Human milk immune factors, maternal nutritional status, and infant sex: The INSPIRE study.

OBJECTIVES: Breastfeeding is an energetically costly and intense form of human parental investment, providing sole-source nutrition in early infancy and bioactive components, including immune factors. Given the energetic cost of lactation, milk factors may be subject to tradeoffs, and variation in concentrations have been explored utilizing the Trivers-Willard hypothesis. As human milk immune factors are critical to developing immune system and protect infants against pathogens, we tested whether concentrations of milk immune factors (IgA, IgM, IgG, EGF, TGFß2, and IL-10) vary in response to infant sex and maternal condition (proxied by maternal diet diversity [DD] and body mass index [BMI]) as posited in the Trivers-Willard hypothesis and consider the application of the hypothesis to milk composition. METHODS: We analyzed concentrations of immune factors in 358 milk samples collected from women residing in 10 international sites using linear mixed-effects models to test for an interaction between maternal condition, including population as a random effect and infant age and maternal age as fixed effects. RESULTS: IgG concentrations were significantly lower in milk produced by women consuming diets with low diversity with male infants than those with female infants. No other significant associations were identified. CONCLUSIONS: IgG concentrations were related to infant sex and maternal diet diversity, providing minimal support for the hypothesis. Given the lack of associations across other select immune factors, results suggest that the Trivers-Willard hypothesis may not be broadly applied to human milk immune factors as a measure of maternal investment, which are likely buffered against perturbations in maternal condition.

Household food insecurity is prevalent in a cohort of postpartum women who registered in the Canada Prenatal Nutrition Program in Toronto.

OBJECTIVE: To assess the prevalence, severity and socio-demographic predictors of household food insecurity among vulnerable women accessing the Canada Prenatal Nutrition Program (CPNP) and to examine associations between household food insecurity and breastfeeding practices to 6 months. DESIGN: Cohort investigation pooling data from two studies which administered the 18-item Household Food Security Survey Module at 6 months postpartum and collected prospective infant feeding data at 2 weeks and 2, 4 and 6 months. Household food insecurity was classified as none, marginal, moderate or severe. Logistic regression analyses were performed to assess predictors of household food insecurity and associations between household food security (any and severity) and continued and exclusive breastfeeding. SETTING: Three Toronto sites of the CPNP, a federal initiative targeting socially and/or economically vulnerable women. PARTICIPANTS: 316 birth mothers registered prenatally in the CPNP from 2017 to 2020. RESULTS: Household food insecurity at 6 months postpartum was highly prevalent (44 %), including 11 % in the severe category. Risk of household food insecurity varied by CPNP site (P < 0·001) and was higher among multiparous participants (OR 2·08; 95 % CI 1·28, 3·39). There was no association between the prevalence or severity of food insecurity and continued or exclusive breastfeeding to 6 months postpartum in the adjusted analyses. CONCLUSIONS: Household food insecurity affected nearly half of this cohort of women accessing the CPNP. Further research is needed on household food insecurity across the national CPNP and other similar programmes, with consideration of the implications for programme design, service delivery and policy responses.

Investigating infant feeding development in wild chimpanzees using stable isotopes of naturally shed hair.

Measuring the relative contributions of milk and non-milk foods in the diets of primate infants is difficult from observations. Stable carbon (δ13 C) and nitrogen (δ15 N) isotopes in hair can be used to physiologically track infant feeding through development, but few wild studies have done so, likely due to the difficulty in collecting hair non-invasively. We assessed infant feeding at different ages in wild chimpanzees (Pan troglodytes) at Ngogo, Uganda using δ13 C and δ15 N of keratin in 164 naturally shed hairs from 29 infants (61 hairs), 6 juveniles (7 hairs), 28 mothers (67 hairs) and 14 adult males (29 hairs). Hairs were collected when they stuck to feces during defecation or from the ground after chimpanzees groomed or rested. We could not distinguish between the hairs of infants and mothers using strand length and diameter. Infants 1-2 years old were most enriched in 13 C and 15 N and showed means of 1.1‰ in δ13 C and 2.1‰ in δ15 N above their mothers. Infants at 2 years had hair δ13 C values like those of their mothers, which suggests infants began relying more heavily on plants around this age. While mother-infant δ13 C and δ15 N differences generally decreased with offspring age, as is expected when infants rely increasingly more on independent foraging through development, milk seemed to remain an important dietary component for infants older than 2.5 years, as evidenced by continuing elevated δ15 N. We showed that stable carbon and nitrogen isotopes in naturally shed hairs can feasibly detect trophic level differences between chimpanzee infants and mothers. Since it can mitigate some of the limitations associated with behavioral and fecal stable isotope data, the use of hair stable isotopes is a useful, non-invasive tool for assessing infant feeding development in wild primates.

