Physiological mechanisms, behavioral and psychological factors influencing the transfer of milk from mothers to their young

The mother-child interface: A neurobiological metamorphosis

From the start of pregnancy, mother and child induce reciprocal neurobiological changes in the brain that will prove critical for neurodevelopment and survival of both. Molecular communication between mother and fetus is constantly active and persists even after the fetus starts to synthesize its hormones in late gestation. Intriguingly, some mother and fetus exchange cells remain in the other's brain and body with long-lasting effects and memories that do not follow the laws of classical genetics but involve complex epigenetic mechanisms. After childbirth, mother and child go through a transitional phase, a sort of limbo in which both will have a peculiar functioning profile, which is adaptive for contingencies but also renders them vulnerable. The interplay between these two "limbo" states allows for an easier transition to the subsequent phases of development. In this review, we will trace mother's and child's path from pregnancy to the months following birth and, in particular, unravel i) the key features of pregnancy and brain development and the reciprocal influences; ii) how a transitory pattern of functioning characterize mother and child, moving them toward more flexible and evolved forms; and iii) how mother and fetus act during childbirth to promote neuroprotection, pain reduction, and neurophysiological changes. Therefore, this review covers a wide range of topics, integrating neuroanatomical, neurological, biochemical, neurophysiological, and psychological studies in a meaningful way, trying to integrate them in a holistic view of the mother-child interface that is usually neglected.

Emotional intelligence and stress and their relationship with breastfeeding self-efficacy in mothers of premature infants

BACKGROUND

Premature infants need to be hospitalized in the neonatal intensive care unit (NICU) for long periods of time, which can increase anxiety and stress in their mothers. Additionally, the breastfeeding rate is lower among preterm infants. This study aimed to determine stress levels and emotional intelligence in mothers of preterm infants and their relationship with breastfeeding self-efficacy.

METHODS

This descriptive-correlational study was performed with a convenience sampling of 210 mothers of premature infants admitted to the neonatal intensive care unit in Tabriz, Iran in 2021. Data collection tools included socio-demographic checklist, perceived stress scale (PSS14), Dennis' breastfeeding self-efficacy scale, and the Schering emotional intelligence questionnaire. Data were analyzed using SPSS software version 16 via descriptive and inferential statistics (Pearson correlation and one-way ANOVA and modified general linear model).

RESULTS

Study findings demonstrated that most of the mothers had low stress (75.2%) and high breastfeeding self-efficacy (61.9%). The mean (SD) of emotional intelligence of the participants was 88.18 (16.60), ranging from 33 to 165. The results of the general linear model by modifying the demographic characteristics showed that the variables of emotional intelligence (B = 0.23, P = 0.03), stress (B=-0.56, P = 0.01), gestational age (B = 2.81, P < 0.001) and number of deliveries (B = 9.41, P < 0.001) were predictors of breastfeeding self-efficacy.

CONCLUSION

The findings showed that mothers of preterm infants had low emotional intelligence, and the majority of them had low perceived stress and high breastfeeding self-efficacy. Findings highlight the importance of addressing maternal stress and enhancing emotional intelligence to promote successful breastfeeding in mothers of preterm infants. Healthcare providers and managers are encouraged to offer support and educational programs to mothers of preterm infants, aiming to enhance their emotional intelligence. Further research and interventions focusing on these factors are warranted to improve the overall well-being of both mothers and infants in the neonatal intensive care unit.

Causes of Low Milk Supply: The Roles of Estrogens, Progesterone, and Related External Factors

Low milk supply (LMS) poses a significant challenge to exclusive and continued breastfeeding, affecting ∼10% to 15% of mothers. Milk production is intricately regulated by both endocrine and autocrine control mechanisms, with estrogens and progesterone playing pivotal roles in this process. In addition to endogenously produced hormones, external substances capable of interfering with normal hormonal actions, including phytoestrogens, mycoestrogens, synthetic estrogens, and hormonal contraceptives, can influence milk production. The effects of these extrinsic hormones on milk production may vary based on maternal body mass index. This comprehensive review examines the multifaceted causes of LMS, focusing on the involvement of estrogens, progesterone, and related external factors in milk production. Furthermore, it investigates the interplay between hormonal factors and obesity, aiming to elucidate the endocrine mechanisms underlying obesity-associated LMS. Insights from this review provide valuable perspectives for developing interventions to improve milk production and address the challenges associated with LMS.

