Journal of Human Lactation

It has been demonstrated that human milk from mothers who have been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains antibodies against the virus, which could play an important role in protecting the recipient infant against coronavirus disease 2019 (COVID-19). Seroconversion is measured frequently around the world, but the milk conversion rate is unknown.

To determine (1) the prevalence and (2) the dynamics of immunoglobulin A (IgA) antibodies against SARS-CoV-2 in human milk amongst lactating mothers in the Netherlands.

In this large prospective cohort study, lactating mothers (N = 2312) were included between October 12, 2020 and February 24, 2021. Enzyme-linked immunosorbent assay was used to determine levels of IgA antibodies in human milk and immunoglobulin G (IgG) antibodies in serum against the ectodomain of the SARS-CoV-2 spike protein.

A total of 691 (30.6%) participants had SARS-CoV-2 specific antibodies in human milk and/or serum. Of these participants, 524 (23.1%) had IgA antibodies against SARS-CoV-2 in human milk, and 356 (15.7%) had IgG antibodies against SARS-CoV-2 in serum. A total of 199 (8.8%) participants had antibodies in both human milk and serum. SARS-CoV-2 specific IgA antibodies in human milk remain present at least 10 months after a polymerase chain reaction confirmed infection.

The prevalence of IgA antibodies against SARS-CoV-2 in human milk was 23.1% in our cohort. This high prevalence of antibodies in human milk might lead to passive immunity in many breastfed infants and may serve as protection against COVID-19.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines are being administered around the world; however, lactating women were excluded from SARS-CoV-2 vaccine trials. Therefore, knowledge about the effect of vaccination in this specific group is limited. This information is essential to empower lactating women to make a well-informed decision on their choice for vaccination. After natural infection, SARS-CoV-2 specific antibodies are present in human milk, which might offer protection for her newborn. The dynamics of these antibodies in human milk following vaccination remain to be elucidated.

To determine the effect of vaccination with BNT162b2 on the levels of SARS-CoV-2 specific IgA in human milk.

In this prospective longitudinal study, we included lactating women who received the BNT162b2 vaccine. Human milk samples were collected prior to vaccination and 3, 5, 7, 9, 11, 13, and 15 days after both vaccine doses. Samples were analyzed using enzyme-linked immunosorbent assay against the spike protein of SARS-CoV-2.

In total, 366 human milk samples from 26 lactating women were analyzed. A biphasic response was observed, with SARS-CoV-2 specific immunoglobulin A (IgA) starting to increase between day 5 and 7 after the first dose of the vaccine. After the second dose, an accelerated IgA antibody response was observed.

After vaccination with the mRNA-based BNT162b2 vaccine, a SARS-CoV-2 specific antibody response was observed in human milk. The presence of SARS-CoV-2 specific IgA after vaccination is important as antibodies are transferred via human milk, and thereby might provide protection to infants against COVID-19.

Human milk contains antibodies against Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) following Coronavirus Disease 2019 (COVID-19). These antibodies may serve as protection against COVID-19 in infants. However, the evolution of these human milk antibodies over time is unclear.

To elucidate the evolution of immunoglobulin A (IgA) against SARS-CoV-2 in human milk after a SARS-CoV-2 infection.

This longitudinal follow-up study included lactating mothers (N = 24) who had participated in the COVID MILK study. To assess the evolution of SARS-CoV-2 antibodies, serum and human milk samples were collected 14–143 days after the onset of clinical symptoms related to COVID-19. Enzyme-Linked ImmunoSorbent Assay was used to detect antibodies against the ectodomain of the SARS-CoV-2 spike protein.

SARS-CoV-2 antibodies remain present up to 5 months (143 days) in human milk after onset of COVID-19 symptoms. Overall, SARS-CoV-2 IgA in human milk seems to gradually decrease over time.

Human milk from SARS-CoV-2 convalescent lactating mothers contains specific IgA antibodies against SARS-CoV-2 spike protein up to at least 5 months post-infection. Passive viral immunity can be transferred via human milk and may serve as protection for infants against COVID-19.

The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic has infected over 127 million people worldwide, with almost 2.8 million deaths at the time of writing. Since no lactating individuals were included in initial trials of vaccine safety and efficacy, research on SARS-CoV-2 vaccination in lactating women and the potential transmission of passive immunity to the infant through mother’s milk is needed to guide patients, clinicians, and policy makers on whether to recommend immunization during the worldwide effort to curb the spread of this virus.