Key genetic variants associated with variation of milk oligosaccharides from diverse human populations.

Human milk oligosaccharides (HMO), the third most abundant component of human milk, are thought to be important contributors to infant health. Studies have provided evidence that geography, stage of lactation, and Lewis and secretor blood groups are associated with HMO profile. However, little is known about how variation across the genome may influence HMO composition among women in various populations. In this study, we performed genome-wide association analyses of 395 women from 8 countries to identify genetic regions associated with 19 different HMO. Our data support FUT2 as the most significantly associated (P < 4.23-9 to P < 4.5-70) gene with seven HMO and provide evidence of balancing selection for FUT2. Although polymorphisms in FUT3 were also associated with variation in lacto-N-fucopentaose II and difucosyllacto-N-tetrose, we found little evidence of selection on FUT3. To our knowledge, this is the first report of the use of genome-wide association analyses on HMO.

Dietary diversity and social determinants of nutrition among late adolescent girls in rural Pakistan.

The conditions in which adolescent girls mature shape their health, development and nutrition. Nutrient requirements increase to support growth during adolescence, but gaps between consumption and requirements exist in low- and middle-income countries. We aimed to identify and quantify the relationship between dietary intake and diverse social determinants of nutrition (SDN) among a subset of adolescent girls 15-18.9 years (n = 390) enrolled within the Matiari emPowerment and Preconception Supplementation (MaPPS) Trial. The primary outcome, dietary diversity score (DDS), was derived by applying the Minimum Dietary Diversity for Women 10-item scale to 24-h dietary recall data collected three times per participant. To examine the associations between the SDN-related explanatory variables and DDS, we generated a hierarchical, causal model using mixed effects linear regression to account for the cluster-randomized trial design. Using all data, diets lacked diversity (DDS mean ± SD: 3.35 ± 1.03 [range: 1-7; n = 1170]), and the minimum cut-off for dietary diversity was infrequently achieved (13.5%; 95% CI: 11.6-15.6%). Consumption of starches was reported in all recalls, but micronutrient-rich food consumption was less common. Of the SDN considered, wealth quintile had the strongest association with DDS (P < 0.0001). The diets of the sampled Pakistani adolescent girls were insufficient to meet micronutrient requirements. Poverty was the most important predictor of a diet lacking in diversity, indicating limited purchasing power or access to nutritious foods. Dietary diversification and nutrition education strategies alone are unlikely to lead to improved diets without steps to tackle this barrier, for example, through fortification of staple foods and provision of supplements.

High levels of breastmilk feeding despite a low rate of exclusive breastfeeding for 6 months in a cohort of vulnerable women in Toronto, Canada.

Exclusive breastfeeding (EBF) for 6 months is a global public health goal, but measuring its achievement as a marker of population breastmilk feeding practices is insufficient. Additional measures are needed to understand variation in non-EBF practices and inform intervention priorities. We collected infant feeding data prospectively at seven time points to 6 months post-partum from a cohort of vulnerable women (n = 151) registered at two Canada Prenatal Nutrition Program sites in Toronto, Canada. Four categories of breastmilk feeding intensity were defined. Descriptive analyses included the (i) proportion of participants in each feeding category by time point, (ii) use of formula and non-formula supplements to breastmilk, (iii) proportion of participants practising EBF continuously for at least 3 months; and (iv) frequency of transitions between feeding categories. All participants initiated breastmilk feeding with 70% continuing for 6 months. Only 18% practised EBF for 6 months, but 48% did so for at least 3 continuous months. The proportion in the EBF category was highest from 2 to 4 months post-partum. Supplemental formula use was highest in the first 3 months; early introduction of solids and non-formula fluids further compromised EBF at 5 and 6 months post-partum. Most participants (75%) transitioned between categories of breastmilk feeding intensity, with 35% making two or more transitions. Our data show high levels of breastmilk provision despite a low rate of EBF for 6 months. Inclusion of similar analyses in future prospective studies is recommended to provide more nuanced reporting of breastmilk feeding practices and guide intervention designs.

