Initiation of human lactation: secretory differentiation and secretory activation

Measuring Postpartum Milk Production Following Antenatal Milk Expression in Mothers of Infants With Congenital Anomalies

BACKGROUND

Mothers of infants with congenital anomalies may experience challenges with milk production. Antenatal milk expression (AME) is thought to support milk production, as past research suggests it facilitates secretory activation. However, past research relied on self-reported data.

PURPOSE

This study examined secretory activation and coming to volume, 2 critical stages of postpartum milk production, by measurement of human milk biomarkers from days 1 to 7 and 24-hour milk volume from birth until day 14 in mothers of infants with congenital anomalies who practiced AME.

METHODS

Women carrying infants with congenital anomalies received AME education, did AME, gave birth, and recorded their 24-hour pumping frequency and milk volume. An ion selective electrode (ISE) and laboratory analysis were used to measure human milk biomarkers.

RESULTS

Sixteen mothers completed AME, and all infants were born at term. Most mothers (87.5%) had normal biomarkers at least once, but biomarkers did not stay in normal range. Four mothers (25%) experienced secretory activation within 72 hours after birth. The pumping frequency and 24-hour milk volume varied. Only 9 (56.25%) mothers secreted ≥500 mL of milk by day 14.

IMPLICATIONS FOR PRACTICE

AME may offer benefits, but secretory activation does not appear to be impacted. The ISE shows promise as a nursing-driven intervention to screen for potential milk volume concerns.

IMPLICATIONS FOR RESEARCH

Further research is needed on AME and human milk biomarkers in this at-risk population.

Assessment of Cell Isolation From Human Milk Using Immunomagnetic Beads

BACKGROUND

There is increasing interest in better understanding the immune cell composition of human milk and how these cells interact with neonatal immune development. However, consistent methods for immune cell isolation from human milk are lacking.

RESEARCH AIM

Our aim was to systematically compare available cell isolation techniques to isolate T lymphocytes from human milk samples.

METHODS

This repeated measures study design compared three cell isolation methods using human milk samples: (1) centrifugation, (2) immunomagnetic bead isolation, and (3) a combination of both methods. We assessed the proportion and viability of CD3+, CD4+, CD25+ and regulatory T cells using flow cytometry in isolated cells to compare the performance of these isolation methods.

RESULTS

Immunomagnetic separation is a feasible method to isolate T lymphocytes in human milk, similar to blood. It improves target cell enrichment and cell viability compared to centrifugation, which may be an advantage when the goal is to characterize rare cell types or when cells are further used in functional assays. No excess cell activation (CD25 positivity) was observed with the use of magnetic beads.

CONCLUSION

Immunomagnetic separation of human milk T lymphocytes may have advantages over centrifugation depending on the intended downstream use of cells.

Promoting Accurate Language on Lactation from Prenatal to Postpartum

ABSTRACT

Lactation is a vital function of reproduction and population dynamics as human milk supports infant survival and development. Although the physiological processes of lactation have largely remained unchanged throughout human history, contemporary practices in human milk provision have expanded the original lexicon, resulting in ambiguity and potential misrepresentations in lactation-related language. We provide an overview of the anatomy and physiology of lactation to emphasize the importance of precise and consistent language as most nurses and health care professionals receive little to no education in their programs of study about lactation and breastfeeding. Concrete definitions and explanations on how to use the science of human milk and the physiology of lactation are crucial for evidence-based lactation education, support, and intervention. LactaPedia, an online comprehensive human lactation glossary, is freely accessible to nurses and the public to remain updated on lactation-related language as well as offer feedback on the relevancy and usability of any fundamental terminology. Precise and consistent use of lactation-related language will overall improve communication between nurses and multidisciplinary teams and thereby enhance care and outcomes for families.

Opportunities to Overcome Barriers to Lactation-Recommendations for Best Practices

INTRODUCTION

Women represent over 50% of graduating medical students in the United States and approximately 20% of current neurosurgical residents in training. An increase in female representation requires an increase in advocacy efforts related to pregnancy. Although there is extensive literature on pregnancy in neurosurgical residents, the postpartum period, sometimes referred to as the "fourth trimester", is frequently overlooked. This study was performed in order to characterize the lactation experiences of female neurosurgeons and neurosurgical trainees and compare their experiences to their peers in other medical specialties.

METHODS

A 62-question survey examining lactation experiences was developed and electronically disseminated to members of Women In Neurosurgery, the social media group Dr. MILK, and to neurosurgical residency Program Directors throughout the United States.

RESULTS

Seventy-eight responses were received (neurosurgery: 10, other surgical specialty: 19, nonsurgical specialty: 49). When asked if respondents met their goal for lactation duration, 26 nonsurgical, 13 other surgical, and 8 neurosurgery respondents responded affirmatively (p = 0.059). A significantly greater proportion of neurosurgery respondents reported that expression of breastmilk at work caused anxiety compared to nonsurgical respondents (p = 0.02). Overall, 59% of respondents felt that they did not have adequate time to express breastmilk at work, and 69% had to stop expressing breastmilk at work prior to completely emptying. Fifty-three percent of respondents were fearful of being unable to feed their baby secondary to the inability to express breastmilk. Twenty percent reported never being able to consume sufficient liquid at work, and 17% reported never being able to consume sufficient calories at work. Additional cited barriers included limited mentorship (68%), inconvenient lactation spaces (58%), perceived discrimination (32%), and breast pump malfunction (28%).

CONCLUSION

Women residents across medical specialties face significant barriers to successful lactation experiences. With limited mentorship in lactation across medical specialties, advocacy efforts and lactation support are vitally needed for the protection of the health of physician mother and baby.

Mapping the current knowledge on leucocytes in human breastmilk: a scoping review protocol

INTRODUCTION

The immunological composition of breastmilk has gained research interest as breastfeeding has been persistently correlated with improved health outcomes in children. Immune cells, also known as leucocytes, are key components of the body's immune system, but they remain understudied in breastmilk. The relevance of breastmilk leucocytes for breastfeeding-mediated immune benefits remains controversial. To identify the current state-of-the-art on breastmilk leucocyte research, unearth knowledge gaps and propose research priorities, a scoping review is necessary.

METHODS AND ANALYSIS

This scoping review will address the general question of what is known about leucocytes in human breastmilk. The development of this scoping review protocol adhered to the recommendations set forth by the Joanna Briggs Institute guidelines. Peer-reviewed research articles published in English, French or Spanish will be eligible for inclusion in the scoping review. The initial literature search was conducted in January 2024 within the Medline, Embase, Cochrane Central and BVS databases.

ETHICS AND DISSEMINATION

This review does not require ethics approval. Our dissemination strategy includes peer-review publication and presentations at conferences and to relevant stakeholders.

REGISTRATION DETAILS

This protocol was registered in Open Science Framework (available at: https://osf.io/kwfsy) on 19 February 2024.

From Mind to Milk: The Influence of Psychological Factors on the Composition of Human Breast Milk

Background/Objectives: Breast milk is a complex fluid crucial for infant development, nutrition, and immunological and neurodevelopmental support. Recent findings suggest that factors regarding mental health, such as stress, anxiety, and postpartum depression (PPD), may influence the composition of breast milk. This review aims to synthesize current knowledge regarding the relationship between a mother's mental state and the biochemical profile of human milk, focusing mainly on nutrients, hormones, immune factors, and microbiota. Methods: A systematic literature search was conducted in PubMed and the Web of Science using predefined keywords related to psychological factors and milk composition. Studies involving validated psychological assessment tools and only human subjects were included, in accordance with PRISMA guidelines. Results: Findings indicated that maternal stress and PPD are associated with alterations in breast milk composition. Elevated cortisol and changes in melatonin and prolactin levels have been observed. Immune components, such as secretory immunoglobulin A and transforming growth factor beta 2, exhibit variable responses depending on stress type and duration. Lower concentrations of docosahexaenoic acid and polyunsaturated fatty acid have been observed among mothers diagnosed with depression. Additionally, maternal psychological distress may influence infants' gut microbiota composition, potentially affecting long-term health outcomes. Conclusions: The maternal psychological state plays an essential role in shaping the composition of human breast milk. Understanding these associations highlights the need for mental health support during the postpartum period to optimize infant development. Future research should focus on the molecular mechanisms underlying these changes and potential interventions to mitigate adverse effects.

Comparing perceived heating effect and intensity of therapeutic ultrasound between breast tissue and calf muscle in lactating women: An observational study

OBJECTIVE

Therapeutic ultrasound (TUS) is the most common physiotherapy treatment for inflammatory conditions of the lactating breast. However, effective parameters for treatment are unknown, and based on musculoskeletal evidence. This study's aims were to determine the difference in heat perception (using TUS) between lactating breast and calf muscle tissue and the range of intensities required for heating perception in healthy lactating women.

