The rates of medically assisted births have been in constant increase all over Europe and westernized countries specifically (R Simms and R Hayman 2010). It is now better understood that the type of birth one goes through can cause dysfunctions in the body, leading to various different complaints. As osteopaths we will come along treating newborns all through our careers. It is therefore interesting to see how birth can lead to specific lesions and how osteopathy could help in these cases. Here we have chosen to investigate the consequences on the diaphragm, crucial structure in the optimal function of both thoracic and abdominal cavities, which acts as an engine for visceral dynamics (Finet G. Williame C. 2000). This study was undertaken in order to see if medically assisted births inclined a newborn to diaphragm dysfunctions more than in cases of an unaided vaginal delivery. This was achieved by analyzing 140 case histories selected randomly from the E S.0 children’s clinic database from September 2011 to November 2012 Comparison between caesarean sections, forceps and ventouse deliveries with ‘natural vaginal birth was done through a data collection sheet. The results showed that an association existed between medically assisted births, unaided deliveries and presence or not of diaphragm lesions. However no statistical significance allowed us to come to confirm or reject our hypothesis.