Eligibility Criteria
Any cross sectional, observational, cohort studies and RCT studies comparing FS (standing, kneeling, sitting, squatting and birthing ball and lateral positions) against supine position, were peer-reviewed and reported in original research articles were considered for the present review.
All pregnant women with normal labor at health facility, the main comparison was the use of any upright or lateral position during the second stage of labor (FSP) compared with supine or lithotomy/recumbent/semi-recumbent positions.
The primary outcome is duration of second stage of labor. No secondary outcome was taken in to consideration.
We excluded studies reported in languages other than English, systematic review and meta analysis, studies considering high risk pregnancy and inaccessible full-text articles.
Search strategy
Data base (www.crd.york.ac.uk/prospero) was explored to confirm whether systematic review or meta-analysis existed before. The titles of all appropriate abstracts and titles collected from electronic and manual searches were entered into the EndNote-7 reference software. The reference lists of all the articles were also scrutinized for further studies.
Potentially relevant articles for the review were identified by searching bibliographical Databases: Medline/PUBMED, JBI library and SCOPUS. Google scholar and Google were searched to include all pre-reviewed articles. Search terms used were directly related to the title: women, labor second stage, upright position, duration, supine position and birth. In the search strategy we included combination of keywords extracted from the title: effect Or influence AND maternal OR women AND positions (standing, kneeling, all four, sitting, squatting, lateral, supine) AND birth OR delivery OR parturition AND duration AND second stage of labor. Additional relevant articles were identified by searching the reference lists of full-text articles and grey literatures from Google and Google scholar.
Study selection
Each title and abstract was screened by two independent reviewers using a standardized form(12). Each full text article was reviewed by two independent reviewers using standardized inclusion criteria: (a) presents primary data analysis; (b) uses a quantitative method of data collection and analysis (quantitative studies); (c) discusses maternal birth position in relation to duration of second stage; (d) discusses childbirth occurring in health facilities; and (e) was published in English. Discrepancies during title and abstract and full text screening were resolved by discussion with a third reviewer until consensus was reached.
Quality assessment
All papers selected for inclusion were subjected to a rigorous, independent appraisal by the investigators using standardized critical appraisal instruments adopted from JBI. The tool addresses both the external and internal validity and has multiple items for each type of study for risk of bias. Furthermore, it has nine items for cross-sectional and thirteen items for RCT to be used. The overall risk of study bias ranked into one of the four levels (High, Moderate, Low, Very Low), for inclusion or exclusion of studies. The reviewers for this study interpret this ranking system based on the recommendation from JBI reviewer manual, (High=75-100%, Moderate=50-75%, Low= 25-50% and <25%). Hence we decided to include studies which score with high (75-100%) and moderate (50-75%). Accordingly, only one paper lies in the moderate range and the others seven lie in the high range(13).
To ascertain scientific rigor, we used the Preferred Reporting of Systematic Reviews and Meta-Analysis (PRISMA) guidelines for systematic data analysis (14). The two reviewers were blinded to each other for screening of studies, data extraction, and risk of bias assessment parts of the review. If any differences seen when we compare results from the two reviewers, the third reviewer was communicated.
Data extraction and outcome of interest
Data were extracted from each study included in the review using a pre-constructed criteria based on the standardized JBI data extraction tool (15). Two authors extract data and they compared the results; discrepancies were resolved by discussion by the reviewer made, for the decision third reviewer was contacted. We were contacted the original authors of the eligible studies through email or phone for further clarification of data. For each study we extracted the following domains.
i) Author(s) and years of publication
ii) Study designs (cross sectional, observational, cohort and RCT studies)
iii) Country or region
iv) Sample size for each groups
v) Main findings (mean and standard deviation of second stage duration in each group)
The outcome of interest was duration elapsed in the second stage of labor measured in minutes
Data Analysis
We undertook an initial descriptive analysis of the studies. Heterogeneity between estimates was assessed using the I2 statistic, to describe the percentage of variation not because of sampling error across studies. An I2 values above 75% indicates considerable heterogeneity (16)
Potential influences on mean estimates was investigated using subgroup analyses, we compared mean estimates by region, within studies. Pooled mean difference of labor duration of FSP birthing positions versus supine position in the second stage was analyzed using statistical meta-analysis software STATA version11.