METHOD

This repeated measures study recruited lactating mothers who exclusively breastfed infants aged 6 months or younger who responded to social media posts and flyers placed in medical offices. TUS was sequentially applied to the breast and calf, starting from 1Wcm2. The intensity at which participants reported first perceived warmth and then most tolerable warmth (or 2.5Wcm2) for the breast and the calf was recorded.

RESULTS

Fifty mothers (mean age, BMI = 31.6 years, 26.5), first perceived warmth at lower intensities in the breast (Z = -3.637,p < 0.001), but there was no difference between locations for most tolerable warmth (Z = -1.165,p = 0.244). Factors associated with higher perception of first warmth were antidepressant use (β = 0.369[95 %CI:0.103-0.635],p = 0.007) and calf location (β = 0.286[95 %CI:0.055-0.516],p = 0.015). Higher body mass index was the only factor associated with higher perception of tolerable warmth (β = 0.024[95 %CI:0.004-0.044],p = 0.017). The range of intensities required to perceive heating in the breast were 1-2.5Wcm2.

CONCLUSIONS

As perception of breast and calf warmth differs, TUS parameters used to treat musculoskeletal conditions may not be appropriate for inflammatory conditions of the lactating breast. Additional studies are needed to determine the tolerability and effectiveness of TUS using different intensities when treating women with ICLB.

Human milk as a complex natural product

Covering: up to the end of 2024Breastfeeding is one of the most effective ways to promote child health. However, characterizing the chemistry that fortifies the benefits of breastfeeding remains a grand challenge. Current efforts in the community are focused on characterizing the roles of the different carbohydrates, proteins, and fats in milk. The goal of this review is to highlight and describe current knowledge about the major classes of macromolecules in human milk and their potential role in infant health and wellness.

The prospective associations of fetal growth-related pregnancy complications with subsequent breastfeeding duration and markers of human milk production

BACKGROUND

The development of the breast for lactation occurs throughout pregnancy. It is unknown whether pregnancy complications resulting in poor fetal growth can affect breastfeeding (BF) success.

OBJECTIVES

We examined whether fetal growth-related pregnancy complications were associated with earlier BF cessation and changes in the concentrations of human milk biomarkers of low milk production.

METHODS

We used data from the Growing Up in Singapore Toward healthy Outcomes study (n = 954). Human milk concentrations of protein, lactose, citrate, sodium, potassium, and zinc at 3 wk postpartum were available for 180 mother-infant dyads. We examined the associations of fetal growth measures, including term infants born small-for-gestational-age (SGA) (<10th percentile), pregnancies complicated by fetal growth deceleration (second to third trimester fetal growth dropped between major centiles), elevated umbilical artery resistance (>90th percentile) or hypertensive disorders of pregnancy (HDP) with 1) risk of ceasing BF (Cox regression) and 2) concentrations of human milk components (weighted linear regression).

RESULTS

Adjusting for maternal education, smoking exposure, BF intentions, and prepregnancy BMI (in kg/m2), individuals who delivered SGA infants and those with HDP were more likely to breastfeed for a shorter duration when compared to those with uncomplicated pregnancies {adjusted hazard ratio [95% confidence interval (CI)]: 1.45 (1.11, 1.89) and 1.61 (1.14, 2.29), respectively}; associations were nonsignificant for fetal growth deceleration and umbilical artery resistance. SGA was not associated with concentrations of human milk biomarkers, but compared to participants with uncomplicated pregnancies, milk produced by those with HDP contained lower zinc concentrations [adjusted β coefficient (95% CI): -0.56 mg/L (-1.08, -0.04) mg/L].

CONCLUSIONS

Individuals with HDP and those with SGA infants tend to breastfeed for a shorter duration; however, only HDP appear to be associated with biomarkers of compromised milk production. Further research and support are needed to help individuals with HDP and SGA achieve their BF goals. This trial was registered at clinicaltrials.gov as NCT01174875.

Re-embarking in ART while still breastfeeding: an unresolved question

Infertile women may request to embark on a new course of Assisted Reproductive Technologies (ART) in pursuit of a second child while still breastfeeding their first child. Breastfeeding is a time of profound hormonal changes that may interfere with ovarian physiology and uterine receptivity. Prolactin and oxytocin can mediate a plethora of potential detrimental effects. However, robust evidence to advise in favor or against ART during breastfeeding is lacking. In this narrative review, we reviewed the literature with the intent to shed light on this neglected issue. Possible adverse effects on ART success emerged for ovulatory mechanisms, folliculogenesis, uterine contractions, uterine peristalsis, and early embryo development. A negative impact of exogeneous hormones on infant health might be considered only for stimulation cycles. Overall, most concerns can be claimed for the clinical setting of ovarian stimulation, followed by the one of embryo transfer in a natural cycle and, finally, by the embryo transfer in a hormone replacement treatment preparation. However, in general, it seems wise to wait for breastfeeding to be discontinue before re-embarking on IVF, also considering that a too short interpregnancy interval may be deleterious to pregnancy outcomes. On the other hand, one must also recognize that available evidence is insufficient to deny access to treatments for women requesting earlier access. These women must be informed regarding the non-fully reassuring evidence.

Milk Composition Is Predictive of Low Milk Supply Using Machine Learning Approaches

Background/Objectives: The causes of low milk supply are multifactorial, including factors such as gene mutations, endocrine disorders, and infrequent milk removal. These factors affect the functional capacity of the mammary gland and, potentially, the concentrations of milk components. This study aimed to investigate the differences in milk composition between mothers with low and normal milk supply and develop predictive machine learning models for identifying low milk supply. Methods: Twenty-four-hour milk production measurements were conducted using the test-weigh method. An array of milk components was measured in 58 women with low milk supply (<600 mL/24 h) and 106 with normal milk supply (≥600 mL/24 h). Machine learning algorithms were employed to develop prediction models integrating milk composition and maternal and infant characteristics. Results: Among the six machine learning algorithms tested, deep learning and gradient boosting machines methods had the best performance metrics. The best-performing model, incorporating 14 milk components and maternal and infant characteristics, achieved an accuracy of 87.9%, an area under the precision-recall curve (AUPRC) of 0.893, and an area under the receiver operating characteristic curve (AUC) of 0.917. Additionally, a simplified model, optimised for clinical applicability, maintained a reasonable accuracy of 78.8%, an AUPRC of 0.776, and an AUC of 0.794. Conclusions: These findings demonstrate the potential of machine learning models to predict low milk supply with high accuracy. Integrating milk composition and maternal and infant characteristics offers a practical approach to identify women at risk of low milk supply, facilitating timely interventions to support breastfeeding and ensure adequate infant nutrition.

Effect of oxytocin nasal spray pretreatment on postoperative acute stress disorder in patients with accidental traumatic fracture: a single-centre prospective randomised controlled clinical trial study protocol

INTRODUCTION

Patients undergoing surgical procedures are often prone to developing acute stress disorder (ASD) postoperatively. Presently, oxytocin nasal spray has shown significant potential in the treatment of stress-related neuropsychiatric diseases. However, there are few reports on the use of oxytocin nasal spray in postoperative ASD, a condition that can potentially develop into a high-risk factor for post-traumatic stress disorder. This study aims to investigate the effect of pretreatment with oxytocin nasal spray on postoperative ASD in patients with accidental trauma and fracture to provide new clinical insights for the prevention of postoperative ASD.

METHODS AND ANALYSIS

This study is a single-centre, double-blind, randomised controlled clinical trial. The trial aims to recruit 328 patients with accidental traumatic fractures who underwent surgical treatment. Participants will be randomly categorised into two groups: a control group (0.9% normal saline nasal spray, 1 mL) and an oxytocin group (oxytocin nasal spray, 1 mL/40 IU) at a ratio of 1:1 using the random number table method. The primary outcome is the incidence of ASD on postoperative days 1-3. Secondary outcomes include patient resilience, anxiety, depression and pain scores on postoperative days 1-3. The exploratory results include the concentrations of stress response indicators such as malondialdehyde, cortisol and superoxide dismutase in the saliva before the first intervention and on days 1-3 after surgery.

ETHICS AND DISSEMINATION

The trial was approved by the clinical research ethics committee of the General Hospital of the Western Theater Command (identifier: 2024EC3-ky014). The findings of this trial will be disseminated in a peer-reviewed journal and in national or international paediatric research to guide future practice.

TRIAL REGISTRATION NUMBER

ChiCTR2400082612.

