Prevalence of exclusive breastfeeding practice and its association with maternal employment in Ethiopia: a systematic review and meta-analysis

Background Exclusive breastfeeding is defined as the practice of providing only breast milk for an infant for the first 6 months of life without the addition of any other food or water, except for vitamins, mineral supplements, and medicines. Findings are inconsistent regarding the prevalence of exclusive breastfeeding in Ethiopia. Full-time maternal employment is an important factor contributing to the low rates of practice of exclusive breastfeeding. Empowering women to exclusively breastfeed, by enacting 6 months’ mandatory paid maternity leave can increase the rate of exclusive breastfeeding in the first 6 months of life up to 50%. The purpose of this review was to estimate the pooled prevalence of exclusive breastfeeding and its association with full-time maternal employment in the first 6 months of life for infants in the context of Ethiopia. Methods The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline was used in this systematic review and meta-analysis. All observational studies reporting the prevalence of exclusive breastfeeding and its association with maternal employment in Ethiopia were considered. The search was conducted from 6 November 2020 to 31 December 2020 and all papers published in the English language from 1 January 2015 to 31 December 2020 were included in this review. Results Forty-five studies were included in the final analysis after reviewing 751 studies in this meta-analysis yielding the pooled prevalence of EBF 60.42% (95% CI 55.81, 65.02) at 6 months in Ethiopia. Those full-time employed mothers in the first 6 months were 57% less likely to practice exclusive breastfeeding in comparison to mothers not in paid employment in Ethiopia (OR 0.43; 95% CI 0.31, 0.61). Conclusions Full-time maternal employment was negatively associated with the practice of exclusive breastfeeding in comparison to unemployed mothers. The prevalence of exclusive breastfeeding in Ethiopia is low in comparison to the global recommendation. The Ethiopian government should implement policies that empower women. The governmental and non-governmental organizations should create a conducive environment for mothers to practice exclusive breastfeeding in the workplace. Supplementary Information The online version contains supplementary material available at 10.1186/s13006-021-00432-x.


