Does Insulin Explain the Relation between Maternal Obesity and Poor Lactation Outcomes? An Overview of the Literature

Maternal Breast Growth and Body Mass Index Are Associated with Low Milk Production in Women

BACKGROUND

Maternal breast volume is determined by the quantity of glandular and adipose tissue, and it undergoes significant changes during pregnancy. These changes are intricately linked to the development of glandular tissue, which most likely reflects lactation capacity. Evidence indicates that women with overweight or obesity exhibit larger breast volume compared to those with a normal body mass index (BMI), emphasizing the close relationship between breast volume and maternal adiposity. Hence, we aim to investigate breast volume growth and maternal BMI as potential risk factors for low milk production.

METHODS

Lactating women (n = 609) from the Perth metropolitan area in Western Australia between 2011 and 2023 were included in the analysis. Twenty-four-hour milk production measurements were conducted using the test weighing method, and milk removal frequencies were recorded. Mothers completed questionnaires regarding demographic, obstetric and infant details. Linear and logistic regression models were used to determine maternal and infant factors associated with milk production.

RESULTS

Here we show that increasing maternal age and BMI are associated with low milk production. Moreover, larger pre-pregnancy breast volume and breast growth are associated with both higher BMI and milk production.

CONCLUSIONS

Women who are older, have an obese BMI and who have minimal pre-pregnancy breast volume and breast growth should be provided with antenatal screening and breastfeeding support as they are more likely to experience low milk production.

Incidence and factors influencing delayed onset of lactation: a systematic review and meta-analysis

BACKGROUND

Breastfeeding has many benefits for mothers and infants. Lactogenesis II is one of the key steps in the implementation of breastfeeding. If lactogenesis II occurs more than 72 h after delivery, it is termed delayed onset of lactation (DOL). DOL is associated with decreased milk production, shortened breastfeeding time, and pathological neonatal weight loss. A comprehensive summary of the incidence and factors influencing DOL is needed to provide a basis for improving breastfeeding practices and health outcomes.

METHODS

Studies on the incidence and factors influencing DOL were retrieved from 13 Chinese and English databases (PubMed, Embase, Web of Science, Cochrane Library, CINAHL, etc.) from database inception to August 2023. Two researchers independently conducted the study screening, data extraction and quality evaluation. Stata 16.0 SE software was used for data analysis, and sensitivity analysis and publication bias tests were also performed. The qualitative description method was used to analyse studies that could not be combined quantitatively.

RESULTS

A total of 35 studies involving 19,176 parturients, including 4,922 who had DOL, were included. The mean Newcastle‒Ottawa scale score of the included studies was ≥ 6, indicating that the quality was relatively high. Finally, the incidence of DOL was 30%, and 13 factors influencing DOL with robust results and no publication bias were obtained: prepregnancy body mass index (overweight or obesity), gestational diabetes, gestational hypertension, thyroid disease during pregnancy, serum albumin levels (< 35 g/L), parity, (unscheduled) caesarean section, caesarean section history, daily sleep duration, gestational age, birth weight (< 2.5 kg), breastfeeding guidance and daily breastfeeding frequency. However, there were still six influencing factors with undetermined associations: age, gestational weight gain, birth weight (≥ 4 kg), anxiety, time of first breastfeeding session (maternal separation) and breast massage or treatment.

CONCLUSIONS

The incidence of DOL is high. Clinicians should pay attention to parturients at high risk of DOL and formulate targeted prevention strategies according to the influencing factors to reduce the occurrence of DOL and promote better maternal and infant outcomes.

TRIAL REGISTRATION

PROSPERO (ID: CRD42023458786), September 10, 2023.

Ramadan Fasting in Individuals with Metabolic Dysfunction-Associated Steatotic Liver Disease, Liver Transplant, and Bariatric Surgery: A Narrative Review

Metabolic dysfunction-associated steatotic liver disease is a growing worldwide pandemic. A limited number of studies have investigated the potential effect of Ramadan fasting on metabolic dysfunction-associated steatotic liver disease (MASLD). There is no single medication for the treatment of MASLD. There is a growing interest in dietary intervention as potential treatment for metabolic diseases including MASLD. The aim of this study was to discuss the epidemiology, pathogenesis, and risk factors of MASLD and the potential effects of Ramadan fasting on MASLD, liver transplant, and bariatric surgery. We searched PubMed and SCOPUS databases using different search terms. The literature search was based on research studies published in English from the year 2000 to the 2024. Thirty-two studies were included in this review. Ramadan fasting reduced body weight and improved lipid profile, anthropometric indices, fasting plasma glucose, plasma insulin, and inflammatory cytokines. Ramadan fasting improved risk factors of nonalcoholic fatty liver disease and might improve MASLD through weight reduction. However, further studies are needed to assess the safety and effectiveness of Ramadan fasting in liver transplant recipients and bariatric surgery.

The human milk endocannabinoidome and neonatal growth in gestational diabetes

Objective

Endocannabinoids and their N-acyl-ethanolamines (NAEs) and 2monoacyl-glycerols (2-MAGs) congeners are involved in the central and peripheral regulation of energy homeostasis, they are present in human milk and are associated with obesity. Infants exposed in utero to gestational diabetes mellitus (GDM) are more likely to develop obesity. The objective of this cross-sectional study is to compare the profile of eCBome mediators in milk of women with gestational diabetes (GDM+) and without (GDM-) and to assess the association with offspring growth. The hypothesis is that the eCBome of GDM+ human milk is altered and associated with a difference in infant growth.

Methods

Circulating eCBome mediators were measured by LC-MS/MS in human milk obtained at 2 months postpartum from GDM+ (n=24) and GDM- (n=29) women. Infant weight and height at 2 months were obtained from the child health record. Z-scores were calculated.

Results

Circulating Npalmitoylethanolamine (PEA) was higher in human milk of GDM+ women than in GDM- women (4.9 ± 3.2 vs. 3.3 ± 1.7, p=0.04). Higher levels were also found for several 2monoacyl-glycerols (2-MAGs) (p<0.05). The levels of NAEs (β=-4.6, p=0.04) and especially non-omega-3 NAEs (B=-5.6, p=0.004) in human milk were negatively correlated with weight-for-age z-score of GDM+ offspring.

Conclusion

The profile of eCBome mediators in human milk at 2 months postpartum was different in GDM+ compared to GDM- women and was associated with GDM+ offspring growth at 2 months.

Clinical trial registration

ClinicalTrials.gov, identifier (NCT04263675 and NCT02872402).

Is Maternal Body Weight or Composition Associated with Onset of Lactogenesis II, Human Milk Production, or Infant Consumption of Mother's Own Milk? A Systematic Review and Meta-Analysis

Maternal adiposity impacts lactation performance, but the pathways are unclear. We conducted a systematic review to understand whether maternal adiposity (body mass index [BMI] or percentage fat mass) is associated with onset of lactogenesis II (copious milk; hours), human milk production (expressed volume/24 h), and infant consumption of mother's own milk (volume/24 h). We used random-effects standard meta-analyses to compare the relative risk (RR) of delayed lactogenesis II (>72 h) between mothers classified as underweight (BMI <18.5 kg/m2), healthy weight (BMI, 18.5-24.9 kg/m2), and overweight/obese (BMI ≥25 kg/m2) and random-effects meta-regressions to examine associations with hours to lactogenesis II and infant milk consumption. The certainty of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation approach. We included 122 articles. Mothers with underweight (RR: 0.64; 95% CI: 0.49, 0.83; I2 = 39.48%; 8 articles/data points) or healthy weight status (RR: 0.67; 95% CI: 0.57, 0.79; I2 = 70.91%; 15 articles/data points) were less likely to experience delayed lactogenesis II than mothers with overweight/obesity. We found no association between maternal BMI and time to onset of lactogenesis II (β: 1.45 h; 95% CI: -3.19, 6.09 h; P = 0.52, I2 = 0.00%; 8 articles, 17 data points). Due to limited data, we narratively reviewed articles examining BMI or percentage fat mass and milk production (n = 6); half reported an inverse association and half no association. We found no association between maternal BMI (β: 6.23 mL; 95% CI: -11.26, 23.72 mL; P = 0.48, I2 = 47.23%; 58 articles, 75 data points) or percentage fat mass (β: 7.82 mL; 95% CI: -1.66, 17.29 mL; P = 0.10, I2 = 28.55%; 30 articles, 41 data points) and infant milk consumption. The certainty of evidence for all outcomes was very low. In conclusion, mothers with overweight/obesity may be at risk of delayed lactogenesis II. The available data do not support an association with infant milk consumption, but the included studies do not adequately represent mothers with obesity. This study was registered in PROSPERO as 285344.

