Perceived insufficient milk supply in New Zealand mothers during the first-year postpartum : this thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Nutrition and Dietetics at Massey University, Albany, New Zealand

Abstract

Background: Mothers rarely achieve breastfeeding (BF) recommendations and there are numerous reasons that may lead to early cessation. However, insufficient milk supply is a frequently reported cause. Current research on perceived insufficient milk supply (PIM) itself is limited. Numerous factors are suggested to play a part in the occurrence of PIM, including: demographic, psychological as well as feeding practices and management factors. Aim. To determine the factors associated with PIM and the impact that this has on BF practices. Methods: Secondary analysis of the data collected from Manawatu Mother and Baby Study. Sixty-­one women were included. Interviews about maternal demographics, obstetric characteristics and BF practices were conducted on women approximately 2 weeks postpartum, then at 2 weekly intervals throughout the first three months, and finally once per month until the infants first birthday. Bivariate associations and logistic regression analyses were conducted to determine the relation of PIM with variables, as well as with BF duration. Results: PIM was reported by 44% of the participants and was the main reason for introduction of infant formula. Formula use was a significant predictor for PIM (R2=0.22) and was explained by formula being used in response to PIM. We found that PIM was a significant predictor of BF duration (any BF 5 months R2=0.44, full BF 5 months R2=0.13, any BF 12 months R2=0.32). Additionally, maternal importance of BF at 4 weeks can also predict the duration of BF. Conclusion: PIM plays a significant role in the introduction of infant formula and BF cessation. However, the absence of a significant relationship between PIM and demographic variables makes it difficult to identify mothers who may be at risk of PIM. Further research is required to try identify mothers at risk of PIM, in order to help prevent or resolve it.