[The worrying rise in the frequency of cesarean section]

The rise in the incidence of Cesarean section over the last thirty years is due to several factors. In particular, maternal age is increasing, parity is declining, and situations potentially requiring Cesarean section are more frequently encountered than before (prematurity, medically assisted procreation, antenatal diagnosis, previous Cesarean section, etc.). Medicolegal pressure is also increasing, and the precautionary principle is leading more and more physicians to propose Cesarean section rather than trial labor. However, although the risks of this form of delivery have decreased, they are still higher than those of vaginal delivery, except in the emergency setting. Moreover, various pathophysiologic studies have demonstrated marked changes in the elevator muscles, nerves and pelvic support after vaginal delivery. The maternal morbidity and mortality of elective caesarean delivery at term, before the onset of labor, appear to be similar to those associated with vaginal birth. However, the maternal risks (particularly placenta praevia, placenta accreta, and uterine rupture) during subsequent pregnancies following Cesarean delivery require careful evaluation. After Cesarean section, the risk of placenta praevia during the next pregnancy is between 1% and 4%. There is subsequently a linear increase, with the risk of placenta praevia reaching nearly 10% after four Cesarean deliveries. The risks and benefits of each form of delivery are extremely difficult to weigh up, and predictors of safe vaginal delivery are lacking.