Expressed Breast Milk Feeding Practices in Hong Kong Chinese Mothers of Healthy Full-term Infants

Breastfeeding provides optimal nutrients for infants and is one of the most important public health issues. Globally, breastfeeding initiation rates are high with around 95% of all infants receiving some breastmilk. Over the past two decades, the mode of breastfeeding has been evolving and an increasing number of mothers are now choosing to feed their infant by expressed breast milk rather than directly at the breast. However, only few recent studies have described the rates and practices of breast milk expression, and the effect of expressed breast milk feeding on breastfeeding duration remains unclear. Furthermore, although breastfeeding self-efficacy has been shown to significantly predict breastfeeding duration, no study has investigated the predictive effect of breastfeeding self-efficacy on the mode of breastfeeding. Therefore, this thesis aims to (1) identify the prevalence and predictors of expressed breast milk feeding; (2) examine the association between expressed breast milk feeding and breastfeeding duration; (3) examine the predictive effect of breastfeeding self-efficacy on the mode of breastfeeding and (4) describe the experiences of expressed breast milk feeding in Hong Kong mothers.

A prospective cohort was conducted on 821 healthy mothers with term births who were recruited from two public hospitals in Hong Kong. They were followed in a series of telephone calls until six-month postpartum or until they stopped breastfeeding, whichever came first. A qualitative descriptive design was conducted to explore the antecedents to and the experiences of expressed breast milk feeding in a sub-sample of 25 participants who were recruited into the quantitative study. Participants with a high proportion of expressed breast milk feeding at one month postpartum were invited to participate. An open-ended interview guide that was developed based on the breastfeeding self-efficacy theory was used in semi-structured in-depth interviews.

During the first 6-month postpartum, 14% to 20% of the participants were only feeding expressed breast milk and 85% had given expressed breast milk at least once. Returning to employment was the strongest predictor of expressed breast milk feeding. Expressed breast milk feeding only at 1.5 months was associated with an increased risk of breastfeeding cessation in participants supplementing with infant formula but not on breastfeeding duration among participants who were exclusive breastfeeding. Each point increase in breastfeeding self-efficacy score was associated with 5% lower odds of feeding only expressed breast milk at 6 months postpartum.

The qualitative study showed that adverse direct breastfeeding experience, which led to fear of direct breastfeeding among participants, was an important antecedent to expressed breast milk feeding. Expressed breast milk feeding was considered as more time-consuming than direct breastfeeding, but it provided a greater sense of control and security to the participants.

In the future, the prevalence of expressed breast milk feeding is likely to increase due to the high rates of maternal employment rate and continuous advancements in breast pump technology. The drawbacks and benefits of expressed breast milk feeding need to be addressed in antenatal breastfeeding education and breastfeeding support should be enhanced to ensure that direct breastfeeding is well established prior to hospital discharge.