Does Antenatal Expressing Affect Onset of Lactogenesis for Women With Diabetes? Results From a Randomised Controlled Trial and Cohort Study

BACKGROUND

Previously it was recognised onset of Lactogenesis II was delayed in women with Type I diabetes compared to women without diabetes, but the effect of gestational diabetes was unclear. Some clinicians suggest pregnant women with diabetes express breastmilk in late pregnancy to hasten onset of Lactogenesis II.

AIMS

To confirm if Lactogenesis II occurs later in women with diabetes in pregnancy, and test if advice to express antenatally hastens Lactogenesis II.

MATERIALS AND METHODS

Data from the DAME (Diabetes Antenatal Milk Expression) randomised controlled trial collected at recruitment and 2 weeks postpartum were compared with a concurrent purposively recruited cohort of women without diabetes in pregnancy. Timing of lactogenesis and adjusted percentage differences were calculated. Study sample was women from both studies with complete data for included measures to assess onset of Lactogenesis II (maternal perception).

RESULTS

Delayed onset of lactation (≥ 72 h postpartum) was similar in DAME trial arms: standard care 58.6% (143/244); antenatal expressing 55.8% (148/265) but lower in comparison cohort 46.9% (90/192). Percentage difference between groups (adjusted for parity, delivery mode, BMI and gestation): DAME standard arm and comparison cohort 12.3% (95% CI 2.6%-22.0%; p = 0.01) DAME intervention arm and comparison cohort 8.3% (95% CI -1.2%-17.8%; p = 0.09) DAME standard care and intervention 4.0% (95% CI -4.5%-12.5%; p = 0.35).

CONCLUSIONS

Lactogenesis II occurs later for women with diabetes in pregnancy than women without diabetes. Our findings do not provide evidence that antenatal expressing hastens onset of lactation in women with diabetes in pregnancy.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: ACTRN12611000217909.

The Refractive Index of Human Milk Serum: Natural Variations and Dependency on Macronutrient Concentrations

The refractive index (RI) of human milk serum (also known as whey, milk soluble fraction or milk plasma) depends on the individual molecular species dissolved in the serum and their concentrations. Although the human milk serum RI is known to influence milk analysis methods based on light scattering, the RI dependency on human milk serum composition is currently unknown. Therefore, we systematically evaluate how the RI depends on natural variations in macronutrient concentrations in the soluble fraction. We measure RI variations in serum simulating samples with controlled macronutrient concentrations, as well as skimmed and whole fore-, bulk, and hindmilk from 19 donors. For both types of samples, we relate the measured RI to the macronutrient composition. From the serum simulating samples, we observe that the RI depends more on variations in whey protein, than carbohydrate concentrations, while minerals have negligible influence. For all donated samples, the average RI was 1.3470 (range 1.3466-1.3474). Per donor, no significant differences were observed in RI between fore-, bulk, and hindmilk. We conclude that protein and solids-not-fat (i.e., the total contribution of carbohydrates, proteins and minerals present in milk) concentrations are most predictive for human milk serum RI.

Gestational Diabetes Mellitus, Breastfeeding, and Progression to Type 2 Diabetes: Why Is It So Hard to Achieve the Protective Benefits of Breastfeeding? A Narrative Review

Women diagnosed with gestational diabetes mellitus (GDM) face a significantly heightened risk of developing type 2 diabetes mellitus (T2DM) later in life. Breastfeeding (BF) has been identified as a potential strategy to delay or prevent T2DM; however, women with GDM often encounter barriers in initiating and maintaining adequate BF practices compared to those with uncomplicated pregnancies. This paradox prompts an exploration into the causes of these BF challenges and considers the possibility of reverse causation: Does prolonged and intensive BF mitigate the risk of subsequent glucose dysregulation and T2DM? Alternatively, do women with compromised insulin secretion and sensitivity, who are predisposed to T2DM, struggle to sustain intensive BF practices? This narrative review aims to explore the interplay between GDM, BF, and T2DM development by examining the different factors that present BF challenges among women with GDM. Understanding these dynamics is crucial for establishing realistic BF expectations and developing effective clinical and public health strategies to support BF in this high-risk population.

Evaluation the protective role of baicalin against H2O2-driven oxidation, inflammation and apoptosis in bovine mammary epithelial cells

Mastitis is one of the most common diseases in dairy farms. During the perinatal period, the bovine mammary epithelial cells (BMECs) of High-yielding dairy cows accelerate metabolism and produce large amounts of reactive oxygen species (ROS). It is one of the primary causes of mastitis and will lead to the breakdown of redox balance, which will induce oxidative stress, inflammation, and apoptosis. Baicalin is a flavonoid substance extracted from the root of natural plant Scutellaria baicalensis, which has anti-inflammatory, anti-oxidant, anti-viral and other biological functions. In this research, hydrogen peroxide (H2O2) was used to construct a mastitis oxidative stress model, and relevant mechanisms were analyzed by immunofluorescence techniques, qRT-PCR and Western Blot to explore how baicalin affects BMECs' oxidative stress and inflammation caused by H2O2, as well as to provide new perspectives on the combined application of baicalin in the prevention and treatment of mastitis. The results demonstrated that baicalin treatment could reduce the accumulation of H2O2-induced intracellular ROS and decrease the expression of inflammatory cytokines Tumor Necrosis Factor-α (TNF-α), interleukin 6 (IL-6), interleukin-1β (IL-1β) and the apoptosis rate. The inhibitory effect of baicalin on H2O2-induced intracellular ROS accumulation and the expression of inflammatory cytokines and apoptotic factors in BMECs was blocked by pretreatment with the Nuclear factor erythroid 2-related factor 2 (Nrf2) inhibitor retinoic acid (RA) prior to H2O2 and/or baicalin treatment. In summary, baicalin could served as a natural antioxidant agent to regulate cell apoptosis through its anti-inflammatory, antioxidant and anti-apoptotic effects to combat BMECs damage caused by H2O2.

A Longitudinal Observation of Antenatal Milk Expression in Mothers of Infants with Congenital Anomalies

Background: For mothers of infants with congenital anomalies, antenatal milk expression (AME), known as hand expression during late pregnancy, allows mothers to contribute to their newborn's care through colostrum collection. However, research is limited by self-report of AME adherence and colostrum volume. Objective: This study examined the ability of participants to adhere to a recommended protocol on AME for any removal and measurement of colostrum during late pregnancy. Materials and Methods: A prospective, longitudinal, observational design was used. Our recommended protocol involved hand expression of 5 minutes per breast for a total of 10 minutes for each AME session twice per 24 hours for any colostrum from 37 0/7 weeks gestation until birth. Women received AME education, completed milk logs, and attempted AME. The study team verified all colostrum volumes. Results: Nineteen women (10 nulliparous) participated, with 13 (68%) carrying infants with major organ system defects and 6 (32%) carrying infants with congenital heart defects. Most participants (52.6%) completed more than half but fewer than all AME sessions. Seven participants (36.8%) fully adhered, completing two AME sessions daily until hospital admission. Eighteen participants (94.7%) could remove milk (80-100% of the time). The 24-hour colostrum volume (median 0.35 mL, interquartile range [IQR] 0.065-0.845) and the total colostrum volume (median 3.99 mL, IQR 1.35-6.82) from AME varied. Conclusions: Among a small group of women of infants with congenital anomalies, adherence to a recommended protocol is feasible but varied by AME session frequency. Most women could collect colostrum for future infant feeding.

Regulation of gene expression in milk secretory pathways during secretory activation in Holstein cows

Increased transcription of genes involved in lactose synthesis is a key feature of secretory activation of the mammary gland. We determined which genes are transcriptionally regulated during the transition from colostrum to milk in cows and whether more frequent milking of one udder half would increase milk yields and alter gene expression. We enrolled 12 Holstein cows immediately after calving, harvested colostrum, then randomly assigned one udder half to 12 h (2X) or 6 h (4X) milking intervals for 48 h after first milking. After 48 h, all quarters were milked twice daily until d7, when final quarter milk yields were collected. Yields and composition of colostrum and milk were recorded for each 12 h interval. After each milking, a strip sample of hind milk was collected for isolation of RNA from milk fat and quantification of selected transcripts via qPCR. Milk, milk fat, total protein, and lactose yields increased significantly over the initial 48 h and at d7 after calving. Quarters on 4X treatment produced more milk than the contralateral 2X quarters. Genes upregulated concomitantly with milk yields encoded α-lactalbumin (LALBA), β-1,4-galactosyltransferase (B4GALT1), fatty acid synthase (FASN), β casein (CSN2), and folate receptor α (FOLR1). Downregulated genes encoded monosaccharide transporters (SLC2A3, SLC2A8, SLC35A2) and enzymes involved in galactose synthesis (HK1, PGM1, GALE). Three genes were initially downregulated but later upregulated at d7 (LPIN1, SLC2A1, UGP2). Notably, milking frequency had no effect on gene expression. Sequential upregulation first of genes encoding the former enzymes, then of UGP2, may be necessary for copious milk production. However, the local effects of milking frequency on milk production during lactogenesis do not appear to be controlled by transcription of these genes related to lactose synthesis.