Breast hypoplasia markers among women who report insufficient milk production: A retrospective online survey

OBJECTIVES

To estimate the proportions of anatomical breast characteristics suggestive of breast hypoplasia among breastfeeding women self-reporting low milk supply. We also explored breast hypoplasia risk factors.

DESIGN

Online survey conducted between October 2021 and January 2022.

SETTING

Five low milk supply Facebook groups.

PARTICIPANTS

487 women reporting low milk supply with their first child born ≥ 37 weeks gestation within 5 years of participation in this study, and residing in the USA, Australia or the UK. We present data on the primary outcome ('breast type') for 399 women. Women were excluded if the dyad was separated for more than 24 hours during the hospital stay, or if the mother reported removing milk less than 6 times per day from each breast on most days before being aware of having insufficient milk production.

PRIMARY AND SECONDARY OUTCOME MEASURES

The proportions of proposed breast hypoplasia markers including atypical breast type, widely spaced breasts, breast asymmetry, stretch marks on the breast and lack of pregnancy breast growth. We also estimated the odds of having breast hypoplasia markers in at-risk groups compared to reference groups, adjusting for covariates.

RESULTS

Approximately 68% reported at least one atypical breast (270/399; 95% CI: 62.9%, 72.1%). Around 47% reported widely spaced breasts (212/449; 95% CI: 42.7%, 52.7%), 72% a lack of pregnancy breast growth (322/449; 95% CI: 68.3%, 77.4%), and 76% stretch marks on the breast (191/250; 95% CI: 70.7%, 81.3%). Multiple logistic regression analyses identified being overweight during pubertal years as a risk factor for atypical breast type and lack of pregnancy breast growth.

CONCLUSIONS

Participants in low milk supply Facebook groups reported high rates of breast hypoplasia markers. Being overweight during adolescence was a risk factor for breast hypoplasia markers. These findings should be confirmed in well-conducted large cohort studies to determine the strongest combination of hypoplasia markers in predicting low supply.

Alterations of milk oligosaccharides in mothers with gestational diabetes mellitus impede colonization of beneficial bacteria and development of RORγt+ Treg cell-mediated immune tolerance in neonates

Gestational diabetes mellitus (GDM) is an increasing public health concern that significantly increases the risk of early childhood allergic diseases. Altered maternal milk glycobiome may strongly affect gut microbiota and enteric-specific Treg cell-mediated development of immune tolerance in GDM infants. In this study, we found that, compared with healthy Chinese mothers, mothers with GDM had significantly lower levels of total and specific human milk oligosaccharides (HMOs) in their colostrum that subsequently increased with extension of lactation. This alteration in HMO profiles significantly delayed colonization of Lactobacillus and Bifidobacterium spp. in their breast-fed infants, resulting in a distinct gut microbial structure and metabolome. Further experiments in GDM mouse models indicated that decreased contents of milk oligosaccharides, mainly 3'-sialyllactose (3'-SL), in GDM maternal mice reduced colonization of bacteria, such as L. reuteri and L. johnsonii, in the neonatal gut, which impeded development of RORγt+ regulatory T (Treg) cell-mediated immune tolerance. Treatment of GDM neonates with 3'-SL, Lactobacillus reuteri (L. reuteri) and L. johnsonii promoted the proliferation of enteric Treg cells and expression of transcription factor RORγt, which may have contributed to compromising ovalbumin (OVA)-induced allergic responses. In vitro experiments showed that 3'-SL, metabolites of L. johnsonii, and lysates of L. reuteri stimulated differentiation of mouse RORγt+ Treg cells through multiple regulatory effects on Toll-like receptor, MAPK, p53, and NOD-like receptor signaling pathways. This study provides new ideas for the development of gut microbiota and immune tolerance in GDM newborns.

Prevalence and risk factors of delayed onset lactogenesis II in China: a systematic review and meta-analysis

BACKGROUND

In 2017, China proposed to achieve the goal that 50% of infants aged 0-6 months should be exclusively breastfed by 2025 proposed by the World Health Assembly in 2012. However, delayed onset lactogenesis II has adverse effects on breastfeeding and thus on neonatal health. There has been no meta-analysis of the prevalence and risk factors of delayed onset lactogenesis II among parturient women in China. To provide best practices, updated evidence-based evidence is needed to supplement reviews on this topic.

OBJECTIVE

The purpose of this systematic review and meta-analysis was to quantitatively analyze the prevalence and risk factors of delayed onset lactogenesis II in China.

METHODS

We identified relevant studies by searching literature published prior to October 2022 in PubMed, Web of Science, China National Knowledge Infrastructure, Wanfang, and VIP databases for all available observational studies. Stata 16.0 were used for performing the systematic review and meta-analysis.

RESULTS

The researchers examined data from 14 observational studies involving 17610 females. The prevalence of delayed onset lactogenesis II from these studies was 31% (95% CI = 25.0%-38.0%, p < .001), and the prevalence showed a significant increasing trend in China over the past decade. The frequency of breastfeeding was >2 times per day at 24-48 h after delivery was one protective factor against delayed onset lactogenesis II (OR = 0.41). The significant risk factors for delayed onset lactogenesis II were breastfeeding initiation > 30min after birth (OR = 1.31), maternal age > 35 years (OR = 2.19), primiparous women (OR = 2.38), maternal overweight/obesity (OR = 2.22), cesarean section (OR = 1.33), anxiety (OR = 3.23), depression (OR = 3.21) and gestational hypertension (OR = 3.43).

CONCLUSIONS

There is a high incidence of delayed onset lactogenesis II in Chinese parturient women. We identified eight risk factors and one protective factor for DOL II. These findings suggest health care professionals should pay attention to these risk parturients so as to better provide early preventive interventions to increase the breastfeeding rate.

Maternal inflammatory, lipid and metabolic markers and associations with birth and breastfeeding outcomes

Background

Conditions in utero influence intrauterine and postnatal infant growth and a few studies indicate that maternal inflammation and insulin resistance might affect birth and breastfeeding outcomes. Furthermore, hormones in human milk (HM) may influence infant appetite-regulation and thereby milk intake, but the associations are less understood.

Objective

(1) To investigate associations between maternal inflammatory, lipid and metabolic markers and birth and breastfeeding outcomes, and (2) to assess predictors of maternal inflammatory, lipid and metabolic markers in pregnancy.

Methods

Seventy-one mother-infant dyads participating in the Mothers, Infants and Lactation Quality (MILQ) study were included in the present study. Fasting blood samples were collected around 28th gestational week, and HM samples at three time points from 1.0 to 8.5 months, where milk intake was assessed using 24-h test weighing. Maternal plasma inflammatory, lipid and metabolic markers included high-sensitive C-reactive protein (hs-CRP), tumor-necrosis factor-α (TNFα), interferon-γ (IFNγ), Interleukin (IL)-6, IL-8, high-, low-, and very-low-density lipoprotein (HDL, LDL, VLDL), total-cholesterol, triglycerides, leptin, adiponectin, insulin, C-peptide, the homeostasis model assessment of insulin resistance (HOMA-IR) and glucose concentration at t = 120 min following an oral glucose tolerance test. Of these, TNFα, IFNγ, IL-6, IL-8, leptin, adiponectin and insulin were also measured in HM samples.

Results

HDL in pregnancy was inversely associated with gestational age (GA) at birth and GA-adjusted birthweight z-score, whereas triglycerides and glucose (t = 120) were positively associated with GA-adjusted birthweight z-score. Higher hs-CRP, VLDL and triglycerides were associated with a higher placental weight. Furthermore, higher HDL, insulin, leptin and HOMA-IR were associated with longer duration of exclusive breastfeeding (EBF). Higher pre-pregnancy BMI was the main predictor of higher levels of hs-CRP, log-TNFα, leptin, insulin, C-peptide, and HOMA-IR.

