Cesarean section odds ratios.

Cesarean section (CS) rates for primiparas, multiparas with and without previous CS were investigated in seven obstetrical settings. Despite the great diversity of global CS rates (5.3 to 17.4%), common CS odds ratios of 3.0 and 37 have been found for primiparas and multiparas with previous CS, respectively. Internal links between CS odds ratios have also been investigated for some anomalies associated with CS (fetal distress, non-vertex presentation, hypertension, dystocia, small for dates new born and prematurity), suggesting that perinatal services may be evaluated on CS aspects according to a single general interventionist/conservative clinical attitude. Data from two additional obstetrical settings were used to verify the findings in terms of perinatal evaluation.