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.

Characterization of Three Cases of Primary Hypogalactia in Jalisco, Mexico

INTRODUCTION

Human lactation should be taken into account as an important issue for the international agenda. Despite advances in lactation information and knowledge, insufficient milk production is still a concern for mothers and health practitioners, including International Board Certified Lactation Consultants and others. Primary hypogalactia, or insufficient milk production is uncommon, but should be considered when there is poor weight gain and decreased urine output in infants despite good latch-on and suckling, or anatomic differences in the physical exam of the lactating breast.

MAIN ISSUE

This case series presents three cases illustrating insufficient milk production resulting in infants who experienced significant dehydration and poor weight gain.

MANAGEMENT

Primary hypoplasia was diagnosed by means of a thorough interview and physical examination that entailed a consultation with a physician who was also an International Board Certified Lactation Consultant.

CONCLUSION

Awareness of an infant's feeding needs and proper evaluation of a child's health status is paramount if health care providers are to identify the important factors contributing to breastfeeding problems. In some instances, breastfeeding goals cannot be achieved, and then the provider's role becomes support in coming to terms with persistent insufficient milk production, and coordinating appropriate supplementation to meet each baby's nutritional needs.

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.

Inhibiting SETD7 methyl-transferase activity impairs differentiation, lipid metabolism and lactogenesis in mammary epithelial cells

SETD7 (SET7/9, KMT7) is a lysine methyltransferase that targets master regulators of cell proliferation and differentiation. Here, the impact of inhibiting SETD7 catalytic activity on mammary epithelial cell differentiation was studied by focusing on genes associated with epithelial differentiation, lactogenesis, and lipid metabolism in HC11 and EpH4 cell lines. Setd7 mRNA and protein levels were induced upon lactogenic differentiation in both cell lines. Inhibition of SETD7 activity by the compound (R)-PFI-2 increased cell proliferation and downregulated E-cadherin, beta-catenin, lactoferrin, insulin-like growth factor binding protein 5, and beta-casein levels. In addition, inhibition of SETD7 activity affected the lipid profile and altered the mRNA expression of the phospholipid biosynthesis-related genes choline phosphotransferase 1, and ethanolamine-phosphate cytidylyltransferase. Altogether, the results suggest that inhibiting SETD7 catalytic activity impairs mammary epithelial and lactogenic differentiation.

Novel At-Home Mother's Milk Conductivity Sensing Technology as an Identification System of Delay in Milk Secretory Activation Progress and Early Breastfeeding Problems: Feasibility Assessment

BACKGROUND

Prolonged exclusive breastfeeding is a public health priority and a personal desire by mothers; however, rates are low with milk supply challenges as a predominant cause. Early breastfeeding management at home is key. Milk electrolytes, mainly sodium ions, are accepted as biomarkers of secretory activation processes throughout the first weeks after birth and predictors for prolonged breastfeeding success, although they are not incorporated into routine care practice.

OBJECTIVE

The aim of this study was to test the feasibility of a novel handheld smartphone-operated milk conductivity sensing system that was designed to compute a novel parameter, milk maturation percent (MM%), calculated from milk sample conductivity for tracking individual secretory activation progress in a real-world home setting.

METHODS

System performance was initially evaluated in data collected from laboratory-based milk analysis, followed by a retrospective analysis of observational real-world data gathered with the system, on the spot in an at-home setting, implemented by lactation support providers or directly by mothers (N=592). Data collected included milk sample sensing data, baby age, and self-reported breastfeeding status and breastfeeding-related conditions. The data were retroactively classified in a day after birth-dependent manner. Results were compared between groups classified according to breastfeeding exclusivity and breastfeeding problems associated with ineffective breastfeeding and low milk supply.

RESULTS

Laboratory analysis in a set of breast milk samples demonstrated a strong correlation between the system's results and sodium ion levels. In the real-world data set, a total of 1511 milk sensing records were obtained on the spot with over 592 real-world mothers. Data gathered with the system revealed a typical time-dependent increase in the milk maturation parameter (MM%), characterized by an initial steep increase, followed by a moderate increase, and reaching a plateau during the first weeks postpartum. Additionally, MM% levels captured by the system were found to be sensitive to breastfeeding status classifications of exclusive breastfeeding and breastfeeding problems, manifested by differences in group means in the several-day range after birth, predominantly during the first weeks postpartum. Differences could also be demonstrated for the per-case time after birth-dependent progress in individual mothers.

CONCLUSIONS

This feasibility study demonstrates that the use of smart milk conductivity sensing technology can provide a robust, objective measure of individual breastfeeding efficiency, facilitating remote data collection within a home setting. This system holds considerable potential to augment both self-monitoring and remote breastfeeding management capabilities, as well as to refine clinical classifications. To further validate the clinical relevance and potential of this home milk monitoring tool, future controlled clinical studies are necessary, which will provide insights into its impact on user and care provider satisfaction and its potential to meet breastfeeding success goals.

