The HiLo-Trial has enrolled 7️⃣0️⃣0️⃣ babies Congratulations and Thank you!

We would like to congratulate all sites for recruiting 700 of 1200 patients. Congratulations, what an achievement! Thank you to everyone involved and being part of the HiLo-journey and thanks to all the parents who have consented for their babies to be part of this trial.

Oxygen is a vital element in the care of preterm infants and has been given more often than any other drug over the past 80 years. Despite this, we know very little about how much or how little oxygen is safe particularly at birth. Preterm birth, or birth before 37 weeks’ gestation, is occurring in 8% of pregnancies in Canada. Preterm birth is associated with many health complications, particularly when the birth happens before 29 weeks’ gestation. At this gestational age, the lungs are not fully developed and it is not uncommon for infants to have problems breathing at the time of birth. One complication that can arise is when an infant stops breathing and needs to be resuscitated. When preterm babies need to be resuscitated doctors must take special care because of the immaturity of the brain and lungs. Oxygen is used to resuscitate babies who need it, but unfortunately there is disagreement about the best oxygen concentration to use. Oxygen concentration is important because both too much and too little oxygen can cause brain injury. In the HiLo-trial we compare the effects of resuscitating babies less than 29 weeks’ gestational age with either a low oxygen (30%) concentration or a high oxygen (60%) concentration. The oxygen concentrations have been selected using the best available knowledge at the time of the start of the trial. The trial design is a cluster cross over design, in which each sites recruits a certain number of infants in each arm. Once the target number in one arm has been reached, the site is changing over to the other arm. Once both targets (which are equal numbers) are recruited, the site is closed for recruitment.