Investigation of Relationships between Intakes of Human Milk Total Lipids and Metabolic Hormones and Infant Sex and Body Composition

Human milk (HM) composition, including metabolic hormones and lipids, is influenced by various factors, including lactation stage and, potentially, infant sex, which may affect infant body composition (BC) development. We aimed to: (a) characterize the longitudinal concentration and intake profiles of HM leptin, adiponectin, insulin, and total lipids; (b) determine if their concentrations and intakes differ by infant sex; and (c) explore the intakes relationships with the development of infant BC. Milk samples (n = 501) were collected from 82 mother-infant dyads during the first 6 months postpartum. Infant 24 h HM intake was measured, and the average cumulative HM component intakes were calculated. The statistical analysis used linear mixed modeling. Intakes of HM leptin, adiponectin, insulin, and total lipids increased to 1 month postpartum and then remained stable. HM intake and total lipids intake but not hormone intakes were positively associated with infant BC (fat-free mass, fat-free mass index, fat mass, fat mass index, percentage fat mass, and fat mass to fat-free mass ratio). HM component concentrations and intakes did not differ by sex. These findings advance our understanding of the temporal nature of HM components, emphasizing the role of infant 24 h HM and total lipids intake in development of infant lean and adipose tissue.

Having Enough Milk to Sustain a Lactation Journey: A Call to Action

The rates of human milk feeding are suboptimal worldwide. Recommendations for healthy, term mother-infant dyads include early breastfeeding initiation, frequent skin-to-skin contact, and frequent breastfeeding. The normal physiology of lactation can be affected by prenatal factors such as diabetes, obesity, and excessive gestational weight gain. Furthermore, birth-related factors such as early-term gestation, stressful labor, unscheduled cesarean birth, and postpartum hemorrhage can additionally disrupt recommended practices such as early initiation of breastfeeding and skin-to-skin contact. Given that the first 2 to 3 days postpartum are critical to achieving timely secretory activation and establishing an adequate volume of milk, a proactive approach to care can include building awareness of risk factors and development of protocols for the effective early initiation of lactation.

Dual role of pregnancy in breast cancer risk

Reproductive history is one of the strongest risk factors for breast cancer in women. Pregnancy can promote short-term breast cancer risk, but also reduce a woman's lifetime risk of breast cancer. Changes in hormone levels before and after pregnancy are one of the key factors in breast cancer risk. This article summarizes the changes in hormone levels before and after pregnancy, and the roles of hormones in mammary gland development and breast cancer progression. Other factors, such as changes in breast morphology and mammary gland differentiation, changes in the proportion of mammary stem cells (MaSCs), changes in the immune and inflammatory environment, and changes in lactation before and after pregnancy, also play key roles in the occurrence and development of breast cancer. This review discusses the dual effects and the potential mechanisms of pregnancy on breast cancer risk from the above aspects, which is helpful to understand the complexity of female breast cancer occurrence.

Drugs in Human Milk Part 1: Practical and Analytical Considerations in Measuring Drugs and Metabolites in Human Milk

Human milk is a remarkable biofluid that provides essential nutrients and immune protection to newborns. Breastfeeding women consuming medications could pass the drug through their milk to neonates. Drugs can be transferred to human milk by passive diffusion or active transport. The physicochemical properties of the drug largely impact the extent of drug transfer into human milk. A comprehensive understanding of the physiology of human milk formation, composition of milk, mechanisms of drug transfer, and factors influencing drug transfer into human milk is critical for appropriate selection and use of medications in lactating women. Quantification of drugs in the milk is essential for assessing the safety of pharmacotherapy during lactation. This can be achieved by developing specific, sensitive, and reproducible analytical methods using techniques such as liquid chromatography coupled with mass spectrometry. The present review briefly discusses the physiology of human milk formation, composition of human milk, mechanisms of drug transfer into human milk, and factors influencing transfer of drugs from blood to milk. We further expand upon and critically evaluate the existing analytical approaches/assays used for the quantification of drugs in human milk.

Epithelial IL-2 is critical for NK cell-mediated cancer immunosurveillance in mammary glands

Interleukin 2 (IL-2) is the first identified cytokine and its interaction with receptors has been known to shape the immune responses in many lymphoid or non-lymphoid tissues for more than four decades. Active T cells are the primary cellular source for IL-2 production and epithelial cells have never been considered the major cellular source of IL-2 under physiological conditions. It is, however, tempting to speculate that epithelial cells could potentially express IL-2 that regulates the intricate interactions between epithelial cells and lymphocytes. Datamining our recently published single-cell RNAseq in the mouse mammary gland identified IL-2 expression in mammary epithelial cells, which is induced by prolactin via the STAT5 signaling pathway. Furthermore, epithelial IL-2 plays a crucial role in maintaining the physiological functions of natural killer (NK) cells within the mammary glands. IL-2 deletion in the mammary epithelial cells leads to a significant reduction in the number and function of NK cells, which in turn results in defective immunosurveillance, expansion of luminal epithelial cells, and tumor development. Interestingly, T cells in the mammary glands are not changed, indicating the specific regulation of NK cells by epithelial IL-2 production. In agreement, we also found that human epithelial cells express IL-2 and NK cells express the highest level of IL2RB among all the immune cells. Here, we provide the first evidence that epithelial cells produce IL-2, which is critical for maintaining the physiological functions of NK cells in immunosurveillance.

Human Milk-The Biofluid That Nourishes Infants from the First Day of Life

Human milk is a biofluid with a unique composition among mammalian milks. Besides this milk's major components, its bioactive compounds, like hormones, immune factors, and oligosaccharides, are unique and important for infant growth and development. The best form of nutrition for term and preterm infants is the mother's own milk. However, in the absence of the mother's own milk, donor milk should be made available. Milk banks support neonatal intensive care units by providing preterm infants with human milk that generally has reasonable nutritive value for this sensitive population. However, neither mother's own milk nor donor milk has sufficient energy content for the growth of preterm babies, so adequate human milk supplementation is crucial for their progress. Due to the different characteristics of human breast milk, as well as ubiquitous environmental pollutants, such as microplastics, new methods are required for monitoring the quality and characteristics of human milk, which will lay a solid foundation for the further development and progress of human milk research.

The Role of Progesterone in Elf5 Activation and Milk Component Synthesis for Cell-Cultured Milk Production in MAC-T Cells

Prolactin is essential for mammary gland development and lactation. Progesterone also induces ductal branching and alveolar formation via initial secretory differentiation within the mammary gland. Herein, we aimed to evaluate the role of progesterone as a prolactin substitute for the production of cell-cultured milk components in MAC-T cells. Cells were treated with various hormones such as prolactin (PRL), progesterone (P4), 17β-estradiol (E2), cortisol (COR), and insulin (INS) for 5 d. MAC-T cells cultured in a P4 differentiation media (2500 ng/mL of P4, 25 ng/mL of E2, 25 ng/mL of COR, and 25 ng/mL of INS) showed similar levels of E74-like factor 5 (Elf5) and milk component synthesis (α-casein, β-casein, α-lactalbumin, β-lactoglobulin, and triglycerides) compared to those cultured in a PRL differentiation media (5000 ng/mL of PRL, 500 ng/mL of CORT, and 50 ng/mL of INS). The levels of α-casein and triglycerides in the optimal P4 differentiation media were present at comparable levels to those in the PRL differentiation media. Our results demonstrated that P4 induces the activation of Elf5 and the synthesis of milk components in MAC-T cells, similar to PRL. Therefore, P4 may be used as an effective substitute of PRL for cell-cultured milk production in in vitro frameworks.

Evaluation of the Impact of a Midwife-Led Breastfeeding Group Intervention on Prevention of Postpartum Depression: A Multicentre Randomised Clinical Trial

Postpartum depression is a significant health issue affecting both mothers and newborns during the postpartum period. Group support interventions during this period have proven effective in helping women cope with depression and improving breastfeeding rates. This study aimed to assess the effectiveness of a midwife-led breastfeeding support group intervention on breastfeeding rates, postpartum depression and general self-efficacy. This was a multicentric cluster randomised controlled trial with control and intervention groups and was not blinded. It was conducted in Andalusia (southern Spain) from October 2021 to May 2023. A total of 382 women participated in the study. The results showed a significant difference in exclusive breastfeeding rates at 4 months postpartum between the groups (control 50% vs. intervention 69.9%; p < 0.001). Additionally, there was a lower mean score on the Edinburgh Postnatal Depression Scale in the intervention group (12.49 ± 3.6 vs. 13.39 ± 4.0; p = 0.044). Similarly, higher scores of general self-efficacy were observed among breastfeeding women at 2 and 4 months postpartum (77.73 ± 14.81; p = 0.002 and 76.46 ± 15.26; p < 0.001, respectively). In conclusion, midwife-led breastfeeding support groups enhanced self-efficacy, prolonged breastfeeding and reduced postpartum depression 4 months after giving birth.

