Payment mechanisms represent the instrumental dimension of purchasing in health. Given their nature, they can incentive providers and insurers in a positive or negative way. Having in mind that public and private sectors operate under different incentives, it is feasible to discuss whether current payment mechanisms for childbirth have an effect or not on C-sections rates. The purpose of this article is to provide the elements for the onset of the following discussion: given the characteristics of labour and childbirth, which is the best payment mechanism for it? Should insurers establish different payment mechanisms for C-sections and vaginal childbirths as a strategy for the promotion of vaginal birth? Which is the real trade-off and right balance between financial risk among insurance and provider in order to satisfy women´s and newborns´ rights?.