(1) To determine whether SARS-CoV-2 specific immunoglobins are found in human milk after vaccination, and (2) to characterize the time course and types of immunoglobulins present.

A longitudinal cohort study of lactating women (N = 7) who planned to receive both doses of the Pfizer-BioNTech or Moderna SARS-CoV-2 vaccine between December 2020 and January 2021 provided milk samples. These were collected pre-vaccination and at 11 additional timepoints, with the last sample at 14 days after the second dose of vaccine. Samples were analyzed for levels of SARS-CoV-2 specific immunoglobulins A and G (IgA and IgG).

We observed significantly elevated levels of SARS-CoV-2 specific IgG and IgA antibodies in human milk beginning approximately 7 days after the initial vaccine dose, with an IgG-dominant response.

Maternal vaccination results in SARS-CoV-2 specific immunoglobulins in human milk that may be protective for infants.

Although mother’s own milk decreases prematurity-associated morbidities, mothers of infants born preterm and very low birth weight experience a significantly shorter lactation duration. Little is known regarding factors associated with lactation cessation during the hospitalization of a very low birth weight infant.

To determine demographic, social, and personal factors associated with lactation cessation by 6-weeks postpartum in mothers delivering very low birth weight infants.

We used a retrospective, longitudinal, two-group comparison design using data from a randomized control study. Mothers of very low birth weight infants (N = 142) were enrolled from a labor and delivery unit associated with a Level 4 neonatal intensive care unit. Demographic, social, and health information was obtained from the medical records. Participants were surveyed regarding lactation goals, experience, and reason(s) for cessation.

Participants who did not continue lactating for more than 6 weeks were more likely to be unemployed (p = .019), Medicaid eligible (p = .009), less educated (p < .031), smoke (p = .002), provide less skin-to-skin care (p = .007), and to delay the decision to provide their milk to their infant (p = .007). After Bonferroni adjustment, only minutes of skin-to-skin care remained statistically significant. Insufficient maternal milk production was the most common reason for lactation cessation.

While the etiology of lactation cessation is often non-modifiable, strategies aimed at maintaining mother’s own milk production, smoking cessation, increasing skin-to-skin care, and promoting an earlier decision to lactate, may prolong lactation duration in this vulnerable population.

This RCT was registered (2012-00071) with ClinicalTrials.com on 6/28/2013.

The expansion of the Baby-Friendly Hospital Initiative to neonatal wards, known as the Neo-BFHI, provides recommendations to support breastfeeding, as outlined in the Three Guiding Principles, the expanded Ten Steps, and the International Code for Marketing of Breast-Milk Substitutes. In 2017, Russia participated in an international survey about compliance with the Neo-BFHI.

To assess breastfeeding support policies and practices in Russian neonatal wards at the country and federal district level in accordance with the Neo-BFHI recommendations.

This study was a prospective cross-sectional survey. We used the Neo-BFHI Self-Assessment questionnaire to collect data from neonatal wards that had all levels of care. A total of N = 60 Russian neonatal wards in hospitals that have ever been designated Baby-Friendly or planned to do so participated in the survey.

Compliance scores at the federal district and country level ranging from 0–100 were used to summarize results. The median country overall score was 90 (IQR = 83 – 93). Respect for mothers, continuity of care, having a breastfeeding policy, and rooming-in had the highest median scores. Family-centered care, antenatal informing, skin-to-skin contact, and human milk use had the lowest median scores. Neonatal wards in the hospitals that were ever designated as Baby-Friendly had significantly higher scores than those that were never designated. Most respondents (n = 48, 80%) expressed a desire to obtain Neo-BFHI designation in their neonatal wards.

Neo-BFHI recommendations can be successfully implemented in Russian neonatal wards at hospitals designated Baby-Friendly or planning to be designated.

Cross-jurisdictional sharing is gaining traction as an option for increasing the effectiveness and efficiency of public health services in local health departments.

Assess whether breastfeeding initiation among participants in the Special Supplemental Nutrition Program for Women, Infants and Children changed with the addition of a trained breastfeeding specialist funded by cross-jurisdictional integration.

A longitudinal retrospective comparative difference in difference design using state-based program data, pre- and post-integration was undertaken. Three local county health departments (n = 5) that fully integrated into one Community Health Board during January 2015, and four neighboring Community Health Boards (n = 4) that did not integrate, were included.