Milk Biomarkers of Secretory Activation in Breast Pump-Dependent Mothers of Preterm Infants: An Integrative Review

Background: Lack of mother's own milk (MOM) at discharge from the neonatal intensive care unit (NICU) is a global problem and is often attributable to inadequate MOM volume. Evidence suggests that the origins of this problem are during the first 14 days postpartum, a time period that includes secretory activation (SA; lactogenesis II, milk coming in). Objectives: To describe and summarize evidence regarding use of MOM biomarkers (MBMs) as a measure of SA in pump-dependent mothers of preterm infants in the NICU and to identify knowledge gaps requiring further investigation. Methods: An integrative review was conducted using Whittemore and Knafl methodology incorporating the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist. A search using electronic databases MEDLINE (through PubMed) and CINAHL (Cumulative Index to Nursing and Allied Health Literature) and reference lists of included articles was conducted. Results: Of the 40 articles retrieved, 6 met the criteria for inclusion. Results revealed the following five findings: (1) Achievement of SA defined by MBMs is delayed and/or impaired in mothers of preterm infants. (2) MBMs are associated with pumped MOM volume. (3) Achievement of SA defined by MBMs is associated with pumping frequency. (4) Delayed and/or impaired achievement of SA defined by MBMs may be exacerbated by maternal comorbidities. (5) There is a lack of consensus as to which MBM(s) and analysis techniques should be used in research and practice. Conclusions: MBMs hold tremendous potential to document and monitor achievement of SA in mothers of preterm infants, with multiple implications for research and clinical practice.

Molecular complexity of mammary glands development: a review of lactogenic differentiation in epithelial cells

The mammary gland is a dynamic organ with various physiological processes like cellular proliferation, differentiation, and apoptosis during the pregnancy-lactation-involution cycle. It is essential to understand the molecular changes during the lactogenic differentiation of mammary epithelial cells (MECs, the milk-synthesizing cells). The MECs are organized as luminal milk-secreting cells and basal myoepithelial cells (responsible for milk ejection by contraction) that form the alveoli. The branching morphogenesis and lactogenic differentiation of the MECs prepare the gland for lactation. This process is governed by many molecular mediators including hormones, growth factors, cytokines, miRNAs, regulatory proteins, etc. Interestingly, various signalling pathways guide lactation and understanding these molecular transitions from pregnancy to lactation will help researchers design further research. Manipulation of genes responsible for milk synthesis and secretion will promote augmentation of milk yield in dairy animals. Identifying protein signatures of lactation will help develop strategies for persistent lactation and shortening the dry period in farm animals. The present review article discusses in details the physiological and molecular changes occurring during lactogenic differentiation of MECs and the associated hormones, regulatory proteins, miRNAs, and signalling pathways. An in-depth knowledge of the molecular events will aid in developing engineered cellular models for studies related to mammary gland diseases of humans and animals.

Breastfeeding and Postpartum Depression: A Review of Relationships and Potential Mechanisms

PURPOSE OF REVIEW

Postpartum depression (PPD) and breastfeeding are important, interrelated health factors. It is established that women who breastfeed exclusively have lowered likelihood of developing significant PPD. Yet, many questions remain around what factors are involved. The purpose of this review is to provide updated information about the relationship between PPD and breastfeeding.

RECENT FINDINGS

Both psychological and physiological factors have emerged as important moderators and mechanisms of the relationship between postpartum depression and breastfeeding. Breastfeeding self-efficacy, self-compassion, and engagement with the infant during feeding all modify or mediate the relationship, and a complex dynamic relationship among cortisol, oxytocin, progesterone, and estrogen is involved. Importantly, recent intervention studies suggest psychosocial interventions may impact both breastfeeding and mood. Providers and researchers should recognize the interrelationship between the breastfeeding and PPD and apply this understanding to patient care through integrated education and care for both mood and breastfeeding enhancement.

The contributions of parental lactation on offspring development: It's not udder nonsense!

The Developmental Origins of Health and Disease (DOHaD) hypothesis describes how maternal stress exposures experienced during critical periods of perinatal life are linked to altered developmental trajectories in offspring. Perinatal stress also induces changes in lactogenesis, milk volume, maternal care, and the nutritive and non-nutritive components of milk, affecting short and long-term developmental outcomes in offspring. For instance, selective early life stressors shape the contents of milk, including macro/micronutrients, immune components, microbiota, enzymes, hormones, milk-derived extracellular vesicles, and milk microRNAs. In this review, we highlight the contributions of parental lactation to offspring development by examining changes in the composition of breast milk in response to three well-characterized maternal stressors: nutritive stress, immune stress, and psychological stress. We discuss recent findings in human, animal, and in vitro models, their clinical relevance, study limitations, and potential therapeutic significance to improving human health and infant survival. We also discuss the benefits of enrichment methods and support tools that can be used to improve milk quality and volume as well as related developmental outcomes in offspring. Lastly, we use evidence-based primary literature to convey that even though select maternal stressors may modulate lactation biology (by influencing milk composition) depending on the severity and length of exposure, exclusive and/or prolonged milk feeding may attenuate the negative in utero effects of early life stressors and promote healthy developmental trajectories. Overall, scientific evidence supports lactation to be protective against nutritive and immune stressors, but the benefits of lactation in response to psychological stressors need further investigation.

Infant factors that impact the ecology of human milk secretion and composition-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 3

Infants drive many lactation processes and contribute to the changing composition of human milk through multiple mechanisms. This review addresses the major topics of milk removal; chemosensory ecology for the parent-infant dyad; the infant's inputs into the composition of the human milk microbiome; and the impact of disruptions in gestation on the ecology of fetal and infant phenotypes, milk composition, and lactation. Milk removal, which is essential for adequate infant intake and continued milk synthesis through multiple hormonal and autocrine/paracrine mechanisms, should be effective, efficient, and comfortable for both the lactating parent and the infant. All 3 components should be included in the evaluation of milk removal. Breastmilk "bridges" flavor experiences in utero with postweaning foods, and the flavors become familiar and preferred. Infants can detect flavor changes in human milk resulting from parental lifestyle choices, including recreational drug use, and early experiences with the sensory properties of these recreational drugs impact subsequent behavioral responses. Interactions between the infant's own developing microbiome, that of the milk, and the multiple environmental factors that are drivers-both modifiable and nonmodifiable-in the microbial ecology of human milk are explored. Disruptions in gestation, especially preterm birth and fetal growth restriction or excess, impact the milk composition and lactation processes such as the timing of secretory activation, adequacy of milk volume and milk removal, and duration of lactation. Research gaps are identified in each of these areas. To assure a sustained and robust breastfeeding ecology, these myriad infant inputs must be systematically considered.

Macronutrient composition of term and preterm human milk of different socio economic groups

Assessment of the nutritional composition of Human Breast Milk (HBM) is important to understand its sufficiency as the sole nutrient source in infants. The present study is aimed to analyze the proximate composition along with total amino acid and fatty acid profile in term and preterm HBM of different socio economic status. This cross sectional study included, 120 lactating mothers with term or preterm gestation from maternity hospitals located in Hyderabad, Telangana. Nutritional proximate, total amino and fatty acid profiles were estimated in pooled human milk collected from each participant within the first week of postpartum. The macronutrient composition in term was similar to that of preterm breast milk. The essential amino acid Leucine was significantly high in preterm (8.91 ± 0.18) when compared to term (8.61 ± 0.23). ω-5 fatty acid Myristoleic acid was significantly high in preterm (0.14 ± 0.02) when compared to term (0.11 ± 0.02), whereas ω-6 fatty acids like Docosadienoic Acid and Eicosadienoic acid were found to be significantly high in term when compared to preterm. Further, it was also found that the mono unsaturated and ω-9 fatty acids were significantly high in lower socio economic group, whereas, poly unsaturated and ω -3 and 6 fatty acids were significantly high in upper socio economic group. The present study concludes that, nutritional composition like essential amino and fatty acids of human milk vary significantly between different gestational age as well as in socio economic groups.

Leveraging mHealth and a milk expression frequency biomarker during postpartum to prolong lactation among parents of critically ill infants: a pilot study

OBJECTIVE

To assess the feasibility and potential benefits of personalized biomarker-based text messages in prolonging lactation among parents of critically ill infants.

