Gestational Diabetes and Antenatal Human Milk Expression

The incidence of GDM has been increasing worldwide and varied globally. Women with previous GDM have a 7-fold higher risk of developing diabetes mellitus over their lifetime. It has emerged global public health concern. Studies found that women with GDM breastfeed her baby significantly reduce the risk of Type 2 Diabetes and cardiometabolic disease, and improve postpartum glucose metabolism. However, evidence shows that GDM women have breastfeeding challenges and barriers. Women with diabetes experience delay in lactogenesis and infant have increased risk hypoglycaemia, they require blood monitoring and are often admit to the neonatal unit. As a result, the infants are more likely to have early receiving of formula supplementation. Besides, evidence indicated that low maternal confidence, increase depressive symptoms and breastfeeding self-efficacy among GDM women. Therefore, early lactation support was necessary. Greater support for GDM women reduces the risks of hypoglycaemia, formula supplementation and early weaning. It has been proposed that hand expression of breast milk in pregnancy may promote breastfeeding. Mothers with diabetes can express colostrum antenatally for use rather than infant formula if necessary.

Though Antenatal Milk Expression (AME) advises women at risk of early lactation problems, very limited evidence regarding the safety and efficacy of the practice. Also, very limited evidence investigated the AME for diabetes women for improving infant outcomes. Few studies found that AME increased confidence and contributed to better preparation on breastfeeding, but AME on depressive symptoms is under examined.

In Hong Kong, AME is not widely practice with inconsistent advice. It may raise concern on culture diversity regarding conservative culture in Chinese. There is lack of local article on the feasibility and acceptability of AME practice for GDM women in Hong Kong. Local clinical protocol on the implementation of AME and instructions on the practice is also absent. Given cultural differences in breastfeeding motivation and self-regulation as compared with those of oversea countries, the motivation of Hong Kong pregnant women engages in antenatal education and receiving social and breastfeeding support may be differ from women in the West. Thus, it is important to evaluate the efficacy and experience of AME on Hong Kong Chinese to assess cultural acceptability and effectiveness in supporting baby-friendly hospital practice and breastfeeding continuation.

Limited qualitative study compares breastfeeding self-efficacy on GDM women and positive impacts of the self-efficacy on breastfeeding prevalence and duration. Besides, qualitative study on the experiences and perceptions of GDM women on breastfeeding, and the experience on the collection and storage of expressed colostrum are very rare.

This blocked randomized, parallel-armed controlled trial with mixed method study design which integrating with quantitative and qualitative study will be conducted to examine (1) the acceptability and feasibility of AME as breastfeeding intervention to improve breastfeeding for GDM women, how and why AME works or does not work using qualitative research; (2) to understand the experience and perceptions of antenatal milk expression among the GDM women and (3) to investigate the efficacy of AME practice on the breastfeeding exclusivity. The secondary aims are determining whether AME as mediating variables in the effect on the breastfeeding self-efficacy among Hong Kong GDM women in Hong Kong.

The study hypotheses are (1) Antenatal human milk expression (AME) will increase breastfeeding exclusivity on hospital discharge, at 4 weeks and 8 weeks postpartum compare women receiving standard care (2) AME will improve the breastfeeding self-efficacy and reduce depressive symptoms of women after birth.