Long-term health outcomes and mechanisms associated with breastfeeding

Heatwaves and wildfires suffocate our healthy start to life: time to assess impact and take action

Adverse environmental exposures in utero and early childhood are known to programme long-term health. Climate change, by contributing to severe heatwaves, wildfires, and other natural disasters, is plausibly associated with adverse pregnancy outcomes and an increase in the future burden of chronic diseases in both mothers and their babies. In this Personal View, we highlight the limitations of existing evidence, specifically on the effects of severe heatwave and wildfire events, and compounding syndemic events such as the COVID-19 pandemic, on the short-term and long-term physical and mental health of pregnant women and their babies, taking into account the interactions with individual and community vulnerabilities. We highlight a need for an international, interdisciplinary collaborative effort to systematically study the effects of severe climate-related environmental crises on maternal and child health. This will enable informed changes to public health policy and clinical practice necessary to safeguard the health and wellbeing of current and future generations.

Excretion of polybrominated diphenyl ethers and AhR activation in breastmilk among firefighters

Excretion of toxicants accumulated from firefighter exposures through breastmilk represents a potential hazard. We investigated if firefighting exposures could increase the concentration of polybrominated diphenyl ethers (PBDEs) and aryl hydrocarbon receptor (AhR) activation in excreted breastmilk. Firefighters and non-firefighters collected breastmilk samples prior to any firefighting responses (baseline) and at 2, 8, 24, 48, and 72 hours after a structural fire (firefighters only). Five PBDE analytes (BDEs 15, 28, 47, 99, and 153) detected in at least 90% of samples were summed for analyses. The AhR in vitro DR CALUX® bioassay assessed the mixture of dioxin-like compounds and toxicity from breastmilk extracts. Baseline PBDEs and AhR response were compared between firefighters and non-firefighters. Separate linear mixed models assessed changes in sum of PBDEs and AhR response among firefighters over time and effect modification by interior or exterior response was assessed. Baseline PBDE concentrations and AhR responses did not differ between the 21 firefighters and 10 non-firefighters. There were no significant changes in sum of PBDEs or AhR response among firefighters over time post-fire, and no variation by interior or exterior response. Plots of sum of PBDEs and AhR response over time demonstrated individual variation but no consistent pattern. Currently, our novel study results do not support forgoing breastfeeding after a fire exposure. However, given study limitations and the potential hazard of accumulated toxicants from firefighter exposures excreted via breastfeeding, future studies should consider additional contaminants and measures of toxicity by which firefighting may impact maternal and child health.

Role of milk glycome in prevention, treatment, and recovery of COVID-19

Milk contains all essential macro and micro-nutrients for the development of the newborn. Its high therapeutic and antimicrobial content provides an important function for the prevention, treatment, and recovery of certain diseases throughout life. The bioactive components found in milk are mostly decorated with glycans, which provide proper formation and modulate the biological functions of glycosylated compounds. The glycome of milk consists of free glycans, glycolipids, and N- and O- glycosylated proteins. Recent studies have shown that both free glycans and glycan-containing molecules have antiviral characteristics based on different mechanisms such as signaling, microbiome modulation, natural decoy strategy, and immunomodulatory action. In this review, we discuss the recent clinical studies and potential mechanisms of free and conjugated glycans' role in the prevention, treatment, and recovery of COVID-19.

A New Safety Scoring System for the Use of Psychotropic Drugs During Lactation

BACKGROUND

Psychotropic drugs are frequently used to treat postpartum women with psychiatric diagnoses, especially psychotic disorder, major depression, and bipolar mood episodes. Pharmacotherapy in breastfeeding mothers is a major challenge.

STUDY QUESTION

This article presents a new safety scoring system for the use of psychotropic drugs during lactation.

STUDY DESIGN

The scoring system is based on the following 6 safety parameters: reported total sample, reported maximum relative infant dose, reported sample size for relative infant dose, infant plasma drug levels, prevalence of reported any adverse effect, and reported serious adverse effects. The total score ranges from 0 to 10. Higher scores represent a higher safety profile.

RESULTS

According to this scoring system, sertraline and paroxetine, respectively, had the highest scores representing "very good safety profile." Citalopram, olanzapine, and midazolam were assigned to "good safety profile." Among drugs evaluated in this article, trifluoperazine, aripiprazole, amisulpride, clozapine, doxepin, zaleplon, and zolpidem are not recommended owing to safety scores ≤3.

