Journal of Human Lactation

Subclinical mastitis is an asymptomatic inflammatory condition of the lactating mammary glands possibly associated with premature interruption of breastfeeding and poor weight gain in infants. However, data on human milk composition in mothers with subclinical mastitis are limited and inconsistent. Although human milk from donors with subclinical mastitis may be used after pasteurization if it meets the criteria, whether the composition is suitable for donor human milk remains unknown.

This study assessed the human milk composition of participants with subclinical mastitis and verified the safety of donor human milk, including that from mothers with subclinical mastitis.

This cross-sectional survey included 106 milk samples collected between March 2022 and January 2023. Subclinical mastitis status was assessed using the sodium-potassium ratio, which was measured using an ion-selective electrode. The concentrations of lactoferrin and secretory Immunoglobulin A were analyzed using an enzyme-linked immunosorbent assay. True protein, fat, carbohydrate, and energy levels were analyzed using a mid-infrared transmission spectroscopy.

In human milk from the subclinical mastitis group, lactoferrin and true protein concentrations were significantly increased compared to those without subclinical mastitis. A positive correlation was observed between lactoferrin and secretory Immunoglobulin A levels.

Increased immunological substances and protein concentrations in human milk are similar to those observed in clinical mastitis, indicating an inflammatory response in the body, even in asymptomatic individuals. Immunological substances and proteins are beneficial for preterm infants. Therefore, human milk from mothers with subclinical mastitis is suitable for use by milk banks.

Nipple trauma and pain pose a challenge, leading to premature discontinuation of breastfeeding. Moisturizing therapies, including lanolin and hydrogel dressings, have been proposed for nipple trauma and pain management. Despite the availability of multiple approaches, evidence for moisturizing therapy is lacking.

This review aimed to determine the efficacy of moisturizing therapy in treating nipple trauma and nipple pain in lactating women.

A systematic review based on the PRISMA-P guidelines was conducted. Seven databases were systematically searched and screened, and 24 studies were analyzed. The interventions were categorized as high, moderate, or low, based on their moisturization levels. Sample characteristics, interventions, and outcomes were examined.

A total of 21 interventions were identified: high moisturization (two types), moderate moisturization (12 types), and low moisturization (seven types). Hydrogel dressings, lanolin, and breast milk are commonly used interventions. Although intervention and effectiveness evaluation methods differed between studies and could not be compared, results in 10 (41%) of the studies demonstrated that one intervention with more moistening was more effective. Of the three studies categorized as including high moistening interventions, two (66%) supported their effectiveness compared to low moistening interventions; however, two of the three studies were judged to be at high risk of bias, and some reported adverse events.

Moisturization interventions show promise for treating nipple trauma and pain more than drying nipples or using breast milk, but high moisturization needs cautious use due to few rigorous trials and the presence of reported risks. Methodological challenges and the lack of robust trials hinder evidence synthesis and robust conclusions.

背景： 乳頭損傷や乳頭痛は産褥早期に授乳を断念する要因である。その対処法として、ラノリンやハイドロジェルドレッシングによる保湿療法が提案されている。しかし、乳頭損傷や乳頭痛に対する保湿療法の効果に関する検討は不足している。

目的： 本システマティックレビューは、授乳中の乳頭損傷と乳頭痛の治療における保湿の有効性を検討することを目的とした。

方法： PRISMA-Pガイドラインに基づく系統的レビューを実施した。7つのデータベースを用いて、体系的に検索とスクリーニングを行い、最終的に24件の文献を対象とした。介入方法を保湿レベルに基づいて高保湿、中保湿、低保湿に分類し、サンプル特性や、介入、および結果について検討した。

結果： 高保湿（2種類）、中保湿（12種類）、低保湿（7種類）の合計21種類の介入が特定された。ハイドロジェルドレッシング、ラノリン、母乳の塗布が一般的な介入として使用されていた。介入および効果の測定方法は研究間で異なり、結果の統合は困難であったが、10件（41％）でより高い保湿の介入が効果的であるとされていた。高保湿に分類された3件のうち2件（66％）が低保湿の介入と比較して効果的であるとされたが、2件（66％）はバイアスリスクが高いと判定された文献であり、有害事象の報告もあった。

結論： 保湿療法は乾燥や母乳の塗布と比較して乳頭損傷や乳頭痛の対処法として有望であるが、高保湿の対処法には厳密な無作為化比較試験の不足と有害事象の報告があり、慎重な検討が必要である。堅牢な実験研究の不足と方法論的な課題が、結果の統合とエビデンスの確立の妨げとなっている。

Back translated by Katsumi Mizuno, PhD, MD, IBCLC

Pumping is a common practice in the United States, but it can be uncomfortable and lead to concerns about milk supply. The fit of the flange, or breast shield, used while pumping can contribute to or alleviate these problems. Flanges are available in a wide variety of sizes, and there are inconsistencies in guidance provided by healthcare providers and pump manufacturers for parents choosing a size. There have been no studies comparing different methods of sizing in terms of comfort and milk output.