Evolution, diversification and function of the maternal-infant dyad in mammalian feeding

The evolution of the mother/infant dyad providing a source of nutrition for infants is essential for the origin and subsequent diversification of mammals. Despite the importance of this dyad, research on maternal and infant function is often treated independently. Our goal is to synthesize the work on maternal and infant function, discuss our own studies of suckling, and compare the origins of lactation and suckling with their ensuing diversification. Our central premise is that while extensive work has demonstrated variation across mammals in the maternal aspect of this system, very little has been done to address how this relates to infant function. We start with a discussion of the fundamental anatomy and physiology of both mother and infant. We next discuss the origin of mammary glands and milk, and infant suckling, which is distinct from their subsequent diversification. We then discuss the diversification of maternal and infant function, highlighting the evolutionary diversity present in maternal function (both anatomically and physiologically), before arguing that the diversity of infant function is unexplored, and needs to be better studied in the future. We end by discussing some of the holes in our understanding, and suggestions for future work that can address these lacunae. This article is part of the theme issue 'Food processing and nutritional assimilation in animals'.

Are Pediatric Residents in Saudi Arabia Equipped to Provide Breastfeeding Care? A Cross-Sectional Study

Background

There is a progressive reduction in breastfeeding rates in Saudi Arabia. Counseling and support from health-care providers are useful in overcoming barriers to continuing breastfeeding. However, medical education and residency programs often do not adequately provide breastfeeding training.

Objective

To determine the knowledge, comfort level, perception, and clinical practices of pediatric residents regarding breastfeeding in Saudi Arabia and to measure the level and type of education received during their residency training.

Materials and Methods

This cross-sectional study included pediatric residents from across Saudi Arabia who were registered with the Saudi Commission for Health Sciences and was conducted from February 2021 to January 2022. A validated self-reported questionnaire was used to elicit information from the respondents. Knowledge score was calculated as a percentage of correct answers.

Results

A total of 253 residents completed the survey. The mean knowledge score was 58.4% ± 22.7%, which was lower than the cut-off threshold of good knowledge. Almost half of the residents (49.4%) were confident about addressing breastfeeding-related concerns. Although nearly all residents (91.7%) agreed that breastfeeding promotion is part of their role, 35% never or rarely met the mother before birth to discuss breastfeeding. Didactic teaching was the most prevalent educational tool during their training (34.3%); however, most residents preferred learning through interactive workshops (83.7%) and following lactation consultants (82.8%).

Conclusion

Despite positive perceptions and confidence in providing breastfeeding care, pediatric residents in Saudi Arabia lack optimal knowledge of breastfeeding. These findings indicate the need for enhancing breastfeeding curricula in pediatric residency programs to improve breastfeeding consultation and management.

Breastfeeding and the patient's perspective

PURPOSE

The purpose of this article is to summarize available data on breastfeeding in patients with a cancer diagnosis.

MATERIALS AND METHODS

A review of available literature in the MEDLINE database was performed and the data summarized. In addition, two patient interviews were conducted to gain insight into the patient perspective.

RESULTS

Breastmilk is the nutritional standard for human infants and understanding the implications of a cancer diagnosis on lactation is important in optimizing maternal and infant outcomes. Though limited, available data suggest that breastfeeding may be a safe and appropriate option for some patients undergoing treatment of a malignancy.

CONCLUSIONS

Patient experiences with breastfeeding in the setting of a cancer diagnosis vary widely, and depend on the type of malignancy, the timing of the diagnosis, and the indicated treatment. Breastfeeding may be an appropriate option for certain patients after multidisciplinary counseling. Alternatives to breastfeeding exist for patients who are unable to or do not desire to breastfeed.

Internal factors affecting the mother's psychological capital in exclusive breastfeeding during the COVID-19 pandemic

Background:

During the pandemic, in terms of breastfeeding, most mothers experience anxiety and discomfort. The impact of this condition will decrease the production of breast milk. The purpose of this study was to determine the internal factors that affect the psychological capital of mothers when breastfeeding during the COVID-19 pandemic in Petiken Village, Gresik.

Design and methods:

This study was an analytical study with a cross-sectional approach. The population of this study was all breastfeeding mothers who had babies aged 6–12 months. The sampling technique used was simple random sampling involving 102 respondents. The independent variables were motivation, perception, and attitude. The dependent variable was psychological capital. Data were collected from June to July 2021. The data analysis was conducted using the logistic regression test to determine the variable with a significance level of p < 0.05.

Results:

The results of the multivariate analysis showed that the motivation variable was p = 0.036. Motivation had effect on psychological capital. While the perception variable was p = 0.056 (p > 0.05), the perception had no effect on psychological capital. The attitude variable p = 0.055 (p > 0.05), the attitude had no effect on psychological capital. The factor that affects the mother’s psychological capital in relation to exclusive breastfeeding during the COVID-19 pandemic was motivation.

