Early Maternal and Neonatal Morbidity Associated With Operative Delivery in Second Stage of Labour: A Cohort Study

Abstract

Obstetricians frequently must decide the best way of minimizing morbidity when labor arrests at full cervical dilation. This prospective cohort study contrasted maternal and neonatal morbidity when selecting either instrumental vaginal delivery or cesarean delivery. The study group, 393 women, all had a singleton pregnancy at term with cephalic presentation, and all delivered a liveborn infant. Cesarean delivery was performed in 209 instances, and instrumental vaginal delivery succeeded in 184 cases. Roughly one fourth of women had immediate section with no attempt at vaginal delivery. Cesarean delivery was likelier after attempted ventouse delivery than after an attempt at forceps delivery. There were 58 deliveries using forceps alone, 67 ventouse deliveries, and 59 utilizing both methods. Risk factors favoring cesarean delivery included a maternal body mass index greater than 30, a birth weight above 4 kg, an occipitoposterior presentation, and station at the ischial spines. Suspected fetal distress was similarly frequent in the two groups. No women died, and none had thromboembolism. Major bleeding was more frequent with cesarean delivery but less likely if done by a senior rather than a middle-grade trainee. Discharge within 48 hours was likelier after vaginal delivery. Serious maternal injuries included extension of the uterine incision and third-degree vaginal tears. There were no perinatal deaths, but two infants had symptoms of hypoxic-ischemic encephalopathy. Trauma such as facial and scalp bruising was significantly less common after cesarean delivery. Six vaginally delivered infants had brachial plexus injuries. Two infants had intracerebral bleeding when cesarean delivery was performed after failed instrumental delivery. Neonatal trauma was significantly likelier after failed vaginal instrumental delivery than after immediate cesarean delivery but less common than with successful instrumental delivery. This study supports the use of safe instrumental vaginal delivery when labor arrests, given appropriate circumstances such as availability of an operating theater and a skilled obstetrician. This approach is favored over cesarean delivery unless cephalopelvic disproportion is clearly present.