STUDY DESIGN

Thirty-six participants were randomized to receive either daily texts with Mother's Own Milk (MOM) sodium levels or standard care. Surveys at months 1 and 3 assessed whether infants were receiving exclusive MOM feeding, any MOM feeding, and whether the parent was still lactating. Kaplan-Meier and log-rank tests were used for time-to-event analysis within and between intervention and control groups.

RESULTS

Participants were predominantly on Medicaid (72%), delivered infants <1500 g, and by c-section (56%). Kaplan-Meier probabilities at month 3 suggest prolonged MOM feeding (63% [0.95CI, 0.43-0.91] vs. 41% [0.95CI, 0.21-0.67]) and lactation (63% [0.95CI, 0.42-0.95] vs. 37% [0.95CI, 0.18-0.76]) in the enhanced group compared to the control group.

CONCLUSION

Personalized biomarker-based text messages are feasible and may prolong lactation and MOM feeding among parents of critically ill infants.

Oral administration of domperidone in the first or third week of lactation: effects on prolactin concentrations and mammary gene expression in sows and piglet growth

The scope of the present study is endocrine and metabolic control of sow lactation. This project aimed to determine the impact of increasing prolactin concentrations via oral administration of the dopamine receptor antagonist domperidone in the first or third week of lactation in sows. Effects on sow hormonal and metabolic status, lactational performance, and gene expression in mammary epithelial cells were determined. Primiparous sows were divided in 3 treatments: 1) 10 mL of vehicle (table syrup) per os twice daily during the first and third weeks of lactation (Control, CTL, n = 23), 2) 0.5 mg/kg of domperidone per os twice daily during the first week of lactation (LACT1, n = 23), or 3) 0.5 mg/kg of domperidone given per os twice daily during the third week of lactation (LACT3, n = 22). Treated sows also received 10 mL of the vehicle twice daily during the other treatment period. Litter size was standardized to 12 ± 1 and piglets were weighed at birth, 24 h, and on d 8, 15, 22 (weaning), 35, and 56. Sow feed intake was recorded daily. Representative milk samples were obtained on d 7 and 21 of lactation for compositional analyses, and milk fat globules were used to measure mRNA abundances of various genes. Jugular blood samples were obtained from sows on d 1, 7, 14, and 21 of lactation to measure concentrations of prolactin, IGF-1, insulin, urea, and FFA. Concentrations of prolactin were increased (P < 0.01) at the end of the 7-d treatment period with domperidone, whether imposed in the first (LACT1) or third (LACT 3) week of lactation. No other blood variables were affected by treatments and neither was milk composition (P > 0.10). Sow BW, backfat thickness, or feed intake were not altered by treatments (P > 0.10), but piglet BW tended to be greater in litters from LACT3 compared with CTL sows on d 22 and 35 (P ≤ 0.10). Gene expression of EGF in milk fat globules tended to be (LACT1, P < 0.10) or was increased (LACT3, P < 0.05) after treatment, and the effect in LACT1 sows was maintained until d 21 of lactation. The mRNA abundance of SPP1 was increased (P < 0.05) in LACT1 vs CTL sows on d 7, and that of 3 major milk proteins tended to be (CSN1S2 and WAP, P < 0.10) or was greater (LALBA, P < 0.05) in LACT3 vs CTL sows on d 21 of lactation. Oral administration of domperidone during the first or third week of lactation increased prolactin concentrations and altered mRNA abundances of selected genes in milk fat globules. Yet, only the LACT 3 treatment positively affected piglet performance.

The Relationship between Psychological Suffering, Value of Maternal Cortisol during Third Trimester of Pregnancy and Breastfeeding Initiation

Background and Objectives: Cortisol, the stress hormone, is an important factor in initiating and maintaining lactation. Maternal suffering during pregnancy is predictive for the initiation and shorter duration of breastfeeding and can also lead to its termination. The aim of this study is to evaluate the relationship between the level of salivary cortisol in the third trimester of pregnancy and the initiation of breastfeeding in the postpartum period in a cohort of young pregnant women who wanted to exclusively breastfeed their newborns during hospitalization. Materials and Methods: For the study, full-term pregnant women were recruited between January and May 2022 in the Obstetrics and Gynecology Clinic of the Mureș County Clinical Hospital. Socio-demographic, clinical obstetric and neonatal variables were collected. Breastfeeding efficiency was assessed using the LATCH Breastfeeding Assessment Tool at 24 and 48 h after birth. The mean value of the LATCH score assessed at 24 and 48 h of age was higher among mothers who had a higher mean value of salivary cortisol measured in the third trimester of pregnancy (p < 0.05). A multivariate logistic regression model was used to detect risk factors for the success of early breastfeeding initiation. Results: A quarter of pregnant women had a salivary cortisol level above normal limits during the third trimester of pregnancy. There is a statistically significant association between maternal smoking, alcohol consumption during pregnancy and the level of anxiety or depression. Conclusions: The most important finding of this study was that increased salivary cortisol in the last trimester of pregnancy was not associated with delayed initiation/absence of breastfeeding.

Endocrine changes during the peripartal period related to colostrogenesis in mammalian species

This review discusses endocrine and functional changes during the transition from late gestation to lactation that are related to the production of colostrum in different mammalian species. Species covered in this article include ungulate species (cattle, sheep, goats, pigs, horses), rodents (rat, mouse), rabbits, and carnivores (cats, dogs), as well as humans. An immediate availability of high quality colostrum for the newborn after birth is crucial in species where a transfer of immunoglobulins (Ig) does not or only partially occur via the placenta during pregnancy. Declining activity of gestagens, in most species progesterone (P4), is crucial at the end of pregnancy to allow for the characteristic endocrine changes to initiate parturition and lactation, but the endocrine regulation of colostrogenesis is negligible. Both, the functional pathways and the timing of gestagen withdrawal differ considerably among mammalian species. In species with a sustaining corpus luteum throughout the entire pregnancy (cattle, goat, pig, cat, dog, rabbit, mouse, and rat), a prostaglandin F2α (PGF2α)-induced luteolysis shortly before parturition is assumed to be the key event to initiate parturition as well as lactogenesis. In species where the gestagen production is taken over by the placenta during the course of gestation (e.g., sheep, horse, and human), the reduction of gestagen activity is more complex, as PGF2α does not affect placental gestagen production. In sheep the steroid hormone synthesis is directed away from P4 towards estradiol-17β (E2) to achieve a low gestagen activity at high E2 concentrations. In humans the uterus becomes insensitive to P4, as parturition occurs despite still high P4 concentrations. However, lactogenesis is not completed as long as P4 concentration is high. Early colostrum and thus Ig intake for immune protection is not needed for the human newborn which allows a delayed onset of copious milk secretion for days until the placenta expulsion causes the P4 drop. Like humans, horses do not need low gestagen concentrations for successful parturition. However, newborn foals need immediate immune protection through Ig intake with colostrum. This requires the start of lactogenesis before parturition which is not fully clarified. The knowledge of the endocrine changes and related pathways to control the key events integrating the processes of colostrogenesis, parturition, and start of lactation are incomplete in many species.

Hormonal regulation of mammary gland development and lactation

Lactation is critical to infant short-term and long-term health and protects mothers from breast cancer, ovarian cancer and type 2 diabetes mellitus. The mammary gland is a dynamic organ, regulated by the coordinated actions of reproductive and metabolic hormones. These hormones promote gland development from puberty onwards and induce the formation of a branched, epithelial, milk-secreting organ by the end of pregnancy. Progesterone withdrawal following placental delivery initiates lactation, which is maintained by increased pituitary secretion of prolactin and oxytocin, and stimulated by infant suckling. After weaning, local cytokine production and decreased prolactin secretion trigger large-scale mammary cell loss, leading to gland involution. Here, we review advances in the molecular endocrinology of mammary gland development and milk synthesis. We discuss the hormonal functions of the mammary gland, including parathyroid hormone-related peptide secretion that stimulates maternal calcium mobilization for milk synthesis. We also consider the hormonal composition of human milk and its associated effects on infant health and development. Finally, we highlight endocrine and metabolic diseases that cause lactation insufficiency, for example, monogenic disorders of prolactin and prolactin receptor mutations, maternal obesity and diabetes mellitus, interventions during labour and delivery, and exposure to endocrine-disrupting chemicals such as polyfluoroalkyl substances in consumer products and other oestrogenic compounds.