Conclusion:

It is expected that mothers have a high motivation which can affect the mother’s psychological capital. It is needed to increase and succeed at providing exclusive breastfeeding.

Dietary Intake of Polyphenols Enhances Executive/Attentional Functioning and Memory with an Improvement of the Milk Lipid Profile of Postpartum Women from Argentina

Puerperium may lead to memory and executive/attentional complaints that interfere with women’s daily life. This might be prevented by dietary compounds, such as neuroprotective polyphenols. Their bioactivity depends on their effects on lipid metabolism in different tissues, such as the brain, fat, and breast. Thus, a polyphenol-related cognitive improvement may be associated with changes of lipids in human milk, which are key for infant neurodevelopment. A cross-sectional study was conducted on 75 postpartum women from Córdoba (Argentina), involving several neuropsychological tests. Diet was registered to identify polyphenol intake and food pattern adherence, with sociodemographic and other psychological variables (insomnia, stress, subjective cognitive complaints) being also studied. Triacylglycerols, cholesterol, and their oxidative forms were analyzed as milk biomarkers. Multivariate statistical methods were applied. Results confirmed that women who consumed polyphenols presented better executive/attentional performance (i.e., higher correct responses, conceptual level responses, complete categories, verbal fluency; lower attentional interferences, and perseverative errors) and word retention with lower interference. Polyphenols were positively associated with milk lipids, which were higher in women with better cognition. Furthermore, they had lower oxidized triacylglycerols. In conclusion, polyphenolic intake during postpartum may improve executive/attentional functioning, memory, and milk lipid profile.

Taurine: A Maternally Derived Nutrient Linking Mother and Offspring

Mammals can obtain taurine from food and synthesize it from sulfur-containing amino acids. Mammalian fetuses and infants have little ability to synthesize taurine. Therefore, they are dependent on taurine given from mothers either via the placenta or via breast milk. Many lines of evidence demonstrate that maternally derived taurine is essential for offspring development, shaping various traits in adults. Various environmental factors, including maternal obesity, preeclampsia, and undernutrition, can affect the efficacy of taurine transfer via either the placenta or breast milk. Thus, maternally derived taurine during the perinatal period can influence the offspring’s development and even determine health and disease later in life. In this review, I will discuss the biological function of taurine during development and the regulatory mechanisms of taurine transport from mother to offspring. I also refer to the possible environmental factors affecting taurine functions in mother-offspring bonding during perinatal periods. The possible functions of taurine as a determinant of gut microbiota and in the context of the Developmental Origins of Health and Disease (DOHaD) hypothesis will also be discussed.

Randomized Clinical Trial of a Prenatal Breastfeeding and Mental Health Mixed Management Intervention

BACKGROUND

The continuity of maternal depressive symptoms throughout the perinatal period and breastfeeding problems have adverse influences on breastfeeding.

RESEARCH AIM

To compare the feeding patterns and breastfeeding experiences, maternal health and mental health, and breastfeeding self-efficacy between women with depressive symptoms who participated in a prenatal individualized mixed management intervention and those who received usual care.

METHODS

Chinese primigravida (N = 182) with an Edinburgh Postnatal Depression Scale score ≥ 9 in late pregnancy (≥ 28 weeks and < 35 weeks) were randomly assigned to the intervention group (n = 84) or the control group (n = 84). Intervention group participants received four sessions of individualized mixed management combining psycho-education and breastfeeding education. Breastfeeding self-efficacy, feeding patterns, maternal depression, and health status were evaluated in both groups.

RESULTS

Significant differences were noted between the groups in breastfeeding self-efficacy at 42 days postpartum (p < .05) and feeding patterns at 3 months and 6 months postpartum (p < .05). Repeated measures analysis of variance showed significant differences in the EPDS scores between groups at three postpartum time points (p < .05). The intervention group had significantly lower postpartum depression as diagnosed by the MINI (p < .05).

CONCLUSIONS

A prenatal individualized mixed management intervention holds promise as an effective prevention and health promotion program addressing breastfeeding outcomes and maternal mental health.This RCT was registered (ChiCTR-IOR-17013761) with Chinese Clinical Trial Registry, http://www.chictr.org.cn/enIndex.aspx on 12/7/2017.

Impaired Lactation: Review of Delayed Lactogenesis and Insufficient Lactation

It is estimated that as many as 1 in 20 women worldwide are unable to successfully breastfeed or provide adequate nutrition for their infants through their breast milk alone. Compromised nutrition in the early stages of life places the infant at risk for insufficient growth as well as serious and potentially disabling or life-threatening complications. This review summarizes risk factors associated with impaired lactation that may result in either delayed lactogenesis or insufficient lactation. The risk factors for insufficient lactation are categorized into preglandular, glandular, and postglandular causes. Impaired lactation can occur despite maternal motivation, knowledge, support, and appropriate breastfeeding technique. Although there is no clear way to predict who will experience impaired lactation, knowledge about the risk factors can enable health care professionals to better identify at-risk mother-infant dyads. Early intervention may help prevent infant complications associated with inadequate nutritional intake.

