Authors' objectives

To examine the efficacy and perinatal and maternal safety of misoprostol as a cervical ripening and labour induction agent.

Searching

Searches for the years 1986 to 1995 of the Bibliographic Retrieval Service, MEDLINE, Current Contents and Silver Platter were made (search terms given). The reference lists of studies and review articles were screened for further references.

Study selection

Assessment of study quality

The validity of primary studies was evaluated according to the Moher checklist for RCTs (Control Clin Trials 1995; 16:62-73). Each study's methodological attributes were assessed for quality by two investigators,who were blinded to study authorship and institutional affilitation.

Data extraction

The authors do not state how the data were extracted for the review, or how many of the authors performed the data extraction.

Methods of synthesis

Results of the review

Eight studies were included, with a total of 966 patients (488 treated with misoprostol and 478 controls).

The results of the analysis demonstrated that women receiving misoprostol had a lower Caesarean rate than controls (15% vs. 21.5%; OR 0.67; 95% CI 0.48, 0.93; P = .02) and were significantly more likely to experience vaginal delivery within 24 hours (OR 2.64, 95% CI 1.87, 3.71). Misoprostol use was associated with a 4.6 hour reduction in the interval from first dose to delivery (all deliveries) (95% CI, -3.5, -5.7; P<.001) and a 5.6 hour reduction in the interval from first dose to vaginal delivery (95% CI, -3.8, -7.5; P=0.028). The incidence of spontaneous labour was significantly higher in the misoprostol group (OR 8.20, 95% CI 5.70, 11.78) and the percentage of women requiring oxytocin administration was significantly lower (OR 0.29, 95% CI 0.21, 0.41).

No differences in the incidence of low 5-minute Apgar scores and admissions to the neonatal intensive care unit were noted between groups. Women receiving misoprostol were significantly more likely than controls to experience tachysytole (OR 2.70, 95% CI 1.80, 4.04), although the incidence of hyperstimulation syndrome (foetal heart rate abnormalities associated with tachysystole) were not significantly different between groups, OR 1.91 (95% CI, 0.98, 3.13).

Authors' conclusions

Published data demonstrate the safety and efficacy of intravaginal misoprostol for cervical ripening and labour induction.

CRD commentary

Overall this is a high quality systematic review. The literature search was well described and fairly comprehensive, although no attempt was made to search for grey literature or unpublished material. However little information on the inclusion and exclusion criteria for the review was presented. Validity assessment of the studies was conducted in a blinded manner by two authors using a recognised quality assessment scale. Details regarding methodological quality and outcomes were presented in table format, although insufficient information was provided regarding the actual interventions used. The data synthesis was conducted in an appropriate manner, using both random-effects and fixed-effect models, and the potential reasons for any differences between studies were investigated statistically.

Bibliographic details

Sanchez-Ramos L, Kaunitz A M, Wears R L, Delke I, Gaudier F L. Misoprostol for cervical ripening and labor induction: a meta-analysis. Obstetrics and Gynecology 1997; 89(4): 633-642. [PubMed: 9083326]

Other publications of related interest

Hofmeyr GJ. Misoprostol administered vaginally for cervical ripening and labour induction in the third trimester (Cochrane Review). In: The Cochrane Library, Issue 3, 1998. Oxford: Update Software.

Indexing Status

Subject indexing assigned by NLM

MeSH

Cervix Uteri /drug effects /physiology; Female; Humans; Labor, Induced; Misoprostol; Oxytocics; Pregnancy; Randomized Controlled Trials as Topic

AccessionNumber

11997000445

Database entry date

31/10/1998

Record Status

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.