Conclusion

Maternal lipid and metabolic markers influenced birthweight z-score and placental weight as well as duration of EBF. Furthermore, pre-pregnancy BMI and maternal age predicted levels of several inflammatory and metabolic markers during pregnancy. Our findings indicate that maternal lipid and metabolic profiles in pregnancy may influence fetal growth and breastfeeding, possibly explained by overweight and/or higher placental weight.

Clinical trial registration

https://clinicaltrials.gov/, identifier NCT03254329.

Galactagogue Food Consumption, Perception of Insufficient Milk Supply, and Exclusive Breastfeeding in Chinese Postpartum Women: An Analysis of Repeated Measures

INTRODUCTION

Little research has explored galactagogue food consumption in China. This study aims to investigate consumption patterns and how they relate to perceived insufficient milk supply and exclusive breastfeeding.

METHODS

Data were collected from postpartum women in China at six time points: baseline demographic questionnaire before hospital discharge (T0), galactagogue food questionnaire at 1 month postpartum (T1), Hill and Humenick Lactation Scale at 6 weeks postpartum (T2), and breastfeeding practices at 1, 2, 3 and 4 months postpartum (T1, T3, T4, T5).

RESULTS

Of 218 participants who completed the galactagogue food questionnaire, 64.68% were consumers. No association was found between galactagogue food consumption and perceived insufficient milk supply. Consumers were less likely to breastfeed exclusively.

DISCUSSION

Future research should emphasize a deeper understanding of consumer behaviors and family support in providing professional guidance on postpartum nutrition that considers not only social and cultural experiences but also broader medical aspects.

The relationship between pregnancy count and duration of breast-feeding with metabolic syndrome (Fasa Persian cohort study)

BACKGROUND

Changes that occur during pregnancy and after that during breastfeeding induce some symptoms similar to metabolic syndrome (MetS) risk factors. This study aims to determine the relationship between pregnancy, as well as the duration of breastfeeding and MetS controlling the effect of other risk factors like hypertension, glucose intolerance, triglyceride, central obesity, and reduction of high-density lipoprotein in women of Fasa Persian Cohort Study.

MATERIALS AND METHODS

In this cross-sectional study, 5015 women aged 35-70 years were investigated in the Sheshdeh region from 2016 to 2021, and the information related to the disease symptoms was collected through questionnaires, examinations, and laboratory tests. MetS was calculated based on two guidelines according to adult treatment panel III (ATP III) and international diabetes federation (IDF) methods. For reporting the data, the odds ratio with its 95% confidence interval was used. In order to eliminate the effect of confounders, logistic regression was used.

RESULTS

Prevalence of MetS showed a descending trend in women with up to two pregnancies and it reached 22.6% and 22.4% using ATPIII and IDF methods respectively, while with an increase in the number of pregnancies of more than two, MetS prevalence was ascending. The prevalence of MetS did not have any specific trend across various breastfeeding duration groups. Multivariate analysis approved that the odds ratio of developing MetS in comparison with women who had two pregnancies was significantly increasing trend when the pregnancy counts increased.

CONCLUSION

The chance of developing MetS based on both IDF and ATP III methods after adjustment for confounding effects would grow with an increase in the number of pregnancies to more than two and breast-feeding of more than seven years. It is recommended that women with more than two pregnancies or the long duration of breast-feeding women undergo a specialized examination to investigate and control MetS problems so that future diseases could be prevented.

Mediators of the association between maternal body mass index and breastfeeding duration in 3 international cohorts

BACKGROUND

Maternal obesity has been associated with shorter breastfeeding duration, but little is known about mediating factors explaining this association. It is important to assess these relationships across diverse populations because breastfeeding is culturally patterned.

OBJECTIVES

We investigated the association of prepregnancy maternal body mass index (BMI) with breastfeeding outcomes and potential mediators of this relationship in 3 culturally diverse international cohorts.

METHODS

We analyzed 5120 singleton pregnancies from mother-child cohorts in Spain (INfancia y Medio Ambiente), Greece (Rhea), and the United States (Project Viva). Outcome variables were duration of any and exclusive breastfeeding. A priori hypothesized mediators in the association of maternal prepregnancy BMI with breastfeeding were birthweight (BW), maternal prenatal C-reactive protein (CRP), cesarean delivery, maternal dietary inflammatory index (DII) during pregnancy, gestational age at delivery, and gestational diabetes mellitus (GDM). We estimated the association between BMI and breastfeeding duration using linear regression adjusting for confounders. Mediation analysis estimated direct and indirect effects of maternal overweight/obesity on breastfeeding for each mediator.

RESULTS

Women with overweight and obesity had shorter duration of any and exclusive breastfeeding compared with normal-weight women (any: overweight β = -0.79 mo, 95% CI: -1.17, -0.40; obese β = -1.75 mo 95% CI: -2.25, -1.25; exclusive: overweight β = -0.30 mo, 95% CI: -0.42, -0.16; obese β = -0.73 mo, 95% CI: -0.90, -0.55). Significant mediators (% change in effect estimate) of this association were higher CRP (exclusive: 5.12%), cesarean delivery (any: 6.54%; exclusive: 7.69%), and higher DII (any: 6.48%; exclusive: 7.69%). GDM, gestational age, and BW did not mediate the association of maternal weight status with breastfeeding.

CONCLUSIONS

Higher prepregnancy BMI is associated with shorter duration of any and exclusive breastfeeding. Maternal dietary inflammation, systemic inflammation, and mode of delivery may be key modifiable mediators of this association. Identification of mediators provides potential targets for interventions to improve breastfeeding outcomes.

Knowledge Gaps and Current Evidence Regarding Breastfeeding Issues in Mothers with Chronic Diseases

The prevalence of chronic maternal disease is rising in the last decades in the developed world. Recent evidence indicated that the incidence of chronic maternal disease ranges from 10 to 30% of pregnancies worldwide. Several epidemiological studies in mothers with chronic diseases have mainly focused on the risk for adverse obstetric outcomes. Evidence from these studies supports a correlation between maternal chronic conditions and adverse perinatal outcomes, including increased risk for preeclampsia, cesarean section, preterm birth, and admission in the Neonatal Intensive Care Unit (NICU). However, there is a knowledge gap pertaining to the management of these women during lactation. This review aimed at summarizing the available research literature regarding breastfeeding in mothers with chronic diseases. Adjusted and evidence-based support may be required to promote breastfeeding in women with chronic diseases; however, our comprehension of breastfeeding in this subpopulation is still unclear. The literature related to breastfeeding extends in various scientific areas and multidisciplinary effort is necessary to compile an overview of current evidence and knowledge regarding breastfeeding issues in mothers with chronic diseases.

An equitable, community-engaged translational framework for science in human lactation and infant feeding-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 5

Human milk is the ideal source of nutrition for most infants, but significant gaps remain in our understanding of human milk biology. As part of addressing these gaps, the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project Working Groups 1-4 interrogated the state of knowledge regarding the infant-human milk-lactating parent triad. However, to optimize the impact of newly generated knowledge across all stages of human milk research, the need remained for a translational research framework specific to the field. Thus, with inspiration from the simplified environmental sciences framework of Kaufman and Curl, Working Group 5 of the BEGIN Project developed a translational framework for science in human lactation and infant feeding, which includes 5 nonlinear, interconnected translational stages, T1: Discovery; T2: Human health implications; T3: Clinical and public health implications; T4: Implementation; and T5: Impact. The framework is accompanied by 6 overarching principles: 1) Research spans the translational continuum in a nonlinear, nonhierarchical manner; 2) Projects engage interdisciplinary teams in continuous collaboration and cross talk; 3) Priorities and study designs incorporate a diverse range of contextual factors; 4) Research teams include community stakeholders from the outset through purposeful, ethical, and equitable engagement; 5) Research designs and conceptual models incorporate respectful care for the birthing parent and address implications for the lactating parent; 6) Research implications for real-world settings account for contextual factors surrounding the feeding of human milk, including exclusivity and mode of feeding. To demonstrate application of the presented translational research framework and its overarching principles, 6 case studies are included, each illustrating research gaps across all stages of the framework. Applying a translational framework approach to addressing gaps in the science of human milk feeding is an important step toward the aligned goals of optimizing infant feeding across diverse contexts as well as optimizing health for all.