Endocannabinoid modulation of dopamine release during reward seeking, interval timing, and avoidance

Endocannabinoids (eCBs) are neuromodulators that influence a wide range of neural systems and behaviors. In the current review, we describe our recent research showing how eCBs, particularly 2-arachidonoylglycerol (2-AG), concurrently shape mesolimbic dopamine (DA) release and associated behavior. We will restrict our discussion by emphasizing three distinct behaviors: reward seeking, interval timing, and active avoidance. During reward seeking we find that 2-AG is necessary to observe cue-evoked DA release events that are thought to represent the value of a rewarding outcome. We then describe data showing that 2-AG modulates unique patterns of DA release and behavior observed under conditions of periodic reinforcement. These data are discussed within the context of interval timing and adjunctive behavior. eCB modulation of DA release is also implicated in defensive behavior, including the avoidance of harm. As in reward seeking, our data suggest that the concentration of DA that is evoked by a warning signal can represent the value of an avoidance outcome. And, disrupting eCB signaling concomitantly reduces the concentration of the avoidance value signal and active avoidance. Disruptions in reward seeking, interval timing, and defensive behavior are commonly observed in a variety of movement disorders (e.g., Parkinson's and Huntington's disease) and disorders of motivation (e.g., addiction). We believe our data on eCB-DA interactions have implications for the development of novel pharmacotherapies to treat these disorders. Thus, we conclude by discussing how eCB pharmacology might be harnessed to treat disorders of movement and motivation.

Risk Factors for Delayed Onset of Lactogenesis II Among Primiparous Mothers from a Brazilian Baby-Friendly Hospital

BACKGROUND

Low milk supply is frequently reported as a reason for exclusive breastfeeding cessation.

RESEARCH AIMS

To determine the occurrence of, and the risk factors associated with, delayed onset of lactogenesis II among primiparas seen at a Baby-Friendly Hospital in Brazil.

METHOD

We conducted a prospective longitudinal observational cohort study of 224 primiparas who had a singleton delivery. Data were first collected at the hospital. We assessed the onset of lactogenesis on day four postpartum, based on maternal reports of changes in breast fullness. Breastfeeding practices and Edinburgh Postnatal Depression Scale were evaluated on day seven postpartum. Using Poisson regression, we assessed significant factors associated with delayed onset of lactogenesis II.

RESULTS

Delayed lactogenesis II occurred in 18.8% (n = 42) of participants and was significantly associated with alcohol drinking during pregnancy (IRR = 2.710, 95% CI [1.469, 4.996]); Edinburgh Postnatal Depression Scale scores ≥ 10 (IRR = 2.092, 95% CI [1.118, 3.916]), and the age of the mother (IRR: 1.081, 95% CI [1.039, 1.125]).

CONCLUSION

Postpartum depression and alcohol ingestion during pregnancy may be associated with lactogenesis II delay, but more research is needed to elucidate the directionality of these relationships. Older mothers are at risk of delayed lactogenesis II onset. The frequency of delayed lactogenesis in this population is similar to the rates seen in previous Latin America studies and much lower than the ranges seen in North America, possibly because of the low proportion of obesity and severe gestational diabetes in this sample.

Effects of Launaea taraxacifolia and resveratrol on milk yield and serum prolactin and oxytocin levels: a lactogenic study

Inadequacy of milk supply to meet the increasing human population coupled with a decreasing livestock population has necessitated the need for a potent galactogoue. The aim of this study was to compare the lactogenic effects of Launaea taraxacifolia (PLT) and resveratrol in Wistar rats. After parturition, 25 primiparous female Wistar rats were randomly allocated into five groups of 5 dams each. Dams in groups I, II, III, IV and V were administered distilled water (DW: 2 ml/kg), metochlopromide (MET: 15 mg/kg), resveratrol (RES: 5 mg/kg), n-hexane leaf fraction of L. taraxacifolia (PLT: 333 mg/kg) and the combination of RES + PLT (CO: 5 mg + 333 mg/kg); respectively, for 12 days. Pup weight gain was used to quantify milk yield. Serum was harvested from the dams and assayed for prolactin and oxytocin. The PLT and CO groups had significantly higher (p < 0.05) milk yield than DW group. Serum concentration of prolactin was significantly higher (p < 0.05) in the PLT group, while the combination group had the highest (p < 0.05) concentration of oxytocin compared to DW group. In conclusion, L. taraxacifolia and resveratrol exhibited galactopoietic potentials individually by stimulating hyperprolactinaemia, while their combination increased milk production by increasing serum oxytocin activity.