The Utilization of Sodium Concentration in Human Milk from Pump-Dependent Mothers of Preterm Infants as a Measure of Milk Production

Objective: This study investigated changes in sodium concentrations in human milk from mothers of premature infants using different breast pumps for 14 days postpartum, and the correlation between the sodium concentration in mother's own milk (MOM) and the volume pumped. Study Design: This randomized controlled study recruited 66 mothers of premature infants delivered in our hospital from February to December 2018, and we assigned them to three groups using an envelope method. In intervention group 1, a hospital-grade electric breast pump was used from postpartum day 1 to 14; in intervention group 2, a hospital-grade electric breast pump was used on postpartum days 1 to 5 and a normal personal electric breast pump on postpartum days 6 to 14; in the control group, a personal normal electric breast pump was used from postpartum day 1 to 14. Data recorded included the breast milk volume pumped and milk sodium concentration. Results: The average daily volume of MOM pumped differed statistically (p < 0.05) between the intervention and control groups at postpartum days 7 and 14. The average daily volume pumped did not differ between intervention groups 1 and 2 by postpartum day 14 (p > 0.05). However, the time taken for the sodium concentrations to normalize differed significantly (p < 0.01). At postpartum day 5, the sodium concentrations of 73% of intervention group 1 and 2 mothers were within normal limits, and they were maintained until day 14. In comparison, only 41% of the controls had normal MOM sodium levels on day 5, and they were still high on day 7 in 27.3% of controls. Conclusions: In the early stage of lactation initiation (within 5 days postpartum), using a hospital-grade electric breast pump promotes lactation in mothers who deliver prematurely and the sodium concentrations normalize more quickly. Sodium can be used as an objective biomarker of MOM to evaluate the possibility of delayed lactation in mothers of premature infants, and it could assist interventions in the early postpartum period. Trial Registration: Chinese Clinical Trial Registry, ChiCTR2200061384.

Progress in Research on Key Factors Regulating Lactation Initiation in the Mammary Glands of Dairy Cows

Lactation initiation refers to a functional change in the mammary organ from a non-lactating state to a lactating state, and a series of cytological changes in the mammary epithelium from a non-secreting state to a secreting state. Like the development of the mammary gland, it is regulated by many factors (including hormones, cytokines, signaling molecules, and proteases). In most non-pregnant animals, a certain degree of lactation also occurs after exposure to specific stimuli, promoting the development of their mammary glands. These specific stimuli can be divided into two categories: before and after parturition. The former inhibits lactation and decreases activity, and the latter promotes lactation and increases activity. Here we present a review of recent progress in research on the key factors of lactation initiation to provide a powerful rationale for the study of the lactation initiation process and mammary gland development.

Using QTL to Identify Genes and Pathways Underlying the Regulation and Production of Milk Components in Cattle

Milk is a complex liquid, and the concentrations of many of its components are under genetic control. Many genes and pathways are known to regulate milk composition, and the purpose of this review is to highlight how the discoveries of quantitative trait loci (QTL) for milk phenotypes can elucidate these pathways. The main body of this review focuses primarily on QTL discovered in cattle (Bos taurus) as a model species for the biology of lactation, and there are occasional references to sheep genetics. The following section describes a range of techniques that can be used to help identify the causative genes underlying QTL when the underlying mechanism involves the regulation of gene expression. As genotype and phenotype databases continue to grow and diversify, new QTL will continue to be discovered, and although proving the causality of underlying genes and variants remains difficult, these new data sets will further enhance our understanding of the biology of lactation.

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.

Lactogenesis and breastfeeding after immediate vs delayed birth-hospitalization insertion of etonogestrel contraceptive implant: a noninferiority trial

BACKGROUND

Initiating a progestin-based contraceptive before the drop in progesterone required to start lactogenesis stage II could theoretically affect lactation. Previous studies have shown that initiating progestin-based contraception in the postnatal period before birth-hospitalization discharge has no detrimental effects on breastfeeding initiation or continuation compared with outpatient interval initiation. However, there are currently no breastfeeding data on the impact of initiating the etonogestrel contraceptive implant in the early postnatal period immediately in the delivery room.

OBJECTIVE

This study examined the effect of delivery room vs delayed birth-hospitalization contraceptive etonogestrel implant insertion on breastfeeding outcomes.

STUDY DESIGN

This was a noninferiority randomized controlled trial to determine if time to lactogenesis stage II (initiation of copious milk secretion) differs by timing of etonogestrel implant insertion during the birth-hospitalization. We randomly assigned pregnant people to insertion at 0 to 2 hours (delivery room) vs 24 to 48 hours (delayed) postdelivery. Participants intended to breastfeed, desired a contraceptive implant for postpartum contraception, were fluent in English or Spanish, and had no allergy or contraindication to the etonogestrel implant. We collected demographic information and breastfeeding intentions at enrollment. Onset of lactogenesis stage II was assessed daily using a validated tool. The noninferiority margin for the mean difference in time to lactogenesis stage II was defined as 12 hours in a per-protocol analysis. Additional electronic surveys collected data on breastfeeding and contraceptive continuation at 2 and 4 weeks, and 3, 6, and 12 months.