Breastfeeding rates are high in a prenatal community support program targeting vulnerable women and offering enhanced postnatal lactation support: a prospective cohort study.

BACKGROUND: In Canada, 91% of all mothers initiate breastfeeding, but 40-50% stop by 6 months and only 34% breastfeed exclusively for 6 months, with lower rates among socially and/or economically vulnerable women. The Canada Prenatal Nutrition Program (CPNP) aims to support breastfeeding among vulnerable women, but there is no formal framework or funding for sites to integrate proactive postnatal breastfeeding support. This research aimed to i) describe infant feeding practices among clients of one Toronto CPNP site using charitable funds to offer a lactation support program (in-home lactation consultant visits, breast pumps); ii) determine whether breastfeeding outcomes at 6 months differ based on maternal sociodemographics and food insecurity; and iii) assess utilization of the lactation support program. METHODS: Infant feeding practices were collected prospectively at 2 weeks, 2, 4 and 6 months postpartum via telephone questionnaires (n = 199). Maternal sociodemographics were collected at 2 weeks and food insecurity data at 6 months postpartum. Program monitoring records were used to determine utilization of the lactation support program. RESULTS: Ninety-one percent of participants were born outside of Canada; 55% had incomes below the Low-Income Cut-Off; and 55% reported food insecurity. All participants initiated breastfeeding, 84% continued for 6 months and 16% exclusively breastfed for 6 months. Among breastfed infants, ≥76% received vitamin D supplementation. Approximately 50% of infants were introduced to solids before 6 months. Only high school education or less and food insecurity were associated with lower breastfeeding rates. Overall, 75% of participants received at least one visit with a lactation consultant and 95% of these received a breast pump. CONCLUSIONS: This study provides initial evidence that postnatal lactation support can be delivered within a CPNP site, with high uptake by clients. While all participants initiated breastfeeding and 84% continued for 6 months, adherence to the recommended 6 months of exclusive breastfeeding was low. Further research is needed to better understand the barriers to exclusive breastfeeding and how to support this practice among vulnerable women. Study registered at clinicaltrials.gov as NCT03400605 .

Premasticated food transfer by wild chimpanzee mothers with their infants: Effects of maternal parity, infant age and sex, and food properties.

Premasticated food transfer, when an individual partially breaks down food through chewing and feeds it to another individual, usually mouth-to-mouth, is described widely across human cultures. This behavior plays an important role in modern humans' strategy of complementary feeding, which involves supplementing maternal milk in infant diets with processed, easily digestible versions of adult foods. The extent to which other primates engage in premasticated food transfer with infants is unclear, as premasticated food transfers have been only occasionally reported in other ape species. We investigated premasticated food transfers in 62 mother-infant pairs of wild chimpanzees at Ngogo, Uganda, as well as unresisted food taking, when mothers passively allow infants to seize food. We evaluated the presence or absence and rates of premasticated food transfer and unresisted food taking relative to maternal parity and infant age and sex and assessed the food species and part used. We found that chimpanzee mothers regularly shared premasticated food with their infants aged between 6 months and 4 years, but they were more likely to share, and more frequently shared, with younger infants. The frequency with which females shared premasticated food may relate to maternal experience, as multiparous females shared premasticated food more often than did first-time mothers, which we did not find with unresisted food taking. Both easy-to-chew, commonly eaten foods and tougher, rarely eaten foods were shared. Premasticated food transfer and unresisted food taking may be infant-rearing strategies to facilitate the transition from a diet of exclusive maternal milk to solid food during early infancy. Premasticated food transfer in particular may provide energetic, immune, or growth benefits to infants through reduced chewing effort and maternal saliva. Given our findings in chimpanzees and earlier reports in other ape species, we suggest that the foundation of complementary feeding, a uniquely hominin strategy, might have been present in a common ancestor shared with the other great apes in the form of premasticated, mouth-to-mouth food transfer by mothers with their offspring.