Maternal and Neonatal Hair Cortisol Levels and Psychological Stress Are Associated With Onset of Secretory Activation of Human Milk Production

BACKGROUND

Several factors can influence the production of mothers' own milk.

PURPOSE

To assess the influence of maternal psychological stress, maternal cortisol levels, and neonatal hair cortisol levels on timing of secretory activation.

METHODS

A prospective study was conducted at 2 public health centers in Andalusia, Spain. Participants were 60 pregnant women and their 60 neonates. Hair cortisol levels and psychological stress (pregnancy-specific stress [Prenatal Distress Questionnaire, PDQ] and perceived stress [Perceived Stress Scale, PSS]) were evaluated during the third trimester and the postpartum period. This study was part of the GESTASTRESS cohort study on the effects of stress during pregnancy.

RESULTS

Higher PDQ and PSS scores (P < .05) in the third trimester were associated with later onset of secretory activation. Higher postpartum maternal hair cortisol levels were associated with a delayed secretory activation of mother's own milk (P < .05).

IMPLICATIONS FOR RESEARCH

Future studies should look at the influence of psychological stress and cortisol levels on hormones involved in mother's own milk production.

IMPLICATIONS FOR PRACTICE

Neonatal nurses and other healthcare providers should be familiar with levels of neonates' exposure to maternal prenatal stress prior to birth.

Mothers, Fathers, and Others: Neural Substrates of Parental Care

Parental care is essential for the survival of offspring in altricial mammalian species. However, in most mammals, virgin females tend to avoid or attack infants. Moreover, most males demonstrate avoidance and aggression toward infants, and have little to no involvement in parental care. What mechanisms suppress avoidance, and support approach towards pups, to promote maternal care? In biparental and cooperatively breeding species, what mechanisms allow nonmothers (i.e., fathers and alloparents) to demonstrate parental care? In this review we consider the mechanisms that subserve parental care in mothers, fathers, and others (i.e., alloparents). We emphasize recent discoveries and research trends with particular emphasis on neuroendocrinology, neuroplasticity, transcriptomics, and epigenetics. Finally, we consider outstanding questions and outline opportunities for future research.

The association between baby care books that promote strict care routines and infant feeding, night-time care, and maternal-infant interactions

Baby care books that promote strict infant care routines are popular, but little research has considered their impact upon maternal infant care behaviours. We explored whether mothers who have read these books guide their infant care behaviours based on their concepts and how this is associated with infant feeding, night-time care, and response to infant's needs. Three hundred and fifty-four U.K. mothers with a baby aged 0-12 months completed an online questionnaire exploring use of baby care books, motivations for use, whether guidance was followed, and infant care behaviours. Mothers who read the books were drawn to them for information about how to settle their infant, infant sleep, and infant feeding behaviour. Those who read the books were less likely to breastfeed, feed responsively, have their infant sleep in the same room, cuddle their infant to sleep, or respond promptly to infant cries. Although the causality between reading these books and care cannot be determined through this study design, and is likely bidirectional with some reading the books to confirm existing preferences, around 25-40% of mothers noted the information determined their care decisions. Regardless of specific causal pathways, there is an association between these books and behaviours that go against infant feeding and responsive care recommendations. Understanding what drives mothers to follow these books and increasing support for new mothers in these areas is important. The findings will be important for those supporting mothers in the perinatal period in starting conversations around responsive infant care.

Intimate partner violence and subsequent premature termination of exclusive breastfeeding: A cohort study

Objective

The objective of this study was to examine whether exposure to Intimate Partner Violence (IPV) is associated with premature termination of Exclusive Breastfeeding (EB). Per WHO recommendations, this was defined as ceasing breastfeeding or supplementing with other foods or liquids before the child was 6 months old.

Method

It is a prospective cohort study set in Moshi, Tanzania consisting of 1128 pregnant women with live singleton births. Women were enrolled during pregnancy and followed up with interviews during pregnancy, after birth and 2–3 years postpartum, using structured questionnaires. Emotional, physical and sexual IPV exerted by the current partner was assessed at 34 weeks gestational age with WHO questionnaires. Months of EB was assessed 2–3 years postpartum. Premature termination of EB was defined as less than 6 months of EB. Analyses were made using a logistic regression model adjusted for maternal age, education, HIV-status, alcohol use during pregnancy and parity. Confounding variables were determined using a theoretical framework approach, i.e. a Directed Acyclic Graph model to minimize bias.

