BACKGROUND AND PURPOSE:

• Amniotomy is commonly performed to accelerate the course of labor
  • Amniotomy may shorten labor and decrease risk of cesarean delivery when performed in spontaneous labor
• The benefit of early amniotomy for women undergoing induction of labor (IOL) is unclear
• Kim et al. (AJOG, 2019) examined the efficacy and safety of early amniotomy during IOL

METHODS:

• Systematic review and meta-analysis
• Data sources
  • Medline, Embase, and Web-of-Science databases (from conception to end-of-search date, Dec. 31, 2018)
• Inclusion study criteria
  • RCTs
  • Comparing early amniotomy prior to active phase of labor to spontaneous or late amniotomy
  • Full articles in English
  • Singleton viable term fetus
  • Patients undergoing IOL for any indication
• Study design and data analysis
  • Pooled data using the random-effects and fixed-effects models after assessing for the presence of heterogeneity
  • Risk of bias assessed
  • Subanalysis of nulliparous only was performed
• Primary outcomes
  • Cesarean delivery
  • Time to delivery
• Secondary outcomes
  • Intrapartum infectious morbidity | Operative delivery and indication for cesarean | Cord prolapse | Uterine hyperstimulation | Meconium-stained amniotic fluid | Neonatal outcomes, including NICU admission

RESULTS:

• 7 studies | Total of 1,775 patients
  • Early amniotomy group: 884 patients
  • Late/spontaneous amniotomy group: 891 patients
  • There were differences in IOL indications noted between studies
• Early amniotomy was associated with a shorter time to delivery
  • Mean difference –3.62 hours (95% CI, –6.09 to –1.16)
• Subanalysis: In nulliparous women, early amniotomy was associated with a 5-hour shorter time to delivery
  • Mean difference –5.12 hours (95% CI, –8.47 to –1.76)
• No differences found in
  • Rate of cesarean delivery: Relative risk (RR) 1.09 (95% CI, 0.80 to 1.49)
  • Rate of intrapartum infectious morbidity: RR 1.42 (95% CI, 0.77 to 2.61)
• There were no differences in any of the other secondary outcomes evaluated
• Only 2 cases of cord prolapse noted (data from 5 studies) both in the early amniotomy group

CONCLUSION:

• Authors note these results are consistent with previous retrospective data Cochrane review regarding faster time to delivery
• Cord prolapse incidence was no higher than that reported in the literature, but authors acknowledge this present meta-analysis was not powered for this outcome  
• Authors acknowledge study limitations, including study heterogeneity and underpowered for some of the secondary outcomes including neonatal infection
• The authors state that

Although our results show a shorter time to delivery with early amniotomy, there is no substitute for sound clinical judgment that incorporates the entire clinical context

Learn More – Primary Sources:

Role of early amniotomy with induced labor: a systematic review of literature and meta-analysis

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Does Elective Induction of Labor at 39 Weeks Gestation Lead to Improved Maternal and Newborn Outcomes?

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