How do breastfeeding workplace interventions work?: a realist review
International Journal for Equity in Health volume 20, Article number: 148 (2021)
Women are representing an increasing share of the labor force, thus, raising the need to accommodate breastfeeding working mothers at the workplace. While there is an emerging body of evidence supporting the positive influence of workplace lactation programs on breastfeeding outcomes, there is a lack of literature on the mechanisms underlying those interventions. Aims of this realist review were three-fold: to uncover underlying mechanisms, determine who benefits the most from such interventions and important contextual factors influencing uptake.
Purposive bibliographic searches on Medline, Web of Science Core Collection, CINAHL, Global Health, LILACS, Global Index Medicus, Business Source Complete, Proquest Dissertations and Theses and Open Access Theses and Dissertations were conducted to identify relevant publications. Included publications (qualitative and quantitative) described interventions aiming to improve the breastfeeding behavior of working mothers, that were initiated by the employer, reported on breastfeeding outcomes and had a clearly defined workplace. Publications only focusing on maternity leave or that were not published in English, Spanish, Portuguese or German were excluded. A realist approach was followed to identify how workplace interventions work, who benefits the most and the important contextual factors.
The bibliographic search yielded a total of 4985 possible publications of which 37 publications were included in the realist analysis. Effective workplace breastfeeding interventions activate three mechanisms: 1) awareness of the intervention, 2) changes in workplace culture, manager/supervisor support, co-worker support and physical environments, and 3) provision of time. Contextual factors such as the distance between the workplace and the infant and the type of workplace may influence the degree of activation of the underlying mechanisms for programs to positively impact breastfeeding outcomes.
In order to be effective, workplace breastfeeding interventions need to: raise awareness of the intervention(s) available among working mothers as well as their work environment, change the workplace culture, foster manager/supervisor support and co-workers support, provide enough time and adequate space and facilities for women to breastfeed or express breastmilk during the workday.
This article is a part of the Interventions and policy approaches to promote equity in breastfeeding collection, guest-edited by Rafael Pérez-Escamilla, PhD and Mireya Vilar-Compte, PhD
In the last decades, the number of women entering the labor force has steadily increased and women are representing a larger share of the labor market than ever before . Globally, women’s labor force participation rate is 48.5%, which demonstrates their growing and significant contribution to their various national economies . Because of women’s growing presence in the labor market, there is an increasing number of employers seeking to accommodate the needs of working women who choose to have children and want to breastfeed. Indeed, employers already recognizing the importance of breastfeeding, have offered various levels of lactation support especially for women working in the formal but not the informal sector [3, 4].
It is well established that breastfeeding is associated with numerous short- and long-term health benefits for the breastfeeding mother and the breastfed child. As such, breastfed children have lower risk for morbidity and mortality from infectious diseases, increased intelligence scores, and a reduction in risk for overweight and perhaps diabetes in later life [5,6,7]. For mothers, breastfeeding is associated with lower risk for breast cancer, ovarian cancer and type 2 diabetes .
Despite the various benefits of breastfeeding and the WHO/UNICEF recommendation for exclusive breastfeeding for 6 months, globally only about 44% of infants < 6 months of age were exclusively breastfed in 2019 . This is still below the goal of at least 50% by 2025 defined in the Global Nutrition Targets 2025 by UNICEF and WHO . Maternal employment is often cited as a major barrier to breastfeeding  and returning to work is associated with early cessation of breastfeeding [12, 13].
Previous research has shown a positive association between workplace lactation support and interventions with higher breastfeeding rates and duration of breastfeeding . Relatively low-cost interventions such as lactation rooms and nursing breaks may reduce absenteeism and improve workplace performance, commitment and retention, while also improving breastfeeding outcomes [11, 15]. Also, mothers receiving other types of workplace support such as provision of electric breast pumps, access to lactation professionals, and refrigerators for storing their breastmilk in the workplace were more likely to initiate and continue breastfeeding after returning to work [14, 16]. Availability of employer-sponsored childcare and flexible schedules can also increase an employee’s likelihood of success with breastfeeding . Therefore, more and more countries and organizations are introducing measures to support working mothers in reaching their breastfeeding goals , thus, enabling mothers to better combine their work requirements and their infant feeding goals.
While there is an emerging body of evidence supporting the positive influence of workplace lactation programs on breastfeeding outcomes [14,15,16, 19], there is a lack of literature on the mechanisms underlying those interventions. An understanding of these mechanisms is crucial in learning how to operationalize, implement and disseminate robust and effective lactation programs. Systematic reviews focus on the outcome and the level of outcome, thus on statistical inferences, but do not investigate the underlying mechanisms or context of the intervention leading to those outcomes. However, in order to find how interventions work in different contexts, statistical inferences are insufficient. Disentangling the underlying mechanisms linking intervention, context and outcome are needed to support the policymaking and implementation processes under ‘real world’ conditions. Thus, in addition to probability considerations, plausibility and adequacy considerations  need to be taken into account in order to understand how workplace-based breastfeeding interventions actually work.
