Table 1.

Patient demographics

N=	54
Gestational age at birth, mean (range), weeks	29.7 (23.0–40.0)
Age at time of AUS, mean (range), days	35.3 (1–159)
Birth weight, mean (range) kg	1.52 (0.45–4.5)
Weight at time of AUS, mean (range), kg	2.0 (0.5–5.50)
Male sex n(%)	34 (63)
Race n(%)
White	12 (22.2)
African-American	18 (33.3)
Asian	7 (13)
More than one race/unknown	17 (31.5)
Comorbidities n(%)	50 (92.6)
Prematurity	42 (77.8)
Patent ductus arteriosus	6 (11.1)
Intraventricular hemorrhage	6 (11.1)
Cardiac abnormality	8 (14.8)
Mechanical Ventilation	26 (48.1)