Controlling for confounders and interactions, the relative rate of change over time in breastfeeding initiation rates was greater in the integrated jurisdiction than neighboring Community Health Boards, but not statistically significant. When the integrated Community Health Board’s original three local health departments were considered separately, the relative rate of change over time in breastfeeding rates was greater for one local health department in comparison to three neighbor Community Health Boards (p = .037, .048, and .034, respectively).

The addition of a specialized breastfeeding nutritionist led to improved breastfeeding initiation rates. The increase was significant only in the largest original local health department, which also had the lowest breastfeeding initiation rate pre-merger. The greatest positive change was seen in this local health department where the specialist staff was physically located. Public health staff specialization can lead to increases in economic efficiency and in improved delivery of public health services.

Human milk feeding reduces the incidence and costs of several maternal and childhood illnesses. Initiation and success of human milk feeding are influenced by race, socioeconomic status, and family support. The influence of early in-hospital lactation assistance in breastfeeding success has been not well described.

We aimed to determine how suspected known factors influencing breastfeeding success influence in-hospital human milk feeding rates. Second, we aimed to examine how timing of lactation assistance is related to success of human milk feeding during the newborn hospitalization for healthy infants.

We conducted a retrospective cohort study of term infants born between January 1, 2014 and December 31, 2016 at a large tertiary academic hospital. We considered “success” to be 100% human milk feeding during the birth hospitalization, and compared differences in success by demographics, payor, race, and initial feeding preference. Influences of lactation assistance on success were analyzed using multivariable logistic regression.

Mean success with exclusive human milk feeding among 7,370 infants was 48.9%, (n = 3,601). Successful participants were more likely to be 39–40 weeks’ gestation (64.9%, n = 2,340), non-Hispanic/non-Latino (80.0%, n = 2,882), and using private insurance (69.2%, n = 2,491). Participants who had early feeding assisted by an International Board Certified Lactation Consultant (IBCLC) before being fed any formula were more likely to be successful than participants who had a feeding assisted by a non-IBCLC nurse (80% vs. 40% respectively).

Success for exclusive human milk feeding during newborn hospitalization is strongly associated with several factors. Early intervention with IBCLCs can greatly improve breastfeeding success.

Breastfeeding mothers have been avoiding foods in their diet based on ancient beliefs that it can prevent/reduce unsettled infant crying–fussing behavior.

This study aimed to explore (1) the prevalence of maternal dietary changes during the postpartum period; (2) the demographic and infant feeding differences between women who made dietary changes and those who did not; (3) the reasons for dietary change; and (4) what specific foods were avoided.

A prospective, cross-sectional 2-group comparison using an online survey mixed-methods design was advertised via social media and Australian websites. Anonymous volunteers who were presently breastfeeding or had breastfed for any length of time in the past were eligible.

Of 1,262 participants, 966 (77%) avoided foods/beverages in their diet. The most commonly avoided beverages were alcohol (79%) and coffee (44%), and the most commonly avoided foods were chili (22%), milk-chocolate (22%), cabbage (20%), onion (20%), and garlic (16%). Reasons for dietary avoidance related to baby being unsettled (31%), baby having wind/gas (29%), colic (11%), and crying (10%). Of 245 participants who removed dairy, 80 (33%) did not substitute with calcium-rich alternatives. Food and beverage avoidance commenced as early as 1 week postpartum and continued until mean (SD) infant age of 9 (5) months.

It is commonplace for breastfeeding mothers to avoid foods and beverages for reasons associated with infantile colic. Of major concern is the duration of food avoidance during a time of increased nutritional requirements. This information may assist in improving the nutritional support given to breastfeeding mothers.

Optic neuritis is a rare condition that can lead to sudden blindness and also could be a precursor to multiple sclerosis. When it occurs postpartum during lactation, it is called lactation optic neuritis.

We present four cases of optic neuritis in lactating mothers, two of which had additional features of demyelinating disease upon neurological imaging.

All participants were treated with high dose intravenous steroids followed by 11 days of oral steroids, per the optic neuritis treatment trial, which led to complete recovery of vision. Two participants with demyelinating disease on magnetic resonance imaging scans were advised to wean, because of a need for immunosuppressive therapy later.

Optic neuritis during lactation should be suspected following acute loss of vision. Prompt referral to an ophthalmologist is mandated for early diagnosis and treatment to prevent long-term co-morbidities.

Inconsistent information exists regarding indicators of secretory activation in mothers delivering very low birth weight infants.