The aim of this research was to examine differences in milk output and comfort using two methods of flange sizing.

A within-subject cross-over design with a convenience sample of parents exclusively feeding their own human milk was used to compare comfort and milk yield between using smaller-fit and standard-fit flanges. Participants pumped for 1 week with each set of flanges and recorded milk output and comfort outcome measures. Data were collected on participant demographics, nipple measurements, and flange sizes used.

When compared to the newer small-size fitting, participants using the standard fit flanges had significantly less milk output (mean difference = −15.0 g, 95% CI [−25.0, −5.0], d = −0.51, p = 0.004) and less comfort (mean difference = −1.2, 95% CI [−1.6, −0.91], d = −1.23, p < 0.001).

Flange fitting is a process that should be individualized to the patient and may require a trial of one or more sizes during a pumping session. Smaller sizes determined using this individualized process and starting with nipple tip measurement may be used without compromising milk output or comfort.

Favipiravir is a known anti-influenza agent that has been used globally, especially during the coronavirus disease 2019 (COVID-19) pandemic. This drug has been important for treating influenza and other emerging infectious diseases, although it was ultimately proven to be ineffective for COVID-19. Currently, no studies have reported the human-milk transfer of favipiravir at doses of 1,600–3,600 mg/day in the treatment of diseases, including COVID-19.

A 38-year-old mother gave birth at 38 gestational weeks because of severe respiratory distress caused by COVID-19. Considering her illness and the inadequate information available on the safety of favipiravir in breastfeeding, she chose formula feeding for her infant. However, she still provided human milk and blood samples for the analysis of drug concentrations.

Five concentrations of favipiravir in the mother’s milk and four in maternal blood were measured (3.0–80.9 and 3.5–78.4 μg/ml, respectively). Metabolites of favipiravir were not measured. The relative infant dose was 15.2%. The favipiravir concentration in human milk was as high as 80.9 μg/ml at 1.3 hours after the medication was given, when maternal blood levels are considered to be at their highest; however, favipiravir concentration was low in human milk immediately before medication administration (5.9–9.7 μg/ml).

Breastfeeding is not contraindicated in mothers undergoing favipiravir therapy and would be safer immediately before medication. Avoiding feeding at the peak time (1.3 hours after medication) minimizes infant exposure.

Shifts in women’s maternal roles may contribute to the global low prevalence of exclusive breastfeeding.

To investigate the association between maternal gender-role ideologies and exclusive breastfeeding in rural China.

Cross-sectional studies were conducted in 10 counties in Shaanxi Province using random sampling in 2021 and 2023. Data on breastfeeding practices, maternal gender-role ideology, and expected educational attainment from 586 rural participants were collected through structured questionnaires. Multivariable regression analysis was employed to explore the association between maternal gender-role ideology and exclusive breastfeeding.

The prevalence of exclusive breastfeeding within 6 months in rural western China was 18.8%. Women with more egalitarian gender-role ideologies were more likely to engage in exclusive breastfeeding (OR = 1.34, 95% CI [1.04, 1.72]), particularly for female infants (OR = 1.63, 95% CI [1.09, 2.43]). Furthermore, women with stronger egalitarian gender-role ideologies were found to exhibit a greater propensity for financial investment in their children (Beta = 0.20, 95% CI [0.01, 0.40]) and hold higher educational expectations for their daughters (OR = 1.50, 95% CI [1.00, 2.25]).

Maternal gender-role ideology positively correlates with exclusive breastfeeding. More policies should be implemented on gender equality in rural China, and cultural perspectives should be incorporated into the analysis of breastfeeding practice.

Medical students should have adequate knowledge and positive attitudes toward breastfeeding to support breastfeeding dyads. No studies in Croatia have explored breastfeeding knowledge, attitudes or intentions among medical students.

