Results
A total of 30591 deliveries were recorded. Advanced maternal age was an independent risk factor (RF) in groups 1, 2A, 3, and 4A; diabetes was a RF in groups 1 and 5; obesity was a RF in groups 1 and 2A and a protective one in group 5; hypertension was a RF in groups 2A, 5 and 10; macrosomia was a RF in groups 1, 2A and 3; use of obstetric analgesia was either a RF in group 1, and a protective factor in groups 2A, 5 and 10; immigrant status was either a protective factor in groups 1 and 10, and a RF in group 4A.