Environmental chemical TCPOBOP disrupts milk lipid homeostasis during pregnancy and lactation

Humans are exposed to different kinds of environmental contaminants or drugs throughout their lifetimes. The widespread presence of these compounds has raised concerns about the consequent adverse effects on lactating women. The constitutive androstane receptor (CAR, Nr1i3) is known as a xenobiotic sensor for environmental pollution or drugs. In this study, the model environmental chemical 1, 4-bis [2-(3, 5-dichloropyridyloxy)] benzene, TCPOBOP (TC), which is a highly specific agonist of CAR, was used to investigate the effects of exogenous exposure on lactation function and offspring health in mice. The results revealed that TC exposure decreased the proliferation of mammary epithelial cells during pregnancy. This deficiency further compromised lobular-alveolar structures, resulting in alveolar cell apoptosis, as well as premature stoppage of the lactation cycle and aberrant lactation. Furthermore, TC exposure significantly altered the size and number of milk lipid droplets, suggesting that TC exposure inhibits milk lipid synthesis. Additionally, TC exposure interfered with the milk lipid metabolism network, resulting in the inability of TC-exposed mice to efficiently secrete nutrients and feed their offspring. These findings demonstrated that restricted synthesis and secretion of milk lipids would indirectly block mammary gland form and function, which explained the possible reasons for lactation failure and retarded offspring growth.

Implications of placentation type on species-specific colostrum properties in mammals

Maternal care is essential to optimally support survival of the offspring. During evolution of mammalian species, different phenotypes have evolved in relation to gestation length, number, size, and maturation stage of the offspring at parturition, as well as colostrum and milk composition. The aim of the present review is to describe relationships between placental function and colostrum and milk composition in different mammalian species. Species covered in this article include humans, rabbits, rodents (rat and mouse), carnivores (cats and dogs), and a variety of ungulate species (cattle, sheep, goats, pigs, and horses). Species-specific aspects are elucidated with a special focus on the transfer of passive immunity. In this regard, the structure and thus the capability of the placenta to transport immunoglobulins from maternal to fetal circulation in utero dictates the necessity of the passive transfer of immunity via colostrum. Consequently, species with exclusive postpartal transfer of immunity such as in all ungulate species have greater immunoglobulin G concentrations in colostrum than species with a prepartal transfer in utero, where especially immunoglobulin A with its local immune function in the gastrointestinal tract is present in colostrum (e.g., rabbit and human). In terms of the nutritional purpose, suckling frequency is an important factor determining the gross composition of colostrum as well as in the mature milk of these species. Milk of nidicolous animals with long intervals in-between suckling events contains more fat than milk of nidifugous animals with constant access to their mother. However, the importance of colostrum and milk consumption for newborn animals and human babies goes beyond nutrition and the transfer of immunity. Numerous bioactive components such as growth factors, hormones, and oligosaccharides are enriched in colostrum and transition milk, which support the development of the intestinal tract and local immune system.

Protocol for an observational study investigating hormones triggering the onset of sustained lactation: the INSIGHT study

INTRODUCTION

Lactation is a hormonally controlled process that promotes infant growth and neurodevelopment and reduces the long-term maternal risk of diabetes, cardiovascular disease and breast cancer. Hormones, such as prolactin and progesterone, mediate mammary development during pregnancy and are critical for initiating copious milk secretion within 24-72 hours post partum. However, the hormone concentrations mediating lactation onset are ill defined.

METHODS AND ANALYSIS

The primary objective of the investigating hormones triggering the onset of sustained lactation study is to establish reference intervals for the circulating hormone concentrations initiating postpartum milk secretion. The study will also assess how maternal factors such as parity, pregnancy comorbidities and complications during labour and delivery, which are known to delay lactation, may affect hormone concentrations. This single-centre observational study will recruit up to 1068 pregnant women over a 3-year period. A baseline blood sample will be obtained at 36 weeks' gestation. Participants will be monitored during postpartum days 1-4. Lactation onset will be reported using a validated breast fullness scale. Blood samples will be collected before and after a breastfeed on up to two occasions per day during postpartum days 1-4. Colostrum, milk and spot urine samples will be obtained on a single occasion. Serum hormone reference intervals will be calculated as mean±1.96 SD, with 90% CIs determined for the upper and lower reference limits. Differences in hormone values between healthy breastfeeding women and those at risk of delayed onset of lactation will be assessed by repeated measures two-way analysis of variance or a mixed linear model. Correlations between serum hormone concentrations and milk composition and volume will provide insights into the endocrine regulation of milk synthesis.

ETHICS AND DISSEMINATION

Approval for this study had been granted by the East of England-Cambridgeshire and Hertfordshire Research Ethics Committee (REC No. 20/EE/0172), by the Health Research Authority (HRA), and by the Oxford University Hospitals National Health Service Foundation Trust. The findings will be published in high-ranking journals and presented at national and international conferences.

TRIAL REGISTRATION NUMBER

ISRCTN12667795.

Manual Method vs Breast Pump for Breast Milk Expression in Mothers of Preterm Babies During First Postnatal Week: A Randomized Controlled Trial

Objectives

To compare breast milk volume between manual method and breast pump expression in mothers of preterm infants at different time point of first week.

Design

Randomized controlled trial.

Setting

Postpartum ward of Obstetrics department and tertiary level neonatal intensive care unit (NICU) in a single institution in Orissa between October, 2020 and May, 2021.

Participants

Mothers who delivered before 34 completed weeks of gestation.

Interventions

Manual breastmilk expression (ME) group using Marmet technique and breast pump milk expression (PE) group using pigeon manual breast pump, initiated milk expression within one hour of delivery.

Outcome measures

Expressed breast milk (EBM) volume in mothers of preterm infants at different time point of first week, and cumulative milk volume.

Results

Out of 170 mothers (83 PE and 87 ME group), 7-days milk volume data was available for 137 (71 ME and 66 PE) mothers. In per protocol analysis for 126 mothers (63 in each group), the median (IQR) EBM volume on day 2 and day 7 of ME and PE groups were similar [10 (5,20) vs 12 (5,28), P=0.10] and [280 (220–356) vs 280 (220–360), P=0.66]. The median (IQR) cumulative EBM volume over first 7 days in ME group was not significantly different from PE group [733 (593–995) vs 848.5 (571–1009)] P=0.55). A similar number of mothers in the PE and ME group [56 (88.9%) vs 58 (92%); P=0.14] provided exclusive breast milk for their neonates during the first week. Similar results were found on intention to treat analysis.

Conclusion

EBM volume expressed was comparable between mothers expressing manually or with breast pump.

Progress in Personalized Psychiatric Therapy with the Example of Using Intranasal Oxytocin in PTSD Treatment

Post-traumatic stress disorder (PTSD) is a severe mental disorder that results in the frequent coexistence of other diseases, lowers patients' quality of life, and has a high annual cost of treatment. However, despite the variety of therapeutic approaches that exist, some patients still do not achieve the desired results. In addition, we may soon face an increase in the number of new PTSD cases because of the current global situation-both the COVID-19 pandemic and the ongoing armed conflicts. Hence, in recent years, many publications have sought a new, more personalized treatment approach. One such approach is the administration of intranasal oxytocin (INOXT), which, due to its pleiotropic effects, seems to be a promising therapeutic option. However, the current findings suggest that it might only be helpful for a limited, strictly selected group of patients.

Cortisol, Prolactin, and Breastmilk Volume; A Promising Pattern for Reducing Postpartum Depression

BACKGROUND: Research shows postnatal depression and shorter breastfeeding are consistently related, but their causal effect remains debatable. To reduce the impact of mental disorders in the perinatal period, lactation may give a significant neuroendocrine effect. AIM: This study aimed to examine hormonal patterns and estimated breastmilk volume of mothers with depression. MATERIALS AND METHODS: This study was conducted during the three-trimester to 6-week postnatal period. It involved 60 pregnant women from South Sulawesi, Indonesia. Analysis of variance with repeated measures was used to compare and review fluctuations and effect sizes of cortisol, prolactin, and breastmilk volume of mothers with depression symptoms. RESULTS: The mean cortisol levels rose in the 4th week and decreased in the 6th week in both groups. There was no substantial difference in the cortisol levels between these periods (p = 0.534; p = 0.553; and p = 0.660), but the prolactin levels continuously increased by 2 weeks and substantially progressed in the 4th and 6th weeks (p < 0.028, p < 0.009), respectively. There was no positive association between cortisol and prolactin levels (p = 0.384). The breastmilk volume was higher every week only in mothers without depression and it slightly decreased in other categories. This study emphasized the prolactin’s protective effect size on a stressful environment characterized by high cortisol; a significant rise in prolactin levels occurred in the 2nd and 4th weeks of postnatal, marking the higher lactation. CONCLUSIONS: Breastfeeding hormones may provide protection against postpartum depression in moms. It is critical to establish a history of prior trauma in nursing mothers in order to facilitate diagnosis and proper care.

