Medicaid formularies.

Social Determinants of Health

SDoH are defined as the conditions in the environments where people are born, live, learn, and work that affect individuals’ health, functioning, and quality of life.⁷³ SDoH of economic instability; education access and quality; health care access and quality; food insecurity, defined as worry about and/or lack of access to food; housing hardship, defined as experiencing with difficulty paying rent or mortgage, overcrowding, frequent moves, and/or homelessness; and transportation insecurity, defined as an inability to access safe and timely transportation to fulfill basic needs, have also been associated with child health disparities starting in the neonatal period. Families experiencing these SDoH have less consistent access to a medical home and lower rates of attendance at routine well-child visits,⁷⁴ contributing to poorer infant health outcomes.⁷⁵ SDoH, especially food insecurity, at the intersection of structural and historical inequity in the United States, is negatively associated with breastfeeding intent, initiation, and continuation^73,76 leading to breastfeeding disparities among low-income and racial and ethnic minoritized women. Health care providers’ biased assumptions about Black women’s lower interest and intent to breastfeed can negatively affect the quality of hospital-based breastfeeding and lactation support⁷⁷ and decrease likelihood of offering outpatient lactation support.⁷⁸ The birth hospitalization provides pediatric clinicians with a critical opportunity to engage obstetric providers to advance interdisciplinary team management of the mother–newborn dyad through co-ordinated SDoH screening using brief validated screening tools and through health system and community-based resources and referrals to address SDoH concerns to empower parents prior to hospital discharge.⁷⁵ See Table 1 for additional resources. Addressing maternal food insecurity and housing hardship concerns with referral to programs such as WIC and the housing choice voucher program, may also positively influence increased breastfeeding rates through improved maternal perceived safety and reduced stress.^79,80

Breastfeeding and Substance Use

An estimated 5% of US pregnant women use illicit substances.^81,82 In 2017, the American College of Obstetricians and Gynecologists published a practice guideline for universal screening for substance use using a validated screening questionnaire.⁸³ Prenatal screening for substance use remains inequitable with hospital clinicians significantly more likely to order urine drug testing for newborns of Black mothers compared to other racial and ethnic groups, including White mothers.⁸⁴ Black mothers who use substances are more likely than White mothers to be reported to child protective services,⁸⁵ and positive screening questionnaire or positive urine drug test can lead members of the health care team to recommend against breastfeeding the newborn. These patterns contribute to poor maternal and newborn health outcomes.⁸⁶ Murosko and colleagues⁸⁶ provide steps for interdisciplinary newborn care teams to center equity in newborn urine and/or meconium toxicology testing decisions.

Breastfeeding in the setting of maternal history of non-prescribed substance use and abuse recovery can be complex. The Academy of Breastfeeding Medicine 2023 clinical protocol affirms breastfeeding as an option for those who stop non-prescribed substance use by time of delivery while emphasizing the importance of appropriate multidisciplinary follow-up care.⁸⁷ For further discussion of high value, equitable care for infants with prenatal opioid exposure, see Frances Y. Cheng and colleagues’ article, “Neonatal Opioid Withdrawal Syndrome,” in this issue.

Breastfeeding in Nuanced Newborn Care Situations

Providing comprehensive pediatric care in the newborn nursery setting often includes modification of routine breastfeeding recommendations when patient care is complex. Late preterm infants (LPI) and low birth weight infants benefit from exclusive human milk feeding, as formula exposure is associated with increased risk of necrotizing enterocolitis and all-cause mortality.^9,88 However, LPIs (34w0d–36w5d) are increasingly cared for in the routine newborn nursery and frequently experience breastfeeding difficulties requiring medically indicated supplementation and should receive advanced lactation support during birth hospitalization and be connected to continuing lactation support after discharge⁸⁹ For postpartum patients with twins/ multiples, many desire to breastfeed; however, initiation, exclusivity and duration lags singleton births.^90,91 During birth hospitalization of multiples, it is important to provide breastfeeding support and encourage frequent feeding, individually assess each infant at the breast, and teach milk expression to feed if supplementation is medically necessary.⁹²

Lactation Support

When pregnant patients deliver in hospitals with supportive maternity care practices, breastfeeding initiation and exclusivity improves.⁹³ After birth hospitalization discharge, patients experiencing breastfeeding difficulties should be connected to lactation support in the outpatient setting.⁹⁴ Formal breastfeeding support in the United States is typically conducted by physicians practicing breastfeeding medicine,⁹⁵ lactation consultants,⁹⁶ peer counselors, and organizations like WIC and La Leche League. Additionally, telemedicine breastfeeding support (video visits, phone calls, text messaging), while not hands on, is highly effective to support any and exclusive breastfeeding, especially for low-income women living in high income countries.⁹⁷

Novel and Emerging Evidence

Breastmilk is a dynamic living fluid and our understanding of the human microbiome and implications for lifelong health is rapidly changing and expanding. Current evidence points toward a critical period during infancy for breastmilk exposure to establish a “healthy” infant gastrointestinal microbiome establishment.⁹⁸ Alterations in the microbiome through formula feeding, maternal diet, antibiotic exposure, and environmental stressors changes the gut microflora and may contribute to life-long health concerns and chronic diseases.^98,99 Human milk oligosaccharides function as a pre-biotic within the infant’s gastrointestinal track and promote growth of Bifidobacterium, Lactobacillus, and Bacteroides.^98,100 The presence of Bifidobacteria within the infant’s gut microbiome promotes the development of the immune system, impacting the risk of childhood infections such as diarrhea.¹⁰⁰ Directly feeding from the breast, rather than via bottle alone, allows the cross-talk or “bi-directional bacterial transfer” between the infant oral cavity and maternal breast, increasing bacterial diversity, presence of oral flora, and of Bifidobacterium in the human milk.^98,101 Exclusive breast pumping can alter the infant’s gut microflora through reduced bacterial sharing.⁹⁸

KEY POINTS.

• The health benefits of breastfeeding for infants and their lactating parent are numerous.

• Skin to skin contact, especially immediately after birth, is critical to stabilize transition to extrauterine life and support successful and prolonged breastfeeding.

• For postpartum patients living with chronic infectious conditions including human immunodeficiency virus, hepatitis B, and hepatitis C, counseling about infant feeding decisions and the safety of human milk feeding is crucial.

• Most medications are safe while breastfeeding and pediatric clinicians can access online evidence-based resources to guide clinical care.

• Social determinants of health are critical variables for clinicians to consider in the care of newborns and their families to ensure equitable access to the benefits of breastfeeding for all.

CLINICS CARE POINTS.

• Breastfeeding is the optimal mode of infant feeding, and pediatric clinicians play a key role in supporting its establishment.

• Pediatric clinical providers need to know where to access evidence-based information to help with clinical decision making regarding the safety of human milk feeding; a selection of resources.

• Newborns, whether they are exclusively breastfeeding or consuming less than 1L infant formula, are recommended to be supplemented with 400 IU of vitamin D daily. Despite OTC availability, newborns with Medicaid insurance may benefit from the pediatric clinical provider prescribing vitamin D to facilitate insurance coverage.

• Families should receive education and have the opportunity to discuss the role breastmilk plays in establishment of infant microbiome and long-term health outcomes.

• Addressing identified social needs during the birth hospitalization through services and referrals to additional resources can support increased duration of breastfeeding.