Four studies (n=1,456) were included: one retrospective cohort study with a control group (1,436 women undergoing TOLAC), one case series (n=18) and two case reports (n=2).
The retrospective cohort study (1,436 women undergoing TOLAC, including 122 women who had undergone amnioinfusion) found no increase in uterine rupture following amnioinfusion for women with previous Caesarean section (1 out of 122; 0.8%) compared with women with no previous Caesarean section versus (0%) or with the overall rate of uterine rupture at the same unit (1.1% overall). The study found that amnionitis was significantly increased in women undergoing amnioinfusion with previous Caesarean section compared with women with no previous Caesarean section (relative risk 1.75, 95% confidence interval: 1.19, 2.58).
The case series (n=18) found that 3 of the 18 women had a repeat Caesarean section and 15 women had a vaginal delivery, giving a successful trial of labour rate of 83%. No cases of uterine rupture or dehiscence were detected.
The two case reports each described one woman who required repeat Caesarean section following amnioinfusion for oligohydramnios. Both women were found to have uterine rupture or dehiscence.