Background
Breastfeeding is a core part of the 2030 agenda for Sustainable Development Goals (SDG) which is linked with many targets of the SDGs, especially with the third target which deals with ending preventable maternal and neonatal death [1]. Exclusive breastfeeding (EBF) is defined as the practice of providing only breast milk for an infant for the first 6 months of life without the addition of any other food or water, except for vitamins, mineral supplements, and medicines [2]. Currently, the global prevalence of EBF for infants aged zero to 6 months is only 38%, which is far behind to making EBF during the first 6 months of life the norm for infant feeding. Researchers indicate that 11.6% of mortality in children under 5 years of age was contributed by non-exclusive breastfeeding [3,4].
In 2012, the World Health Assembly endorsed a comprehensive implementation plan on maternal, infant, and young child nutrition with six specified global nutrition targets for 2025.The fifth target aims to increase the rate of EBF in the first 6 months up to 50% and only 31 of 194 countries were practicing according to this endorsement in 2018 [5,6]. According to the 2015 UNICEF report, the worldwide rate of EBF is low compared to the 2012 World Health Assembly endorsement, with the following EBF rates reported in western and central Africa (25%), East Asia and Pacific (30%), South Asia (47%), Central America and the Caribbean (32%), eastern and southern Asia (51%), least developed countries (46%) and worldwide (38%) respectively [7]. Between 1985 and 1995, global rates of EBF were raised by 2.4%, however, 25 countries raised their rates of EBF by 20% or more after 1995 [8,9]. Similarly, Cambodia and Malawi showed an increment of EBF from 11 to 74% and 3 to 71% respectively between 1992 and 2010 [10].
Another study conducted in 13 western African countries and sub-Saharan countries showed the prevalence of EBF for infants under 6 months of age ranges from 13.0% in Côte d'Ivoire to 58.0% in Togo and 45.2% in sub-Saharan countries respectively [11,12]. Besides this, according to the 2016 Ethiopian demographic health survey (EDHS), the prevalence of EBF for infants under 6 months was 58% [13]. According to a study conducted in Latin America and the Caribbean countries, Bangladesh and others, EBF for the first 3 months of life can prevent 55% of infant deaths related to diarrheal disease and acute respiratory infection [14][15][16][17].
Similarly, a study conducted in Ghana and Ethiopia showed that the risk of neonatal death was higher for infants with non-exclusive breastfeeding [18,19]. Inadequate rates of EBF result from different factors such as inadequate maternity leave (shorter paid maternity leave which enforces mother to return to work early before 6 months of infant's age) [20,21], workplace policies that don't support a woman's ability to breastfeed when she returns to work [22], and caregiver and societal belief which favor non-exclusive breastfeeding before 6 months of age of infants [23][24][25]. Some evidence showed that empowering women to exclusively breastfeed, by enacting 6 months' mandatory paid maternity leave, as well as policies that encourage women to breastfeed in the workplace and public can increase the rate of EBF in the first 6 months of life up to 50% [26,27]. Another piece of evidence showed that longer paid maternity leave helps the mothers to practice EBF effectively [28].
The Indian and Vietnamese governments have been successfully protecting EBF by the implementation of supportive policies that guarantee mothers get 6 months of paid maternity leave and by prohibiting the use of marketing breast milk substitutes with legislation before 6 months of infant's age [29,30]. Whereas, contrary to the World Health Organization's recommendation, the Constitution of Ethiopia and Labour Proclamation recommends employed mothers get fully paid maternity leave of 120 working days only (30 days antenatal and 90 days postnatal leave) and the proclamation doesn't support women to breastfeed in the workplace and the public area after they return to work [31].
In Ethiopia, many studies have been conducted to determine the prevalence of EBF and its associated factors between 1 January 2015 to 31 December 2020. These studies showed that different maternal and health service-related factors influenced the practice of EBF in addition to maternal employment [32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49][50]. We selected maternal employment from other factors to investigate its effect on the practice of EBF because of the following reasons: The first reason is that maternal employment was an important factor, which ultimately influences EBF, especially in our country where the Labour Proclamation recommends only 120 working days paid maternity leave which forces mothers to return quickly to their job before 6 months after delivery. The second reason is that the primary studies conducted previously found inconsistent evidence regarding the effect of maternal employment on EBF. Most showed a negative association of maternal employment with EBF with the presence of great variation among them [32][33][34][35][36][37][40][41][42][43][44][45][46][47][48][49][50]. Only two studies [38,39] showed a positive association of maternal employment with EBF.
As far as we are aware, even if there were small and fragmented studies, there is no published systematic review and meta-analysis in Ethiopia, which has investigated the pooled prevalence of EBF and its association with maternal employment using primary studies published between 1 January 2015 to 31 December 2020, which is in line with the third target of the SDGs by 2030. The objective of this systematic review and metaanalysis was to estimate the pooled prevalence of EBF and its association with full-time maternal employment in the context of Ethiopia. This systematic review will generate concrete evidence that helps policymakers and program planners to make an appropriate intervention and remold some policies concerning maternal employment and the practice of EBF for the benefit of mothers and infants in Ethiopia.

Methods
The current systematic review and meta-analysis was reported by using the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) [51] guideline to determine the pooled prevalence of EBF practice and its association with maternal employment.

Research question / hypothesis according to CoCoPop (condition, context, population) criteria
What is the prevalence of Exclusive breastfeeding (EBF) and its association with full-time maternal employment among mothers with infants less than 5 years of age in the context of Ethiopia?

Searching strategies
The international databases, including PubMed, Google Scholar, Science Direct, and Cochrane library, Scopus, CINAHL, and Web of Science were systematically searched. The search was conducted using the following keywords: "Prevalence", "Exclusive Breastfeeding", "Feeding, Breast", "Breastfeeding", "Breastfeeding, exclusive", "Factors", "Determinants", "Maternal employment", and Ethiopia. The search terms were used separately and in combination using Boolean operators including "OR" or "AND" and the search was conducted from 6 November 2020 to 31 December 2020. All papers published until 31 December 2020 were included in this review.

