Explaining variance in breastfeeding intentions and behaviors among a cohort of Midwest mothers using a theory of planned behavior-based structural model

Background

The Theory of Planned Behavior (TPB) has guided the investigation of breastfeeding since the 1980’s, incorporating the major constructs of attitudes, subjective norms/normative beliefs, perceived behavioral control, and intentions. The purpose of this research study was to define a TPB-based structural latent variable model so as to explain variance in breastfeeding intentions and behaviors among a cohort of Midwest breastfeeding mothers.

Methods

The longitudinal descriptive study utilized questionnaire data collected from a convenience sample of 100 women with low-risk pregnancies with the intention to breastfeed at three separate time points (> 30 weeks antepartum, 10 and 60 days postpartum). Data were coded and analyzed using IBM SPSS, SAS and the lavaan package in R.

Results

Participants were predominantly White (94%, n = 94), married (95%, n = 95), college-educated (96%, n = 96), and had previous breastfeeding experience (75%, n = 75). The majority gave birth vaginally (79%, n = 75). Varimax analysis revealed a plurality of factors within each domain. Attempts to fit a structural model, including both hierarchical and bi-factor latent variables, failed, revealing a lack of statistical significance and poor fit statistics.

Conclusion(s)

These findings illustrate the importance of using methods that fit the phenomena explained. Contributors to poor model fit may include outdated tools lacking cultural relevance, a change in social norms, or a failure to capture the possible influence of social media and formula marketing on breastfeeding behaviors. The null finding is a significant finding, indicating the need to revisit and refine the operationalization and conceptual underpinnings of the TPB through qualitative methods such as exploring the lived experiences of breastfeeding women in the Midwest region.

Use of a Portable Point-of-Care Instrumentation to Measure Human Milk Sodium and Potassium Concentrations

Objective: Human milk (HM) sodium (Na) and potassium (K) concentrations, as well as the Na and K ratio (Na:K), are associated with stages of lactation and breast health. Portable point-of-care instruments to measure HM biomarkers related to secretory activation or tight junction disturbances would supply clinicians immediate information for individualized lactation care. This study compared HM concentrations of Na and K and Na:K measured by a biochemist with inductively coupled plasma optical emission spectrometry (ICP-OES) and measured by a clinician with ion-selective electrode probes (ISEPs). Design: HM samples (n = 92) were participant collected and donated on day 10 postpartum through a convenience sample of breastfeeding women in West Michigan. Na and K concentrations were determined using ICP-OES and ISEPs. Bland-Altman plots, paired sample t-test, and logistic regressions were completed using R 3.4.4 and R Studio 1.2.1335 with package Lattice. Results: Na concentrations were not significantly different with ICP-OES (13.0 ± 14.8 mM) and ISEPs (12.6 ± 13.7 mM, p = 0.06), whereas K concentrations (ICP-OES 16.1 ± 1.9 mM, ISEPs 14.4 ± 2.4 mM, p < 0.001) and Na:K (ICP-OES 0.81 ± 0.92, ISEPs 1.01 ± 1.62, p = 0.011) were significantly different. Between both methods, the Na, K, and Na: K linear relationships were statistically significant. Conclusion: With additional longitudinal and clinical usefulness research clinicians could use ISEPs to collect and interpret relevant lactation data to support individualized lactation interventions.

The Interaction of Donor Human Milk Availability and Race/Ethnicity on Provision of Mother's Own Milk for Very Low Birth Weight Infants

Objective: To compare (1) differences in mother's own milk (MOM) provision and enteral feeding outcomes, (2) differences in preterm formula and donor human milk (DHM) uses as bridges to exclusive MOM feedings at discharge, and (3) MOM and enteral feeding outcomes for racial/ethnic subgroups before and after the implementation of a hospital DHM feeding program. Methods: Retrospective data from 313 very low birth weight (VLBW; birth weight <1,500 g) infants born between January 2011 to December 2012 (pre-DHM, n = 157) and April 2013 to March 2015 (DHM, n = 156) were analyzed. Results: For this predominantly low-income and minority VLBW infant cohort, the percent of enteral fed hospitalization days was higher in the DHM group (pre-DHM 94% [88, 97] versus DHM 98% [95, 99], p < 0.001). Although MOM remained the predominant first enteral feeding type, significantly fewer DHM infants received MOM (pre-DHM 89% versus DHM 75%, p = 0.001). During days of life 1-14, a lower percentage of DHM infants received 100% MOM (pre-DHM 68% versus DHM 55%, p = 0.02). For the entire cohort, the risk for MOM discontinuation was significantly associated with maternal young age, multiparity, non-Hispanic Black race/ethnicity, and low income. Implementation of a DHM program did not predict duration of MOM feedings. However, non-Hispanic White infants had a longer duration of MOM feedings with DHM availability. Conclusions: Our findings highlight the importance of using precise dose and exposure period methodology to determine the impact of DHM on MOM provision. In addition, DHM availability may be associated with varying effects on MOM provision among racial/ethnic groups.