CONCLUSIONS

Most psychotropic drugs examined in this article have "moderate" or "low" safety profile.

Use of Psychotropic Medication During Lactation in Postpartum Psychiatric Patients: Results from an 8-Year Clinical Sample

Objective: The aim of this study was to examine the lactation status and prevalence of use of psychotropic medications in perinatal psychiatric patients. Methods: Clinical data collated for a period of 8 years were retrospectively retrieved from patient registers. The sample included a total of 263 postpartum patients who were followed up for at least 4 weeks. Psychiatric diagnoses were ascertained by a structured clinical interview. Results: The most commonly administered psychotropic medications were paroxetine (43.3%), sertraline (31.9%), olanzapine (12.2%), and quetiapine (6.1%). Of the 242 patients who received psychotropic medication, 41 (16.9%) discontinued breastfeeding. The discontinuation in most cases was not due to psychiatrist's recommendation or adverse events due to medications. Conclusion: Paroxetine and sertraline are frequently used by postpartum psychiatric patients in our clinical sample. In addition, the results suggesting that most psychiatric patients included in this study can continue breastfeeding during pharmacotherapy should be confirmed by data derived from further clinical samples.

Maternal Immunization: Nature Meets Nurture

Vaccinating women in pregnancy (i.e., maternal immunization) has emerged as a promising tool to tackle infant morbidity and mortality worldwide. This approach nurtures a 'gift of nature,' whereby antibody is transferred from mother to fetus transplacentally during pregnancy, or postnatally in breast milk, thereby providing passive, antigen-specific protection against infections in the first few months of life, a period of increased immune vulnerability for the infant. In this review, we briefly summarize the rationale for maternal immunization programs and the landscape of vaccines currently in use or in the pipeline. We then direct the focus to the underlying biological phenomena, including the main mechanisms by which maternally derived antibody is transferred efficiently to the infant, at the placental interface or in breast milk; important research models and methodological approaches to interrogate these processes, particularly in the context of recent advances in systems vaccinology; the potential biological and clinical impact of high maternal antibody titres on neonatal ontogeny and subsequent infant vaccine responses; and key vaccine- and host-related factors influencing the maternal-infant dyad across different environments. Finally, we outline important gaps in knowledge and suggest future avenues of research on this topic, proposing potential strategies to ensure optimal testing, delivery and implementation of maternal vaccination programs worldwide.

Linking isotope analysis and paleopathology: An andean perspective

This paper reviews the significant advances in isotopic investigations in Andean South America and directs scholars to explore new theoretical and analytical directions, specifically the applicability of isotope data to paleopathology. Excellent preservation and large skeletal collections of human remains make the Central Andes ideal for biogeochemical reconstructions and advancements in isotopic methods. Our aims are twofold: first, we present a meta-analysis of stable and radiogenic isotope research in the Central Andes since 1985, and highlight those that combine analyses of isotope ratios and pathological conditions. Second, we discuss useful directions for incorporating stable isotope analysis more explicitly in studies of paleopathology in the Andes more in the future. Principle research foci have described dietary variation and regional population mobility since the 1980s, where early methodological explorations identified significant trends in isotopic variation. For the years 1980-2017, we identified 96 scholarly publications through a meta-data analysis of major peer-reviewed journals, book chapters, and conference proceedings. These demonstrate specific trends in topical and methodological preferences across the Andean region and a shift from 10 publications pre-1997 to 67 in the last 10 years. However, combined isotope and paleopathology studies in this region remain sparse; given the ecological, geological, and cultural complexity of the Central Andes, analyses of pathological conditions in different regions would significantly benefit from the information on diet, mobility, and local ecology that isotope ratios provide. Isotope analysis requires destruction of archaeological tissues, and interpreting isotope data can be complex, but it can also provide unique insights into the pathogenesis of multifactorial conditions and assist differential diagnosis. Therefore, we also discuss research designs for pairing isotopic and paleopathological variables that will allow researchers to better capture disease ecologies in archaeological samples and their variation across different regions, within related sites, and within individual lifespans.