Given the need for an approach that accounts for context, the objective of this study was to follow a realist approach to better understand how worksite related breastfeeding programs work across different contexts. We followed the realist review approach as it does not focus on making statements about the strength of quantitative vs. qualitative study designs but rather it integrates and values the different perspectives offered by them and enable the researcher to unravel and understand underlying pathways. Furthermore, workplace breastfeeding interventions meet the seven criteria of complex service interventions that can best be examined through the lens of a realist review  (Table 1).
In order to inform policy makers and employers about workplace breastfeeding interventions, the specific questions we aimed to answer though this realist review were: 1) How do breastfeeding interventions at the workplace work?, 2) Who benefits the most from such interventions across different contexts?, and 3) What are important contextual factors which determine whether different mechanisms produce their intended breastfeeding outcomes?
A protocol was written and made publicly available a priori at https://osf.io/phndm/. Due to time limitations, grey literature searches as well as citation chaining as described in the protocol were not conducted.
Search methods and criteria for identification of studies
The search of the bibliographic databases was conducted by a medical research librarian. Controlled vocabulary and keywords for the two concepts “breastfeeding” and “workplace” were used for the search of the bibliographic databases in order to achieve high specificity (Table 2). In databases without subject indexing, we achieved high specificity by searching for the concepts of breastfeeding and workplace in titles and author-provided keywords. The Medline search is provided in Table 3; the remaining searches are provided in Additional file 1.
The results from the search of all bibliographic databases were deduplicated in EndNote X9 and imported to Covidence systematic review software (Veritas Health Innovation, Melbourne, Australia. Available at www.covidence.org). Both software packages were used in the versions licensed at Yale University.
In order to be included, the publications must have described interventions that aimed to or could be expected to improve the breastfeeding behavior of working mothers and that were initiated by the employer, its representative, an employer-like persona or the work supervisor of the parent(s). Furthermore, the study must have reported on breastfeeding outcomes (quantitative or qualitative) and the workplace must have been clearly defined (either real or virtual space). Any data that described breastfeeding behavior were considered as breastfeeding outcomes. Therefore, studies reporting on quantitative breastfeeding outcomes (e.g. exclusive breastfeeding rate, exclusive breastfeeding duration, breastfeeding cessation, duration of any breastfeeding) as well as on qualitative breastfeeding outcomes were included. No date limit for publications nor limitation on types of data collected in the study (qualitative vs. quantitative data) were applied as inclusion or exclusion criteria.
Publications that only focused on maternity leave and that were not published in English, Spanish, Portuguese or German were excluded. Publications only focusing on maternity leave interventions were excluded because the review’s focus is workplace breastfeeding interventions that can be fully influenced by the employer. Maternity leave interventions are often regulated, at least to some extend by governments, and are thus, not under the sole control of the employer. Publications that were published in languages other than English, Spanish, Portuguese or German are listed in a separate supplementary table (Additional file 2). Literature reviews were excluded from the analysis.
The inclusion criteria as well as the maternity leave exclusion criteria were applied to the title-abstract screening stage. Articles initially selected for full-text screening were screened in detail for all inclusion and exclusion criteria. Exclusions at the full-text screening stage were grouped into following reasons: 1) intervention was not initiated by the employer, 2) breastfeeding outcomes not reported, 3) article focused on maternity leave, 4) article not published in English, Spanish, Portuguese or German, and 5) other reasons. All screening rounds were conducted by two reviewers following a consensus approach (KL and VT). Discrepancies were resolved through discussion and consultation with a third reviewer (RPE).
Non-peer-reviewed documents (e.g., conference papers, press releases, etc.) were not included. When such documents were retrieved in the database searches, the document’s authors were contacted for more information when deemed necessary. Dissertations were handled as peer-reviewed articles and authors were not contacted.
Goal of the data extraction was to find context-mechanism-outcome (CMO) patterns that can potentially explain the relationship between the intervention and the outcome by understanding the underlying mechanism in the context in which the intervention takes place. Focusing the data extraction on contexts, mechanisms and outcomes is important to identify reasons behind program successes or failures instead of just identifying successful and unsuccessful interventions . Data extraction was conducted by the two reviewers. The data points extracted from peer-reviewed articles were: year of publication, type of study/publication, country, implementation (type, components/activities and approach), context (full-/part-time employment, type of work position, length of maternity leave, etc.), sample size, implementation period, intervention population and implementation outcomes (acceptability, adaptation, appropriateness, cost, feasibility, fidelity, penetration and sustainability). Additionally, breastfeeding outcomes were extracted to better understand the influence of the intervention on breastfeeding outcomes.
For the development of a CMO framework, we defined the intervention types, intervention category, context categories as well as the breastfeeding outcome for each included study. The CMO framework and findings were summarized and discussed in a narrative synthesis.