Galactagogues and Lactation: Considerations for Counseling Breastfeeding Mothers

ABSTRACT

Development of a milk supply is a complex process that is not always understood by women who are breastfeeding. Galactagogues are substances commonly used by breastfeeding women who perceive that they have an insufficient milk supply. They can be herbal substances or pharmaceuticals. Herbal galactagogues are advertised and sold to women as capsules, cookies, milk shakes, and teas, as well as other forms of herbal supplements. Herbal galactagogues are classified as dietary supplements and not reviewed or regulated by the U.S. Food and Drug Administration. There are limited data on their safety and efficacy. Women experiencing problems with their milk supply should receive a thorough and thoughtful assessment of the situation. There are many factors that should be considered when counseling breastfeeding women about use of galactagogues. The physiology of lactation, process of milk supply development, and the evidence for use of galactagogues are reviewed to add to the knowledge of nurses and other health care providers working with women who are breastfeeding.

Delayed secretory activation and low milk production in women with gestational diabetes: a case series

Background

Gestational diabetes mellitus (GDM) is major pregnancy complication that is associated with short- and long-term consequences for both mother and infant, including increased risk of diabetes later in life. A longer breastfeeding duration has been associated with a reduced risk of diabetes, however, women with GDM are less likely to exclusively breastfeed and have shorter breastfeeding duration. While the timing of breastfeeding initiation and milk removal frequency affects subsequent breastfeeding outcomes, little is known about early infant feeding practices and milk production in women with GDM. This case series offers detailed prospective breastfeeding initiation data, as well as the first report of objective measures of milk production in women with GDM.

Case presentation

In this case series, we present the early infant feeding practices of eight women with GDM that gave birth at term gestation. Women recorded the timing of initiation of breastfeeding and secretory activation, as well as their breastfeeding, expression and formula feeding frequencies on postpartum days 1, 7 and 21. Measurement of 24 h milk production volume was performed at 3 weeks postpartum using the test weight method. We observed a delayed first breastfeed (> 1 h) in 6 (75%) cases, formula use in hospital in 5 (63%) cases and delayed secretory activation in 3 (38%) cases. At 3 weeks postpartum, 2 cases had measured milk productions that were insufficient to sustain adequate infant weight gain.

Conclusions

Our data suggest that despite early and frequent milk removal, women with GDM are at greater risk of delayed secretory activation and low milk supply. Cohort studies that consider co-morbidities such as obesity are needed to determine the lactation outcomes of women with GDM.

A nation‐wide study on the common reasons for infant formula supplementation among healthy, term, breastfed infants in US hospitals

In‐hospital infant formula supplementation of breastfed infants reduces breastfeeding duration, yet little is known about common reasons for infant formula supplementation. We examined the three most common reasons for in‐hospital infant formula supplementation of healthy, term, breastfed infants in the US reported by hospital staff. Hospital data were obtained from the 2018 Maternity Practices in Infant Nutrition and Care survey (n = 2045), which is completed by hospital staff. An open‐ended question on the top three reasons for in‐hospital infant formula supplementation was analyzed using thematic qualitative analysis and the frequencies for each reason were reported. The top three most common reasons for in‐hospital infant formula supplementation reported by hospital staff included medical indications (70.0%); maternal request/preference/feelings (55.9%); lactation management‐related issues (51.3%); physical but non‐medically indicated reasons (36.1%); social influences (18.8%); perceived cultural/societal/demographic factors (8.2%) and medical staff/institutional practices (4.7%). These findings suggest that a variety of factors should be considered to address unnecessary infant formula supplementation. Lactation management support delivered in a timely and culturally sensitive manner and targeted to mother‐infant dyads with potential medical and physical indications may reduce unnecessary in‐hospital infant formula supplementation.

The three most commonly reported reasons by hospital staff for infant formula supplementation were found to be related to medical indications (70.0%); maternal request/preference/feelings about breastfeeding such as frustration or lack of confidence (55.9%); lactation management‐related issues (51.3%); physical but non‐medically indicated reasons (36.1%); social influences (18.8%); perceived cultural/societal/demographic factors (8.2%); and medical staff/institutional practices (4.7%).

Underlying many of the reported three most common reasons for infant formula supplementation is potentially lack of lactation management support that considers the social influences (e.g. from family and friends) and that is culturally relevant.

These findings suggest that a variety of factors should be considered to address unnecessary infant formula supplementation.

Unique Transcriptomic Changes Underlie Hormonal Interactions During Mammary Histomorphogenesis in Female Pigs

Successful lactation and the risk for developing breast cancer depend on growth and differentiation of the mammary gland (MG) epithelium that is regulated by ovarian steroids (17β-estradiol [E] and progesterone [P]) and pituitary-derived prolactin (PRL). Given that the MG of pigs share histomorphogenic features present in the normal human breast, we sought to define the transcriptional responses within the MG of pigs following exposure to all combinations of these hormones. Hormone-ablated female pigs were administered combinations of E, medroxyprogesterone 17-acetate (source of P), and either haloperidol (to induce PRL) or 2-bromo-α-ergocryptine. We subsequently monitored phenotypic changes in the MG including mitosis, receptors for E and P (ESR1 and PGR), level of phosphorylated STAT5 (pSTAT5), and the frequency of terminal ductal lobular unit (TDLU) subtypes; these changes were then associated with all transcriptomic changes. Estrogen altered the expression of approximately 20% of all genes that were mostly associated with mitosis, whereas PRL stimulated elements of fatty acid metabolism and an inflammatory response. Several outcomes, including increased pSTAT5, highlighted the ability of E to enhance PRL action. Regression of transcriptomic changes against several MG phenotypes revealed 1669 genes correlated with proliferation, among which 29 were E inducible. Additional gene expression signatures were associated with TDLU formation and the frequency of ESR1 or PGR. These data provide a link between the hormone-regulated genome and phenome of the MG in a species having a complex histoarchitecture like that in the human breast, and highlight an underexplored synergy between the actions of E and PRL during MG development.

Associations of Metabolic and Obstetric Risk Parameters with Timing of Lactogenesis II

Lactogenesis II is the onset of copious milk production following parturition. Delayed onset of lactogenesis II (DLII) often contributes to poorer lactation performance, which may adversely affect maternal and child health. The present study aims to identify the metabolic and obstetric risk factors for DLII in a secondary analysis of a prospective cohort study following pregnant women through postpartum. We defined the onset of lactogenesis II as delayed if it occurred ≥72 h postpartum. Multiple logistic regression analyses were conducted to evaluate the associations of metabolic and obstetric variables with DLII. Median onset of lactogenesis II was 72.4 h (IQR 60.4–91.6) postpartum, and 55.4% (98 of 177) of women experienced DLII. Time to first breast contact ≥ 2 h postpartum compared to ≤1 h postpartum was associated with DLII (OR 2.71 95% CI 1.12–6.53) with adjustment for age, race, pregravid BMI, primiparity, and mode of delivery, while metabolic variables were not significantly associated with DLII. In this comprehensive examination of potential metabolic and obstetric parameters, earlier timing of putting the infant to the breast remained significantly associated with earlier onset of milk coming in after consideration of the other potential risk factors. Obstetrical practices, including putting the baby to the breast later, may have an important impact on the timing of lactation, and interventions are needed to address this concern.

Prepregnancy Body Mass Index Is Associated with Time-Dependent Changes in Secretory Activation Measures During the First 7 Days Postpartum in Breast Pump-dependent Mothers of Premature Infants

Background: Little is known about the biology of secretory activation (SA) in overweight and obese (OW/OB) mothers who are breast pump dependent with a premature infant in the neonatal intensive care unit. Objective: To compare time-dependent changes in daily pumped milk volume, maternal milk sodium (Na) concentration, and Na-to-potassium (K) ratios (Na:K) in the first 14 days postpartum in breast pump-dependent mothers with prepregnancy body mass index (BMI) <27 and BMI ≥27 kg/m². Design/Methods: This secondary analysis for 39 subjects, 44% (n = 17) with prepregnancy BMI <27 and 56% (n = 22) with BMI ≥27, included transformed data of outcome measures, chi-square, t-tests, and growth curve models. Results: For days 1-7, daily pumped milk volume increased significantly more rapidly for mothers with BMI <27 (65.82 mL/d) versus BMI ≥27 (33.08 mL/d), but the daily rate of change in pumped milk volume during days 8-14 was not statistically different. Daily milk Na concentration decreased significantly faster in BMI <27 (-3.93 mM/d) versus BMI ≥27 (-2.00 mM/day) during days 1-7, but was not significantly different for days 8-14. No statistical differences were noted for Na:K ratio for either time period. Conclusion: These data add biologic evidence to previous research, suggesting delayed or impaired SA in OW/OB mothers, and suggest that the window of opportunity for research and clinical interventions is days 1-7 postpartum in this population.