Psychological effects of breastfeeding on children and mothers

While the nutritional and physical health benefits of breastfeeding are well established, accumulating research demonstrates the far-reaching psychological effects of breastfeeding on children and their mothers. Here, we provide a non-exhaustive review of the empirical evidence, showing that breastfeeding impacts children's brain, cognitive, and socio-emotional development. In mothers, research is presented indicating that breastfeeding influences mood, affect, stress, and maternal care. The current review aims to provide a broad overview of existing findings on the psychological effects of breastfeeding, highlighting the important role that breastfeeding plays across several dimensions of psychological functioning. We also discuss the potential mechanisms that may underpin the observed effects, provide a constructive commentary on the limitations of the existing work, and put forth some considerations when evaluating this line of research.

Association Between Breastfeeding Initiation and Duration and Autism Spectrum Disorder in Preschool Children Enrolled in the Study to Explore Early Development

Studies report inconsistent findings on the relationship between ASD and breastfeeding. We explored associations between ASD and breastfeeding initiation (yes/no) and duration (months categorized in tertiles) in the Study to Explore Early Development, a community-based case-control study in six sites in the Unites States. We adjusted for various child and mother demographic and pregnancy factors. Breastfeeding initiation was reported in 85.7% of mothers of children with ASD and 90.6% of mothers of controls. After adjustment, we found no significant difference in breastfeeding initiation (adjusted odds-ratio [aOR]: 0.88 and 95% confidence interval (CI) 0.60-1.28). However, mothers of children with ASD were less likely to report duration of breastfeeding in the high (≥12 months) versus low tertile (<6 months) (aOR and 95% CI: 0.61 [0.45-0.84]) or the middle (6-<12 months) versus low tertile (0.72: 0.54-0.98). The association of ASD and breastfeeding duration was slightly attenuated when the presence of the broader autism phenotype (BAP) in the mother was accounted for, but still remained for the highest tertile. This association does not appear to be totally explained by maternal BAP. We were unable to distinguish whether the difference in duration was due to difficulties breastfeeding children who later develop ASD, other factors not adjusted in our study, or greater ASD risk resulting from shorter breastfeeding duration. Longitudinal studies that compare reasons why mothers stop breastfeeding between ASD and controls and establish a temporal relation between ASD and breastfeeding are needed. Future studies should also evaluate interactions between ASD risk genes and breastfeeding. Autism Research 2019, 12: 816-829. © 2019 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: In this study, we compared breastfeeding practices between mothers of children with and without autism spectrum disorder (ASD). We found that the percentage of mothers who started breastfeeding was similar between the two groups, but mothers of children with ASD breastfed for a shorter amount of time compared to mothers of children without ASD. Future studies are needed to evaluate the reasons why the duration of breastfeeding was shorter for mothers of children with ASD compared to those without ASD.

Informing the management of acute malnutrition in infants aged under 6 months (MAMI): risk factor analysis using nationally-representative demographic & health survey secondary data

BACKGROUND

Tackling malnutrition is a global health priority, helping children both survive and thrive. Acute malnutrition (wasting) in infants aged under 6 months (u6m) is often neglected. Worldwide, some 8.5 million infants u6m are affected yet recent World Health Organization malnutrition guidelines highlight numerous evidence gaps on how to best manage them. To inform future research, policy and programming, we aimed to identify risk factors associated with infant u6m wasting.

METHODS

We did secondary data analysis of nationally representative, cross sectional Demographic and Health Surveys conducted in the last 10 years. We compared wasted infants u6m (weight-for-length <-2 z-scores) vs. non-wasted (weight-for-length ≥-2 z-score). We used simple and adjusted (for infant age, sex, socio-economic status) logistic regression to calculate odds of wasting associated with risk factors spanning three broad categories: household-related; maternal-related; infant-related.

RESULTS

We analysed 16,123 infants u6m from 20 countries. Multiple risk factors were statistically associated with wasting. These included: poverty (Odds ratio, OR 1.22 (95% CI [1.01-1.48], p = 0.04)); low maternal body mass index (adjusted OR 1.53(1.29-1.80, p < 0.001); small infant size at birth (aOR 1.32(1.10-1.58, p < 0.01)); delayed start of breastfeeding (aOR 1.31(1.13-1.51, p < 0.001)); prelacteal feed (aOR 1.34(1.18-1.53, p < 0.001)); recent history of diarrhoea (aOR 1.37(1.12-1.67, p < 0.01)); mother disempowered (experiences violence; does not make decisions about health issues; does not engage with health services such as antenatal care, does not give birth in a health facility). 'Protective' factors associated with significantly decreased odds of infant u6m wasting included: educated mother (OR 0.64(0.54-0.76, p < 0.001)); mother in work (OR 0.82(0.72-0.94, p < 0.01)); currently breastfed (aOR 0.62(0.42-0.91, p = 0.02)), exclusively breastfed (aOR 0.84(0.73-0.97, p = 0.02).