Eligibility criteria Inclusion criteria
Study area: Only studies conducted in Ethiopia.
Publication condition: Articles published in peerreviewed journals.
Study design: All observational study designs (Crosssectional, case-control, and cohort) reporting the prevalence of EBF or associations between maternal employments with EBF were considered.
The outcome of interests: Studies reported data on the prevalence of EBF or the association between EBF and maternal employment were considered.
Language: Articles reported in the English language were considered.
Publication year: only studies published from 1 January 2015 to 31 December 2020 were considered.

Exclusion criteria
Study conducted in women with HIV / AIDS, preterm newborn, and newborn in an intensive care unit Study with abstracts without full text and qualitative studies, symposium / conference and case reports. Articles, which were not fully accessed, after at least two email contacts with the primary author, were excluded and experimental, intervention, and review articles were excluded.

Outcome measurement
This systematic review has two main outcomes. The first one is the prevalence of EBF practice, which is defined as the practice of providing only breast milk for an infant for the first 6 months of life without the addition of any other food or water, except for vitamins, mineral supplements, and medicines [2]. The prevalence was calculated from each primary study by dividing the number of women breastfeeding exclusively by the total number of all women who had participated in the study multiplied by 100. The second outcome was to investigate the association between full-time maternal employment and the practice of EBF for which we calculated the Ln odds ratio (Ln OR) meaning the base e logarithm or (loge (OR)) results of the primary studies that examined the relationship between maternal employment and practice EBF.

Data extraction
Two authors (GE and YM) independently assessed the quality of each original study and any disagreements at the time of data abstraction were resolved through discussion and consensus. Data were extracted using a standardized data extraction format, which was adopted from the Joanna Briggs Institute (JBI) data extraction format [52]. The following data such as primary authors, publication year, and study area, study design, sample size, the prevalence of exclusive breastfeeding, the quality score of each study, the association between maternal employment and EBF with their respective odds ratio (OR), characteristics of study participants and response rate were extracted.

Quality assessment
The Joanna Briggs Institute Critical Appraisal tools for use in JBI Systematic Reviews (JBI-MAStARI) was used for critical appraisal of studies [53]. The tool has eight major criteria for critical appraisal of each primary study. Accordingly, primary studies with a score of equal or greater than 50% and above were included in the metaanalysis research.

Statistical analysis
Data were extracted in Microsoft Excel format and analysis was done using STATA version 11 software. We calculated the standard error for each original study using the binomial distribution format. Heterogeneity regarding reported prevalence was assessed by computing p-values for Cochrane Q-statistics and I 2 tests. I 2 test statistics of 25, 50, and 75% were declared as low, moderate, and high heterogeneity respectively [54]. The test statistic showed that there was significant heterogeneity among the included studies (98.8%; p = < 0.001), and because of this a random-effects meta-analysis model was used to estimate the DerSimonian and Laird pooled effect. To minimize the random variations between primary studies, subgroup analysis was done by region in Ethiopia, sample size, and publication year of primary studies. Besides the above, univariate meta-regression was conducted by considering the same three subgroups as covariates to identify the possible sources of heterogeneity, but none was found to be statistically significant.
We checked publication bias by funnel plot subjectively and Egger's and Begg's tests objectively; a p-value of less than 0.05 was used to declare the statistical   significance of publication bias [55]. For this metaanalysis pooled prevalence of EBF with a 95% confidence interval (CI) was presented with the forest plot. Accordingly, the size of each box corresponds to the weight of the study, the crossed line refers to a 95% confidence interval of the study, and the Ln OR which is the base e logarithm was applied to examine the association between maternal employment and EBF in Ethiopia.

