Maternal Positioning in the Second Stage of Labour and its Relationship with Perineal Trauma: A Systematic Review and...

Perineal trauma is frequent after childbirth and may be influenced by maternal position. We aimed to synthesize pooled estimates comparing positions in the second stage of labour and their association with perineal tears and episiotomy, using a network meta-analysis (NMA) of randomized controlled trials (RCTs).

Systematic review and NMA of RCTs identified in Cochrane Library Plus, EMBASE, Scopus, PubMed, and ClinicalTrials through June 2024, without language or date restrictions. Outcomes were 1st-degree tears (involving skin and mucosa), 2nd-degree tears (involving perineal muscles), and 3rd/4th-degree tears (involving the anal sphincter and rectal mucosa), as well as episiotomy. We estimated pooled odds ratios (ORs) with 95% confidence intervals (CIs) for upright vs supine/lithotomy and performed a network of individual positions. This review article is based exclusively on previously published literature. Therefore, ethical approval was not required and was exempted by the Institutional Review Board.

Nine RCTs (n = 7621) were included. In pooled analyses of upright vs supine/lithotomy, we found no significant differences for 1st-degree tears (OR 1.14, 95% CI 0.76-1.72), 2nd-degree tears (OR 0.98, 95% CI 0.70-1.38), 3rd/4th-degree tears (OR 0.92, 95% CI 0.06-13.93), or episiotomy (OR 0.54, 95% CI 0.22-1.34). In position-level network analyses, standing was ranked lowest-risk for 1st-degree tears (SUCRA 79.1%); squatting ranked lowest-risk for 2nd-degree (SUCRA 93.9%) and for 3rd/4th-degree tears (SUCRA 94.3%); and hands and knees ranked lowest-risk for episiotomy (SUCRA 100%). These position-level findings were based on a limited number of contributing trials and should be interpreted cautiously.

Overall, pooled RCT evidence shows no significant difference in perineal tears of any degree or episiotomy between upright and supine/lithotomy positions. Network estimates suggest potential differences between specific positions, but the evidence is limited and heterogeneous. Birthing position should primarily reflect women's preferences and comfort, while considering other key predictors of perineal trauma (e.g. parity, operative delivery, and episiotomy itself). In addition, the findings from this meta-analysis can be used to provide individualized counselling, taking into account each woman's specific risk factors. This approach may help inform and guide shared decision-making, supporting women in choosing the birthing position that best aligns with their circumstances, preferences, and clinical profile.