DISCUSSION

Infant u6m wasting is a complex, multifactorial problem associated with many risk factors; knowing them will help shape international and national management strategies. Whilst our observational study cannot prove causation, many factors identified are biologically plausible and/or socially important. They should be considered when assessing and managing infants u6m. Although supporting breastfeeding is core to future interventions, this alone is unlikely to be sufficient; strategies should involve multiple sectors, beyond just health and nutrition. By noting our results, future intervention studies could focus resources and maximise chances of achieving impact.

Protective effect of breastfeeding on recurrent cough in adulthood

RATIONALE

Breastfeeding protects from respiratory infections in early life but its relationship to recurrent cough and other respiratory outcomes in adult life is not well established.

METHODS

Infant feeding practices were assessed prospectively in the Tucson Children's Respiratory Study, a non-selected birth cohort and categorised into formula from birth or introduced <1 month, formula introduced ≥1 to <4 months and exclusive breastfeeding for ≥4 months. Infant feeding was assessed as an ordinal variable representing an increasing dose of breastmilk across the three categories. Recurrent cough was defined at 22, 26 and 32 years as ≥2 episodes of cough without a cold lasting 1 week during the past year. Covariates included participant sex, race/ethnicity and smoking as well as parental smoking, education, age and asthma. Covariates were evaluated as potential confounders for the relation between infant feeding and adult outcomes.

RESULTS

Of the 786 participants, 19% breastfed <1 month, 50% breastfed ≥1 to <4 months and 31% breastfed ≥4 months. The prevalence of recurrent cough at 22, 26 and 32 years was 17%, 15% and 16%, respectively. Each ordinal increase in breastfeeding duration was associated with a decreased risk of recurrent cough in adult life: adjusted OR=0.71, (95% CI: 0.56 to 0.89), p=0.004. Additional adjustment for concurrent adult asthma, wheeze, smoking and lung volume did not change these results.

CONCLUSION

Longer duration of breastfeeding reduces the risk of recurrent cough in adult life, regardless of smoking and other respiratory symptoms, suggesting long-term protective effects on respiratory health.

Breast Milk Cytokines and Early Growth in Gambian Infants

Background: Breast milk provides nutrition for infants but also delivers other bioactive factors that have key protective and developmental benefits. In particular, cytokines are thought to play a role in immunomodulation, although little is known about their impact on health outcomes in early life. Objective: The purpose of this pilot study was to evaluate the relationship between cytokines in breast milk and infant growth outcomes in a low-income setting. Methods: 100 mother-infant pairs were followed up to 2-3 months postpartum as part of a prospective longitudinal cohort study in urban Gambia, West Africa. The concentrations of 9 pro-inflammatory cytokines (IL-1β, IL-2, IL-4, IL-6, IL-10, IL-12, IL-13, IFN-γ, TNFα), IGF-1 and TGFβ2 were measured in colostrum within 12 h of birth and in breast milk at the final visit, scheduled between day 60 and 89 postpartum. Infant weight was recorded and converted to weight-for-age Z-scores (WAZ) at the same time points. Growth outcomes were defined in our study as (a) change in WAZ between birth and final visit (b) WAZ at final visit. Linear regression analysis was used to determine the ability of colostrum and breast milk cytokine concentrations to predict growth outcomes up to 2-3 months postpartum. Results: Gambian infants demonstrated growth faltering across the first 2-3 months postpartum. There was no significant relationship between cytokines in colostrum and subsequent change in WAZ between birth and the final visit, in either unadjusted or adjusted models. However, cytokines in mature breast milk, TNFα, IFNγ, IL1β, IL2, IL4, and IL6, were weak negative predictors of WAZ scores at the final visit, in unadjusted models (p < 0.05). When adjusted for maternal anemia (as a proxy for maternal nutrition), TNFα and IL6 remained significant predictors (p < 0.05). Conclusions: Variations in breast milk cytokine levels do not play a substantial role in the growth faltering observed across early infancy. The potential contribution of other factors, such as micronutrients, hormones or human milk oligosaccharides, must be elucidated. Cytokine levels in mature breast milk were weakly predictive of poor infant growth, possibly reflecting a "read-out" of suboptimal maternal health and nutrition.