Household composition and the infant fecal microbiome: The INSPIRE study.

OBJECTIVES: Establishment and development of the infant gastrointestinal microbiome (GIM) varies cross-culturally and is thought to be influenced by factors such as gestational age, birth mode, diet, and antibiotic exposure. However, there is little data as to how the composition of infants' households may play a role, particularly from a cross-cultural perspective. Here, we examined relationships between infant fecal microbiome (IFM) diversity/composition and infants' household size, number of siblings, and number of other household members. MATERIALS AND METHODS: We analyzed 377 fecal samples from healthy, breastfeeding infants across 11 sites in eight different countries (Ethiopia, The Gambia, Ghana, Kenya, Peru, Spain, Sweden, and the United States). Fecal microbial community structure was determined by amplifying, sequencing, and classifying (to the genus level) the V1-V3 region of the bacterial 16S rRNA gene. Surveys administered to infants' mothers identified household members and composition. RESULTS: Our results indicated that household composition (represented by the number of cohabitating siblings and other household members) did not have a measurable impact on the bacterial diversity, evenness, or richness of the IFM. However, we observed that variation in household composition categories did correspond to differential relative abundances of specific taxa, namely: Lactobacillus, Clostridium, Enterobacter, and Klebsiella. DISCUSSION: This study, to our knowledge, is the largest cross-cultural study to date examining the association between household composition and the IFM. Our results indicate that the social environment of infants (represented here by the proxy of household composition) may influence the bacterial composition of the infant GIM, although the mechanism is unknown. A higher number and diversity of cohabitants and potential caregivers may facilitate social transmission of beneficial bacteria to the infant gastrointestinal tract, by way of shared environment or through direct physical and social contact between the maternal-infant dyad and other household members. These findings contribute to the discussion concerning ways by which infants are influenced by their social environments and add further dimensionality to the ongoing exploration of social transmission of gut microbiota and the "old friends" hypothesis.

A novel fecal stable isotope approach to determine the timing of age-related feeding transitions in wild infant chimpanzees.

OBJECTIVES: Determining nutritional development in wild primates is difficult through observations because confirming dietary intake is challenging. Physiological measures are needed to determine the relative contributions of maternal milk and other foods at different ages, and time of weaning. We used fecal stable carbon and nitrogen isotopes (δ13 C, δ15 N) and fecal nitrogen concentrations (%N) from wild chimpanzees at Ngogo, Uganda, to derive physiological dietary indicators during the transition from total reliance on maternal milk to adult foods after weaning. MATERIALS AND METHODS: We analyzed 560 fecal samples collected non-invasively from 48 infants, their mothers, and 6 juvenile siblings. Most infant and juvenile samples (90%) were matched to samples collected from mothers on the same day. Isotopic assessments were compared with observations of nursing and feeding. RESULTS: Infants ≤1 year old showed average δ15 N, δ13 C and %N ratios that were 2.0‰, 0.8‰ and 1.3% greater than their mothers, respectively, interpreted as trophic level effects. Although data collected on newborns were few, results suggest that solid foods were consumed within 2-5 months after birth. Trophic level differences decreased steadily after 1 year, which indicates a decreasing relative contribution of milk to the diet. Isotopic results indicated infants were weaned by 4.5 years old-more than a year earlier than observations of nipple contacts ceased, which revealed the occurrence of "comfort nursing." Juvenile isotopic signatures indicate no nursing overlap between siblings. DISCUSSION: Our results resemble the stable isotope differences of human babies. This study contributes to a model of chimpanzee nutritional development required to understand early life history patterns in hominins.