Results

Women who were exposed to IPV had more than 50% higher odds of terminating EB before the child was 6 months old compared to women who were not exposed (aOR = 1.62, 95%CI: 1.27–2.06).

Women exposed to all three types of IPV had twice the odds of early termination of EB (aOR = 1.95, 1.12; 3.37). Furthermore, the odds were tripled if exposure happened specifically during the index pregnancy (aOR = 2.93 95%CI: 1.3; 6.6). Stratified analyses showed the most severely affected groups were the mothers older than 30 and those who gave birth to girls.

Conclusions

The results indicated that exposure to IPV is associated with increased risk of premature termination of EB. The odds increase with multiple types of the IPV, especially when exposed during the index pregnancy.

Influence of a Concurrent Exercise Training Program During Pregnancy on Colostrum and Mature Human Milk Inflammatory Markers: Findings From the GESTAFIT Project

BACKGROUND

Although exercise reduces systemic inflammation, information regarding its influence on human milk is scarce or inexistent. Research Aim: The aim of this study was to investigate the influence of an exercise intervention during pregnancy on colostrum and mature human milk inflammatory markers.

METHODS

The authors conducted a pseudorandomized controlled trial. The exercise group followed a concurrent aerobic and strength training, three 60-minutes sessions per week, from the 17th gestational week until delivery. For the specific aims of this study, only women able to produce enough milk were included for data analyses, resulting in 24 exercise and 23 control women. Colostrum and mature human milk proinflammatory and anti-inflammatory cytokines (fractalkine, interleukin [IL]-1β, IL-6, IL-8, IL-10, interferon [IFN]-γ, and tumor necrosis factor [TNF]-α) were measured using Luminex xMAP technology.

RESULTS

The mothers who followed the exercise program had 36% lower IL-8 and 27% lower TNF-α concentrations in their colostrum than those in the control group ( p < .05 and p < .01, respectively). The colostrum from mothers who followed the exercise program also presented borderline significant 22% lower IL-6 ( p < .100). The mature milk from mothers who followed the exercise program had 30% greater fractalkine ( p = .05) and borderline significant 20% higher IL-10 ( p = .100). The exercise intervention did not affect IFN-γ concentrations.

CONCLUSIONS

This concurrent exercise program promoted a less proinflammatory profile in human milk, especially in colostrum. Moreover, it might increase mature human milk fractalkine, which could induce a greater neurodevelopment and neuroprotection in the newborn. This trial was registered at ClinicalTrials.gov (NCT02582567) on October 20, 2015.

Breastfeeding practices in the United Kingdom: Is the neighbourhood context important?

Breastfeeding is an important public health issue worldwide. Breastfeeding rates in the United Kingdom, particularly for exclusive breastfeeding, are low compared with other OECD countries, despite its wide-ranging health benefits for both mother and child. There is evidence that deprivation in the structural and social organisation of neighbourhoods is associated with adverse child outcomes. This study aimed to explore whether breastfeeding initiation, exclusive breastfeeding for at least 3 months, and any type of breastfeeding for at least 6 months were associated with neighbourhood context measured by neighbourhood deprivation and maternal neighbourhood perceptions in a nationally representative U.K.

SAMPLE

A cross-sectional analysis was conducted using data from the Millennium Cohort Study. Logistic regression was carried out on a sample of 17,308 respondents, adjusting for individual- and familial-level socio-demographic characteristics. Neighbourhood deprivation was independently and inversely associated with breastfeeding initiation. Compared with the least deprived areas, the likelihood of initiating breastfeeding was 40% lower in the most deprived neighbourhoods (OR: 0.60, 95% CI [0.50, 0.72]). The relationship between both exclusive and any type of breastfeeding at 3 and 6 months respectively with neighbourhood deprivation after adjustment for potential confounders was not entirely linear. Breastfeeding initiation (OR: 0.78, 95% CI [0.71, 0.85]), exclusivity for 3 months (OR: 0.84, 95% CI [0.75, 0.95]), and any breastfeeding for 6 months (OR: 0.82, 95% CI [0.73, 0.93]) were each reduced by about 20% among mothers who perceived their neighbourhoods lacking safe play areas for children. Policies to improve breastfeeding rates should consider area-based approaches and the broader determinants of social inequalities.