RESULTS

We enrolled and randomized 95 participants; 77 participants were included in the modified intention-to-treat analysis (n=38 in the delivery room group and n=39 in the delayed group) after excluding 18 because of withdrawing consent, changing contraceptive or breastfeeding plans, or failing to provide primary outcome data. A total of 69 participants were included in the as-treated analysis (n=35 delivery room, n=34 delayed); 8 participants who received the etonogestrel implant outside the protocol windows were excluded, and 2 participants from the delivery room group received the etonogestrel implant at 24 to 48 hours and were analyzed with the delayed group. Participants were similar between groups in age, gestational age, and previous breastfeeding experience. Delivery room insertion was noninferior to delayed birth-hospitalization insertion in time to lactogenesis stage II (delivery room [mean±standard deviation], 65±25 hours; delayed, 73±61 hours; mean difference, -9 hours; 95% confidence interval, -27 to 10). Onset of lactogenesis stage II by postpartum day 3 was not significantly different between the groups. Lactation failure occurred in 5.5% (n=2) participants in the delayed group. Ongoing breastfeeding rates did not differ between the groups, with decreasing rates of any/exclusive breastfeeding over the first postpartum year. Most people continued to use the implant at 12 months, which did not differ by group.

CONCLUSION

Delivery room insertion of the contraceptive etonogestrel implant does not delay the onset of lactogenesis when compared with initiation later in the birth-hospitalization and therefore should be offered routinely as part of person-centered postpartum contraceptive counseling, regardless of breastfeeding intentions.

Etonogestrel Implant in the Postpartum Period and its Impact on Biochemical Markers in Secretory Activation: A Pilot Study

BACKGROUND

Secretory activation is characterized biochemically in human milk by a fall in sodium concentration, an increase in potassium concentration, and a decreased sodium to potassium ratio. These markers can be used to identify a delay in secretory activation which can result from hormonal birth control.

RESEARCH AIM

To evaluate if the insertion of the Etonogestrel implant early in the postpartum period would delay the time to secretory activation as measured by biochemical markers.

METHODS

We conducted a prospective, longitudinal, non-randomized, observational cohort study. Women with singleton pregnancies were identified as wanting either no birth control or the Etonogestrel implant in the postpartum period. Human milk samples were collected starting at 12 hours after delivery, and then in 12-hour increments. Samples were tested for sodium and potassium levels.

RESULTS

As in the unadjusted models, there was evidence of a difference in sodium levels at two days postpartum, with the sodium level higher by 32.29 mM (95% CI [7.39, 57.20], p = .013) in the implant group than in the no birth control method group. A difference at day 2 was observed in the ratio (sodium/potassium) levels, with a higher mean ratio in the implant group by 2.49 (95% CI [0.14, 4.85], p = .039). For potassium levels, the only difference was observed at day 4, with lower values in the implant group (p = .045).

CONCLUSION

The transition from colostrum to copious milk secretion is delayed by the early insertion of the Etonogestrel device. This is evidenced by the delay in biochemical markers normally seen in secretory activation.

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.

Exploring the Prescribing Process of Domperidone for Low Milk Supply: A Qualitative Study Among Mothers, IBCLCs, and Family Doctors

BACKGROUND

When mothers are confronted with milk supply problems, taking domperidone is regularly suggested. However, domperidone has been associated with sudden cardiac death and caution in prescribing is advised. In 2016, a multidisciplinary group of authors from a tertiary academic hospital (Erasmus MC) published a clinical protocol in a leading Dutch physicians' journal to support Dutch family physicians in prescribing domperidone to stimulate lactation.

RESEARCH AIM

To explore consumer and health care provider perspectives and experiences regarding the prescribing of domperidone for lactation insufficiency following publication of a national clinical protocol.

METHODS

A cross-sectional qualitative study was performed using semi-structured interviews (N = 40) based on a topic list covering the prescribing process. Participants were mothers (n = 18) who had been advised to try domperidone to boost their milk supply between November 2016 and May 2018, their International Board Certified Lactation Consultants (n = 9), and their family physicians (n = 15). Another group of participants (mothers; n = 6) answered short questionnaires. All interviews were recorded, transcribed and analyzed using ATLAS.ti software. The resulting list of codes was organized according to the topics.

RESULTS

In the process leading to domperidone use to stimulate lactation, participant family physicians relied on the IBCLC, pharmacist, or mother to guide the prescription of domperidone, often citing the published national clinical protocol as back up. The medical safeguards incorporated in the protocol (e.g., taking medical history, physical exam, performing electrocardiograms, limiting dosage) were usually not implemented.

CONCLUSIONS

Though the availability of a national clinical protocol in which the prescribing of domperidone for lactation is supported appeared to increase the willingness of participant family physicians to prescribe, gaps were identified between clinical practice and this clinical protocol for prescribing domperidone.

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.

TMT based deep proteome analysis of buffalo mammary epithelial cells and identification of novel protein signatures during lactogenic differentiation

The lactating mammary gland harbours numerous matured alveoli with their lumen surrounded by differentiated mammary epithelial cells (MECs), which are exclusively involved in milk synthesis and secretion. Buffalo (Bubalus bubalis) is the second major milk-producing animal, and its physiology is different from cattle. The complete protein machinery involved in MECs differentiation is still not defined in ruminants, in particular, buffalo. Therefore, we have studied the differential expression of regulated proteins in the in vitro grown buffalo MECs (BuMECs) at different time points (on 3, 6, 12, and 15 days) of their differentiation in the presence of lactogenic hormones. TMT-based MS analysis identified 4,934 proteins; of them, 681 were differentially expressed proteins (DEPs). The principal component analysis suggested a highly heterogeneous expression of DEPs at the four-time points of hormone treatment, with most of them (307) attained the highest expression on 12 days. Bioinformatics analysis revealed the association of DEPs with 24 KEGG pathways. We observed few new proteins, namely ABCA13, IVL, VPS37, CZIB, RFX7, Rab5, TTLL12, SMEK1, GDI2, and TMEM131 in BuMECs. The function of one of the highly upregulated proteins, namely involucrin in the differentiation of BuMECs was confirmed based on biochemical inhibition assay. The results further conclude that the proteins with higher abundance can be considered as the potential biomarkers for differentiation, and they may have a significant association with the lactation process in buffalo too. The proteome dataset obtained can be used to understand the species-specific variations among other lactating animals.