Description of articles found through bibliographic search
The bibliographic database search yielded a total of 4879 possible documents. After removing a total of 1522 duplicates, 3357 citations were screened at the title-abstract phase in Covidence. From these 3357 citations, 156 were eligible for full-text screening. Separately, the search on Open Access Theses and Dissertations (OATD) resulted in a total of 106 possible documents. Because of technical issues with the exportation of search results, the 106 documents from OATD were handled outside of Covidence during the title-abstract screening, thus, only one reviewer screened the OATD search results. A total of 10 OATD documents were found to be eligible for the full text screening. After removing 6 documents that had already been screened in Covidence as a result of the other searches, 4 OATD documents were imported into Covidence for the full-text screening. This led to a total of 160 articles that were eligible for the full-text screening which was conducted by two reviewers. At the full-text screening phase a total of 123 articles were excluded, leaving 37 articles for analysis. Articles were excluded for the following reasons: intervention was not initiated by the employer (32 articles), no report of breastfeeding outcomes (49 articles), not published in English, Spanish, Portuguese or German (4 articles) or for other reasons (38 articles). Subcategories under “other reasons” included articles which could not be delivered via interlibrary loan (10 articles), literature reviews (7 articles) and duplications discovered during full text screening (2 articles). Only one reason for exclusion could be recorded in Covidence. An overview of the screening process is depicted in Fig. 1.
The 37 articles that were included in the realist analysis came from 11 countries. The majority of publications were from studies conducted in the United States of America (19 articles [22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,37,38,39,40];). The other publications came from studies in Taiwan (5 articles [41,42,43,44,45];), Brazil (4 articles [46,47,48,49];), Thailand (2 articles [50, 51];), Australia , China , Ethiopia , Indonesia , Mexico , Spain  and Turkey  (each 1 article). The 37 articles resulted from 33 single studies published over a period of 35 years; from 1985 to 2020. An overview of the included studies is given in Tables 4, 5, 6, 7, 8 and 9.
The intervention sample in all but one study, was conformed by employed women. Sahip and Turan  described the effects of a workplace health program for expectant fathers in Turkey. The intervention was delivered by specially trained workplace physicians and consisted of six 3–4 h sections: 1) health during pregnancy, 2a) pregnancy nutrition, 2b) birth, 3) communication techniques, 4) infant health care and feeding, 5) fatherhood, and 6) family health after birth. Children of fathers in the education group had 2.38 times the odds to be breastfed within the first hour after birth than children of fathers in the control group (95% confidence interval (CI): 1.24–4.61). Also, children of fathers in the education group had 3.44 (95% CI: 1.74–6.82) times the odds for exclusive breastfeeding at 3 months, 2.64 (95% CI: 1.36–5.09) times the odds for any breastfeeding at 9 months and 0.19 (95% CI: 0.09–0.37) times the odds for supplementary feeding before 6 months compared to children of fathers in the control group.
To better understand how workplace breastfeeding interventions work and how their influence on breastfeeding outcomes differs in different contexts, we categorized the interventions described in the analyzed articles into 4 types of intervention and 15 intervention categories (Table 10). To develop a CMO framework (Fig. 2), we analyzed the outcomes per intervention category. We concentrated our analysis on the outcomes on changed breastfeeding behavior as well as changes in perceived workplace breastfeeding culture (e.g., how common breastfeeding at the workplace is), manager/supervisor support, co-worker support and in the physical environment. It is to mention, that workplace breastfeeding outcomes can also lead to additional outcomes that were out of scope of this review such as job satisfaction [22, 31].
Our analysis revealed three potential mechanisms or factors that might explain how workplace interventions influence breastfeeding habits at the workplace: 1) having more time to breastfeed during work, 2) awareness of the intervention among mothers, supervisors and co-workers and 3) change in culture, management/supervisor support, co-worker support and/or physical environment. Having more time to breastfeed can be directly achieved for example by providing lactation breaks or flexible working hours or indirectly for example by changing the physical environment (e.g., providing lactation rooms [43, 54]) or co-worker support (e.g., by raising the understanding of co-worker through a communication strategy such that the co-worker support flexible work schedule). The mechanism of awareness about the intervention acts directly on the mother as well as indirectly through raising awareness of others; e.g. supervisors and co-workers who can then direct the mother to the lactation program. As long as the mother is not aware of the intervention, she cannot use it, and thus, her breastfeeding habit at the workplace will not change due to the intervention [25, 43, 44]. Supervisor awareness was also important in order to be able to advise their pregnant employees of corporate lactation programs. Therefore, changes in culture, management/supervisor support, co-worker support and/or physical environment are mechanisms and associated with changes in breastfeeding habits of employed mothers [23, 31, 33, 35, 36, 38, 41, 42].
The analysis of outcomes based on their intervention category also led to the identification of important contextual factors. The context in which the intervention is implemented determines whether it is sufficient to affect breastfeeding outcomes. We identified the following contexts: breastfeeding−/family-friendly business designations [32, 41], distance between workplace and infant [50, 53, 54], flexibility of work schedule/workload , marital status , maternal education level [24, 31, 57], maternal health conditions , number of offered lactation services [26, 28, 34], parity , race/ethnicity [24, 26], shift work [29, 40, 42,43,44], time of registration to program [26, 34], type of employment (full-time vs. part-time) , type of salary (fixed vs. hourly) [24, 39], type of workplace [24, 42,43,44]. As an example of how different work-related contexts require different implementation mechanisms, or, lead to different outcomes for similar interventions, we will concentrate on the context of distance between workplace and infant as well as the contexts of flexibility of work schedule/workload, shift work and type of workplace.
