Strengths and limitations:
The strengths of this study are the study size, and the unbiased and
random selection of the participants from all of Denmark, meaning that
there was no selection for social status, income, race etc. All samples
were handled in the same way, and analyzed in the same labouratory, thus
minimizing analytic variance. We were not able to account for lifestyle
factors associated with maternal request for CS or factors increasing
the risk of CS. Further, we did not have any information regarding
length of labour.