Effect of Type of Pregnancy on Transcriptional and Plasma Metabolic Response in Sheep and Its Further Effect on Progeny Lambs

Simple Summary

The present study was carried out in order to determine the effect of type of pregnancy on the mammary gland development, evaluated through the transcriptional expression of genes that are associated to angiogenesis and cell turnover/lactogenesis and the metabolic response of the animals. For this, six twin and seven single-bearing ewes were fed with naturalized pasture from day −45 pre-partum until day +70 post-partum, taking samples of mammary tissue and plasma at different times from the birth until weaning. The results showed the type of pregnancy could only explain a few differences in the transcriptional expression of in some genes that are involved in angiogenesis and cell turnover/lactogenesis in the mammary gland tissue, which had no impact on the metabolic status of ewes or the metabolic response in plasma, performance, and muscle transcriptional expression of the lambs.

Abstract

The following study was performed in order to determine the effect of type of pregnancy on the transcriptional expression of genes that are engaged in angiogenesis and cell turnover/lactogenesis in the ewe mammary gland, evaluating its impact on the plasma metabolic response. In addition, an assessment of its further influence on plasma metabolic response, performance, and muscle transcriptional expression of lipogenic enzymes in progeny lambs was made. Thirteen Ile de France sheep (six twin- and seven single-bearing ewes) were allocated to graze ad libitum naturalized pasture from d 45 pre-partum to day 70 post-partum, while keeping their lambs on the same diet until day 60 after weaning. The samples were collected at different times and analyzed by qRT-PCR and plasma metabolic indicators. The data were processed using SPSS package. The results showed that twin-bearing ewes overexpressed VEGFR1 at birth, and BCL2 at birth and day 35 post-partum; however, single-bearing ewes overexpressed CAIV and IGF1 at day 35 post-partum. Similar metabolite concentrations in blood plasma were found between groups of ewes. The plasma metabolic response in lambs was similar between groups and it did not influence their performance, where a similar transcriptional expression of lipogenic enzymes in muscle was observed. Therefore, the type of pregnancy can explain the slight differences in mRNA expression that were found in angiogenesis and cell turnover/lactogenesis in mammary gland, although these differences not only did not affect the plasma metabolic response in ewes, but they also had no influence on plasma metabolic response, performance, and muscle transcriptional expression of their lambs.

Measures of Secretory Activation for Research and Practice: An Integrative Review

Background: Maternal concern about inadequate milk volume commonly emerges in the first 2 weeks postpartum, a critical lactation period that includes secretory activation. This review summarizes the biology of secretory activation and evaluates the accuracy and feasibility of published measures of secretory activation. Materials and Methods: A systematic search of measures of secretory activation for mothers of healthy term and preterm infants yielded 62 abstracts. Following additional screening, 15 publications qualified for quantitative synthesis review and were evaluated with respect to accuracy (validated with another measure of secretory activation in the same mother) and feasibility (accessibility, cost, and ease of use). Results:Maternal perception of milk coming in (MP) is the most feasible measure, but its accuracy has not been established. Patterns of increase in maternal milk volume have been validated with maternal milk-borne biomarkers in breastfeeding, and breast pump-dependent mothers and normal values have been published. Accuracy of serial maternal urinary lactose concentrations has not been established for secretory activation and lacks feasibility. Maternal milk biomarkers are the accurate standard to which other measures are compared but currently lack feasibility for routine use. Conclusions: Use of secretory activation measures can personalize lactation care by matching maternal risk with appropriate diagnostics. Priorities for research and practice include validation of MP as a population-based screening tool, implementation of techniques that measure patterns of increase in milk volume for moderate risk populations, and the development of milk biomarker science for point-of-care use in the most complicated lactation scenarios.

Oxytocin, Vasopressin and Prolactin in New Breastfeeding Mothers: Relationship to Clinical Characteristics and Infant Weight Loss

BACKGROUND

Maternal milk production requires the neuropeptide oxytocin. Individual variation in oxytocin function is a compelling target for understanding low milk production, a leading cause of breastfeeding attrition. Complicating the understanding of oxytocin pathways is that vasopressin may interact with oxytocin receptors, yet little is known about the role of vasopressin in lactation.

RESEARCH AIMS

The aims of this study were (1) to describe maternal plasma oxytocin, vasopressin, and prolactin patterns during breastfeeding following low-risk spontaneous labor and birth in healthy first-time mothers and (2) to relate hormone patterns to maternal characteristics and breastfeeding measures.

