Vaginal birth after Caesarean section: an Australian multicentre study

Retrospective analysis of medical records and individual case review was un dertaken at 11 major obstetric hospitals for a 5 year period from July 1992 to June 1997 to investigate rates of vaginal birth after Caesarean section (VBAC), the occurrences of uterine rupture, and the outcomes for mother an d infant following rupture. Total deliveries were 234,015, of which 21,452 or 9.2% were associated with one or more previous Caesarean sections. Within this scar group, 5419 pati ents or 25.3% were delivered vaginally. There were 62 cases of significant uterine rupture with no maternal deaths. Perinatal mortality with rupture was 25% and serious maternal complication s (usually hysterectomy) occurred in 25% of those with uterine rupture. In women attempting vaginal delivery after a previous lower segment Caesarean section, the uterine rupture rate was estimated at 0.3%, with 0.05% experie ncing a perinatal death and 0.05% requiring a hysterectomy. Although VBAC rates in Australia remain lower than many overseas reported s eries, rates are increasing. While rupture continues to be associated with serious adverse outcomes, the incidence of rupture during trial of labour i s low and appears to be associated with a better outcome than rupture of an unscarred uterus.