Background/Aims Significant weight loss during early life can be of serious concern and assessing weight is key in decisions regarding supplementation. However, supplementation is a significant risk factor for early breastfeeding cessation. Recognising differential causes of weight loss supports identification of genuinely unwell infants and targets practices that support exclusive breastfeeding appropriately. This study's aim was to identify whether maternal fluid balance/load is associated with neonatal weight loss. Methods The databases CINAHL, MEDLINE, EMBASE, EMCARE were searched for relevant literature. Data were extracted using a structured form based on the Cochrane handbook. Meta-analysis was not possible because of the heterogeneity of all aspects of study design and outcome definitions. Results Eight studies presented original data. Four reported an association between maternal intravenous fluid intake and neonatal weight loss, and four did not. No two studies collected the same outcome data at the same time, using the same comparator or intervention. Conclusions Further research is required to clarify the relationship between maternal fluid intake and neonatal weight loss in a clinically useful way.