Background Basic life support guidelines recommend placing spontaneously breathing children and adults on their side. Though the majority of preterm newborns breathe spontaneously, they are routinely placed on their back after birth. We hypothesised that they would breathe more effectively when placed on their side.

Objective To determine whether preterm newborns placed on their left side at birth, compared with those placed on their back, have higher preductal oxygen saturation (SpO₂) at 5 min of life.

Design/methods We randomised infants <32 weeks to be placed on their back or on their left side immediately after birth. Respiratory support was given with a T-piece and face mask with initial fraction of inspired oxygen (FiO₂) of 0.3. The FiO₂ was increased if SpO₂ was <70% at 5 min.

Results We enrolled 87 infants, 41 randomised to back and 46 to left side. The groups were well matched for demographic variables. Fourteen (6 back and 8 left side) infants did not receive respiratory support in the first 5 min. The mean (SD) SpO₂ was not different between the groups (back 72 (23) % versus left side 71 (24) %, p=0.956). We observed no adverse effects of placing infants on their side and found no differences in secondary outcomes between the groups.

Conclusions Preterm infants on their left side did not have higher SpO₂ at 5 min of life. Placing preterm infants on their side at birth is feasible and appears to be a reasonable alternative to placing them on their back.

Trial registration number ISRCTN74486341.