METHODS

Eligible women were recruited before hospital discharge. Forty-six participants enrolled and 35 attended the study visit. Participants kept a journal of breastfeeding frequency, symptoms of lactogenesis, and infant weight. Plasma samples were obtained at breastfeeding onset on Day 4-5 postpartum, and repeated after 20 min. Hormones were measured with immunoassays. Infant weight change, milk transfer, and onset of lactogenesis were also measured.

RESULTS

Baseline oxytocin and vasopressin were inversely related to one another. Oxytocin and prolactin increased significantly across the 20-min sampling period while vasopressin decreased. Higher oxytocin was associated with higher maternal age, lower BMI, shorter active labor, physiologic labor progression, and less weight loss in the newborn. Higher vasopressin correlated with younger maternal age, higher BMI, and greater newborn weight loss.

CONCLUSIONS

Oxytocin and vasopressin have contrasting relationships with maternal clinical characteristics and newborn weight gain in early breastfeeding infants. Further study is needed to understand how oxytocin and vasopressin influence lactation outcomes.

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

BACKGROUND

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

RESEARCH AIMS

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

METHOD

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

RESULTS

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

CONCLUSION

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

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

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

Delayed Lactogenesis II is Associated With Lower Sleep Efficiency and Greater Variation in Nightly Sleep Duration in the Third Trimester

BACKGROUND

Metabolic and hormonal disturbances are associated with sleep disturbances and delayed onset of lactogenesis II.

RESEARCH AIMS

The aim of this study was to measure sleep using wrist actigraphy during gestation weeks 22 and 32 to determine if sleep characteristics were associated with blood glucose, body mass index, gestational related disease, delayed onset of lactogenesis II, or work schedule.

METHODS

Demographic data were collected at study intake from primiparous women who wore a wrist actigraph during gestation weeks 22 (n = 50) and 32 (n = 44). Start and end sleep time, total nighttime sleep, sleep efficiency, wake after sleep onset, and sleep fragmentation were measured. Night to night variability was assessed with the root mean square of successive difference. Blood glucose levels, body mass index, and gestational disease data were abstracted from medical charts. Timing of lactogenesis II was determined by survey.

RESULTS

Between gestation week 22 and 32, sleep efficiency decreased and fragmentation increased (p < .05). During gestation week 32, blood glucose was negatively correlated with sleep duration, and positively related to fragmentation (p < .05). Women who experienced delayed lactogenesis II had lower sleep efficiency and greater fragmentation (p < .05), and greater night-to-night variability in sleep start and end time, efficiency, and duration during gestation week 32 (p < .05).

CONCLUSION

Women with better sleep efficiency and more stable nightly sleep time are less likely to experience delayed onset of lactogenesis II. Interventions to improve sleep may improve maternal health and breastfeeding adequacy.

Effect of Diet and Type of Pregnancy on Transcriptional Expression of Selected Genes in Sheep Mammary Gland

Simple Summary

An experiment was designed to determine the effect of diet and type of pregnancy on the mammary gland development, measured by the transcriptional expression of genes involved in angiogenesis and cell turnover/lactogenesis. To that end, twin and single-bearing ewes were fed naturalized pasture or red clover from day −45 pre-partum until day +60 post-partum, taking samples of mammary tissue at day −10, +30 and +60 post-partum. The results showed that the group of twin-bearing ewes fed red clover was the best combination to increase the expression of genes associated to angiogenesis and cell turnover/lactogenesis in the mammary gland.

Abstract

These trials were carried out to determine firstly the effect of diet and type of pregnancy on the transcriptional expression of genes involved in angiogenesis and cell turnover/lactogenesis inside the sheep mammary gland from late gestation to late lactation. Eighteen Ile de France sheep, 8 twin- and 10 single-bearing ewes were alloted into two groups according to their diet, either based on ad libitum naturalized pasture or red clover hay plus lupine from day −45 pre-partum until day +60 post-partum. Samples from diets and mammary glands were collected at day −10 pre partum (time 1), day +30 (time 2) and day +60 post-partum (time 3) and analyzed by qRT-PCR. Additionally, samples from longissimus dorsi muscle were taken from lambs twice, at weaning and 45 days later, to determine the effect of the maternal treatment with regard to diet and type of pregnancy, on the mRNA expression of genes involved in lipid metabolism. The data was processed using the lme4 package for R, and SPSS Statistics 23.0 for Windows^®. The results showed that the group of twin-bearing ewes fed red clover showed a higher expression of genes involved in angiogenesis before lambing and in cell turnover/lactogenesis during late lactation, explained by a lamb survival mechanism to delay apoptosis as a way to keep a secretory cells population and boosted by the diet quality, assuring a longer milk production potential during late lactation. Regarding lambs, apparently the maternal diet would influence the transcriptional expression of lipogenic enzymes in the longissimus dorsi muscle after weaning, but further studies are necessary to validate these results. In summary, Twin-bearing ewes fed red clover performed best at increasing the expression of genes associated with angiogenesis and cell turnover/lactogenesis in the mammary gland.

Early initiation and regular breast milk expression reduces risk of lactogenesis II delay in at-risk Singaporean mothers in a randomised trial

INTRODUCTION

Lactogenesis II (LaII) failure can be prevented in at-risk mothers with simple proactive interventions. In a randomised trial, we investigated the efficacy of early and regular breast milk expression in establishing LaII, using an electric double-breast pump.

