[Differences in cesarean sections between spontaneous and induced labour].

BACKGROUND The induction of labour (IOL) may be associated with complications for pregnant women. The aim was to assess the differences in the number of caesarean sections between spontaneous or induced labour. METHODS Historical groups from 841 women with induced labour and 2,534 women with an spontaneous onset of labour over a three- year period (from 2009 to 2011). They were carried out in "Mancha Centro" Hospital (Alcázar de San Juan). It was used a multivariate analysis through binary logistic regression to control confounding variables. RESULTS The prevalence of IOL was 22,9%. The most frequent indications were: Premature Rupture of Membranes (22,7%), bad- controlled Diabetes (22,5%). It was reported a relation between induced labour and cesarean section risk due to parity (nulliparous OR= 2.68, IC 95%: 2.15- 3.34 and multiparous OR= 2.10, IC 95%: 1.72- 2.57). Postterm pregnancy (37,1%), pathological monitor (35.3%) and hypertensive diseases of pregnancy (34%) reported the highest risks of cesarean section. The IOL was related to other factors: a long- time length first -stage of labour (OR= 6.00; IC 95%: 4.02- 8.95), use of epidural analgesia (OR= 3.10; IC 95%: 2.24- 4.29) and blood transfusion needs (OR= 3.33; IC 95%: 1.70- 9.67). CONCLUSION Independently of parity, The IOL increases the risk to: have a longer duration first- stage, use epidural analgesia, need a blood transfusion and have a cesarean section. This relation is stronger when induction is due to postterm pregnancy, pathological monitor or hypertensive diseases. No relation was found among induced labour and second- stage duration, episiotomy, perineal tears, excessive blood loss or uterine rupture.