Prepregnancy Obesity and Breastfeeding in the First Month of Life: A Birth Cohort

Objective: This study aimed to investigate the association between prepregnancy obesity and disruption of exclusive breastfeeding (EBF) within the first month of life. Materials and Methods: This was a prospective cohort study conducted among Brazilian mothers and their babies born between February and December 2017. Research was conducted in all maternity hospitals in Vitória da Conquista, Brazil. Data collection started in the maternity hospitals of the city and, subsequently, an interview was conducted during a home visit on the 30th day of the child's life. Survival analysis was performed using Kaplan-Meier curves and a log rank test was applied to compare the curves. The association between independent variables and the response variable was assessed using Cox regression, following the conceptual model created for the study. Results: The study analyzed 329 pairs of mothers and babies. The prevalence of prepregnancy obesity was 12%. The prevalence of EBF disruption in the first month of life was 41.1% in nonobese mothers (confidence interval [95% CI]: 35.3-46.9) and 52.6% in obese mothers (95% CI: 36.3-68.4), with a shorter survival time among mothers with prepregnancy obesity (log rank p < 0.05). The risk of EBF disruption in the first month of life was 83% higher among mothers with prepregnancy obesity, after adjusting for confounding variables-demographic, socioeconomic, prenatal maternal data, and childbirth variables (hazard ratio = 1.84; 95% CI: 1.08-3.11). Conclusions: We observed an association between pregestational obesity and disruption of EBF in the first month of life. This finding reinforces the need for a thorough professional approach to the practice of breastfeeding in this population in the prenatal period as well as early puerperium.

Associations between Maternal Diet, Human Milk Macronutrients, and Breast-Fed Infant Growth during the First Month of Life in the SMILE Iwamizawa in Japan

Maternal diet may affect human milk macronutrients, but it remains to be elucidated whether this is also influential in infant growth. This study aimed to examine (1) how maternal diet influences human milk macronutrients, and (2) to what extent the variation in milk macronutrients affects infant growth during the first month of life. In 71 Japanese lactating women, maternal dietary information was collected from the brief-type self-administered diet history questionnaire, and anthropometry of mother-infant dyads was collected from medical records. Macronutrients in milk were analyzed by a Human Milk Analyzer. Maternal retinol intake was associated with the carbohydrate content in human milk at 1-month postpartum (standardized β coefficient: 0.287; p = 0.038). Moreover, the energy content in human milk was associated with an increase in the weight standard deviation score based on the WHO growth standard at 1 month of age (standardized β coefficient: 0.399; p = 0.046). Nevertheless, the milk macronutrient was not associated with the risk of infant growth abnormalities. In conclusion, a part of the maternal diet impacts macronutrient contents in human milk, but milk macronutrients have a limited effect on infant growth only within the normal growth curve during the first month of life.

Fatty Acid Transfer from Blood to Milk Is Disrupted in Mothers with Low Milk Production, Obesity, and Inflammation

BACKGROUND

Obesity is associated with chronic inflammation and is a risk factor for insufficient milk production. Inflammation-mediated suppression of LPL could inhibit mammary uptake of long-chain fatty acids (LCFAs; >16 carbons).

OBJECTIVES

In an ancillary case-control analysis, we investigated whether women with low milk production despite regular breast emptying have elevated inflammation and disrupted transfer of LCFAs from plasma into milk.

METHODS

Data and specimens from a low milk supply study and an exclusively breastfeeding control group were analyzed, with milk production measured by 24-h test-weighing at 2-10 wk postpartum. Low milk supply groups were defined as very low (VL; <300 mL/d; n = 23) or moderate (MOD; ≥300 mL/d; n = 20) milk production, and compared with controls (≥699 mL/d; n = 18). Serum and milk fatty acids (weight% of total) were measured by GC, serum and milk TNF-α by ELISA, and serum high-sensitivity C-reactive protein (hsCRP) by clinical analyzer. Group differences were assessed by linear regression models, chi-square exact tests, and Kruskal-Wallis nonparametric tests.

RESULTS

VL cases, as compared with MOD cases and controls, had higher prevalence of elevated serum hsCRP (>5 mg/L; 57%, 15%, and 22%, respectively; P = 0.004), detectable milk TNF-α (67%, 32%, and 33%, respectively; P = 0.04), and obesity (78%, 40%, and 22%, respectively; P = 0.003). VL cases had lower mean ± SD LCFAs in milk (60% ± 3%) than MOD cases (65% ± 4%) and controls (66% ± 5%) (P < 0.001). Milk and serum LCFAs were strongly correlated in controls (r = 0.82, P < 0.001), but not in the MOD (r = 0.25, P = 0.30) or VL (r = 0.20, P = 0.41) groups (Pint < 0.001).

CONCLUSIONS

Mothers with very low milk production have significantly higher obesity and inflammatory biomarkers, lower LCFAs in milk, and disrupted association between plasma and milk LCFAs. These data support the hypothesis that inflammation disrupts normal mammary gland fatty acid uptake. Further research should address impacts of inflammation and obesity on mammary fatty acid uptake for milk production.

Obesity-derived alterations in the lactating mammary gland: Focus on prolactin

Obesity is a modern pandemic with negative consequences in women's reproductive health. Women with overweight and obesity can develop mammary gland alterations that unable exclusive breastfeeding. Obesity associates with a disturbed lactating mammary gland endocrine environment including a decreased action of the hormone prolactin (PRL), the master regulator of lactation. The PRL receptor and the action of PRL are reduced in the mammary gland of lactating rodents fed an obesogenic diet and are contributing factors to impaired lactation in obesity. Also, treatment with PRL improves milk yield in women with lactation insufficiency. This review focuses on the impact of diet-induced obesity in the lactating mammary gland and how obesity impairs the lactogenic action of PRL. Although obesity alters lactation performance in humans and rodents, the responsible mechanisms have been mainly addressed in rodents.

The Health-Promoting Effects and the Mechanism of Intermittent Fasting

Intermittent fasting (IF) is an eating pattern in which individuals go extended periods with little or no energy intake after consuming regular food in intervening periods. IF has several health-promoting effects. It can effectively reduce weight, fasting insulin levels, and blood glucose levels. It can also increase the antitumor activity of medicines and cause improvement in the case of neurological diseases, such as memory deficit, to achieve enhanced metabolic function and prolonged longevity. Additionally, IF activates several biological pathways to induce autophagy, encourages cell renewal, prevents cancer cells from multiplying and spreading, and delays senescence. However, IF has specific adverse effects and limitations when it comes to people of a particular age and gender. Hence, a more systematic study on the health-promoting effects and safety of IF is needed. This article reviewed the research on the health-promoting effects of IF, providing a theoretical basis, direction for subsequent basic research, and information related to the clinical application of IF.

Determinants of delayed onset of lactogenesis II among women who delivered via Cesarean section at a tertiary hospital in China: a prospective cohort study

BACKGROUND

Cesarean birth is associated with a higher prevalence of delayed onset of lactogenesis II (DOLII) than vaginal birth. DOLII refers to the delayed initiation of copious milk production beyond 72 h after birth. This study aimed to determine the prevalence of, and factors associated with, DOLII among women who delivered via Cesarean section in China.

METHODS

This prospective longitudinal cohort study recruited 468 women who delivered via Cesarean section at a tertiary hospital in China from 9 October 2021 to 17 May 2022. Face-to-face interviews were conducted during their delivery hospital stay to obtain information about demographic, medical, and breastfeeding factors. We assessed the onset of lactogenesis on postpartum day four, based on the maternal perception of changes in breast fullness. The Edinburgh Postnatal Depression Scale (EPDS) was used to screen for postpartum depression. Women with DOLII were interviewed via telephone or WeChat daily for one week postpartum to determine the timing of the onset of lactogenesis II. Univariate and multivariable logistic regression analyses were used to identify the determinants of DOLII.

RESULTS

DOLII was experienced by 156 of 468 participants (33.3%). After adjusting for potential confounders, the odds of DOLII were 95% higher in primiparous women than multiparous women (adjusted odds ratio [aOR] 1.95; 95% confidence interval [CI] 1.29, 2.98), 75% higher in women with a serum albumin concentration < 35 g / L than women with normal serum albumin concentrations (aOR 1.78; 95% CI 1.09, 2.99), increased by 2.03-fold in women with an EPDS score ≥ 10 than women with an EPDS score < 10 (aOR 2.03; 95% CI 1.35, 3.07), and decreased in women with a higher number of breastfeeding sessions in the first 48 h postpartum (aOR 0.88; 95% CI 0.83, 0.93).