METHODS

Mothers with uncomplicated singleton deliveries were randomised to intervention (n = 31) or control (n = 29) groups. The former commenced breast milk expression with an electric pump within one hour of delivery and maintained regular expression with direct breastfeeding. Control mothers directly breastfed without regular pump expression. Expressed milk volumes were analysed for citrate, lactose, sodium and protein.

RESULTS

Median time of LaII was Day 3 (interquartile range [IQR] 1 day) with intervention and on Day 4 (IQR 1 day) among controls (p = 0.03). Biochemical steady-state concentrations were achieved around early Day 4 (sodium, total protein) and Days 4-5 (citrate, lactose). Sodium, protein and lactose levels were similar in both groups over seven days, at 5.80 mM, 0.68 mM and -13.38 mM, respectively. Mean daily milk volume with intervention was 73.9 mL on Day 3 and 225.2 mL on Day 7, greater than controls (25.4 mL on Day 3 and 69.2 mL on Day 7; p < 0.2). Mean infant weights were similar on Day 8 at 3,477 g with intervention and 3,479 g among controls.

CONCLUSION

LaII is established by postnatal Day 3 with early initiation of regular breast milk expression, a useful intervention for mothers at risk of early-onset breastfeeding failure.

Milk Volume at 2 Weeks Predicts Mother's Own Milk Feeding at Neonatal Intensive Care Unit Discharge for Very Low Birthweight Infants

OBJECTIVE

This study sought to determine the maternal prepregnancy, pregnancy, and delivery risk factors that predicted coming to volume (CTV; achieving pumped mother's own milk [MOM] volume ≥500 mLs/day) and the continuation of MOM provision through to discharge from the neonatal intensive care unit (NICU) in mothers and their very low birthweight (VLBW; <1,500 g at birth) infants.

STUDY DESIGN

Secondary analysis of prospectively collected data from 402 mothers of VLBW infants admitted to an urban NICU, including detailed MOM pumping records for a subset (51%) of the cohort. Analyses included inverse probability weighting, multivariate regression, and chi-square statistics.

RESULTS

In this high-risk cohort (51.2% black, 27.1% Hispanic, 21.6% white/Asian; 72.6% low income; 61.4% overweight/obese prepregnancy), CTV by day 14 was the strongest predictor of MOM feeding at NICU discharge (odds ratio [OR] 9.70 confidence interval [95% CI] 3.86-24.38, p < 0.01.). Only 39.5% of mothers achieved CTV by postpartum day 14, an outcome that was predicted by gestational age at delivery (OR 1.41, 95% CI 1.15-1.73, p < 0.01), being married (OR 3.66, 95% CI 1.08-12.39, p = 0.04), black race (OR 7.70, 95% CI 2.05-28.97, p < 0.01), cesarean delivery (OR 0.22, 95% CI 0.08-0.63, p = 0.01), and chorioamionitis (OR 0.14, 95% CI 0.02-0.82, p = 0.03).

CONCLUSION

Continued provision of MOM at NICU discharge can be predicted in the first 14 postpartum days on the basis of achievement of CTV. We posit that CTV can serve as a quality indicator for improving MOM feedings in the NICU and that lactation support resources should target this early critical postbirth period.

Plasma calcium concentrations are decreased at least 9 hours before parturition in multiparous Holstein-Friesian cattle in a herd fed an acidogenic diet during late gestation

Calcium homeostatic mechanisms are challenged in periparturient multiparous dairy cattle due to the rapid transport of large amounts of calcium into the mammary gland associated with colostrogenesis, resulting in decreased plasma total calcium concentration ([Ca]). An unresolved issue is the timing of the decrease in plasma [Ca] relative to the time of parturition, with the consensus view being that plasma [Ca] does not decrease until after parturition. The objective of this study, therefore, was to characterize the change in plasma [Ca] over time in periparturient dairy cattle. Plasma and mid-stream urine samples were collected daily starting 3 d before calving from 104 periparturient Holstein-Friesian dairy cows in a herd fed an acidogenic total mixed ration during the late dry period. Mixed-models ANOVA and linear and multivariable regression analyses were conducted. Plasma [Ca] decreased in periparturient multiparous cattle (n = 70) but not in primiparous cattle (n = 34). Compared with mean values approximately 72 h before parturition ([Ca] = 2.32 mmol/L), mean plasma [Ca] in multiparous cattle first decreased at 9 h before parturition (2.13 mmol/L) and remained decreased for up to 48 h after parturition, with the lowest mean value (1.87 mmol/L) occurring at 28 h after parturition. Mean 24-h urine Ca excretion was calculated to decrease by 3.5 to 3.8 g in periparturient multiparous cattle. Regression analysis indicated that plasma [Ca] in the 12-h period before and 24-h period after parturition was strongly and negatively associated with age but was also negatively associated with milk production indices. We conclude that plasma [Ca] was decreased at least 9 h before parturition in multiparous dairy cattle fed an acidogenic diet in late gestation, and that calcium homeostasis was disrupted for 2 to 3 d around parturition.