The sole implementation of a workplace breastfeeding intervention was not always sufficient to cause a change in breastfeeding habits at the workplace. We found that a large distance between the workplace and the location of the infant as well as commute times are a major barrier for continued breastfeeding after returning to work. Mothers whose children are living far apart from them described the large distance between them and their infants as a reason to stop breastfeeding after return to work; despite the presence of lactation break policies [50, 53], lactation facilities  or even the offer of a drop-off service that brings expressed breastmilk to the local bus and van station from where the breastmilk is transported to rural areas, where the infant is living . Underlying reasons seem to be different: Mothers in Thailand report that they fear that their breastmilk will be spoiled during the long transportation and that grandmothers, who are caring for the infant, lack the knowledge how to handle frozen/expressed breastmilk , in China the legal provision of one-hour feeding break for working mothers of infants aged younger than 1 year is insufficient for mothers whose children are not near the workplace since the provision of lactation facilities is not legally required, thus, requiring mothers to travel to their infant to feed them . While the example in Thailand shows that mechanisms outside the work environment are influential, the example in China shows that the sole provision of time can be insufficient if the physical environment does not support breastfeeding.
Other contexts in which the sole implementation of breastfeeding interventions at the workplace are insufficient, are workplaces with a busy and/or inflexible work schedule, workplaces other than an office, and type of work such as shift work. Professions such as nurses or physicians have a work schedule that is often influenced by external factors which contributes to inconsistent scheduling. In such a context, the sole provisions of lactation breaks and lactation facilities are inefficient if mothers perceive their co-workers and supervisors as not supportive of them taking breastfeeding breaks . Inflexible environments (e.g., fabric/production workplaces) and workplaces without a specific office as well as shift work are also contexts in which the sole provision of lactation breaks and lactation facilities are insufficient. Mothers working in a clean room (a room that is maintained free of contaminants) in two Taiwanese manufacturing companies had lower breastfeeding rates than their female colleagues having an office space in the same company [42,43,44]. Tsai and colleagues found that office workers and non-shift workers used the lactation breaks and facilities available to them more often than workers of the clean room and shift workers. To be able to use the offered lactation breaks, clean room workers needed to fully change from their clean room suits into normal clothes and then dress back into their clean room suits. This may have left less time to pump, thus, making the available lactation break times too short and less effective for breastfeeding. Chen et al. found that among women who were aware of lactation breaks and facilities, office workers had showed a higher likelihood for continued breastfeeding after returning to work than clean room workers indicating that in this context, the awareness mechanism was not mediating the breastfeeding outcomes. Given the rigid work schedule of clean room and shift workers, it is more likely that among them the intervention of breastfeeding breaks and facilities may not increase the time available for breastmilk expression.
Performance bonuses for manufacturing workers may inhibit the activation of support from co-workers, and thus, the activation of the time-releasing mechanism needed for breastfeeding and expressing breastmilk. Performance bonuses for most Taiwanese manufacturer workers are based on group productivity and individual performance , thus, breastfeeding mothers working in the clean room dependent on their co-workers to take over their duties while they are breastfeeding in order to keep their own performance bonuses and the ones of their co-workers, which may be unrealistic. Therefore, in order to increase breastfeeding rates among manufacturing and shift workers, workplace lactation interventions need to involve the network of co-workers to indirectly enable breastfeeding workers to use lactation breaks and facilities.
To our knowledge, this is the first realist review identifying potential mechanisms underlying the impact of workplace breastfeeding interventions as well as the effect of different contexts on the influence on breastfeeding outcomes of such interventions. Using a realist review approach, we were able to integrate findings from a plethora of study designs including qualitative studies. An innovative aspect from our review is that we were able to develop a pragmatic context-mechanism-outcome (CMO) framework. This framework shows that contextual factors such as long distances between the workplace and the infant will hinder the influence of the intervention at improving breastfeeding outcomes among working mothers. Specifically, our CMO framework identified three mechanisms at work that need to be activated for an intervention to be effective: 1) the awareness of workers, supervisors and co-workers about the availability of entitlement to a given intervention, 2) changes in: perceived breastfeeding culture at the workplace, including manager/supervisor and co-workers support and adequate physical environments, and 3) having time to breastfeed or express breastmilk during work time.
Positive associations between workplace lactation support and interventions have been shown previously [11, 14,15,16,17, 19]. However, systematically understanding how such interventions work has been a major gap. Furthermore, examining how contexts mediate or moderate the influence of workplace breastfeeding interventions across different workforce groups had not been previously done, as far as we know. Our review is impactful because it provides this information at a time when an increasing number of women participate in the labor force [1, 2]. Our review indeed identified mechanisms that if properly taken into account when designing interventions may empower mothers to not have to decide between choosing the best nutrition for their infant or working, thus, helping close a major inequity gap affecting working women with infants globally.
While it is important to lessen breastfeeding inequalities between working and non-working mothers, it is as important to lessen these inequalities among working women. In the course of our analysis, we found that the studies represented a wide spectrum of maternal demographics including age, education level, race and ethnicity, income level, and marital status. Overall, higher breastfeeding rates and longer breastfeeding duration in the workplace were associated with higher maternal education [24, 25, 28, 31, 42,43,44, 54, 55], higher income levels [25, 28], being White [24,25,26] and being married or living with a partner [24, 28]. The included studies did not allow us to examine the underlying pathways that may have explained differences in implementation approaches as a result of differences in socioeconomic and demographic contexts because awareness and/or uptake of the interventions were seldomly examined as a function of the afore mention characteristics. Therefore, future research is needed to elucidate how best to tailor work-based breastfeeding interventions to different contexts.
