Risk factors for severe perineal lacerations during childbirth: A systematic review and meta‐analysis of cohort studies

Abstract

Aims and objectives To evaluate and quantify the best available evidence regarding risk factors for severe perineal lacerations. Background Many studies have evaluated the risk factors for severe perineal lacerations. However, the results of those studies are inconsistent, and meta‐analysis which thoroughly evaluates the risk factors for severe perineal lacerations is still lacking. Design Systematic review and meta‐analysis of cohort studies based on the PRISMA guideline. Methods PubMed, Embase, the Cochrane Library, CINAHL, http://clinicaltrials.gov, CNKI, Wanfang Data, VIP and SinoMed were systematically searched for cohort studies reporting at least one risk factor for severe perineal lacerations from 1 January 2000 to 2 June 2021. Two reviewers independently conducted quality appraisal by NOS scale and extracted data. Data synthesis was conducted via RevMan 5.3 using a random‐effects or fixed‐effects model. Results A total of 47 studies with 7,043,218 women were included. The results showed that prior caesarean delivery (OR: 1.46, 95% CI 1.12–1.92) and pre‐pregnant underweight (OR: 1.31, 95% CI 1.22–1.41) significantly increased the risk of severe perineal lacerations. The results also demonstrated that episiotomy was protective against severe perineal lacerations in forceps delivery (OR: 0.56, 95% CI 0.42–0.74), but not spontaneous vaginal delivery (OR: 1.30, 95% CI 0.81–2.07) or vacuum delivery (OR: 0.76, 95% CI 0.45–1.28). Nulliparity, foetus in occipitoposterior or occipitotransverse position, and midline episiotomy were also independent risk factors for severe perineal lacerations. Conclusions Severe perineal lacerations are associated with many factors, and evidence‐based risk assessment tools are needed to guide the midwives and obstetricians to estimate women's risk of severe perineal lacerations. Relevance to clinical practice This systematic review and meta‐analysis identified some important risk factors for severe perineal lacerations, which provides comprehensive insights to guide the midwives to assess women's risk for severe perineal lacerations and take appropriate preventive measures to decrease the risk.

Predicting obstetric anal sphincter injuries among laboring women: 2 prediction models and 1 risk calculator

“…The results of the systematic review indicated 15 potential risk factors for OASIS: advanced maternal age (35 y and above) (adjusted OR: 1.22, 95% CI: 1.09–1.36), Asian ethnicity (adjusted OR: 2.06, 95% CI: 1.74–2.45), prepregnancy underweight (body mass index ≤18.5 kg/m 2 ) (adjusted OR: 1.31, 95% CI: 1.22–1.41), nulliparity (adjusted OR: 2.39, 95% CI: 1.93–2.96), prior cesarean delivery (adjusted OR: 1.23, 95% CI: 1.07–1.41), estimated birth weight ≥3500 g (adjusted OR: 1.74, 95% CI: 1.58–1.92), fetus in occipitoposterior or occipitotransverse position (adjusted OR: 1.64, 95% CI: 1.41–1.91), gestational age ≥40 weeks (adjusted OR: 1.18, 95% CI: 1.11–1.26), epidural analgesia (adjusted OR: 0.89, 95% CI: 0.81–0.97), labor induction (adjusted OR: 1.05, 95% CI: 1.01–1.09), labor augmentation (adjusted OR: 1.19, 95% CI: 1.06–1.35), operative vaginal delivery (adjusted OR: 2.40, 95% CI: 2.11–2.74), episiotomy (adjusted OR: 1.41, 95% CI: 1.00–2.00), prolonged second stage of labor (adjusted OR: 1.80, 95% CI: 1.70–1.90), and shoulder dystocia (adjusted OR: 1.86, 95% CI: 1.72–2.01)25. The factors known before childbirth and modifiable during childbirth are listed in Table 1.…”

“…Selection of significant predictors for OASIS Significant predictors were selected through a published systematic review and meta-analysis by the researchers of this study, in which cohort studies reported risk factors for OASIS during childbirth were included 25 . Of the 47 studies included in the systematic review, only 4 used a prospective cohort study design; the remaining 43 used a retrospective cohort study design.…”

“…Sensitivity and subgroup analyses were also conducted to select the appropriate OR and 95% CI. Please refer to the systematic review and meta-analysis published by our research team for detailed information on the data source for model development 25 . Among the risk factors identified through systematic review and meta-analysis, only known factors before childbirth and modifiable factors during childbirth were selected to establish prediction models for OASIS to enhance the clinical applicability of the prediction models.…”

“…The results of the systematic review indicated 15 25 . The factors known before childbirth and modifiable during childbirth are listed in Table 1.…”

3D Ultrasound in Pelvic Floor: Is It Useful as a Prognostic Tool in Type of Labor Development and Subsequent Pelvic Floor Diseases?

“…Another relevant aspect in the results of the study is the relationship that may exist between the decrease in thickness of the pubovisceral muscle and the performance of labor induction. In fact, labour induction has been studied as one of the important risk factors for pelvic floor tears [ 45 , 46 , 47 , 48 ]. In our study, patients who had a thickness of the pubovisceral fasciculus less than the average, have a higher probability of labour induction (OR = 3.34; CI 95% 0.94–11.85; p = 0.06).…”