Breastfeeding and the Benefits of Lactation for Women's Health

The offer of the maternal breast to the baby is an unquestionable right of mothers and their children, and all efforts should be made to promote, follow and maintain exclusive breastfeeding for up to 6 months and supplement it until the child completes 2 years of age. Many publications are available in the literature about the qualities of breast milk, its benefits and health repercussions, stimulating the practice of breastfeeding and supporting campaigns for its implementation. However, although it is widely known that breastfeeding is an important step in the reproductive process of women and its practice offers benefits to both mother and child, most of the available information highlights the benefits of breast milk for children, while mention of the effects of breastfeeding on the health of the mother is usually neglected. Thus, the objective of the present study is to highlight the multiple benefits of breastfeeding for the physical and emotional health of the nursing mother. The authors consulted articles published in the databases PubMed, Virtual Health Library and Web of Science using the keywords breastfeeding, breast milk, lactation and maternal health.

No evidence of association of oxytocin polymorphisms with breastfeeding in 2 independent samples

Oxytocin has an important function in breastfeeding via its role in the milk ejection reflex and in attachment and bonding processes. Genetic factors account for a significant part of the individual differences in breastfeeding behavior. OXT and OXTR have been proposed as gene candidates for breastfeeding. Previous studies have focused on certain single-nucleotide polymorphisms (SNPs) within these genes, finding null or inconsistent results. The present study analyses the associations between a wide coverage of polymorphisms in OXT and OXTR and breastfeeding duration from 2 large and independent unselected samples comprising a total of 580 and 2112 female twin mothers from the Murcia Twin Registry (Spain) and QIMR Berghofer Medical Research Institute (Australia), respectively. A total of 19 SNPs in OXT and 137 in OXTR SNPs were covered in both samples. Effects of the OXT and OXTR polymorphisms on breastfeeding duration were calculated by means of linear regression controlling for age at survey time, educational level, interaction between age and educational level and principal components of genetic ancestry. The analyses were conducted independently in the 2 samples and also meta-analyzed. Although some SNPs were associated at an alpha level of .05 with breastfeeding, they did not survive multiple testing correction. We conclude that SNPs within or nearby OXT and OXTR are unlikely to have large effects on breastfeeding behavior.

Intestinal transepithelial permeability of oxytocin into the blood is dependent on the receptor for advanced glycation end products in mice

Plasma oxytocin (OT) originates from secretion from the pituitary gland into the circulation and from absorption of OT in mother's milk into the blood via intestinal permeability. However, the molecular mechanism underlying the absorption of OT remains unclear. Here, we report that plasma OT concentrations increased within 10 min after oral delivery in postnatal day 1-7 mice. However, in Receptors for Advanced Glycation End Products (RAGE) knockout mice after postnatal day 3, an identical OT increase was not observed. In adult mice, plasma OT was also increased in a RAGE-dependent manner after oral delivery or direct administration into the intestinal tract. Mass spectrometry evaluated that OT was absorbed intact. RAGE was abundant in the intestinal epithelial cells in both suckling pups and adults. These data highlight that OT is transmitted via a receptor-mediated process with RAGE and suggest that oral OT supplementation may be advantageous in OT drug development.

Physiology of milk secretion

Milk is a unique and complete nutritive source for the mammal neonate, also providing immune protection and developmental signals. Lactation is a complex process, proper to the mother and child dyad, and including numerous variables ranging from psychological aspects to the secretory functioning of the mammary epithelial cells, all contributing to a successful breastfeeding. This review gives an integrated overview of the physiology of lactation with a particular focus on cellular and molecular mechanisms involved in milk product secretion and their regulations.

Exploring the influence of psychosocial factors on exclusive breastfeeding in Bangladesh

Exclusive breastfeeding is a proven benefit for both mothers and infants and is, therefore, an important public health priority. Intimate partner violence (IPV) is regarded as one of the potential psychosocial risk factors that may negatively affect exclusive breastfeeding (EBF). This study aimed to explore the influence of psychosocial factors including IPV on EBF. Cross-sectional survey data was collected from October 2015 to January 2016 in Chandpur District of Bangladesh from 426 married women, aged 15-49 years, who had at least one child 6 months of age or younger. Multivariate logistic regression models were used in order to investigate whether women who experienced IPV after childbirth, as well as other risk factors such as postpartum depression (PPD) and childhood sexual abuse, were more likely to face difficulties with EBF compared with women who had not experienced these same risk factors. Whilst the initiation rate of breastfeeding was 99.3%, at the time of the woman's interview, the overall EBF rate had fallen to 43.7%. Based on the adjusted model, women who experienced physical IPV (AOR 0.17, 95% CI [0.07, 0.40]) and psychological IPV (AOR 0.51, 95% CI [0.26, 1.00]) after childbirth and women who reported childhood sexual abuse (AOR 0.32, 95% CI [0.13, 0.80]) and PPD (AOR 0.20, 95% CI [0.09, 0.44]) were significantly less likely to exclusively breastfeed their infants than those who had not reported these experiences. Moreover, women with an intended pregnancy and high social support exhibited a higher likelihood of EBF. Our results suggest that preventing or reducing the occurrence of physical IPV, PPD and childhood sexual abuse may improve the EBF duration. Support from family members can assist in this process.