The Economic Impact of Donor Milk in the Neonatal Intensive Care Unit

OBJECTIVE

To assess the cost-effectiveness of mother's own milk supplemented with donor milk vs mother's own milk supplemented with formula for infants of very low birth weight in the neonatal intensive care unit (NICU).

STUDY DESIGN

A retrospective analysis of 319 infants with very low birth weight born before (January 2011-December 2012, mother's own milk + formula, n = 150) and after (April 2013-March 2015, mother's own milk + donor milk, n = 169) a donor milk program was implemented in the NICU. Data were retrieved from a prospectively collected research database, the hospital's electronic medical record, and the hospital's cost accounting system. Costs included feedings and other NICU costs incurred by the hospital. A generalized linear regression model was constructed to evaluate the impact of feeding era on NICU total costs, controlling for neonatal and sociodemographic risk factors and morbidities. An incremental cost-effectiveness ratio was calculated for each morbidity that differed significantly between feeding eras.

RESULTS

Infants receiving mother's own milk + donor milk had a lower incidence of necrotizing enterocolitis (NEC) than infants receiving mother's own milk + formula (1.8% vs 6.0%, P = .048). Total (hospital + feeding) median costs (2016 USD) were $169 555 for mother's own milk + donor milk and $185 740 for mother's own milk + formula (P = .331), with median feeding costs of $1317 and $936, respectively (P < .001). Mother's own milk + donor milk was associated with $15 555 lower costs per infant (P = .045) and saved $1812 per percentage point decrease in NEC incidence.

CONCLUSIONS

The additional cost of a donor milk program was small compared with the cost of a NICU hospitalization. After its introduction, the NEC incidence was significantly lower with small cost savings per case. We speculate that NICUs with greater NEC rates may have greater cost savings.

Impact of Donor Milk on Short- and Long-Term Growth of Very Low Birth Weight Infants

Mother’s own milk (MOM) reduces the risk of morbidities in very low birth weight (VLBW) infants. When MOM is unavailable, donor breastmilk (DM) is used, with unclear impact on short- and long-term growth. This retrospective analysis compared anthropometric data at six time points from birth to 20–24 months corrected age in VLBW infants who received MOM supplements of preterm formula (n = 160) versus fortified DM (n = 161) during neonatal intensive care unit (NICU) hospitalization. The cohort was 46% female; mean birth weight and gestational age (GA) were 998 g and 27.3 weeks. Multilevel linear growth models assessed changes in growth z-scores short-term (to NICU discharge) and long-term (post-discharge), controlling for amount of DM or formula received in first 28 days of life, NICU length of stay (LOS), birth GA, and sex. Z-scores for weight and length decreased during hospitalization but increased for all parameters including head circumference post-discharge. Short-term growth was positively associated with LOS and birth GA. A higher preterm formula proportion, but not DM proportion, was associated with slower rates of decline in short-term growth trajectories, but feeding type was unrelated to long-term growth. In conclusion, controlling for total human milk fed, DM did not affect short- or long-term growth.

"It's Somebody Else's Milk": Unraveling the Tension in Mothers of Preterm Infants Who Provide Consent for Pasteurized Donor Human Milk

BACKGROUND

Pasteurized donor human milk (DHM), rather than preterm infant formula, is recommended for premature infants when mother's milk is not available.

OBJECTIVE

This study explored the maternal decision-making process in providing consent for DHM feedings.

METHODS

In-depth semistructured interviews were conducted with 20 mothers of premature (mean gestational age = 27 weeks, birth weight = 942 grams) infants hospitalized in the neonatal intensive care unit (NICU) in this qualitative, descriptive study. Conventional content analysis was used to analyze the data.

RESULTS

Although only 1 mother had any previous knowledge of DHM, all mothers provided consent for DHM because they "wanted what is best for my baby." Mothers trusted that DHM was better than formula when their infant's feeding requirements exceeded their own milk supply. However, most mothers described a tension between wanting their infants to receive only "their" milk and DHM being "somebody else's milk." This desire to be the only provider of human milk was more common than concerns about the quality and safety of DHM. The mothers' tension was mediated by trusting the NICU clinicians' recommendations, having adequate time to make an informed decision, observing the positive outcomes of DHM, and feeling empowered that they made the best decision for their infant.

CONCLUSION

The experiences of these mothers reflect the importance of approaching mothers for consent only when DHM is needed, respecting mothers' beliefs and values about DHM, and providing help in mediating any tension with regard to their infants receiving "somebody else's milk."