Part 2- Prospective data collection
The second part of the study was the prospective data collection. The
classification can be used for all women either in spontaneous or
induced labour. However the inclusion criteria for the Nor-Why-Cesarean
study were singleton pregnancies with a gestational age of more than
36+6 weeks. Exclusion criteria were multiple pregnancies, deliveries at
a gestational age < 37 weeks and all pre-labour CSs. For the
purpose of the current study, we also excluded all breech deliveries
(Group 6 and 7), thus focusing on women in the TGCS groups 1, 2a, 3, 4a
and 5a, b, respectively (Fig. 2).
After delivery, the study form of ICSCS, designed in cooperation with
the Medical Birth Registry (Supplement 2) was completed by the certified
local project collaborators. Guidance for classification, case examples
and information about the project was available through access to a
cloud-saved project folder. Email contact with the author of the
classification (MR) was available for assistance in the confirmation of
classification of any cases where there was disagreement. The study
forms were sent to the Medical Birth Registry, scanned and read
electronically, and data converted into a statistical file format. Data
collected in the study was then linked case by case through the unique
personal identification number with data routinely collected to the
registry from the electronic obstetric patient record.
The proportion of different subcategories in the ICSCS is presented as
mean and 95% confidence interval of the mean. Non-overlapping
confidence intervals indicate a significant difference between different
proportions.
The project took place under the umbrella of the Medical Birth Registry
of Norway. Collection of perinatal data to the registry is mandatory
without the necessity of written informed consent from the pregnant
women. The study was approved by the research ethics committee (REK Nord
2018/1682-3).