To investigate breastfeeding knowledge, attitudes and intentions among medical students at the University of Split School of Medicine.

A cross-sectional study was conducted from March to April 2023, using online and written questionnaires. All medical students without children were eligible to participate. The validated Breastfeeding Intentions, Attitudes, and Knowledge Questionnaire (BIAKQ) was used. Sociodemographic data were collected. Analysis was conducted using descriptive statistics, t tests, and Mann-Whitney U test.

A total of 357 medical students participated (response rate 64.1%). There was no significant difference between preclinical and clinical students. Students who attended the elective “Breastfeeding Medicine” demonstrated significantly more positive attitudes toward breastfeeding (Mean Rank = 215.62) than those who did not attend (Mean Rank = 173.58; U= 5468.50, p = 0.010); however, no significant difference was found in knowledge or intentions. Female students had significantly more positive attitudes compared to male students (Mean Rank = 189.47 vs. Mean Rank = 150.55, U = 9796.50, p = 0.001), whereas male students expressed significantly more positive intentions (M = 36.97, SD = 5.26 vs. M = 34.44, SD = 5.86, t = −3.69, p = 0.002). The mean knowledge score was 11.92 (SD = 1.43) out of 13 points. Negative attitudes towards breastfeeding beyond 1 year and breastfeeding in public were found.

Despite adequate breastfeeding knowledge, some medical students demonstrated negative attitudes and intentions toward breastfeeding. Including breastfeeding education into core medical subjects focusing on the importance of breastfeeding for maternal and infant health and the risks of formula feeding could help improve attitudes, especially during the clinical years. It would also be important to address prevailing prejudices.

No research has been conducted on the use of deep learning for breastfeeding support.

This study aims to develop a nipple trauma evaluation system using deep learning.

We used an exploratory data analysis approach to develop a deep-learning model for medical imaging. Employing object detection and classification, this Japanese study retrieved 753 images from a previous study. The classification protocol, based on the “seven signs of nipple trauma associated with breastfeeding,” categorized the images into eight classes. For practical purposes, the eight original classes were consolidated into four broader categories: “None,” “Minor,” “Moderate,” and “Severe,” using data augmentation procedures that were consistent with the original classification system. The Precision, Recall, Overall Accuracy, and Area Under the Curve (AUC) were calculated, and the model’s efficiency was evaluated using Frames Per Second (FPS).

The object detector’s high mean average precision and frames per second rate for nipple and areola detection, confirmed exceptional accuracy. The eight-class image classifier returned notable AUC values, with fissures, peeling, purpura, and scabbing exceeding 0.8. The highest average recall and precision was for scabbing, and the lowest for blistering. The four-class classifier accurately predicted severe conditions, with an average AUC > 0.7, whereas categories without classifications and those deemed minor had lower recall and precision rates.

A sophisticated deep learning system detects and classifies nipple trauma automatically, potentially aiding breastfeeding caregivers through objective image assessment and operational improvements.

背景： 母乳育児支援における深層学習の活用に関する研究は行われていない。

目的： 本研究は、深層学習を用いた乳頭損傷評価システムの開発を目的とした。

方法： 本研究では、医療画像を用いた深層学習モデルを開発するため、探索的データ分析アプローチを用いた。物体検出および画像分類の技術を用い、日本で行われた先行研究で撮影された753枚の画像を二次解析した。「授乳に伴う乳頭組織の７所見」に基づき、画像を8クラスに分類した。実用性を考慮し、4つの主要カテゴリ「なし」、「軽度」、「中等度」、「重度」の4つのカテゴリに統合し、元の分類システムに一致するデータ拡張を行った。精度、再現率、Overall Accuracy、AUC（曲線下面積）を算出し、モデルの効率はFPS（Frames Per Second）で評価した。

結果： 物体検出における高いmAP（平均精度）とFPSが示され、乳頭および乳輪の検出精度が確認された。8クラスの画像分類は、亀裂、皮膚剝離、紫斑、痂皮で0.8を超える顕著なAUC値が得られた。再現率と精度が最も高かったのは痂皮であり、水疱で最も低かった。4クラスの画像分類は重度の状態を正確に予測し、平均AUCは0.7を超えたが、傷なしや軽度とされるカテゴリは再現率と精度が低い結果となった。

結論： 深層学習を活用したこの高度なシステムは、乳頭損傷の検出と分類を自動で行うことができ、客観的な画像評価を通じて、母乳育児支援者の教育と業務改善をサポートする有望なツールとなり得る。

Back Translation Completed by Hiroko Hongo, MSW, PhD, IBCLC

Globally, rising trends in gestational diabetes and body mass index contribute to maternal and neonatal morbidity and mortality. Lifestyle modifications and breastfeeding may reverse this effect, although few studies combine these into one intervention.

