1. The recommended minimum necessary CS rate at population level to avoid death and
severe morbidity in the mother lays between 1-5%, according to WHO and others. [15-17]
Regarding neonatal outcomes, studies evaluating the association of CS rates with neonatal
death have shown outcome improvements up to a CS rate of 10%. [2,3,6] Thus the
minimum threshold for a population level CS rate could be considered to lay between 5-
10%.
2. Regarding the upper level, the best known recommended upper limit is 15%, suggested by
WHO in 1985. [9] Although these figures are based on theoretical estimates, two recent
observational studies support that recommendation. [3,6] Both studies assessed the
association between CS rates and mortality and morbidity in mothers and neonates, and
found no reductions in those indicators when frequency of caesarean section was more than
15%. Moreover, one study showed that an increased rate of intervention was associated
with higher mortality and morbidity in mothers and neonates. [6] Until further research
gives new evidence, rates >15% may result in more harm than good. [1]