A qualitative study exploring perceived barriers to infant feeding and caregiving among adolescent girls and young women in rural Bangladesh.

BACKGROUND: Infant feeding and caregiving by adolescent girls and young women in rural Bangladesh remains relatively understudied despite high potential vulnerability of younger mothers and their children due to poverty and high rates of early marriage and childbearing. This key knowledge gap may hamper the effectiveness of maternal, infant and child health interventions not specifically tailored to teenage mothers. This study aimed to narrow this gap by documenting key barriers to optimal infant and young child feeding and caregiving perceived by adolescent girls and young women in rural Bangladesh. METHODS: Focus group discussions and in-depth semi-structured interviews were conducted with 70 adolescent girls and young women participating in a community-based adolescent empowerment program in two rural regions of northwestern Bangladesh. Participants were stratified into three groups: unmarried, married without child, and married with child(ren). Thematic analysis was performed to elucidate dominant ideas regarding challenges with child feeding and caregiving across participant strata. RESULTS: Participants in all three strata and in both geographical regions attributed actual and anticipated caregiving difficulties to five major contextual factors: early marriage, maternal time allocation conflicts, rural life, short birth intervals, and poverty. Indications are that many girls and young women anticipate difficulties in feeding and caring for their future children from an early age, and often prior to motherhood. Participants articulated both perceived need and unmet demand for additional education in infant and young child feeding, childcare, and family planning techniques. CONCLUSIONS: Provision during adolescence of appropriate education, services and financial aid to support best practices for infant feeding and childcare could significantly improve maternal self-efficacy, mental health, nutrition security and young childcare, nutrition and health in rural Bangladesh. Lessons learned can be applied in future programs aimed at supporting adolescent women along a continuum of care.

Prevalence and Characteristics Associated with Breastfeeding Initiation Among Canadian Inuit from the 2007-2008 Nunavut Inuit Child Health Survey.

We aimed to determine the prevalence of, and factors associated with, breastfeeding initiation in Canadian Inuit. We used data from the Nunavut Inuit Child Health Survey, a population-based, cross-sectional survey conducted in the Canadian territory of Nunavut. Inuit children aged 3-5 years in 2007 or 2008 were randomly selected for the survey. Select household, maternal, infant and community characteristics were collected from the child's primary caregiver and entered into logistic regression models as potential predictors of breastfeeding initiation. Analyses were repeated in a subgroup of caregiver reports from biological mothers. The reported prevalence of breastfeeding initiation was 67.6% (95% CI 62.4-72.8) overall and 85.1% (95% CI 80.2-90.1) in a subgroup of caregiver reports from biological mothers. Adjusted prevalence odds ratios (pOR) indicate the primary caregiver was an important determinant of breastfeeding (adopted parent vs. biological mother: pOR = 0.03, 95% CI 0.01-0.07; other vs. biological mother: pOR = 0.33, 95% CI 0.14-0.74). Maternal smoking during pregnancy and having access to a community birthing facility were also potentially important, but not statistically significant (p > 0.05). In conclusion, data from the Nunavut Inuit Child Health Survey indicate breastfeeding is initiated for more than two-thirds of children, but rates are below the national average and this may be one of several pathways to poor health outcomes documented in many Inuit communities. Considered in the particular context of birthing facilities utilization and postnatal care arrangements in Inuit communities, these results suggest that increasing breastfeeding initiation will require health interventions that effectively engage all types of primary caregivers.

Knowledge, attitudes and perceptions on infant and young child nutrition and feeding among adolescent girls and young mothers in rural Bangladesh.

