To evaluate the nutritional status and early nutritional intake of infants with univentricular congenital heart disease.

The included infants underwent a Norwood procedure or hybrid intervention (stage 1) within the first 6 weeks of life, between January 2014 and January 2019, at Children's Health Ireland at Crumlin. Demographic, anthropometric, nutritional intake, and morbidity data were collected.

Data were collected on 90 infants and 1886 neonatal admission days. There was a significant drop in mean weight-for-age z-score (WAZ) between measurements at birth, −0.01 and on discharge post stage 1 surgery −1.45 (P < .01). On hospital discharge (median hospital stay, 25 days) 32% of infants had a WAZ <-2 and 11% had a WAZ <-3. Pre-stage 1, 26% received trophic feeds and 39% received parenteral nutrition. Basal metabolic requirements and target caloric intake (120 kcal/kg) were met on 56% and 13% of admission days, respectively. Infants referred to a dietitian had a shorter time to any form of nutrition support, enteral feeds, and target caloric intake (P < .001, P = .016, and P = .048, respectively). At stage 3 (Fontan) surgery, 15% of infants were classified as stunted (length-for-age z-score [LAZ] <-2).

The greatest decline in nutritional status occurs in the neonatal period, followed by significant growth stunting by the time of the Fontan procedure. Early involvement of dietitians is critical in the care of this nutritionally fragile group. With the currently low rate of preoperative nutritional support, there may be opportunities to improve intake at this critical stage.