CONCLUSIONS

One-third of women with Cesarean section delivery experienced DOLII. DOLII was more likely in women who were primiparous, had a serum albumin concentration < 35 g / L, had a lower frequency of breastfeeding sessions, and had an EPDS score ≥ 10. Women with these risk factors who deliver via Cesarean section may need early breastfeeding support to ensure successful lactation.

Analysis of the Influence of Pre-Pregnancy BMI and Weight Gain during Pregnancy on the Weight of Healthy Children during the First 2 Years of Life: A Prospective Study

Background: Increased pre-pregnancy maternal BMI (pBMI) and gestational weight gain (GWG) have been found to increase infants’ birthweight and result in the programming of child weight and impact its later weight gain. Aim: To assess the impact of pBMI and GWG on the weight of children from birth to 2 years of age and over the duration of breastfeeding. Methods: Single Centre observational prospective longitudinal cohort study. Data were collected from medical records, and medical history. The analysis of multiple linear and mixed models was involved. Findings: 20% of females were overweight, while 13% were obese before the pregnancy. An overall model, including gender and smoking, indicated a significant impact of pBMI category on a child’s birth mass (p = 0.01). The GWG category affected a child’s birth weight (p = 0.018, Effect size 0.41). pBMI did not affect the breastfeeding duration. Conclusion: pBMI and GWG correlate with birth weight and weight in neonatal period, however they become insignificant in later childhood. Weight assessment methods among children aged up to two years of age require standardization. Maternal weight before the pregnancy nor the weight gain during the pregnancy do not influence the length of breastfeeding. The biggest limitation was the small sample size and the failure to account for weight gain per trimester of pregnancy. Further research on a larger population should be continued.

Childhood obesity and adverse cardiometabolic risk in large for gestational age infants and potential early preventive strategies: a narrative review

Accumulating evidence indicates that obesity and cardiometabolic risks become established early in life due to developmental programming and infants born as large for gestational age (LGA) are particularly at risk. This review summarizes the recent literature connecting LGA infants and early childhood obesity and cardiometabolic risk and explores potential preventive interventions in early infancy. With the rising obesity rates in women of childbearing age, the LGA birth rate is about 10%. Recent literature continues to support the higher rates of obesity in LGA infants. However, there is a knowledge gap for their lifetime risk for adverse cardiometabolic outcomes. Potential factors that may modify the risk in early infancy include catch-down early postnatal growth, reduction in body fat growth trajectory, longer breastfeeding duration, and presence of a healthy gut microbiome. The early postnatal period may be a critical window of opportunity for active interventions to mitigate or prevent obesity and potential adverse metabolic consequences in later life. A variety of promising candidate biomarkers for the early identification of metabolic alterations in LGA infants is also discussed. IMPACT: LGA infants are the greatest risk category for future obesity, especially if they experience rapid postnatal growth during infancy. Potential risk modifying secondary prevention strategies in early infancy in LGA infants include catch-down early postnatal growth, reduction in body fat growth trajectory, longer breastfeeding duration, and presence of a healthy gut microbiome. LGA infants may be potential low-hanging fruit targets for early preventive interventions in the fight against childhood obesity.

Developing dietary interventions as therapy for cancer

Cancer cells acquire distinct metabolic preferences based on their tissue of origin, genetic alterations and degree of interaction with systemic hormones and metabolites. These adaptations support the increased nutrient demand required for increased growth and proliferation. Diet is the major source of nutrients for tumours, yet dietary interventions lack robust evidence and are rarely prescribed by clinicians for the treatment of cancer. Well-controlled diet studies in patients with cancer are rare, and existing studies have been limited by nonspecific enrolment criteria that inappropriately grouped together subjects with disparate tumour and host metabolic profiles. This imprecision may have masked the efficacy of the intervention for appropriate candidates. Here, we review the metabolic alterations and key vulnerabilities that occur across multiple types of cancer. We describe how these vulnerabilities could potentially be targeted using dietary therapies including energy or macronutrient restriction and intermittent fasting regimens. We also discuss recent trials that highlight how dietary strategies may be combined with pharmacological therapies to treat some cancers, potentially ushering a path towards precision nutrition for cancer.

Common Complications of Breastfeeding and Lactation: An Overview for Clinicians

Lactation and breastfeeding are core components of reproductive health care and obstetrical providers should be familiar with common complications that may arise in lactating individuals. While many breastfeeding challenges are best addressed by a lactation consultant, there are conditions that fall out of their scope and require care from a clinician. The objective of this chapter is to review common complications of breastfeeding and lactation including inflammatory conditions, disorders of lactogenesis, dermatologic conditions, and persistent pain with lactation.

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.

Is Secretory Activation Delayed in Women with Type Two Diabetes? A Pilot Study

(1) Background: Breastfeeding duration may be reduced in women with type 2 diabetes. Delayed secretory activation (SA) is associated with poorer breastfeeding outcomes; however, no prior studies have examined SA in women with type 2 diabetes. This pilot study aimed to assess SA in women with type 2 diabetes by assessing breastmilk constituents. Secondary aims were to assess breastfeeding rates postpartum, and contributory factors. (2) Methods: A prospective cohort of pregnant women with type 2 diabetes (n = 18) and two control groups with age- and parity-matched nondiabetic pregnant women (body mass index (BMI)) matched (n = 18) or normal-range BMI (n = 18)) were recruited. Breastmilk constituents (citrate, lactose, protein, and fat) were measured twice daily for 5 days postpartum and compared between groups. Associations between peripartum variables, breastmilk constituents, and breastfeeding at 4 months postpartum were explored. (3) Results: Women with type 2 diabetes had a slower increase in breastmilk citrate concentration postpartum, indicative of delayed SA, compared to both control groups. Higher predelivery insulin doses in women with type 2 diabetes were associated with increasing time to SA. Both women with type 2 diabetes and BMI-matched controls were less likely to fully breastfeed at 4 months, compared with normal-BMI controls. (4) Conclusion: SA is delayed in women with type 2 diabetes when compared to BMI-matched and normal-BMI women. Women with type 2 diabetes are less likely to fully breastfeed, at hospital discharge and by 4 months postpartum, compared to women with normal-BMI.

Early Postpartum Patterns of Breastfeeding Exclusivity and Perceived Insufficient Milk by Prepregnancy Body Mass Index

OBJECTIVE

To explore trajectories of breastfeeding exclusivity and perceived insufficient milk (PIM) over the first 8 weeks postpartum among primiparous women and the association of these trajectories with prepregnancy body mass index (BMI).

DESIGN

Secondary analysis of data from a randomized controlled trial.

SETTING

Recruitment for the primary study was conducted in Pittsburgh, Pennsylvania.

PARTICIPANTS

One hundred twenty-two primiparous women with intention to exclusively breastfeed.

METHODS

We used group-based trajectory modeling to classify participants into breastfeeding exclusivity and PIM trajectory groups. We used logistic regression to explore the predictive relationship between prepregnancy BMI and breastfeeding exclusivity and PIM trajectory group memberships.

RESULTS

We identified two trajectories each for breastfeeding exclusivity and PIM over the first 8 weeks postpartum. For breastfeeding exclusivity, one group (n = 60, 49%) had low initial probability of exclusive breastfeeding with linear decline in likelihood of exclusivity over time. The other group (n = 62, 51%) had greater initial probability of exclusive breastfeeding, which remained constant over time. For PIM, one group (n = 41, 34%) had consistently greater probability of endorsing PIM at each time point, whereas the other group (n = 81, 66%) had consistently low probability of endorsing PIM over time. Prepregnancy BMI did not predict group membership in breastfeeding exclusivity, χ2(1) = 2.8, p = .094, or PIM, χ2(1) = 0.72, p = .397.

CONCLUSION

Breastfeeding exclusivity and PIM appeared to be relatively stable phenomena in the postpartum period among a sample of predominately White primiparous women who intended to breastfeed. We did not find a clear association with prepregnancy BMI.