Historical and contemporary aspects of maternal immunity in swine

Maternal immunity plays a pivotal role in swine health and production because piglets are born agammaglobulinemic and with limited cell-mediated immunity, i.e. few peripheral lymphoid cells, immature lymphoid tissues, and no effector and memory T-lymphocytes. Swine do not become fully immunologically competent until about 4 weeks of age, which means that their compromised ability to respond to infectious agents during the first month of life must be supplemented by maternal immune components: (1) circulating antibodies derived from colostrum; (2) mucosal antibodies from colostrum and milk; and (3) immune cells provided in mammary secretions. Because maternal immunity is highly effective at protecting piglets against specific pathogens, strengthening sow herd immunity against certain diseases through exposure or vaccination is a useful management tool for ameliorating clinical effects in piglets and delaying infection until the piglets' immune system is better prepared to respond. In this review, we discuss the anatomy and physiology of lactation, the immune functions of components provided to neonatal swine in mammary secretion, the importance of maternal immunity in the prevention and control of significant pathogens.

Obesity as a Predictor of Delayed Lactogenesis II

BACKGROUND

Lactogenesis II is the onset of copious milk production. A delay in this has been associated with an increased risk of formula supplementation and early cessation of breastfeeding. Prepregnancy obesity has also been associated with decreased breastfeeding rates and early cessation. Research aim: This study aimed to evaluate the effect of prepregnancy obesity on self-reported delayed lactogenesis II.

METHODS

We conducted a prospective observational cohort study of 216 women with a singleton pregnancy and who planned to breastfeed. We compared the onset of lactogenesis II between women with a body mass index (BMI) < 30 kg/m² and women with a BMI ≥ 30 kg/m². Using multivariate logistic regression analyses, we assessed the relationship between maternal BMI and delay of lactogenesis II.

RESULTS

The prevalence of delayed lactogenesis II among women with prepregnancy BMI < 30 kg/m² and BMI ≥ 30 kg/m² was 46.4% and 57.9%, respectively. Delayed lactogenesis II occurred more frequently among women who were obese at the time of delivery ( p < .05). After controlling for the covariates, age, prepregnancy BMI, and gestational weight gain were positively associated with delayed lactogenesis II.

CONCLUSION

Prepregnancy obesity and excessive gestational weight gain are associated with an increased risk of delayed lactogenesis II. Women who are at risk for delay in lactogenesis II and early breastfeeding cessation will need targeted interventions and support for them to achieve their personal breastfeeding goals.

Chamomile reveals to be a potent galactogogue: the unexpected effect

Good habits of breastfeeding have been associated with many long-term health benefits. Nowadays, improvement is seen in the health of children and mothers who practice exclusive breastfeeding for the first six months of life. The search of new potent stimulants for milk production is important to promote lactation, mainly in cases where breastfeeding is a difficult task. This report presents a case of a woman who accidentally realized an abundant amount of milk and had high breast tension, a few hours after consuming chamomile. Although usual consumption of chamomile during pregnancy and lactation are documented for several purposes, the galactogogue effect was never reported. In this case report, we document for the first time the influence of chamomile in a lactating woman by increasing lactogenesis. This article also highlights the need of more research in this field to assure the safety of the intake, by women, of herbal product without the risk for them or the newborns.

The Association of Prenatal Tocolysis and Breastfeeding Duration

BACKGROUND

To date there are no clinical studies analyzing potential effects of tocolytics on breastfeeding duration in humans.

OBJECTIVES

The purpose of this study was to evaluate the association between beta 2 agonists prescribed for tocolysis during pregnancy and breastfeeding duration.

METHODS

We conducted a cross-sectional questionnaire study of 114 mothers and filled in the questionnaire developed to directly address the goals of the study.

RESULTS

There was a statistically significant difference between breastfeeding duration of mothers who were on tocolytics during pregnancy versus those who were not prescribed tocolytics (9.5 ± 5.7 months versus 4.5 ± 2.1 months) p < 0.001. In addition, hypogalactia was statistically significantly more prevalent in mothers with positive history versus mothers with negative history of tocolytic usage p < 0.001.

CONCLUSION

The results of our study indicate that tocolytic treatment in pregnancy is associated with shorter breastfeeding duration and hypogalactia.

Health provider experiences with galactagogues to support breastfeeding: a cross-sectional survey

BACKGROUND

Exclusive breastfeeding for infants up to 6 months is widely recommended, yet breastfeeding rates are relatively low in the US. The most common reason women stop breastfeeding early is a perceived insufficiency of milk. Galactagogues are herbal and pharmaceutical products that can help increase milk supply; however, data on their efficacy and safety is limited. Lactation consultants, obstetricians, and other health providers are an important point of contact for breastfeeding women experiencing challenges with lactation. This study explored providers' perceptions, experiences, and practices in relation to galactagogue recommendation.

METHOD

A cross-sectional survey was conducted among a convenience sample of English-speaking health providers in the US who counsel breastfeeding women and their infants.

RESULTS

More than 70% of respondents reported to recommend galactagogues. The most frequently recommended galactagogue was fenugreek with respondents indicating that they recommend it either 'always' (8.5%) or 'most of the time' (14.9%) and 'sometimes' (46.8%). More than 80% of the respondents indicated that galactagogues were useful for their clients and only one-third reported side effects. Reasons for refraining from recommending galactagogues were insufficient evidence of its efficacy and safety. Respondents reported a wide variety of sources of information used for their own education about galactagogues.