To compare time to the onset of secretory activation using three separate indicators. A secondary aim examined the association between indicators of secretory activation and milk production.

Indicators of secretory activation included maternal perception, volume attainment (production of ≥ 20 mL in two consecutive expression sessions) and biomarkers (sodium and lactose) obtained at volume attainment. Milk production was measured on Days 1–7 and then weekly for 6 weeks.

In 69 mothers of infants born ≤ 32 weeks’ gestation and < 1500 g, we found no correlation in time to secretory activation between indicators. Earlier volume attainment was associated with increased milk production on Days 1–7, 14, 21, and 28 (all p < .007). Participants who exhibited both normal lactose and sodium levels produced more milk on Days 28 and 42 (p = .028 and .011), those with only normal lactose levels produced more on Day 42 (p = .026) and those with only normal sodium levels on Day 28 (p = .036). Earlier secretory activation by volume attainment was associated with increased expression frequency during Days 2–5 (all p < .014) and participants with normal biomarkers expressed more frequently during Days 2–5 (all p < .020).

Mothers of very low birth weight infants are at risk for delayed secretory activation, which may decrease their milk production. Frequent expression during the first 5 days postpartum may promote earlier secretory activation. Valid methods of determining secretory activation are necessary to develop interventions promoting earlier secretory activation.

Hospitalization in neonatal intensive care units with a single-family room design enables continuous maternal presence, but less is known regarding the association with milk production and breastfeeding.

To compare maternal milk production, breastfeeding self-efficacy, the extent to which infants received mother’s milk, and rate of direct breastfeeding in a single-family room to an open bay neonatal intensive care unit.

A longitudinal, prospective observational study comparing 77 infants born at 28– 32° weeks gestational age and their 66 mothers (n = 35 infants of n = 30 mothers in single family room and n = 42 infants of n = 36 mothers in open bay). Comparisons were made on milk volume produced, the extent to which infants were fed mother’s milk, and rate of direct breastfeeding from birth to 4 months’ corrected infant age. Breastfeeding self-efficacy was compared across mothers who directly breastfed at discharge (n = 45).

First expression (6 hr vs. 30 hr, p < .001) and first attempt at breastfeeding (48 hr vs. 109 hr, p < .001) occurred significantly earlier, infants were fed a greater amount of mother’s milk (p < .04), and significantly more infants having single-family room care were exclusively directly breastfed from discharge until 4 months’ corrected age; OR 6.8 (95% CI [2.4, 19.1]). Volumes of milk produced and breastfeeding self-efficacy did not differ significantly between participants in either units.

To increase the extent to which infants are fed mother’s own milk and are exclusively directly breastfed, the design of neonatal intensive care units should facilitate continuous maternal presence and privacy for the mother–infant dyad.

Human milk contains appetite-regulating hormones that may influence infant growth and obesity risk.

We evaluated whether leptin, peptide tyrosine-tyrosine (PYY), glucagon-like peptide-1 (GLP-1), and ghrelin concentrations in human milk (1) changed during feeding (from foremilk to hindmilk) and during the first 6 months of infancy; (2) were explained by maternal factors; and (3) were associated with infant anthropometrics and growth.

Mother–infant dyads (N = 22) participated. Samples of foremilk and hindmilk at 1 month postpartum were collected and analyzed for leptin, PYY, GLP-1, and ghrelin via radioimmunoassay and milkfat percentage estimated via creamatocrit. Samples were also collected in mothers (n = 15) who breastfed through 6 months. Anthropometrics were obtained on all mother–infant dyads at 1 month and all infants at 6 months and 12 months.

At 1 month, milk GLP-1 and milkfat concentration increased from foremilk to hindmilk (p ≤ .05) while leptin and PYY concentrations remained stable during feeding. Milk hormone concentrations and milkfat tended to decline overtime, with lower leptin, PYY, and ghrelin at 6 months versus 1 month (p < .05). At 1 month, milk leptin and milkfat content were associated with maternal markers of adiposity (r = 0.49–0.78, p < .001); whereas, milk PYY was correlated with maternal serum PYY concentration (r = 0.672, p = .001). Average 1-month milk concentrations of GLP-1 and leptin were negatively associated with weight-for-age z-scores at 6 months (r = −0.46, p < .05) and 12 months (r = −0.49, p < .05), respectively.

The content of certain appetite-regulating hormones in human milk may be influenced by maternal factors and play a role in infant growth; much needs to be learned about their role in the obesity protection of breastfed infants.