The available data did also not allow us to determine underlying pathways which may explain differences in breastfeeding outcomes of work-based intervention as a function of type of employment (full-time vs. part-time employment). This is because the study authors did not examine awareness and/or uptake of the intervention as a function of the employment status which would be needed to be able to determine differences in awareness and/or uptake of the intervention among women with different employment status as pathway for the differences seen in breastfeeding outcomes among women with different employment status. One study showed a significant association between part-time employment and higher breastfeeding rates at 6 months while two other studies did not find significant associations [34, 39]. Possible explanations of these inconsistent findings are the heterogeneous use of the term “part-time” and the heterogenous group of part-time working mothers. For example, it is clear that the needs for breastfeeding support of a mother working 8 h a week are likely to be different from the needs of a mother working 40 h a week. However, it is unclear how the needs of a mother working 40 h a week would compare with the needs of a mother working 34 h a week, either as a four-day working week or distributed across all weekdays. Moving forward, instead of using unclear terms like “part-time” employment, future research should consider evaluating workplace breastfeeding interventions based on actual hours worked per day and days worked per week.
While this realist review integrated evidence from a plethora of study designs allowing for the examination of how workplace breastfeeding interventions work across various contexts and uncovering potential pathways for impact, it is not without limitations. Firstly, the review did not include studies that were solely focusing on maternity leave benefits. Rather, it focused on lactation interventions for mothers returning to the workplace. We made this decision because previous work has documented the positive impact of extended duration of maternity leave on breastfeeding outcomes [59, 60] and maternity leave policies are beyond the sole domain of the employers. Secondly, in order to bring focus to the review, we limited the search to studies reporting on breastfeeding outcomes. This limitation omitted publications reporting on other outcomes of workplace breastfeeding interventions such as job satisfaction or health costs for employers, employees and/or society. And lastly, as recommended for realist reviews, we used a purposive rather than a comprehensive screening strategy. Thus, it is possible that a relevant paper could have been available in the databases we searched, but was not retrieved by our queries, as we screened only those papers where the workplace context was explicit in either the title and author keywords or subject headings. To mitigate this risk, we searched in multiple subject-indexed databases, on the reasoning that a paper which was poorly indexed in Medline may have been better indexed in CINAHL or Global Health.
Because of time limitations, we did not conduct grey literature searches as well as citation chaining. It is possible that these omissions led to the introduction of biases. Nevertheless, we think that this is unlikely because the vast majority of grey literature about workplace breastfeeding interventions are technical guidelines on how to implement specific interventions such as lactation rooms , and do not report on breastfeeding outcomes, thus would not have passed the eligibility criteria for inclusion of the present review. Since we searched a plethora of databases, we are confident that our search picked up the vast majority of eligible publication, thus, we estimate the risk of bias introduction due to the missing citation chaining as minimal.
Our review strongly calls for more mixed methods work-based breastfeeding intervention research in low- and middle-income countries, that also includes the very large number of women working in the informal economy. Of the 37 included studies, only one study was conducted in a low-income country  as defined by the World Bank . This is unfortunate, as out of the approximately 7.7 billion people in the world in 2019, 6.5 billion people lived in low-and middle-income countries, and 670 millions lived in low-income countries . None of the included studies of this review focused solely on informal employment and the majority included only formally employed women. While formally employed mothers can be protected by laws and regulations, such as mandated maternity leave, informally employed women may need to depend on other mechanisms that support their informed decisions about infant feeding . Therefore, there is a profound inequity in the selection of settings where the work-based breastfeeding research has been conducted, as well as the type of employment included in those studies (formal vs. informal economy). This is unacceptable given the very high proportion of women employed in the informal sector in low- and middle-income countries . How the policy design and program implementation mechanisms need to differ for delivering effective work-related breastfeeding interventions targeting women employed in the informal vs. the formal economy, still need to be elucidated using qualitative and quantitative implementation research approaches.
Workplace breastfeeding interventions work through raising awareness among employees, supervisors and co-workers, changes in workplace breastfeeding culture, including knowledge, attitudes, and support from managers/supervisors and co-workers, and improvements in the physical environment, alongside with the time release needed by working mothers while at work for breastfeeding or extracting breastmilk. In order to better address breastfeeding inequities affecting working mothers, workplace breastfeeding interventions need to be tailored according to several contextual factors including socioeconomic and demographic characteristics of the mothers or end users. The evidence of this review clearly shows that workplace breastfeeding interventions cannot follow a one-size-fits-all approach, but rather should be tailored for the contextual factors underlying the different working conditions for mothers globally.
Availability of data and materials
Data sharing not applicable to this article as no datasets were generated or analyzed during the current study.
United Nations Women. Progress of the World's Women 2019–2020 - Families in a Changing World. 2019.
