A randomised prospective study comparing the new vacuum extractor policy with forceps delivery.

OBJECTIVE

To compare assisted vaginal delivery by forceps with delivery by vacuum extractor, where a new vacuum extractor policy was employed which dictated the cup to be used in specific situations.

DESIGN

Multicentre randomised controlled trial.

SETTING

Four district general hospitals in the West Midlands.

SUBJECTS

Six hundred-seven women requiring assisted vaginal delivery, of whom 296 were allocated to vacuum extractor delivery and 311 to forceps.

MAIN OUTCOME MEASURES

Delivery success rate, maternal perineal and vaginal injuries, maternal anaesthetic requirements, neonatal scalp and facial injuries.

RESULTS

Of the vacuum extractor group, 85% were delivered by the allocated instrument compared to 90% in the forceps group (odds ratio (OR) 0.64; 95% confidence intervals (CI) 0.4-1.04). However, more women in the vacuum extractor group were delivered vaginally (98%) than in the forceps group (96%). There were significantly fewer women with anal sphincter damage or upper vaginal extensions in the vacuum extractor group (11% vs 17%, OR 0.6; 95% CI, 0.38-0.97). There were significantly fewer women in the vacuum extractor group requiring epidural or spinal anaesthetics (25.4% vs 32.7%, OR 0.69; 95% CI 0.49-0.99) or general anaesthetics (1% vs 4%, OR 0.17; 95% CI 0.04-0.76). Although there were significantly more babies in the vacuum extractor group with cephalhaematomata (9% vs 3%, OR 3.3; 95% CI 1.4-7.4) there were fewer babies in the vacuum extractor group with other facial injuries. There were three babies in the forceps group with unexplained neonatal convulsions.

CONCLUSIONS

Assisted vaginal delivery using the new vacuum extractor policy is associated with significantly less maternal trauma than with forceps. Further studies are required to assess neonatal morbidity adequately.