Interventions to support women with overweight or obesity or gestational diabetes mellitus to initiate and continue breastfeeding: Systematic review and meta-analysis

Exclusive breastfeeding is recommended for the first 6 months of life and benefits both mother and child. Women with overweight/obesity or gestational diabetes are at risk for poor breastfeeding outcomes. This review evaluates the efficacy of breastfeeding interventions in these at-risk populations. The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Five databases were searched for interventions from inception to May 2020. Nineteen trials including 2,740 participants, 226 of which were dyads, were included. Intervention increased any breastfeeding at ≥6 months (OR 1.43, 95% CI [1.05-1.95]), and women in the intervention group were 90% more likely to exclusively breastfeed at 1-2 weeks (OR 1.9, 95% CI [1.17-3.09]) and more than twice as likely to exclusively breastfeed at 4-6 weeks (OR 2.23, 95% CI [1.27-3.90]) within the sensitivity analysis. These findings support breastfeeding interventions improving exclusive early postpartum breastfeeding and any breastfeeding from 6 months in women with gestational diabetes or obesity/overweight. Further randomized controlled trials with harmonized breastfeeding outcome reporting are needed to confirm efficacy.

Lactogenic hormones in relation to maternal metabolic health in pregnancy and postpartum: protocol for a systematic review

INTRODUCTION

Maternal metabolic disease states (such as gestational and pregestational diabetes and maternal obesity) are reaching epidemic proportions worldwide and are associated with adverse maternal and fetal outcomes. Despite this, their aetiology remains incompletely understood. Lactogenic hormones, namely, human placental lactogen (hPL) and prolactin (PRL), play often overlooked roles in maternal metabolism and glucose homeostasis during pregnancy and (in the case of PRL) postpartum, and have clinical potential from a diagnostic and therapeutic perspective. This paper presents a protocol for a systematic review which will synthesise the available scientific evidence linking these two hormones to maternal and fetal metabolic conditions/outcomes.

METHODS AND ANALYSIS

MEDLINE (via OVID), CINAHL and Embase will be systematically searched for all original observational and interventional research articles, published prior to 8 July 2021, linking hPL and/or PRL levels (in pregnancy and/or up to 12 months postpartum) to key maternal metabolic conditions/outcomes (including pre-existing and gestational diabetes, markers of glucose/insulin metabolism, postpartum glucose status, weight change, obesity and polycystic ovary syndrome). Relevant fetal outcomes (birth weight and placental mass, macrosomia and growth restriction) will also be included. Two reviewers will assess articles for eligibility according to prespecified selection criteria, followed by full-text review, quality appraisal and data extraction. Where possible, meta-analysis will be performed; otherwise, a narrative synthesis of findings will be presented.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as no primary data will be collected. The results will be published in a peer-reviewed journal and presented at conference meetings, and will be used to inform future research directions.

PROSPERO REGISTRATION NUMBER

CRD42021262771.

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.

Maternal Psychological Distress and Lactation and Breastfeeding Outcomes: a Narrative Review

PURPOSE

Despite recommendations from the World Health Organization and the American Academy of Pediatrics to exclusively breastfeed infants for their first 6 months of life, 75% of women do not meet exclusive breastfeeding guidelines, and 60% do not meet their own breastfeeding goals. Numerous observational studies have linked maternal psychological distress (eg, perceived stress, anxiety, and depression) with nonoptimal breastfeeding outcomes, such as decreased proportion and duration of exclusive breastfeeding. The physiological mechanisms underlying these associations, however, remain unclear.

METHODS

For this narrative review, we evaluated the evidence of relationships between maternal psychological distress and lactation and breastfeeding outcomes in pregnancy and post partum and the possible physiological mechanisms that facilitate these relationships. We searched PubMed using the following terms: stress, anxiety, depression, breastfeeding, and lactation. Additional search by hand was conducted to ensure a thorough review of the literature.

FINDINGS

Among the studies examined, methods used to assess maternal psychological distress were not uniform, with some studies examining perceived distress via a variety of validated tools and others measuring biological measures of distress, such as cortisol. Evidence supports a role for psychological distress in multiple breastfeeding outcomes, including delayed secretory activation and decreased duration of exclusive breastfeeding. One physiological mechanism proposed to explain these relationships is that psychological distress may impair the release of oxytocin, a hormone that plays a critical role in milk ejection during lactation. Continued impairment of milk ejection may lead to decreased milk production because of incomplete emptying of the breast during each feed. Maternal distress may also yield elevated levels of serum cortisol and decreased insulin sensitivity, which are associated with decreased milk production. The relationship between psychological distress and breastfeeding is likely to be bidirectional, however, in that breastfeeding appears to reduce maternal distress, again possibly via effects on the pleasure or reward pathway and calming effects of oxytocin on the mother. This finding suggests that interventions to support lactation and breastfeeding goals in women who score high on measures of psychological distress would be beneficial for both maternal and infant well-being.

IMPLICATIONS

Evidence to date suggests that maternal psychological distress may impair lactation and breastfeeding outcomes, but stronger study designs and rigorous assessment methods are needed. A better understanding of the physiological mechanisms leading to impaired lactation may assist in the development of early interventions for mothers experiencing distress. In addition, stress-reducing programs and policies should be investigated for their potential to improve breastfeeding outcomes.

Updating Clinical Practices to Promote and Protect Human Milk and Breastfeeding in a COVID-19 Era

The COVID-19 pandemic has impacted breastfeeding and lactation globally, with clinical practices implemented early in the pandemic being mostly anti-breastfeeding, e.g., separation of mothers from their infants, and not evidence based. As the pandemic has progressed, evidence has emerged reconfirming the value of human milk and the importance of protecting and supporting breastfeeding, especially the initiation of lactation. However, it is clear that COVID-19 has changed the clinical care paradigm around breastfeeding and lactation support and, as such, it is imperative that practices adapt and evolve to maintain the emphasis on lactation support. We participated in a round table conference aiming to rescue and develop protocols and practices that support breastfeeding during the COVID-19 pandemic. One key area to target will be to maximize the use of the antenatal period. The early identification of lactation risk factors together with the development of person-centered methods to deliver breastfeeding information and education to parents-to-be will be critical. In addition, the establishment of a hospital culture that values breastfeeding and prioritizes the use of human milk will be integral for the motivation of health care professionals. That culture will also support active management of the initiation of lactation and the development of a 'back-up plan' toolkit to support the mother experiencing lactation difficulties. Post-discharge support will also be crucial with the development of both in-person and virtual lactation support programs, in particular for the immediate post-discharge period to benefit mothers who experience an early discharge process. These measures will allow for a new, adapted framework of practice that acknowledges the current COVID-19 paradigm and maintains the emphasis on the need to protect and support breastfeeding and the use of human milk.

Circadian clocks and their role in lactation competence

Circadian rhythms are 24 h cycles of behavior, physiology and gene expression that function to synchronize processes across the body and coordinate physiology with the external environment. Circadian clocks are central to maintaining homeostasis and regulating coordinated changes in physiology in response to internal and external cues. Orchestrated changes occur in maternal physiology during the periparturient period to support the growth of the fetus and the energetic and nutritional demands of lactation. Discoveries in our lab made over a decade ago led us to hypothesize that the circadian timing system functions to regulate metabolic and mammary specific changes that occur to support a successful lactation. Findings of studies that ensued are summarized, and point to the importance of circadian clocks in the regulation of lactation competence. Disruption of the circadian timing system can negatively affect mammary gland development and differentiation, alter maternal metabolism and impair milk production.

Human Milk Glucose, Leptin, and Insulin Predict Cessation of Full Breastfeeding and Initiation of Formula Use

Objective: We aimed to investigate prospective associations between milk bioactives related to metabolic health (glucose, insulin, leptin, C reactive protein [CRP], and interleukin 6 [IL-6]) and incident formula initiation at 3 and 6 months postpartum. Design: This study included 363 mother-infant dyads who were fully breastfed at 1 month and participated in the prospective Mothers and Infants Linked for Healthy Growth study from pregnancy to 6 months postpartum. Associations between milk glucose, leptin, insulin, CRP, and IL-6 at 1 and 3 months and incident formula feeding (FF) at 3 and 6 months, respectively, were tested using multiple logistic regression, adjusting for numerous potential confounders such as maternal age and prepregnancy body mass index. Results: At 3 months postpartum, 1-month glucose (odds ratio [OR] 0.45 [95% confidence interval (CI): 0.27-0.75], p ≤ 0.01) and smaller decreases in glucose from 1 to 3 months (OR 0.51 [95% CI: 0.28-0.92], p = 0.03) were associated with lower odds of FF, whereas 1-month leptin (OR 2.30 [95% CI: 1.30-4.07], p < 0.01) and larger increase in insulin (OR 1.86 [95% CI: 1.23-2.81], p < 0.01) and leptin (OR 2.17 [95% CI: 1.29-3.68], p < 0.01) from 1 to 3 months were associated with increased odds of FF. At 6 months, insulin increases (OR 2.08 [95% CI: 1.03-4.17], p = 0.04) were associated with higher odds of FF. Conclusions: In a cohort of women with established lactation, 1-month milk glucose, insulin, and leptin predicted initiation of FF at 3 months. Early milk composition may provide a window into mammary gland function, allowing identification of women at risk of not meeting their breastfeeding goals.