Improved infant and young child feeding (IYCF) practices have the potential to improve child health and development outcomes in poorly resourced communities. In Bangladesh, approximately 60% of rural girls become mothers before the age of 18, but most interventions to improve IYCF practices target older mothers. We investigated the knowledge, attitudes and perceptions regarding IYCF among adolescent girls and young women aged 15-23 years old in two rural regions in north-west Bangladesh and identified the main points of concordance with, or mismatch to, key international IYCF recommendations. We compared qualitative data collected during interviews and focus groups with participants who were unmarried, married without a child and married with at least one child, and stratified by region. Qualitative indicators of concordance with international recommendations suggest that IYCF knowledge of participants was limited, irrespective of marriage or maternity. Young mothers in our study were no more knowledgeable about feeding practices than their nulliparous peers. Some participants were well aware of an IYCF recommendation (e.g. to exclusively breastfeed for 6 months), but their interpretation of the recommendation deviated from the intended public health message. Notions of insufficient or 'spoiled' breast milk, gender-based biases in feeding intentions and understandings of infant needs, and generational shifts in feeding practices were commonly reported. Conclusions are that female adolescence is a window of opportunity for improving health outcomes among future children, and increased investment in early education of adolescent girls regarding safe IYCF may be an effective strategy to promote and support improved infant feeding practices.

Home fortification with calcium reduces Hb response to iron among anaemic Bangladeshi infants consuming a new multi-micronutrient powder formulation.

OBJECTIVE: To investigate whether the recommended dietary intake of Ca in anaemic infants compromises the expected Hb response, via home fortification with a new Ca- and Fe-containing Sprinkles™ micronutrient powder (MNP). DESIGN: A double-blind, randomized controlled, 2-month trial was conducted in Bangladesh. Infants were randomized to one of two MNP intervention groups containing Fe and other micronutrients, with or without Ca. Hb, anthropometrics and dietary intake were measured pre- and post-intervention while family demographics were collected at baseline. SETTING: Twenty-six rural villages in the Kaliganj sub-district of Gazipur, Bangladesh. SUBJECTS: One hundred infants aged 6-11 months. RESULTS: A significant increase in Hb (MNP, 13·3 (sd 12·6) g/l v. Ca-MNP, 7·6 (sd 11·6) g/l; P < 0·0001) was noted in infants from both groups. However, infants receiving MNP without Ca had a significantly higher end-point Hb concentration (P = 0·024) and rate of anaemia recovery (P = 0·008). Infants receiving MNP with Ca were more likely to remain anaemic (OR 3·2; 95 % CI 1·4, 7·5). Groups did not differ in dietary intake or demographic and anthropometric indicators. CONCLUSIONS: Although both groups showed significant improvement in Hb status, the nutrient-nutrient interaction between Fe and Ca may have diminished the Hb response in infants receiving the Ca-containing MNP.

Household food insecurity shows associations with food intake, social support utilization and dietary change among refugee adult caregivers resettled in the United States.

Forced migration puts families at risk of household food insecurity and economic hardship. We administered a questionnaire to examine household food insecurity in a sample of 49 recently legally resettled Sudanese refugees with at least one child under age 3 years. Of households polled, 37% had experienced household food insecurity and 12% reported child hunger within the previous month. Increasing severity of household food insecurity was associated with decreased consumption of high-cost, high-nutrient-density food items and increased consumption of some low-cost traditional Sudanese foods by adult caregivers of young children. Furthermore, household food insecurity was associated with decreased household and per capita food expenditure, indicators of more limited dietary change with migration, and indicators of increased social support.

Impact of the COVID-19 pandemic on the adaptability and resiliency of school food programs across Canada.

Introduction: Following the sudden closure of schools due to the pandemic in 2020, many school food program (SFP) operators lost their operating venues and had to innovate to continue distributing meals to children. Our objective was to assess the impact of the COVID-19 pandemic on the delivery, adaptability, and resiliency of school food programs across Canada by conducting a systematic rapid review. Materials and methods: Systematic literature searches identified newspaper articles and social media sources related to the adaptations and challenges faced by school food programs across Canada in response to the COVID-19 pandemic. Included sources were assessed and thematically categorized according to the dimensions of the Analysis Grid for Environments Linked to Obesity (ANGELO) and Getting To Equity (GTE) frameworks to identify factors impacting the delivery, adaptability, and resiliency of school food programs in Canada. Results: School food programs in Canada made various efforts to meet existing and new challenges associated with the delivery of these programs to keep feeding school children, particularly those most vulnerable, during the pandemic. Distribution of food kits, prepared meals and gift cards/coupons were successful pathways in ensuring support for food accessibility to students and their families. Increased collaborations between community members and organizations/stakeholders to help maintain food delivery or collectively offer new modes to deliver foods were most frequently cited as key to facilitating school food programming. However, maintenance and sustainability related to operating costs and funding were identified as key challenges to successful school food programming. Conclusion: Our study highlights the swift and substantial transformation school food programs,, underwent in response to the pandemic, driven by the urgent need to ensure that students still had access to nutritious meals and the importance of policy and resource support to bolster the adaptability and resiliency of these programs. Findings on facilitators and challenges to school food programs during the early months of the COVID-19 pandemic can inform development of guidelines to design a robust national Canadian school food program and help make existing programs more sustainable, adaptable, and resilient.

