A properly conducted trial of a ventouse can prevent unexpected failure of instrumental delivery

A retrospective study over a 5-year period reviewed 71 unexpected failures of instrumental delivery and compared them with a group of 21 trials of ventouse to identify causes for failure and their impact on neonatal outcome. There was a statistically significant difference between the two groups in terms of pre-application assessment of fetal size, maternal pelvis and palpable fetal head above the pelvic brim (P less than 0.00001). There was also a significant difference in neonatal morbidity (P less than 0.01). All 5 neonatal deaths occurred in the failure group and were associated with multiple instrumentation.