Objective: It is well known that a brief exposure to 100% oxygen for only a few minutes 
could be toxic for a preterm infant. The effectiveness of neonatal resuscitation was compared 
with low concentration oxygen (30%) and high concentration oxygen (HOG) (100%).
Methods: Thirty-two preterm neonates were born in Isfahan Shahid Beheshti hospital 
with gestational age of 29-34 weeks who required resuscitation were randomized into 
two groups. The resuscitation was begun with 30% O2 in low concentration oxygen group 
(LOG). The infants were examined every 60-90 seconds and if their HR was less than 100, 
10% was added to the previous FIO2
 (fraction of inspired oxygen) until the HR increased 
to 100 and SO2
 (saturation of oxygen) increased to 85%. In HOG resuscitation begun with 
100% O2
 and every 60-90 seconds, FIO2
 was decreased 10 – 15% until the HR reached to 
100 and SO2
 reached to 85%.
Findings: The FIO2
 in LOG was increased stepwise to 45% and in HOG was reduced to 
42.1% to reach stable oxygen saturation more than 85% at the fifth minute in both groups. 
At the first and third minutes after birth and there was no significant differences between 
groups in heart rate and after 1,2,4 and 5 minutes after the birth there was also no significant 
differences in SO2
 between groups, regardless of the initial FIO2
.
Conclusion: We can safely initiate resuscitation of preterm infants with a low FIO2
(approximately 30%) oxygen and then oxygen should be adjusted with the neonates needs.