More cesareans
Nine trials (4370 women) included in the Cochrane review reported cesarean section rates. Women in the amniotomy group had an increased risk of cesarean delivery compared with the control group, but the difference did not reach statistical significance (relative risk=1.26; 95% CI, 0.98-1.62).8 Because cesarean section was surprisingly rare in this low-risk patient population compared with the national average, the studies were not powered to show statistical significance in this secondary outcome.
What about neonatal outcomes?
No significant differences between the amniotomy and intact groups were noted in less uniformly reported maternal outcomes, including need for oxytocin to augment labor, rate of infection, serious morbidity, or death.8 Likewise, differences in neonatal outcomes—such as sepsis, respiratory failure, admission to the special care unit, and death—weren’t statistically significant. Notably, however, these secondary outcomes occurred too rarely to measure the effect precisely.
Because of the relatively small sample sizes and rarity of complications, the studies have limited ability to address the effect of routine amniotomy on maternal and neonatal morbidity in the general population. Larger studies, with a wider variety of patients, would improve clarity.
Recommendations
The American College of Obstetricians and Gynecologists (ACOG) hasn’t issued a statement on the use of routine amniotomy in normal labor. With regard to labor dystocia, ACOG states that “amniotomy may enhance progress in the active phase and negate the need for oxytocin augmentation, but it may increase the risk of chorioamnionitis.”9
And the ACOG bulletin on induction of labor reports that “the potential risks associated with amniotomy include prolapse of the umbilical cord, chorioamnionitis, significant umbilical cord compression, and rupture of vasa previa.”10