Breastfeeding and infant hospitalisation: analysis of the UK 2010 Infant Feeding Survey

To investigate the contributions of overall breastfeeding duration and exclusive breastfeeding in reducing the risk of hospitalisation for infectious causes, we analysed data from a three-stage survey on infant feeding practices and health outcomes in over 10 000 UK women in 2010-2011. The main outcome measures were risk of overnight hospital admission in the first 8-10 months of infancy. A graded beneficial effect was found between longer duration of any breastfeeding and hospital admission for infectious causes and for respiratory tract infections, with a significantly lower risk in infants breastfed for at least 3 months compared with those never breastfed. The effects were stronger in the subgroup who was also exclusively breastfed. For example, among infants breastfed for 3-6 months, the reduction in risk for infectious causes for those who were also exclusively breastfed for at least 6 weeks was 0.42 (95% CI: 0.22-0.81) and for those not exclusively breastfed for 6 weeks 0.79 (95% CI: 0.49-1.26). Likewise, among infants breastfed for 6 months or more, the odds ratio for those who were also exclusively breastfed for at least 6 weeks was 0.48 (95% CI: 0.32-0.72) and for those not exclusively breastfed for 6 weeks 0.72 (95% CI: 0.48-1.08). The apparent protective effect of any breastfeeding for a long duration may in part be driven by a prolonged period of exclusive breastfeeding. Exclusive breastfeeding in the initial weeks after childbirth and continuing to breastfeed (either exclusively or partially) for at least 3 months, preferably 6 months, may reduce morbidity due to infectious illness in infants.

Baby-led compared with scheduled (or mixed) breastfeeding for successful breastfeeding

BACKGROUND

Baby-led breastfeeding is recommended as best practice in determining the frequency and duration of a breastfeed. An alternative approach is described as scheduled, where breastfeeding is timed and restricted in frequency and duration. It is necessary to review the evidence that supports current recommendations, so that women are provided with high-quality evidence to inform their feeding decisions.

OBJECTIVES

To evaluate the effects of baby-led compared with scheduled (or mixed) breastfeeding for successful breastfeeding, for healthy newborns.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (23 February 2016), CINAHL (1981 to 23 February 2016), EThOS, Index to Theses and ProQuest database and World Health Organization's 1998 evidence to support the 'Ten Steps' to successful breastfeeding (10 May 2016).

SELECTION CRITERIA

We planned to include randomised and quasi-randomised trials with randomisation at both the individual and cluster level. Studies presented in abstract form would have been eligible for inclusion if sufficient data were available. Studies using a cross-over design would not have been eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed for inclusion all potential studies we identified as a result of the search strategy. We would have resolved any disagreement through discussion or, if required, consulted a third review author, but this was not necessary.

MAIN RESULTS

No studies were identified that were eligible for inclusion in this review.

AUTHORS' CONCLUSIONS

This review demonstrates that there is no evidence from randomised controlled trials evaluating the effect of baby-led compared with scheduled (or mixed) breastfeeding for successful breastfeeding, for healthy newborns. It is recommended that no changes are made to current practice guidelines without undertaking robust research, to include many patterns of breastfeeding and not limited to baby-led and scheduled breastfeeding. Future exploratory research is needed on baby-led breastfeeding that takes the mother's perspective into consideration.

Variable postpartum responsiveness among humans and other primates with "cooperative breeding": A comparative and evolutionary perspective

This article is part of a Special Issue "Parental Care".Until recently, evolutionists reconstructing mother-infant bonding among human ancestors relied on nonhuman primate models characterized by exclusively maternal care, overlooking the highly variable responsiveness exhibited by mothers in species with obligate reliance on allomaternal care and provisioning. It is now increasingly recognized that apes as large-brained, slow maturing, and nutritionally dependent for so long as early humans were, could not have evolved unless "alloparents" (group members other than genetic parents), in addition to parents, had helped mothers to care for and provision offspring, a rearing system known as "cooperative breeding." Here I review situation-dependent maternal responses ranging from highly possessive to permissive, temporarily distancing, rejecting, or infanticidal, documented for a small subset of cooperatively breeding primates. As in many mammals, primate maternal responsiveness is influenced by physical condition, endocrinological priming, prior experience and local environments (especially related to security). But mothers among primates who evolved as cooperative breeders also appear unusually sensitive to cues of social support. In addition to more "sapient" or rational decision-making, humankind's deep history of cooperative breeding must be considered when trying to understand the extremely variable responsiveness of human mothers.