Genetic variation in CD38 and breastfeeding experience interact to impact infants' attention to social eye cues

Attending to emotional information conveyed by the eyes is an important social skill in humans. The current study examined this skill in early development by measuring attention to eyes while viewing emotional faces in 7-mo-old infants. In particular, we investigated individual differences in infant attention to eyes in the context of genetic variation (CD38 rs3796863 polymorphism) and experiential variation (exclusive breastfeeding duration) related to the oxytocin system. Our results revealed that, whereas infants at this age show a robust fear bias (increased attention to fearful eyes), their attention to angry and happy eyes varies as a function of exclusive breastfeeding experience and genetic variation in CD38. Specifically, extended exclusive breastfeeding duration selectively enhanced looking preference to happy eyes and decreased looking to angry eyes. Importantly, however, this interaction was impacted by CD38 variation, such that only the looking preferences of infants homozygous for the C allele of rs3796863 were affected by breastfeeding experience. This genotype has been associated with reduced release of oxytocin and higher rates of autism. In contrast, infants with the CA/AA genotype showed similar looking preferences regardless of breastfeeding exposure. Thus, differences in the sensitivity to emotional eyes may be linked to an interaction between the endogenous (CD38) and exogenous (breastfeeding) availability of oxytocin. These findings underline the importance of maternal care and the oxytocin system in contributing to the early development of responding to social eye cues.

Duration of exclusive breastfeeding is associated with differences in infants' brain responses to emotional body expressions

Much research has recognized the general importance of maternal behavior in the early development and programing of the mammalian offspring's brain. Exclusive breastfeeding (EBF) duration, the amount of time in which breastfed meals are the only source of sustenance, plays a prominent role in promoting healthy brain and cognitive development in human children. However, surprisingly little is known about the influence of breastfeeding on social and emotional development in infancy. In the current study, we examined whether and how the duration of EBF impacts the neural processing of emotional signals by measuring electro-cortical responses to body expressions in 8-month-old infants. Our analyses revealed that infants with high EBF experience show a significantly greater neural sensitivity to happy body expressions than those with low EBF experience. Moreover, regression analyses revealed that the neural bias toward happiness or fearfulness differs as a function of the duration of EBF. Specifically, longer breastfeeding duration is associated with a happy bias, whereas shorter breastfeeding duration is associated with a fear bias. These findings suggest that breastfeeding experience can shape the way in which infants respond to emotional signals.

A qualitative study of risk factors related to child malnutrition in Aileu District, Timor-Leste

Improvement in child nutritional status is one of the major health priorities in Timor-Leste. A qualitative study was conducted in Aileu District, adjacent to the capital of Timor-Leste, Dili, in September 2010 to determine the possible risk factors associated with the high prevalence of child malnutrition. In-depth interviews were conducted to 32 guardians of children aged younger than 5 years. It was observed that early termination of exclusive breast-feeding and a short lactation period along with an unsanitary living environment were associated with the nutritional status of children in the study area. Although previous surveys have reported poor food security conditions in the country, no statements from the subjects supported this contention. The identified possible risk factors for child malnutrition were closely linked to each other and were mostly modifiable.

Relevance of brown adipose tissue in infancy and adolescence

Brown adipose tissue (BAT) was thought to disappear after infancy. Recent findings of BAT in patients undergoing positron emission tomography/computed tomography (PET/CT) have renewed the interest in deciphering the relevance of this tissue in humans. Available data suggest that BAT is more prevalent in children than in adults and that its activation during adolescence is associated with significantly lower gains in weight and adiposity. Data also show that pediatric patients with metabolically active BAT on PET/CT examinations have significantly greater muscle volume than patients without identifiable BAT. Both the activity and the amount of BAT increase during puberty. The magnitude of the increase is higher in boys as compared with girls and is closely related to gains in muscle volume. Hence, concurrent with the gains in skeletal muscle during infancy and puberty, all infants and adolescents accumulate large amounts of BAT. These observations are consistent with in vitro investigations suggesting close interactions between brown adipocytes, white adipocytes, and myocytes. In this review, we discuss the potential role of this tissue in regulating weight and musculoskeletal development in children.