International Labour Office. In: Office IL, editor. World Employment and Social Outlook: Trends for Women 2018 – global snapshot. Geneva: International Labour Organization; 2018.
Bhan G, Surie A, Horwood C, Dobson R, Alfers L, Portela A, et al. Informal work and maternal and child health: a blind spot in public health and research. Bull World Health Organ. 2020;98(3):219–21. https://doi.org/10.2471/BLT.19.231258.
International Labour Office. Women and men in the informal economy: a statistical picture (third edition). Geneva: International Labour Organization; 2018.
Kramer MS, Aboud F, Mironova E, Vanilovich I, Platt RW, Matush L, et al. Breastfeeding and child cognitive development: new evidence from a large randomized trial. Arch Gen Psychiatry. 2008;65(5):578–84. https://doi.org/10.1001/archpsyc.65.5.578.
Horta BL, Victora CG. Long-term effects of breastfeeding: a systematic review. Geneva: World Health Organization; 2013.
Harder T, Bergmann R, Kallischnigg G, Plagemann A. Duration of breastfeeding and risk of overweight: a meta-analysis. Am J Epidemiol. 2005;162(5):397–403. https://doi.org/10.1093/aje/kwi222.
Victora CG, Bahl R, Barros AJ, Franca GV, Horton S, Krasevec J, et al. Breastfeeding in the 21st century: epidemiology, mechanisms, and lifelong effect. Lancet. 2016;387(10017):475–90. https://doi.org/10.1016/S0140-6736(15)01024-7.
UNICEF. Infant and young child feeding. 2014-2019. Available from: https://data.unicef.org/topic/nutrition/infant-and-young-child-feeding/. Accessed 1 Dec 2020.
WHO/UNICEF. Global nutrition targets 2025: breastfeeding policy brief (WHO/NMH/NHD/14.7). Geneva: World Health Organization; 2014.
Rollins NC, Bhandari N, Hajeebhoy N, Horton S, Lutter CK, Martines JC, et al. Why invest, and what it will take to improve breastfeeding practices? Lancet. 2016;387(10017):491–504. https://doi.org/10.1016/S0140-6736(15)01044-2.
Fernandez-Canadas Morillo A, Duran Duque M, Hernandez Lopez AB, Muriel Miguel C, Martinez Rodriguez B, Oscoz Prim A, et al. A comparison of factors associated with cessation of exclusive breastfeeding at 3 and 6 months. Breastfeed Med. 2017;12(7):430–5. https://doi.org/10.1089/bfm.2017.0045.
Mandal B, Roe BE, Fein SB. The differential effects of full-time and part-time work status on breastfeeding. Health Policy. 2010;97(1):79–86. https://doi.org/10.1016/j.healthpol.2010.03.006.
Kim JH, Shin JC, Donovan SM. Effectiveness of workplace lactation interventions on breastfeeding outcomes in the United States: an updated systematic review. J Hum Lact. 2019;35(1):100–13. https://doi.org/10.1177/0890334418765464.
Tang X, Patterson P, MacKenzie-Shalders K, van Herwerden LA, Bishop J, Rathbone E, Honeyman D, Reidlinger PD. Workplace programmes for supporting breast-feeding: a systematic review and meta-analysis. Public Health Nutr. 2020:1–13. https://doi.org/10.1017/S1368980020004012.
Hilliard ED. A review of worksite lactation accommodations. Workplace Health Safety. 2017;65(1):33–44. https://doi.org/10.1177/2165079916666547.
Jacknowitz A. The role of workplace characteristics in breastfeeding practices. Women Health. 2008;47(2):87–111. https://doi.org/10.1080/03630240802092357.
Atabay E, Moreno G, Nandi A, Kranz G, Vincent I, Assi T-M, et al. Facilitating working mothers' ability to breastfeed: global trends in guaranteeing breastfeeding breaks at work, 1995-2014. J Hum Lact. 2014;31(1):81–8. https://doi.org/10.1177/0890334414554806.
Dinour LM, Szaro JM. Employer-based programs to support breastfeeding among working mothers: a systematic review. Breastfeed Med. 2017;12(101260777):131–41. https://doi.org/10.1089/bfm.2016.0182.
Victora CG, Habicht JP, Bryce J. Evidence-based public health: moving beyond randomized trials. Am J Public Health. 2004;94(3):400–5. https://doi.org/10.2105/AJPH.94.3.400.
Pawson R, Greenhalgh T, Harvey G, Walshe K. Realist review--a new method of systematic review designed for complex policy interventions. J Health Serv Res Policy. 2005;10(Suppl 1):21–34. https://doi.org/10.1258/1355819054308530.
Waite WM, Christakis D. Relationship of maternal perceptions of workplace breastfeeding support and job satisfaction. Breastfeed Med. 2015;10(4):222–7. https://doi.org/10.1089/bfm.2014.0151.
Hilliard ED. The association between workplace lactation accommodations and corporate lactation programs and breastfeeding duration in working women. Ann Arbor: North Dakota State University; 2018.
Paddock JD. Breastfeeding patterns among employees at a land Grant University. Workplace Health Saf. 2017;65(12):580–94. https://doi.org/10.1177/2165079917701138.
