Anesthetic dose neuraxial blockade increases the success rate of external fetal version: a meta-analysis

This study is a meta-analysis evaluating the efficacy of central neuraxial blockade (CNB) (epidural or spinal) to facilitate fetal version.

A search with no language restriction for all available randomized controlled trials (RCT) was conducted in PUBMED on July 2, 2009, EMBASE 1980 to 2009 Week 27, Ovid MEDLINE(R) 1950 to Week 4 in June 2009, EBM Reviews - Cochrane Central Register of Controlled Trials 2(nd) Quarter 2009, and CINAHL on July 4, 2009. Reference lists of all studies were also checked. Two investigators extracted data independently. The optimal information size (OIS) was calculated on a 50% failure rate of fetal version for a relative reduction of 25% (alpha = 0.05 two-tailed, beta = 0.2).

The OIS was 494. Seven RCTs were found, including 681 pregnant women with a Jadad score from 1 to 3. Central neuraxial blockade increases the success rate of fetal version (risk ratio [RR] = 1.44; 95% confidence interval [CI] = 1.16-1.79; P = 0.001) (random effects model; I(2) = 30.25%; P value for heterogeneity = 0.20). Three studies used a CNB at anesthetic dose of local anesthetic (RR = 1.95; 95% CI = 1.46-2.60; P < 0.001; I(2) = 0.00%; P value for heterogeneity = 0.86; number needed to treat = 4; 95% CI = 3-6). Four studies used an analgesic dose (RR = 1.18; 95% CI = 0.94-1.49; P = 0.15; I(2) = 0.00%; P value for heterogeneity = 0.77). These two subgroups were significantly different one from the other with a P value of 0.007.

Anesthetic dose neuraxial blockade increases the success rate of external fetal version.