Results
As described in Fig. 1    basis of their titles. The remaining 252 studies were screened by their abstracts yielding an additional 189 studies to be excluded. Moreover, 63 full-text articles were assessed for eligibility based on the preset inclusion criteria, and from these, 18 articles were excluded due to the inclusion criteria. Finally, 45 studies fulfilled the inclusion criteria and were included in the systematic review and meta-analysis. As shown in Table 1, all 45 of these studies were published between 1 January 2015 to 31 December 2020. Regarding study design most 42 of the studies are crosssectional study designs. The sample size of the studies ranges from 226 to 5227. The lowest prevalence (29.29%) of EBF was observed in a study conducted in Addis Ababa, Ethiopia [72] whereas the highest prevalence (87.84%) was observed in a study conducted in the Southern Nations, Nationalities, and Peoples (SNNP) and Tigray region, among rural mothers in Ethiopia [81]. From nine regions of Ethiopia, seven regions and two council cities were represented in this meta-analysis. Fifteen of the studies were from Amhara [33-42, 58, 59, 75-77] two from Addis Ababa [64,73], four from Affar [34,56,57,74] four from Oromia [44,60,61,80], twelve from SNNP [45-47, 62-65, 67-70, 72], one from Tigray [71], two from Somalia [48,79], two from Harari [43,78], one from nationwide [49], one from Diredawa [50] and one from SNNP and Tigray [81]. No studies were reported from Benishangul Gumiz and Gagmbela in this review research. Regarding the quality score of each primary study, the score was between the lowest (4) and highest (8) (Additional file 1) and almost all primary studies had a sufficient response rate.

Meta-analysis Pooled prevalence of exclusive breastfeeding in Ethiopia
A total of 45 studies of 33,000 breastfeeding women were included to estimate the pooled prevalence of EBF in the current meta-analysis. The pooled prevalence of EBF at 6 months was 60.42% (95% CI: 55.81, 65.02). The I2 test result indicated high heterogeneity among included studies (I2 98.8%; p = < 0.001), and because of this high heterogeneity the random effect meta-analysis model was used (Fig. 2). We also conducted a univariate meta-regression by considering the year of publication, sample size, and region in Ethiopia as covariates to identify the possible sources of heterogeneity, and unfortunately, none was found to be statistically significant (Table 2). Additionally, publication bias was assessed subjectively and objectively using both a funnel plot and Begg's and Egger's tests respectively. Even if the funnel plot showed the presence of publication bias (Fig. 3), no publication bias was found according to the results of Begg's and Egger's tests for the prevalence of EBF (p = 0.304) and (p = 0.314) respectively.

Subgroup analysis
Subgroup analyses were conducted by splitting all primary studies included in the analysis by region (geographical locations) in Ethiopia, the total sample size, and publication year, to make comparisons between them and as a means of investigating heterogeneity. Accordingly, this systematic review and meta-analysis showed that the highest prevalence of EBF was reported in a study conducted in SNNP and Tigray 87.84% ( (Table 3).

