This paper presents the Protocol for a multicentre study that seeks to analyse the relationship between midwife care during childbirth and spontaneous vaginal birth. Each participating hospital collects outcome data from a sample of all women birthing, determined according to the number of annual births attended by midwives, in each hospital. Data collected are sociodemographic variables (age, nationality, level of education). Clinical variables collected are onset of labour, augmentation of labour, professional (midwife or obstetrician) providing care in the first and second stage of labour, transfer of care between professionals, mobility during labour, pharmacological and non-pharmacological pain-management methods used, if any, position for birth, mode of birth outcomes, Apgar score at 1 and 5 minutes, birth weight, timing of breastfeeding initiation and breastfeeding rates. The Bologna Score scale items, are evaluated also. The midwife’s contribution in the care of normal birth, and the relationship with spontaneous birth (i.e. vaginal birth without the use of instruments) will serve as a basis for further improving the quality of care provided to pregnant women and their families. Phase I of the study ended in January 2017.