Nativity, Country of Education, and Mexican-Origin Women's Breastfeeding Behaviors in the First 10 Months Postpartum

Why do mothers mix milk feed their infants? Results from a systematic review

CONTEXT

Combining or supplementing breastfeeding with formula feeding, also called mixed milk feeding (MMF), is a common infant feeding practice. However, there is no well-established MMF evidence-base for informing and guiding parents. A better understanding of the reasons why mothers practice MMF may facilitate identification of efficient strategies for supporting exclusive breastfeeding, and/or opportunities to prolong breastfeeding, at least partially.

OBJECTIVE

An updated systematic literature review was undertaken with the primary aim of gaining a deeper understanding of the reasons why mothers choose MMF.

DATA SOURCES

Six databases were searched for relevant articles published in English from January 2012 to January 2022.

DATA EXTRACTION

Two reviewers independently performed the screenings and data extraction, and any differences were resolved by a third reviewer. Data from 138 articles were included, 90 of which contained data on MMF reasons/drivers, and 60 contained data on infant age and/or maternal demographic factors associated with MMF.

DATA ANALYSIS

A total of 13 different unique MMF drivers/reasons were identified and categorized according to whether the drivers/reasons related to perceived choice, necessity, or pressure. Risk of bias was evaluated using the Quality Assessment Tool of Diverse Studies and the JBI Systematic Reviews tool. Several different terms were used to describe and classify MMF across the studies. The most commonly reported reasons for MMF were related to a perception of necessity (39% of drivers, eg, concerns about infant's hunger/perceived breast milk insufficiency or breastfeeding difficulties), followed by drivers associated with perceived choice (34%; eg, having more flexibility) and perceived pressure (25%; eg, returning to work or healthcare professionals' advice). This was particularly true for infants aged 3 months or younger.

CONCLUSION

The key global drivers for MMF and their distribution across infant age and regions were identified and described, providing opportunities for the provision of optimal breastfeeding support. A unified definition of MMF is needed in order to enable more comparable and standardized research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42022304253.

Factors associated with breast-feeding initiation and continuation in Canadian-born and non-Canadian-born women: a multi-centre study

OBJECTIVE

To identify factors associated with breast-feeding initiation and continuation in Canadian-born and non-Canadian-born women.

DESIGN

Prospective cohort of mothers and infants born from 2008 to 2012: the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study.

SETTING

General community setting in four Canadian provinces.

PARTICIPANTS

In total, 3455 pregnant women from Vancouver, Edmonton, Winnipeg and Toronto between 2008 and 2012.

RESULTS

Of 3010 participants included in the current study, the majority were Canadian-born (75·5 %). Breast-feeding initiation rates were high in both non-Canadian-born (95·5 %) and Canadian-born participants (92·7 %). The median breast-feeding duration was 10 months in Canadian-born participants and 11 months in non-Canadian-born participants. Among Canadian-born participants, factors associated with breast-feeding initiation and continuation were older maternal age, higher maternal education, living with their partner and recruitment site. Rooming-in during the hospital stay was also associated with higher rates of breast-feeding initiation, but not continuation at 6-month postpartum. Factors associated with non-initiation of breast-feeding and cessation at 6-month postpartum were maternal smoking, living with a current smoker, caesarean birth and early-term birth. Among non-Canadian-born participants, maternal smoking during pregnancy was associated with lower odds of breast-feeding initiation and lower odds of breast-feeding continuation at 6 months, and older maternal age and recruitment site were associated with breast-feeding continuation at 6 months.

CONCLUSIONS

Although Canadian-born and non-Canadian-born women in the CHILD cohort have similar breast-feeding initiation rates, breast-feeding initiation and continuation are more strongly associated with socio-demographic characteristics in Canadian-born participants. Recruitment site was strongly associated with breast-feeding continuation in both groups and may indicate geographic disparities in breast-feeding rates nationally.

Breastfeeding Initiation, Duration, and Supplementation Among Mexican-Origin Women in Texas

BACKGROUND

Mexican-origin women breastfeed at similar rates as white women in the United States, yet they usually breastfeed for less time. In our study, we seek to identify differences in Mexican-origin women's breastfeeding intentions, initiation, continuation, and supplementation across nativity and country-of-education groups.

METHODS

The data are from a prospective cohort study of postpartum women ages 18 to 44 recruited from 8 Texas hospitals. We included 1235 Mexican-origin women who were born and educated in either Texas or Mexico. Women were interviewed at delivery and at 3, 6, 12, 18, and 24 months post partum. Breastfeeding intentions and initiation were reported at baseline, continuation was collected at each interview, and weeks until supplementation was assessed for both solids and formula. Women were classified into 3 categories: born and educated in Mexico, born and educated in the United States, and born in Mexico and educated in the United States.

RESULTS

Breastfeeding initiation and continuation varied by nativity and country of birth, although all women reported similar breastfeeding intentions. Women born and educated in Mexico initiated and continued breastfeeding in higher proportions than women born and educated in the United States. Mexican-born and US-educated women formed an intermediate group. Early supplementation with formula and solid foods was similar across groups, and early supplementation with formula negatively impacted duration across all groups.