Discussion
This systematic review and meta-analysis research was conducted to determine the pooled prevalence of EBF and its association with maternal employment in Ethiopia using a study published between 1 January 2015 and 31 December 2020. According to the results of 45 studies included in this meta-analysis, the pooled prevalence of EBF in Ethiopia is 60.42% (95% CI: 55.81, 65.02). The overall prevalence of EBF in this study is similar to the result of the 2016 Ethiopian Demographic and Health Survey (EDHS) result (58%) [13], and the result of a meta-analysis conducted in Ethiopia (59.3%) [82]. This finding could be attributed to similarities in socio-demographics, methodologies, and the characters of individual studies included in both review and EDHS reports. But, the overall reported prevalence of EBF in this review is higher than the result of meta-analysis result conducted in Iran (49.1%) [83] and 29 Sub-Saharan African (SSA) countries, which showed the prevalence of EBF to be 23.70% in Central Africa and 56.57% in Southern Africa [84]. The pooled prevalence of EBF in this review is also higher than the results of the study conducted in 27 Sub-Saharan African countries (36%) [85], the Demographic and Health Survey of Tanzania (22.9%) [86], Demographic and Health Survey of Madagascar (48.8%) [87] and the study conducted in developing countries (39%) [88]. This variation might be because of methodological differences, differences in infants and maternal socio-demographic characteristics, economics, health service utilization, the gap of the year in which the study was conducted, and the number of studies included in the review. But the overall prevalence of EBF in our review is lower than the result of the primary study conducted in Indian regions, which indicated the prevalence of EBF was 79.2% in southern India and 68.0% in northeastern India respectively [89], the Nepal Demographic and Health Survey result was 66.3% [90], and the result of the study conducted in Ghana, 64% [91]. Based on the subgroup analysis, the highest (87.84%) and lowest (36.64%) prevalence of EBF was reported in a study conducted among rural mothers of SNNP and Tigray region and Addis Ababa City respectively. This regional variation might be because of differences in sociodemographics, and the difference in numbers of the studies included in the two regions during analysis. In addition to the above, the participants of a study conducted in SNNP and Tigray region were rural resident mothers, and according to different kinds of literature being rural in residence for breastfeeding mothers is associated with a high prevalence of EBF practice [66,77,92].
We also performed a subgroup analysis using a year of study publication. Accordingly, the highest (64.60%) and lowest (58.74%) prevalence of EBF were reported in studies published during 2015-2016 and 2017-2020 respectively. This difference could be attributed to the difference in coverage of health information regarding EBF and effective utilization of health extension workers, adherence to the national and international policy by health institutions [93]. Besides, we conducted subgroup analysis using the total sample size of the study, and the highest (64.15%) and lowest (47.38%) prevalence of EBF was reported among studies with a sample size less than 500 and greater than or equal to 1000 respectively. This difference might be associated with a difference in the number of primary studies included in each category during analysis (24 primary studies in the category of the sample size of < 500 and four primary studies in the category of the sample size of ≥1000) respectively. One of the greatest threats to the validity of meta-analytic results is publication bias which generally leads to effect sizes being overestimated and the dissemination of false-   positive results [94][95][96] and because of this, we assessed publication bias and possible sources of heterogeneity using Begg's and Egger's tests and univariate metaregression respectively and no publication bias was found. Full-time maternal employment was negatively associated with the practice of EBF among mothers who returned to work before 6 months in this systematic review and meta-analysis research (OR 0.43; 95% CI 0.31, 0.61). This result is in line with the results of a study conducted in 19 developing countries [97], another study conducted in Iran [98], a study conducted in developing countries [99], and a final study conducted in low and middle-income countries [100]. This similarity could be attributed to mothers who returned to work before 6 months postnatally and who have less frequent contact with their baby and employed mothers who begin liquid and solid based supplementation of food before the recommended age of starting weaning food which will result in the decreased practice of EBF [101]. Some evidence showed that employed mothers face unique barriers to practice EBF and returning to work too early after birth has been shown to affect the practice of EBF. Different kinds of literature showed that the more we increase the legislated duration of paid maternity leave, the more the mothers' practice EBF and this will result in the higher prevalence of EBF [20,102,103].

Limitations of the study
This review has certain limitations. The majority of the primary studies included in the review were crosssectional studies which might affect the outcome variable because of other confounding factors. Studies published in a language other than English were not included in the review and the review addressed only one associated factor (maternal employment) with EBF. The review included some studies with a small sample size which might affect the pooled report of EBF. The last the last limitation is that the study protocol was not registered at the international prospective register of systematic reviews (PROSPERO).

Conclusions
Full-time maternal employment was negatively associated with the practice of EBF in comparison to unemployed mothers. The prevalence of EBF in Ethiopia is low in comparison to the global recommendation. Based on our review findings, we recommended that the Ethiopian government should increase legislated paid maternity leave after delivery beyond currently paid maternity leave and implement policies that empower women. The governmental and non-governmental organizations should create a conducive environment for employed mothers to practice EBF at the workplace.