Dabritz HA, Hinton BG, Babb J. Evaluation of lactation support in the workplace or school environment on 6-month breastfeeding outcomes in Yolo County, California. J Hum Lact. 2009;25(2):182–93. https://doi.org/10.1177/0890334408328222.
Balkam JAJ, Cadwell K, Fein SB. Effect of components of a workplace lactation program on breastfeeding duration among employees of a public-sector employer. Matern Child Health J. 2011;15(5):677–83. https://doi.org/10.1007/s10995-010-0620-9.
Spatz DL, Kim GS, Froh EB. Outcomes of a hospital-based employee lactation program. Breastfeed Med. 2014;9(10):510–4. https://doi.org/10.1089/bfm.2014.0058.
Kozhimannil KB, Jou J, Gjerdingen DK, McGovern PM. Access to workplace accommodations to support breastfeeding after passage of the affordable care act. Women's Health Issues. 2016;26(1):6–13. https://doi.org/10.1016/j.whi.2015.08.002.
Cohen R, Mrtek MB. The impact of two corporate lactation programs on the incidence and duration of breast-feeding by employed mothers. Am J Health Promot. 1994;8(6):436–41. https://doi.org/10.4278/0890-1171-8.6.436.
Wambach K, Britt E. Breastfeeding support experiences of registered nurses in a large Children's hospital system. J Obstet Gynecol Neonatal Nurs. 2018;47(5):632–40. https://doi.org/10.1016/j.jogn.2018.07.007.
Scott VC, Taylor YJ, Basquin C, Venkitsubramanian K. Impact of key workplace breastfeeding support characteristics on job satisfaction, breastfeeding duration, and exclusive breastfeeding among health care employees. Breastfeed Med. 2019;14(6):416–23. https://doi.org/10.1089/bfm.2018.0202.
Hilliard E, Brunt A. Impact of an infant friendly business designation. Health Promot Pract. 2020;21(4):642–53. https://doi.org/10.1177/1524839918807442.
Bai Y, Wunderlich SM. Lactation accommodation in the workplace and duration of exclusive breastfeeding. J Midwifery Women's Health. 2013;58(6):690–6. https://doi.org/10.1111/jmwh.12072.
Johnston Balkam JA. A workplace lactation program: evaluation and impact. Ann Arbor: Union Institute and University; 2006.
Payton CA. An examination of large employer workplace lactation support: organizational support and employee perceptions. Ann Arbor: Thomas Jefferson University; 2018.
Dodgson JE, Duckett L. Breastfeeding in the workplace. Building a support program for nursing mothers. AAOHN J. 1997;45(6):290–8. https://doi.org/10.1177/216507999704500604.
Katcher AL, Lanese MG. Breast-feeding by employed mothers: a reasonable accommodation in the work place. Pediatrics. 1985;75(4):644–7.
Froh EB, Spatz DL. Navigating return to work and breastfeeding in a hospital with a comprehensive employee lactation program. J Hum Lact. 2016;32(4):689–94. https://doi.org/10.1177/0890334416663475.
Ortiz J, McGilligan K, Kelly P. Duration of breast milk expression among working mothers enrolled in an employer-sponsored lactation program. Pediatr Nurs. 2004;30(2):111–9.
Jacknowitz A. An investigation of the factors influencing breastfeeding patterns. Ann Arbor: The RAND Graduate School; 2004.
Lin W-T, Hsieh C-C, Chang F-C, Wang C-L, Lin C-I, Chuang H-Y. Effects of workplaces receiving “accreditation of health workplaces” on breastfeeding promotion, parental leave, and gender equality. J Occup Health. 2020;62(1):e12140. https://doi.org/10.1002/1348-9585.12140.
Tsai S-Y. Impact of a breastfeeding-friendly workplace on an employed mother's intention to continue breastfeeding after returning to work. Breastfeed Med. 2013;8(101260777):210–6. https://doi.org/10.1089/bfm.2012.0119.
Tsai S-Y. Employee perception of breastfeeding-friendly support and benefits of breastfeeding as a predictor of intention to use breast-pumping breaks after returning to work among employed mothers. Breastfeed Med. 2014;9(1):16–23. https://doi.org/10.1089/bfm.2013.0082.
Chen YC, Wu Y-C, Chie W-C. Effects of work-related factors on the breastfeeding behavior of working mothers in a Taiwanese semiconductor manufacturer: a cross-sectional survey. BMC Public Health. 2006;6(100968562):160. https://doi.org/10.1186/1471-2458-6-160.
Lee CC, Chiou ST, Chen LC, Chien LY. Breastfeeding-friendly environmental factors and continuing breastfeeding until 6 months postpartum: 2008-2011 National Surveys in Taiwan. Birth-Issues Perinat Care. 2015;42(3):242–8. https://doi.org/10.1111/birt.12170.
Brasileiro AA, Ambrosano GMB, Marba STM, Possobon RF. Breastfeeding among children of women workers. Revista de saude publica. 2012;46(4):642–8. https://doi.org/10.1590/S0034-89102012005000053.
Santos TR, Sebastião LT, Buccini G. Práticas de amamentação entre mulheres trabalhadoras com creche no local de trabalho. Distúrb comun. 2018;30(2):288–97. https://doi.org/10.23925/2176-2724.2018v30i2p-288-297.
