This study is the largest and one of only a few studies on KMC and breastfeeding in China. Our analysis shows that KMC was associated with a nearly two-fold increase in exclusive breastmilk feeding (outcome) and breast feeding (method) at both discharge and follow-up in late preterm infants. Our results suggest that for late preterm newborns on postnatal wards (with mother), relatively brief exposure to intermittent KMC in facility was associated with increased exclusive breastfeeding at discharge and at follow up.
Preterm infants are at a higher risk for late breastfeeding onset and early breastfeeding cessation when compared to infants born at term (9), due to a series of barriers including but not limited to a lack of adequate breast milk, an immature uncoordinated sucking pattern and increased likelihood of maternal symptoms of depression due to preterm delivery (4,10,11). This also applies to late preterm infants (12,13). Inadequate milk intake contributes to slow weight gain and protracted jaundice in late preterm infants, making routine formula supplementation and early termination of breastfeeding more likely (14).
Our study is consistent with previous evidence from published literature that frequent skin-to-skin contact between mother and baby is crucial to the successful transition to direct breastfeeding in preterm infants (7,11) and initiation of exclusive breastfeeding in healthy full-term babies (15). Early skin-to-skin contact, within the first hour of birth, if possible, facilitates maternal milk production (16,17). While continued skin-to-skin contact on a daily basis accelerate neurophysiological development of the preterm infant (18), which contributes to establishment of effective suckling behavior. KMC on postnatal wards minimizes mother-infant separation time and likely increase breastfeeding (4,19).
It is noteworthy that KMC may play a role in alleviating stress related to preterm birth, encouraging mothers to care for their late preterm infants and breastfeed. Parents of late preterm infants are likely to exhibit a lack of confidence and some may exhibit distress during feeding or symptoms of depression (20–22). A previous study on breastfeeding outcomes for preterm infants in China suggests that mothers of preterm newborns experienced low self-efficacy for breastfeeding and are more likely to have symptoms of depression, contributing to unsuccessful establishment of breastfeeding (4). It is likely that KMC encouraged mothers to relieve their stress and boost their confidence, and in the process nurses and health professionals could provide breastfeeding support, which may increase mothers’ probability to initiate breastfeeding for late preterm infants.
Our analyses indicate that intermittent KMC on postnatal wards may have an impact on exclusive breastfeeding, not only at discharge, but up to 42 days after discharge. Given the extremely low exclusive breastfeeding rate (29.2%) at six months in China (3), our study has strong public health implications. KMC is recommended for newborns under 2000 g, however use of intermittent KMC for late preterm infants on postnatal wards could be encouraged by health professionals in order to improve breastfeeding outcomes. Further studies should be conducted as to whether regular skin to skin contact between mothers and their full-term newborns could be applied with the intention of improving breastfeeding outcome in China.
Despite being the largest study on KMC and breastfeeding in China, there are several limitations to be considered. The study was not a randomized controlled trial, as KMC is known to be beneficial for preterm newborns it was deemed unethical to randomize mothers and babies to a group where they would not be encouraged to practice KMC. It is possible that those who opted to provide KMC may have been more likely to breastfeed their babies than those who chose not to provide KMC; however, we found no significant difference in socio-demographic characteristics (including age and educational attainment) between the two groups. Moreover, the exclusive breastfeeding rate for mothers who did not provide KMC (33.2% at 42 days follow-up) is similar to the national exclusive breastfeeding rate at six months (29.2%); therefore, we believed that the finding that KMC was associated with an increase in breastfeeding is valid.
Secondly, we also noted difference in the KMC vs. no-KMC ratio across four study hospitals especially where in one hospital almost all of the participating mothers chose to provide KMC to their babies. We also did an additional analysis excluding this hospital and the results were similar (see supplementary appendix). Nonetheless, we believe that the four hospitals enrolled are all tertiary hospitals with minimal difference in service delivery capacity, and it would be appropriate and useful to compare breastfeeding pattern between mothers in different hospitals, thus we included all of them in our analysis.
A third limitation is that, those who were not successfully followed-up were excluded from the analysis, which may lead to selection bias. However, the loss to follow-up rate was similar between in the KMC and the no-KMC group (15.4% vs. 14.5%). Within the KMC group, those lost to follow-up reported a higher exclusive breastfeeding rate at discharge than those who were successfully followed-up (60.0% vs. 54.6%), while within the no-KMC group those who were lost reported a lower rate than those who were followed-up (23.5% vs. 34.6%). This suggests that the results of our analysis may underestimate the association between intermittent KMC and improved breastfeeding outcomes as the actual impact may be greater.
Lastly, the major outcome variables of breastfeeding were only collected at hospital discharge and at 42 days follow-up. The study would have benefited from a longer-term outcome variable, e.g. exclusive breastfeeding at 6-months of age, in order to provide a more robust clinical and public health recommendation.