Transcriptome analysis reveals disruption of circadian rhythms in late gestation dairy cows may increase risk for fatty liver and reduced mammary remodeling

Circadian disruption increased insulin resistance and decreased mammary development in late gestation, nonlactating (dry) cows. The objective was to measure the effect of circadian disruption on transcriptomes of the liver and mammary gland. At 35 days before expected calving (BEC), multiparous dry cows were assigned to either control (CON) or phase-shifted treatments (PS). CON was exposed to 16-h light and 8-h dark. PS was exposed to 16-h light to 8-h dark, but phase of the light-dark cycle was shifted 6 h every 3 days. On day 21 BEC, liver and mammary were biopsied. RNA was isolated (n = 6 CON, n = 6 PS per tissue), and libraries were prepared and sequenced using paired-end reads. Reads mapping to bovine genome averaged 27 ± 2 million and aligned to 14,222 protein-coding genes in liver and 15,480 in mammary analysis. In the liver, 834 genes, and in the mammary gland, 862 genes were different (nominal P < 0.05) between PS and CON. In the liver, genes upregulated in PS functioned in cholesterol biosynthesis, endoplasmic reticulum stress, wound healing, and inflammation. Genes downregulated in liver function in cholesterol efflux. In the mammary gland, genes upregulated functioned in mRNA processing and transcription and downregulated genes encoded extracellular matrix proteins and proteases, cathepsins and lysosomal proteases, lipid transporters, and regulated oxidative phosphorylation. Increased cholesterol synthesis and decreased efflux suggest that circadian disruption potentially increases the risk of fatty liver in cows. Decreased remodeling and lipid transport in mammary may decrease milk production capacity during lactation.

Human milk imparts higher insulin concentration in infants born to women with type 2 diabetes mellitus

OBJECTIVE

Human milk (HM) insulin plays many roles for the infant, especially for the newborn. We hypothesized HM insulin in women with type 2 diabetes (T2DM) would be higher than BMI-matched women with either gestational diabetes (GDM) or normal glucose tolerance (NGT). In T2DM, we also assessed macronutrient composition and relationships between maternal glycemic control and HM insulin.

STUDY DESIGN

HM was characterized at 2-weeks postpartum among three BMI-matched groups: T2DM (n= 12), diet-controlled GDM (n= 12), and NGT (n= 12). In T2DM, additional fasting and postprandial HM samples were collected while wearing a continuous glucose monitor (CGM), as well as fasting and 90-minute postprandial samples after a standardized meal at 1-2 weeks postpartum.

RESULTS

Fasting HM insulin was two times higher in T2DM compared to GDM and NGT (p < .001), which were not different from each other. Among T2DM, fasting (p < .001) and postprandial (p = .01) HM insulin levels were between 2 and 5× higher than plasma. Postprandial HM insulin (p = .03) and glucose (p < .001) were increased compared to fasting. Mean nocturnal glucose (p < .01) and maternal hemoglobin A1c (p < .01) positively associated with fasting HM insulin.

CONCLUSIONS

These data are the first to show HM insulin concentrations are doubled in T2DM compared to BMI-matched GDM and NGT. In HM of T2DM, insulin increases postprandially, may be concentrated relative to plasma, and is influenced by maternal glycemic control, with potential clinical implications that merit further study.

Chrononutrition and Breast Milk: A Review of the Circadian Variation of Hormones Present in Human Milk

Introduction

Breast milk contains a wide range of hormones, nutrients, and bioactive compounds. Chrononutrition looks at the interaction between food, both meal timing and meal composition, and circadian rhythms.

Method

This review is a continuation on series on chrononutrition and breast milk. All human studies published in English were included regardless of location or year of publication.

Results

This review identifies the hormonal circadian variation researched in breast milk to date for melatonin, cortisol, cortisone, leptin, and insulin.

Conclusion

The circadian variation observed in some hormones reinforces the superiority of breast milk over formula milk. Melatonin has been the most studied, but more research for all the hormones is needed due to various gaps in the literature and varying levels of study quality. There is insufficient evidence to make recommendations specifically targeting the lactating mother, but we identify and recommend several ideas for future research.

Metabolic Conditions Including Obesity, Diabetes, and Polycystic Ovary Syndrome: Implications for Breastfeeding and Breastmilk Composition

Breastfeeding is internationally recognized as the recommended standard for infant nutrition, informed by evidence of its multiple benefits for both mother and baby. In the context of common metabolic conditions such as polycystic ovary syndrome, diabetes (type 1, type 2, and gestational), and obesity, breastfeeding may be particularly beneficial for both mother and infant. However, there is evidence of delayed lactogenesis and reduced breastfeeding rates and duration in women with these conditions, and the effects of altered maternal metabolic environments on breastmilk composition (and potentially infant outcomes) are incompletely understood. In this review, we explore the relationships between maternal metabolic conditions, lactogenesis, breastfeeding, and breastmilk composition. We examine relevant potential mechanisms, including the central role of insulin both in lactogenesis and as a milk-borne hormone. We also describe the bioactive and hormonal components of breastmilk and how these may link maternal and infant health.

Breastfeeding support and barriers to women with gestational diabetes mellitus: a nationwide cross-sectional survey of hospitals in Japan

BACKGROUND

Despite the benefits of breastfeeding for women with Gestational Diabetes Mellitus (GDM) and their infants, breastfeeding is less likely to be performed by this group. This study aimed to examine the current levels of implementation of breastfeeding support to women with GDM in Japan and to clarify barriers to promoting breastfeeding among this population.

METHODS

A 25-item questionnaire was developed by the authors to investigate the current levels of implementation of breastfeeding support for women with GDM provided in hospitals, and to explore barriers for promoting breastfeeding among these women. The questionnaire was sent to all 1046 hospitals facilitating childbirth in Japan. Descriptive statistics were used to analyze the quantitative data, and content analysis was used to analyze qualitative data from the open-ended questions.

RESULTS

All 296 respondents were included in this study. Regarding breastfeeding support, 95.2% of the respondents provided general information on breastfeeding to GDM women during antenatal midwife consultations. However, the benefits of breastfeeding for preventing type 2 diabetes were addressed by only 48.0%. Likewise, although follow-up services (e.g., telephone support or breastfeeding consultations) were conducted in 88.9% of hospitals, only 50.7% of hospitals informed women that breastfeeding decreases the risk of developing type 2 diabetes after GDM. Regarding barriers, seven categories and 20 subcategories about promoting breastfeeding for women with GDM were extracted and abstracted into the following three themes: Barriers associated with mother and infant, Barriers associated with health professionals, and Organizational barriers.

CONCLUSIONS

In Japan, most hospitals that responded provided general breastfeeding support from the antenatal to postpartum periods. However, the benefits of breastfeeding in terms of preventing the incidence of type 2 diabetes following GDM were insufficiently communicated to women with GDM. Furthermore, there were numerous barriers to promoting breastfeeding among women with GDM.

