Introduction Neonatal care has been considered as one of the first priorities for improving quality of life in children. In 2010, 10% of babies were born prematurely influencing national healthcare policies, economic action plans and political decisions. The use of complementary medicine has been applied to the care of newborns. One previous study documented the positive effect of osteopathic manipulative treatment (OMT) in reducing newborns’ length of stay (LOS). Aim of this multicentre randomised controlled trial is to examine the association between OMT and LOS across three neonatal intensive care units (NICUs).

Methods and analysis 690 preterm infants will be recruited from three secondary and tertiary NICUs from north and central Italy and allocated into two groups, using permuted-block randomisation.

The two groups will receive standard medical care and OMT will be applied, twice a week, to the experimental group only. Outcome assessors will be blinded of study design and group allocation. The primary outcome is the mean difference in days between discharge and entry. Secondary outcomes are difference in daily weight gain, number of episodes of vomit, regurgitation, stooling, use of enema, time to full enteral feeding and NICU costs. Statistical analyses will take into account the intention-to-treat method. Missing data will be handled using last observation carried forward (LOCF) imputation technique.

Ethics and dissemination Written informed consent will be obtained from parents or legal guardians at study enrolment. The trial has been approved by the ethical committee of Macerata hospital (n°22/int./CEI/27239) and it is under review by the other regional ethics committees.

Results Dissemination of results from this trial will be through scientific medical journals and conferences.

Trial registration This trial has been registered at http://www.clinicaltrials.org (identifier NCT01645137).