Food insecurity is associated with attitudes towards exclusive breastfeeding among women in urban Kenya.

This study aimed to document whether food insecurity was associated with beliefs and attitudes towards exclusive breastfeeding (EBF) among urban Kenyan women. We conducted structured interviews with 75 human immunodeficiency virus (HIV)-affected and 75 HIV-status unknown, low-income women who were either pregnant or with a child ≤24 months and residing in Nakuru, Kenya to generate categorical and open-ended responses on knowledge, attitudes and beliefs towards EBF and food insecurity. We facilitated six focus group discussions (FGD) with HIV-affected and HIV-status unknown mothers (n = 50 women) to assess barriers and facilitators to EBF. Of 148 women with complete interview data, 77% were moderately or severely food insecure (FIS). Women in FIS households had significantly greater odds of believing that breast milk would be insufficient for 6 months [odds ratio (OR), 2.6; 95% confidence interval (95% CI), 1.0, 6.8], that women who EBF for 6 months would experience health or social problems (OR, 2.7; 95% CI, 1.0, 7.3), that women need adequate food to support EBF for 6 months (OR, 2.6; 95% CI, 1.0, 6.7) and that they themselves would be unable to follow a counsellor's advice to EBF for 6 months (OR, 3.2; 95% CI, 1.3, 8.3). Qualitative analysis of interview and FGD transcripts indicated that the maternal experience of hunger contributes to perceived milk insufficiency, anxiety about infant hunger and a perception that access to adequate food is necessary for successful breastfeeding. The lived experience of food insecurity among a sample of low-income, commonly FIS, urban Kenyan women reduces their capacity to implement at least one key recommended infant feeding practices, that of EBF for 6 months.

Effects of infant age and sex, and maternal parity on the interaction of lactation with infant feeding development in chimpanzees.

The interaction between infant feeding and maternal lactational physiology influences female inter-birth intervals and mediates maternal reproductive trade-offs. We investigated variation in feeding development in 72 immature wild chimpanzees (Pan troglodytes schweinfurthii) at Ngogo, Kibale National Park, Uganda, and made inferences about maternal lactation over the course of infancy. We compared the percentage (%) of time that mothers nursed infants as a function of infant age and assessed how hourly rates and bout durations of nursing and foraging varied in association with differences in offspring age, sex, and maternal parity. Nursing % times, rates and durations were highest for infants ≤ 6 months old but did not change significantly from 6 months to 5 years old. Nursing continued at a decreasing rate for some 5- to 7-year-olds. Infants ≤ 6 months old foraged little. Foraging rates did not change after 1 year old, but foraging durations and the % time devoted to foraging increased with age. Independent foraging probably became a dietary requirement for infants at 1 year old, when their energy needs may have surpassed the available milk energy. Infants spent as much time foraging by the time they were 4 to 5 years old as adults did. No sex effect on infant nursing or foraging was apparent, but infants of primiparous females had higher foraging rates and spent more time foraging than the infants of multiparous females did. Although no data on milk composition were collected, these findings are consistent with a working hypothesis that like other hominoids, chimpanzee mothers maintained a fixed level of lactation effort over several years as infants increasingly supplemented their growing energy, micronutrient and hydration needs via independent foraging. Plateauing lactation may be a more widespread adaptation that allows hominoid infants time to attain the physiology and skills necessary for independent feeding, while also providing them with a steady dietary base on which they could rely consistently through infancy, and enabling mothers to maintain a fixed, predictable level of lactation effort.

