Aims-The purpose of this study was to examine the occurrence, severity, pattern, and moderators of oxygen desaturation during preterm infant bottle feeding near the time of discharge from the neonatal intensive care unit (NICU) when fed by mothers.Study design-Twenty-two very low birthweight (VLBW) infants [birthweight 1155 ± 293 g, gestational age (GA) 28.1 ± 2.0, postconceptional age (PCA) 36.5 ± 1.6 weeks] were videotaped being bottle-fed by their mothers. Most infants (86%) were discharged within 6 days of the study. Oxygen saturation was continuously monitored and infant feeding behaviors were coded. Oxygen desaturation events (SpO 2 < 90%) were identified and analyzed.Results-Infants averaged 10.8 events during feeding (range 1-28, S.D. 8.9) and spent, on average, 20% of their feeding time (range 0-70%, S.D. 17.98%) with oxygen levels below 90%. One hundred forty of the desaturation events (59%) were classified as mild (SpO 2 85-89), 47 events (20%) were classified as moderate (SpO 2 81-84), and 51 events (21%) were classified as severe (SpO 2 ≤ 80). Events were evenly distributed across infants' feeding time. Receiving supplemental oxygen, beginning the feeding with a higher baseline SpO 2 , and being of older PCA predicted lower percentage of feeding time with SpO 2 below 90% (R 2 = 0.57). Receiving supplemental oxygen and beginning the feeding with a higher baseline SpO 2 predicted less number of desaturation events during the feeding (R 2 = 0.44). Despite similar baseline SpO 2 levels, infants who were on supplemental oxygen had 50% less oxygen desaturation events and spent 33% less time with SpO 2 less than 90%.Conclusion-VLBW infants continue to have desaturation events during feeding when fed by their mothers near the time of discharge. Further research is needed to understand the effect of hypoxemia on the preterm infant's development of oral feeding skills, to study the effects of supplemental oxygen during feeding, and to further develop interventions to minimize desaturation during feeding.