DISCUSSION

Despite little evidence regarding safety and efficacy, some galactagogues are widely recommended and often perceived to be useful. However, concerns about their efficacy and safety remain. In order to assure both providers and users about safety and efficacy, more robust studies as well as better pharmacovigilance systems are needed.

Ultrasonographic findings in the ovine udder during lactogenesis in healthy ewes or ewes with pregnancy toxaemia

Objective of the study was to record, by means of ultrasonographic examination, changes occurring during lactogenesis in the udder of healthy ewes and of ewes with pregnancy toxaemia. The work was carried out in 28 ewes, 16 with pregnancy toxaemia (group A) and 12 healthy controls (group B). B-mode and Doppler ultrasonographic examination of the udder of ewes was performed. During the last month of pregnancy, grey-scale intensity values of mammary parenchyma in group A were significantly greater than in group B (P = 0.007), as was also the progressive increase in grey-scale intensity values in both groups (P < 0.001). Blood mammary input was significantly greater in ewes of group B than in ewes of group A (P < 0.05), as was also the progressive increase in blood input in both groups (P < 0.001). Further, differences between the two groups were identified in pulsatility index (P = 0.007) and in mean blood velocity (P = 0.036), but only during the last fortnight of pregnancy. After lambing, grey-scale values decreased sharply compared to those in pregnancy (P < 0.01), whilst blood input, pulsatility index and mean blood velocity continued the same trend as at the last stage of pregnancy, with differences between the two groups still prevalent (P < 0.05). There was a reverse correlation between grey-scale intensity values and milk quantities (P < 0.035) and a correlation between blood input and milk quantities (P < 0.07). The progressive increase in the diameter of the external pudendal artery was significant (P < 0.001), but no significant differences were evident between the two groups (P > 0.35). Differences between group A and group B in all other haemodynamic parameters studied were not significant, neither throughout the last month of pregnancy (P > 0.25), nor during the first week of lactation (P > 0.06). However, their progressive changes during the last month of pregnancy were significant (P < 0.02).

Delayed onset lactogenesis II predicts the cessation of any or exclusive breastfeeding

OBJECTIVE

To evaluate the association between delayed lactogenesis II (>3 days postpartum; delayed onset lactogenesis II [DLII]) and the cessation of any and exclusive breastfeeding at 4-weeks postpartum.

STUDY DESIGN

We constructed multivariable logistic regression models using data from 2491 mothers enrolled in the prospective Infant Feeding Practice Study II cohort. Models included DLII, known risk factors for breastfeeding cessation (age, education, race, parity/previous breastfeeding, and exclusive breastfeeding plan), and potential confounders identified in bivariate analyses (P ≤ .1). Backward selection processes (P ≤ .1) determined risk factor retention in the final model.

RESULTS

DLII was associated with cessation of any and exclusive breastfeeding at 4-weeks postpartum (OR 1.62; CI 1.14-2.31; OR 1.62; CI 1.18-2.22, respectively); numerous independent risk factors qualified for inclusion in the multivariable model(s) and were associated with the outcome(s) of interest (eg, supplemental nutrition program for women, infants, and children enrollment, onset of prenatal care, feeding on-demand, time initiated first breastfeed, hospital rooming-in, obstetric provider preference for exclusive breastfeeding, and maternal tobacco use).

CONCLUSIONS

Women experiencing DLII may be less able to sustain any and/or exclusive breastfeeding in the early postpartum period. Routine assessment of DLII in postpartum breastfeeding follow-up is warranted. Women with DLII may benefit from additional early postpartum interventions to support favorable breastfeeding outcomes.

C/EBPbeta, but not C/EBPalpha, is essential for ductal morphogenesis, lobuloalveolar proliferation, and functional differentiation in the mouse mammary gland

The CCAAT/enhancer binding proteins (C/EBPs) are differentially expressed throughout mammary gland development and interact with binding sites within the promoter of a milk protein gene, beta-casein. The specific roles of C/EBPbeta and C/EBPalpha in mouse mammary gland development and differentiation have been investigated in mice that carry targeted deletions of these genes. C/EBPbeta-/- virgin mice exhibited cystic, enlarged mammary ducts with decreased secondary branching. Transplantation of C/EBPbeta-/- mammary epithelium into the cleared mammary fat pads of nude mice confirmed that this defect in ductal morphogenesis was intrinsic to the epithelium. When treated with estrogen/progesterone (E+P) to simulate pregnancy, C/EBPbeta-/- mammary glands displayed only limited lobuloalveolar development and ductal side branching. Primary mammary epithelial cells obtained from E+P-treated C/EBPbeta-/- mice that were cultured on extracellular matrix gels did not functionally differentiate in response to lactogenic hormones despite their organization into three-dimensional structures. Expression of beta-casein protein was inhibited 85%-100% and whey acidic protein (WAP) was undetectable. In contrast, no detectable alterations in mammary development or beta-casein expression were observed in mammary outgrowths derived from newborn C/EBPalpha-/- mammary epithelium transplanted into the cleared mammary fat pads of syngeneic hosts. These results demonstrate that C/EBPbeta, but not C/EBPalpha, is required for ductal morphogenesis, lobuloalveolar development, and functional differentiation of mammary epithelial cells.