Supplementary Material for: Discharge Age and Weight for Very Preterm Infants in Six Countries: 2012–2020

Background: Postmenstrual age for surviving infants without congenital anomalies born at 24–29 weeks’ gestational age from 2005 to 2018 in the USA increased 8 days, discharge weight increased 316 grams, and median discharge weight z-score increased 0.19 standard units. We asked whether increases were observed in other countries. Methods: We evaluated postmenstrual age, weight, and weight z-score at discharge of surviving infants without congenital anomalies born at 24–29 weeks’ gestational age admitted to Vermont Oxford Network member hospitals in Austria, Ireland, Italy, Switzerland, the UK, and the USA from 2012 to 2020. Results: After adjustment, the median postmenstrual age at discharge increased significantly in Austria (3.6 days, 99% CI [1.0, 6.3]), Italy (4.0 days [2.3, 5.6]), and the USA (5.4 days [5.0, 5.8]). Median discharge weight increased significantly in Austria (181 grams, 99% CI [95, 267]), Ireland (234 [143, 325]), Italy (133 [83, 182]), and the USA (207 [194, 220]). Median discharge weight z-score increased in Ireland (0.24 standard units, 99% CI [0.12, 0.36]) and the USA (0.15 [0.13, 0.16]). Discharge on human milk increased in Italy, Switzerland, and the UK, while going home on cardiorespiratory monitors decreased in Austria, Ireland, and USA and going home on oxygen decreased in Ireland. Conclusions: In this international cohort of neonatal intensive care units, postmenstrual discharge age and weight increased in some, but not all, countries. Processes of care at discharge did not change in conjunction with age and weight increases.