CONCLUSIONS

Nativity and country of education are important predictors of breastfeeding and should be assessed in pediatric and postpartum settings to tailor breastfeeding support. Support is especially warranted among US-born women, and additional educational interventions should be developed to forestall early supplementation with formula across all acculturation groups.

Breastfeeding rates in immigrant and non-immigrant women: A systematic review and meta-analysis

Breastfeeding benefits mothers and infants. Although immigration in many regions has increased in the last three decades, it is unknown whether immigrant women have better breastfeeding outcomes than non-immigrants. The aim of this study was to conduct a systematic review and meta-analysis to determine whether breastfeeding rates differ between immigrant and non-immigrant women. We searched Medline, Embase, PsycINFO, CINAHL and Google Scholar, 1950 to 2016. We included peer-reviewed cross-sectional and cohort studies of women aged ≥16 years that assessed and compared breastfeeding rates in immigrant and non-immigrant women. Two independent reviewers extracted data using predefined standard procedures. The analysis included 29 studies representing 1,539,659 women from 14 countries. Immigrant women were more likely than non-immigrants to initiate any (exclusive or partial) breastfeeding (pooled adjusted prevalence ratio 1.13, 95% confidence interval [CI] 1.07-1.19; 11 studies). Exclusive breastfeeding initiation was higher but borderline significant (adjusted prevalence ratio 1.20, 95% CI 1.00-1.45; 5 studies, p = 0.056). Immigrant women were more likely than non-immigrants to continue any breastfeeding between 12- and 24-week postpartum (pooled adjusted risk ratio 2.04, 95% CI 1.79-2.32; 3 studies) and > 24 weeks (adjusted risk ratio 1.33, 95% CI 1.02-1.73; 6 studies) but not exclusive breastfeeding. Immigrant women are more likely than non-immigrants to initiate and maintain any breastfeeding, but exclusive breastfeeding remains a challenge for both immigrants and non-immigrants. Social and cultural factors need to be considered to understand the extent to which immigrant status is an independent predictor of positive breastfeeding practices.

Acculturation and Breastfeeding Among Hispanic American Women: A Systematic Review

Introduction Hispanic immigrants are more likely to breastfeed than are Hispanics born in the US, in part due to their acculturation. This paper aims to systematically review the existing literature on the association between acculturation and Hispanics' breastfeeding behaviors. Methods The systematic search used major databases such as Medline and PubMed, and it followed the PRISMA checklist. The scientific quality of the studies was rated using the Quality Assessment Tool for Quantitative Studies. Results We identified 1943 potential citations, of which 18 studies met the eligibility criteria. Overall, while 13 studies suggested that high-acculturated Hispanics were less likely to breastfeed compared with low-acculturated, five studies did not find significant evidence of such an association. Moreover, 12 studies used a static measure or a linear scale, which is not optimal; only three studies utilized bi/multidimensional scales to assess acculturation. Intention to breastfeed was examined in six studies, but the results were inconsistent. Breastfeeding initiation was examined in 11 studies, and two out of eight studies that examined breastfeeding duration, specifically analyzed exclusive breastfeeding at 6 months. Discussion Our results agree with the general hypothesis that higher acculturation is inversely related to breastfeeding rates, independently of income. Researchers used different methodologies to study acculturation and breastfeeding practices, limiting our ability to reach more detailed conclusions. Owing to the lack of a standard methodology for measuring acculturation, future studies should utilize bi/multidimensional scales when studying breastfeeding, in particular, in relation to breastfeeding intention and exclusive breastfeeding at 6 months; preferably according to Hispanic subgroups.

Breastfeeding and the gut-brain axis: is there a role for melatonin?

The benefits of breastfeeding over formula feed are widely appreciated. However, for many mothers breastfeeding is not possible, highlighting the need for a significant improvement in the contents of formula feed. In this article, the overlooked role of melatonin and the melatonergic pathways in breast milk and in the regulation of wider breast milk components are reviewed. There is a growing appreciation that the benefits of breastfeeding are mediated by its effects in the infant gut, with consequences for the development of the gut-brain axis and the immune system. The melatonergic pathways are intimately associated with highly researched processes in the gut, gut microbiome and gut-brain axis. As the melatonergic pathways are dependent on the levels of serotonin availability as a necessary precursor, decreased melatonin is linked to depression and depression-associated disorders. The association of breastfeeding and the gut-brain axis with a host of medical conditions may be mediated by their regulation of processes that modulate depression susceptibility. The biological underpinnings of depression include increased levels of pro-inflammatory cytokines, oxidative stress, kynurenine pathway activity and dysregulation of the hypothalamic-pituitary adrenal axis, all of which can decrease melatonergic pathway activity. The inclusion of the melatonergic pathways in the biological interactions of breast milk and gut development has significant theoretical and treatment implications, as well as being important to the prevention of a host of infant-, child- and adult-onset medical conditions.