Rea MF, Venancio SI, Batista LE, dos Santos RG, Greiner T. Possibilities and limitations of breast-feeding among formally employed women. Revista de saude publica. 1997;31(2):149–56. https://doi.org/10.1590/S0034-89101997000200008.
Osis MJD, Duarte GA, Padua KS, Hardy E, Sandoval LEM, Bento SF. Exclusive breastfeeding among working women with free daycare available at workplace. Revista de saude publica. 2004;38(2):172–9. https://doi.org/10.1590/S0034-89102004000200004.
Butudom A. Behavior outcomes of breastfeeding-friendly policies among mothers working in a factory in Thailand. Ann Arbor: University of Illinois at Chicago; 2018.
Yimyam S, Hanpa W. Developing a workplace breast feeding support model for employed lactating mothers. Midwifery. 2014;30(6):720–4. https://doi.org/10.1016/j.midw.2014.01.007.
Weber D, Janson A, Nolan M, Wen LM, Rissel C. Female employees' perceptions of organisational support for breastfeeding at work: findings from an Australian health service workplace. Int Breastfeed J. 2011;6(101251562):19. https://doi.org/10.1186/1746-4358-6-19.
Chen J, Xin T, Gaoshan J, Li Q, Zou K, Tan S, et al. The association between work related factors and breastfeeding practices among Chinese working mothers: a mixed-method approach. Int Breastfeed J. 2019;14(101251562):28. https://doi.org/10.1186/s13006-019-0223-z.
Kebede T, Woldemichael K, Jarso H, Bekele BB. Exclusive breastfeeding cessation and associated factors among employed mothers in Dukem town, Central Ethiopia. Int Breastfeed J. 2020;15(1):10.
Basrowi RW, Sulistomo AB, Adi NP, Vandenplas Y. Benefits of a dedicated breastfeeding facility and support program for exclusive breastfeeding among Workers in Indonesia. Pediatr Gastroenterol Hepatol Nutr. 2015;18(2):94–9. https://doi.org/10.5223/pghn.2015.18.2.94.
Ibarra-Ortega A, Vasquez-Garibay EM, Larrosa-Haro A, Castro-Albarran J, Vizmanos-Lamotte B. Using a lactation room at the workplace is associated with longer breastfeeding duration in working mothers. Nutricion hospitalaria. 2020;a2e:9100365.
Cervera-Gasch A, Mena-Tudela D, Leon-Larios F, Felip-Galvan N, Rochdi-Lahniche S, Andreu-Pejo L, et al. Female employees' perception of breastfeeding support in the workplace, public universities in Spain: a multicentric comparative study. Int J Environ Res Public Health. 2020;17(17):6402.
Sahip Y, Turan JM. Education for expectant fathers in workplaces in Turkey. J Biosoc Sci. 2007;39(6):843–60. https://doi.org/10.1017/S0021932007002088.
Staehelin K, Bertea PC, Stutz EZ. Length of maternity leave and health of mother and child--a review. Int J Public Health. 2007;52(4):202–9. https://doi.org/10.1007/s00038-007-5122-1.
Steurer LM. maternity leave length and workplace policies' impact on the sustainment of breastfeeding: global perspectives. Public Health Nurs (Boston, Mass). 2017;34(3):286–94.
Secretaría de Salud [Mexican Ministry of Health], Instituto Mexicano del Seguro Social [Mexican Social Security Institute], Fondo de las Naciones Unidas para la Infancia [United Nations Children's Fund (UNICEF)] and Secretaría del Trabajo y Previsión Social [MexicanMinistry of Labor and Social Security]. Guía Para La Instalación Y Funcionamiento De Salas De Lactancia. 2021. https://www.gob.mx/stps/documentos/guia-para-la-instalacion-y-funcionamiento-de-salas-de-lactancia?idiom=es. Accessed 20 Apr 2021.
The World Bank. The World Bank Country and Lending Groups. 2020. https://datahelpdesk.worldbank.org/knowledgebase/articles/906519-world-bank-country-and-lending-groups. Accessed 15 June 2021.
World Development Indicators. 2019. Available from: https://databank.worldbank.org/reports.aspx?source=2&series=SP.POP.TOTL&country=. Accessed 3 Feb 2021.
International Labour Organization. Statistics on the informal economy. 2019. Available from: https://ilostat.ilo.org/topics/informality/#. Accessed 3 Feb 2021.
We gratefully acknowledge the support of the Family Larsson-Rosenquist Foundation.
KL has received a pre-doctoral fellowship grant from the Family Larsson-Rosenquist Foundation. This publication was supported by the Cooperative Agreement Number 5 U48DP006380–02-00 funded by the Centers for Disease Control and Prevention, Prevention Research Center Program (PI: Rafael Pérez-Escamilla). Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the Centers for Disease Control and Prevention or the Department of Health and Human Services. The funders had no role in the published work.
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Litwan, K., Tran, V., Nyhan, K. et al. How do breastfeeding workplace interventions work?: a realist review. Int J Equity Health 20, 148 (2021). https://doi.org/10.1186/s12939-021-01490-7