Associations between use of expressed human milk at 2 weeks postpartum and human milk feeding practices to 6 months: a prospective cohort study with vulnerable women in Toronto, Canada.

OBJECTIVES: To examine whether use of expressed human milk in the first two weeks postpartum is associated with cessation of human milk feeding and non-exclusive human milk feeding up to 6 months. DESIGN: Pooled data from two prospective cohort studies SETTING: Three Canada Prenatal Nutrition Program (CPNP) sites serving vulnerable families in Toronto, Canada. PARTICIPANTS: 337 registered CPNP clients enrolled prenatally from 2017 to 2020; 315 (93%) were retained to 6 months postpartum. EXCLUSIONS: pregnancy loss or participation in prior related study; Study B: preterm birth (<34 weeks); plan to move outside Toronto; not intending to feed human milk; hospitalisation of mother or baby at 2 weeks postpartum. PRIMARY AND SECONDARY OUTCOME MEASURES: Main exposure variable: any use of expressed human milk at 2 weeks postpartum. OUTCOMES: cessation of human milk feeding by 6 months; non-exclusive human milk feeding to 4 months and 6 months postpartum. RESULTS: All participants initiated human milk feeding and 80% continued for 6 months. Exclusive human milk feeding was practiced postdischarge to 4 months by 28% and to 6 months by 16%. At 2 weeks postpartum, 34% reported use of expressed human milk. Any use of expressed human milk at 2 weeks was associated with cessation of human milk feeding before 6 months postpartum (aOR 2.66; 95% CI 1.41 to 5.05) and with non-exclusive human milk feeding to 4 months (aOR 2.19; 95% CI 1.16 to 4.14) and 6 months (aOR 3.65; 95% CI 1.50 to 8.84). TRIAL REGISTRATION NUMBERS: NCT03400605, NCT03589963.

Effect on breastfeeding practices of providing in-home lactation support to vulnerable women through the Canada Prenatal Nutrition Program: protocol for a pre/post intervention study.

BACKGROUND: Only one-third of Canadian infants are exclusively breastfed for the first 6 months of life as recommended. Skilled lactation support in the early postpartum period is one strategy for improving breastfeeding outcomes by building breastfeeding self-efficacy and resolving difficulties. Access to such support is limited among vulnerable women, including those who are new immigrants, low income, under-educated, young or single. The Canada Prenatal Nutrition Program (CPNP) aims to improve birth and breastfeeding outcomes among vulnerable women, but currently lacks a formal framework for providing postpartum lactation support. METHODS: This pre/post intervention study will examine the effect on breastfeeding outcomes of an evidence-based in-home lactation support intervention provided through the CPNP. We will enrol 210 pregnant women who intend to breastfeed and are registered CPNP clients at two sites in Toronto, Canada. During the intervention phase, postpartum home visits by International Board Certified Lactation Consultants (IBCLCs) will be pro-actively offered to registered clients of the two sites. Double-electric breast pumps will also be provided to those who meet specific criteria. Infant feeding data will be collected prospectively at seven time points from 2 weeks to 6 months postpartum. Descriptive and regression analyses will be conducted to measure intervention effects. The primary outcome is exclusive breastfeeding at 4 months postpartum. Secondary outcomes include the duration of any and exclusive breastfeeding, timing of introduction of breastmilk substitutes and timing of introduction of solid foods. Breastfeeding self-efficacy will be assessed prenatally and at 2 weeks and 2 months postpartum. Other measures include maternal socio-demographics, infant feeding intentions, maternal depression and anxiety, and household food insecurity. Monitoring data will be used to assess the reach, uptake and fidelity of intervention delivery. DISCUSSION: Increasing access to skilled lactation support through the CPNP may be an effective means of improving breastfeeding practices among vulnerable women and thereby enhancing health and development outcomes for their infants. This pre/post intervention study will contribute evidence on both the effectiveness and feasibility of this approach, in order to guide the development and further testing of appropriate models of integrating lactation support into the CPNP. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03589963 ) registered July 18, 2018.