Is There an Association Between Breast Hypoplasia and Breastfeeding Outcomes? A Systematic Review

Introduction: Insufficient milk supply is the most common reason for premature breastfeeding cessation. Breast hypoplasia is one reason why women may be inherently unable to make a full milk supply. This review aimed to systematically explore the relationship between breast hypoplasia and breastfeeding duration, milk supply, and lactation onset. Materials and Methods: Medline, CINAHL, ProQuest Central, and the Cochrane Library databases were searched using the keywords "insufficient glandular tissue" or "mammary hypoplasia" or "breast hypoplasia" or "mammary gland hypoplasia" or "droopy breasts" or "snoopy deformity" or "tubular breast*" or "tuberous breast*" AND breastfeeding or "breast feeding" or breast-feeding or lactation. After initially screening 20 records, including reference lists, 9 full texts were assessed for eligibility; 2 were excluded as no breastfeeding outcomes were reported, leaving 7 studies (N = 42 women). Results: The studies in this review drew on results from the oldest included study and plastic surgery literature to define breast hypoplasia. Most women in this review (40/42) ceased exclusive breastfeeding before 1 month postpartum. One case study reported 24-hour milk production, which was 52 mL at 26 weeks postpartum. Conclusion: The relationship between breast hypoplasia and breastfeeding outcomes is underresearched. The co-occurring medical conditions (e.g., polycystic ovary syndrome) of some women provide avenues for future research into the possible pathogenesis of breast hypoplasia resulting in insufficient milk supply. Research is needed to evaluate the reliability of measuring and classifying markers of breast hypoplasia, and prospective studies can help determine the role of breast hypoplasia in milk production. PROSPERO registration number CRD42020191228.

Indicators of Secretory Activation in Mothers of Preterm Very Low Birth Weight Infants

BACKGROUND

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

RESEARCH AIMS

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

METHODS

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

RESULTS

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

CONCLUSION

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

Microenvironmental control of cell fate decisions in mammary gland development and cancer

Cell fate decisions are critical for adequate tissue development, maintenance and regeneration. In the mammary gland, epithelial cell fates are tightly controlled by the microenvironment. Here, we review how cell fate decisions are regulated by components of the microenvironment during mammary gland development and how pathological changes in the microenvironment can alter cell fates, leading to malignancy. Specifically, we describe the current understanding of how mammary cell fate is controlled and directed by three elements: the extracellular matrix, the immune microenvironment, and hormones-and how these elements can converge to create microenvironments that promote a fourth element: DNA damage.

Psychosocial stress and cortisol stress reactivity predict breast milk composition

We studied a sample of 146 Polish, exclusively breastfeeding mothers and their healthy born on time infants to explore the effect of perinatal psychosocial stress on breast milk composition. Maternal perinatal stress was assessed using Recent Life Changes Questionnaire summarizing stressful events from the previous six months. Stress reactivity was determined by administering the cold pressor test and measuring cortisol in saliva samples taken during the test. Breast milk sample was taken to measure energy, protein, fat, lactose, and fatty acid content. Analyses revealed that stress reactivity was positively associated with milk fat and long-chain unsaturated fatty acids and negatively associated with milk lactose. Perinatal psychosocial stress negatively affected energy density, fat as well as medium-chain and long-chain saturated fatty acids in milk. These results, together with previous studies, advocate monitoring maternal psychological status during the peripartum to promote breastfeeding and healthy infant nutrition.

A Comparative Review of the Extrinsic and Intrinsic Factors Regulating Lactose Synthesis

Milk is critical for the survival of all mammalian offspring, where its production by a mammary gland is also positively associated with its lactose concentration. A clearer understanding of the factors that regulate lactose synthesis stands to direct strategies for improving neonatal health while also highlighting opportunities to manipulate and improve milk production and composition. In this review we draw a cross-species comparison of the extra- and intramammary factors that regulate lactose synthesis, with a special focus on humans, dairy animals, and rodents. We outline the various factors known to influence lactose synthesis including diet, hormones, and substrate supply, as well as the intracellular molecular and genetic mechanisms. We also discuss the strengths and limitations of various in vivo and in vitro systems for the study of lactose synthesis, which remains an important research gap.

Measures of Lactation Outcomes in Women Delivering Preterm Infants

BACKGROUND

Mother's own milk (MOM) is well known to decrease prematurity-related morbidities, yet mothers delivering preterm infants often produce insufficient quantities of milk to provide these benefits. Although a critical need exists for research to support lactation success in this vulnerable population, development and investigation of interventions to increase available MOM for infant consumption requires consistent, valid, and reliable measures of lactation outcomes.

OBJECTIVES

The aim of this study was to compare and contrast methods of measuring lactation outcomes in mothers of preterm infants and evaluate their advantages and disadvantages.

METHODS

Measures of lactation outcomes were reviewed and synthesized. Insights on best practices and future research directions are provided.

RESULTS

Volume of MOM produced, lactation duration, and time to onset of secretory activation are important measures of lactation success. The most valid and reliable measure of milk production is likely weighing each vial of expressed milk combined with test weighing when infants breastfeed. Measures of lactation duration should include actual days mothers lactated rather than limiting to infant consumption of MOM as a proxy for duration and include not only whether mothers are lactating at infant discharge but whether they are also lactating at other health-relevant time points during hospitalization. Although time to onset of secretory activation is an important lactation outcome, information regarding valid and reliable indicators of onset in women delivering preterm infants is limited, and investigation of such indicators is a research priority. Variables that may affect lactation outcomes, including time to initiation of expression following delivery, duration of expression sessions, expression method, time spent in skin-to-skin care, maternal demographics and comorbidities, as well as maternal intent to lactate, must be considered when researchers investigate lactation outcomes in mothers of very low birth weight infants.

DISCUSSION

Consistent and valid measures of lactation outcomes are required to produce reliable results from which evidence-based practice recommendations can be developed in order to improve lactation success in this vulnerable population.

Gestational Diabetes Mellitus and Risk of Delayed Onset of Lactogenesis: A Systematic Review and Meta-Analysis

Background: Gestational diabetes mellitus (GDM) may be associated with delayed onset of lactogenesis (DOL), but it is still inconclusive. Objectives: The study aimed to evaluate the association between GDM and DOL, the prevalence and risk factors of DOL in GDM women. Materials and Methods: A comprehensive search was performed in 10 electronic databases from inception to June 1, 2020. To find more eligible studies, the references of finally eligible studies and relevant reviews were traced manually. A meta-analysis was conducted to calculate the pooled estimates of association, prevalence, and risk factors using random- or fixed-effects models. Results: Eleven eligible articles involving 8,150 women were included in this study. GDM women had a higher risk of DOL (odds ratio [OR] = 1.84, 95% confidence interval [CI] [1.34-2.52]). The prevalence of delayed lactogenesis onset in GDM women was 35.0% (effect size [ES] = 0.35, 95% CI [0.30-0.40]). Primipara (OR = 2.54, 95% CI [1.89-3.42]), advanced age (OR = 1.05, 95% CI [1.03-1.08]), prepregnancy obesity (OR = 1.55, 95% CI [1.19-2.03]), and insulin treatment (OR = 3.07, 95% CI [1.71-5.47]) were risk factors of delayed lactogenesis onset in GDM women. Conclusion: GDM negatively affects the timing of lactogenesis onset. The prevalence of delayed lactogenesis onset in GDM women is 35.0%. Primipara, advanced age, prepregnancy obesity, and insulin treatment are independent risk factors of delayed lactogenesis onset in GDM women.

Clinical Implications for Women of a Low-Carbohydrate or Ketogenic Diet With Intermittent Fasting

Obesity in the United States is pervasive and associated with morbidity, mortality, and increased health care costs. For women, obesity may affect stages of life including early menarche, fertility, pregnancy, and menopause as a result of hormonal imbalances and insulin resistance. The insulin-carbohydrate model of obesity has been proposed as an explanation for growing obesity rates and can be used to target weight loss strategies by increasing insulin sensitivity. Together, low-carbohydrate dietary patterns along with intermittent fasting may help individuals with insulin resistance not only lose weight but also increase their insulin sensitivity. The purpose of this article is to review the epidemiology and physiology of obesity and the indicators for health while outlining strategies for nurses and other clinicians to use when counseling women who are following a low-carbohydrate or ketogenic diet with intermittent fasting for weight management.

Maternal production of milk for infants in the neonatal intensive care unit

Mother's own milk (MOM) feeding is a cost-effective strategy to reduce risks of comorbidities associated with prematurity and improve long-term health of infants hospitalized in the Neonatal Intensive Care Unit (NICU). Significant racial and socioeconomic disparities exist in MOM provision in the NICU, highlighting the importance of developing strategies to reduce these disparities. Mothers of infants in the NICU experience many health concerns which may negatively impact lactation physiology. Objective measures of lactation physiology are limited but may assist in identifying mothers at particular risk. Several strategies to assist mothers of hospitalized infants are essential, including maternal education, qualified lactation professionals, early and frequent milk expression with a hospital-grade double electric breast pump, and providing support for transitioning to direct breastfeeding prior to discharge from the NICU.