Factors associated with newborn in-hospital weight loss: comparisons by feeding method, demographics, and birthing procedures.

Full-term newborn normative weight loss and factors influencing this were determined through chart audits (n = 812) at 6 hospitals in Manitoba, Canada. The effects of parity, gestational age, birth weight, sex, length of stay, type of delivery (cesarean vs vaginal), epidural use, and type of infant feeding (exclusively breastfed, partially breastfed, exclusively formula-fed) on percentage weight loss in hospital were analyzed using multiple regression analysis. In-hospital weight loss was 5.09% +/- 2.89% (95% CI, 4.89-5.29), varying by feeding category: exclusively breastfed 5.49% +/- 2.60% (95% CI, 5.23-5.74), partially breastfed 5.52% +/- 3.02% (95% CI, 5.16-5.88), and formula-fed 2.43% +/- 2.12% (95% CI, 2.02-2.85). Factors significantly increasing the percentage weight loss included higher birth weight, female sex, epidural use, and longer hospital stay. Lower percentage weight loss was associated with greater gestational age and exclusive formula feeding. Parity and type of delivery were not significant. Controlling for demographic and delivery-related variables, exclusive formula feeding had the largest impact, with 3.1% less weight loss than exclusive breastfeeding.