To measure postpartum weight retention, breastfeeding duration, hemoglobin A1C, and mean arterial blood pressure at 6 months postpartum among women with elevated pre-pregnancy body mass index.

The electronic Monitoring of Mom’s Schedule study (eMOMS™) was a feasibility, three-arm, randomized controlled trial modeled after a Diabetes Prevention Program and breastfeeding support. A health coach delivered a 12-month virtual intervention. Study arm results were compared using Wilcoxon signed-ranks exact test reporting from a two-sided test and bootstrapped samples with 95% confidence intervals.

Between September 2019 and May 2021, 100 individuals were screened, and 35 were randomized: nine to Group 1, 14 to Group 2, and 12 to Group 3. At baseline, participants averaged 13.0 (SD = 2.5) weeks gestation, with a mean pre-pregnancy body mass index of 29.7 (SD = 3.0). With 5,000 bootstrapped samples, mean weight retention from baseline to 6 months postpartum was: 4.0 kg, 95% CI [1.6, 6.2] for Group 1; 3.7 kg, CI [-1.8, 9.8] for Group 2; and 7.5 kg, CI [4.1, 11.6] for Group 3. Mean (exclusive) breastfeeding duration was 9.3 weeks, 95% CI [0.43, 26.1]; 9.6 weeks, CI [4.4, 15.7]; and 15.1 weeks, CI [6.5, 23.3] for each group, respectively.

Our intervention was positively associated with postpartum weight retention and breastfeeding duration. Future research is needed to assess intervention components.

Peer support programs may be effective for supporting breastfeeding among diverse groups, and in reducing disparities. This study provides insight regarding the implementation and outcomes of a peer breastfeeding support program.

(1) to examine how participation affected the outcomes of breastfeeding motivation, confidence, and coping strategies; and (2) to evaluate satisfaction with the program.

This was a cross-sectional, retrospective study. Seven pilot sites in the United States uniquely implemented a federally-funded peer support program for low-income women. Data were collected using a survey and focus groups/interviews. Over 12 months, 1,296 women participated, comprising 615 peer support pairs. A total of 401 women responded to the survey. Twenty-three focus groups and 63 interviews were conducted across the seven sites.

Participants who enrolled in the program during pregnancy: t (189) = −6.55, p < 0.001, and after the baby was born: t (170) = −2.59, p = 0.001, gained confidence in breastfeeding. More satisfied participants were more likely to breastfeed longer: F (7,352) = 12.75, p < 0.001, and cope with breastfeeding challenges: F (7,352) = 7.83, p < 0.001.

Effective operation strategies of the peer breastfeeding support program have significantly influenced participant satisfaction. Introducing peer support for low-income women to share their breastfeeding experiences would be beneficial in enhancing breastfeeding rates. However, the generalizability of these findings may be limited to this U.S. federally-funded peer support program.

Web-based prenatal education is increasingly employed, but its association with increased breastfeeding and predictors of breastfeeding success is uncertain.

Our primary aim was to evaluate our live, online intervention’s association with exclusive breastfeeding at hospital discharge. Secondarily, we aimed to describe participants’ reports of the intervention on predictors of breastfeeding success.

We used a retrospective quasi-experimental cohort design to assess the association between our intervention and exclusive breastfeeding at discharge. The intervention consisted of an evidence-based live, online, 2-hour class open to all prenatal patients and supporters at our urban community medical center from June 2020 through April 2022. Patient characteristics and breastfeeding rates were extracted from the electronic medical record. Samples were drawn using stratified random sampling. Three logistic regression models were conducted to assess the associations between the intervention and exclusive breastfeeding. Two surveys assessed the participant reports of the intervention.

Samples of the first model, comprised of 160 participants and 160 non-participants, were similar in important characteristics. Participants were 2.12 times (95% CI [1.12, 3.69]) more likely to exclusively breastfeed. Participants reported positively on the impacts of the intervention on breastfeeding predictors.

Our live, online intervention was significantly associated with an increased likelihood of exclusive breastfeeding at hospital discharge. A randomized, prospective examination of the intervention’s association with breastfeeding duration would further define its impact.