Prevalence and Factors Associated With Adequate Milk Supply as Measured by Breastmilk Sodium Among Mothers of Neonates in Kenyatta National Hospital Newborn Unit

Abstract

Background Suboptimal lactation is a common problem experienced by mothers and their babies due to various problems which may result in inadequate breastfeeding, poor weight gain, discouragement to breastfeed exclusively and increased morbidity and mortality. Breastmilk sodium levels are a simple way of determining suboptimal lactation and predicting lactation failure. Objectives They were to determine the prevalence of, and factors associated with poor breastmilk supply as measured by breastmilk sodium levels five days postpartum among mothers with neonates admitted to the newborn unit at Kenyatta National Hospital. We aimed to evaluate how well maternal report of low milk output correlated with that identified by breastmilk sodium levels as a secondary objective Study Methods This was an observational cross sectional at Kenyatta National Hospital Newborn Unit. The inclusion criteria were neonates still in NBU by day 5 of life, able to take oral feeds by age 5 days (those taking expressed breastmilk shall be included), whose mothers must have elected to breastfeed and provided informed consent. The exclusion criteria were neonates older than 5 days, any neonate born at gestation less than 30 weeks, any neonate whose mother is too sick to breastfeed or express breastmilk or a mother who has chosen not to breastfeed. Poor milk supply was considered as a mother unable to regularly produce sufficient milk for her neonate as evidenced by low wet diaper count, requiring formula supplementation or excessive weight loss (>7%). Sampling was carried out in the Newborn Unit on age 4 days. Those eligible were consented and enrolled. The principle investigator interviewed the mothers on age day 5 in the expressing room of the Newborn unit after feeding time to fill in the questionnaire prior to physical examination of both the mother and the neonate and the feeding technique. After completion of the interview- the mother was asked to provide a 4ml breastmilk sample which was transported to the lab in 2 plain vacutainers. The laboratory assessed the breastmilk sodium using the Humalyte Plus machine- an ion selective electrode machine- and the results recorded in the designated lab register. Sodium elevation above 26mmol/L was indicative of low breastmilk supply. Data Management and Analysis Data was collected via serialized questionnaires. It was stored in a password protected hard drive that is only be accessible to the principal researcher and the study supervisors. Analysis was carried out using Statistical Package for Social Scientists (SPSS) version 23. Summary statistics of continuous and categorical variables will be presented as means, medians or proportions as appropriate. Prevalence of poor breastmilk supply was computed as number of mothers with high BM Na as numerator, over the total number of the sample in the denominator, and converted to a percentage. Association between breastmilk sodium levels and the neonatal factors of weight loss and wet diaper count was assessed using Chi square and Mann- Whitney test. The relationship between breastmilk adequacy and various modifiable inhibitors of breastmilk adequacy was evaluated using the Chi square test. Results 7 The present study found a universal inadequacy of breastmilk as denoted by a 100% prevalence (n=93) of elevated breastmilk sodium among mothers of neonates in the newborn unit of Kenyatta National Hospital. Association of breastmilk sodium with neonatal indicators of feeding adequacy- wet diaper count and neonatal weight change was not found to be statistically significant. The evaluation of breastmilk sodium with selected modifiable inhibitors of breastmilk adequacy demonstrated an association between breastfeeding technique and breastmilk adequacy- mothers with poor technique are 1.8 times more likely to have higher breastmilk sodium levels. Maternal perception of her milk supply was not found to have any statistically significant association with breastmilk supply. However, it was noted that 75% of the mothers felt themselves to have adequate milk in contrast to the findings of universally elevated breastmilk sodium which may indicate an over estimation of true breastmilk supply among mothers. Conclusions Maternal breastmilk adequacy and factors affecting supply are largely modifiable. The present study demonstrates that the inadequacy suffered by mother may be higher than thought. Strengthening of education on breastfeeding as well as breastfeeding technique support in the immediate postpartum period may help in reduction of breastmilk inadequacy. Further studies in other centres are required to fully characterise this subset of mothers in Kenya.