Prospective Study Comparing Two Classification Systems for Second-degree Vaginal Tears During Spontaneous Childbirth to Assess Their Ability to Predict Postpartum Complications.

Overview

Second-degree perineal tears are one of the most common complications during vaginal childbirth. These injuries involve the muscles of the perineum but do not affect the anal sphincter. Although frequent, they vary greatly in severity, and their short- and long-term consequences can include pain, bleeding, hidden muscle damage, and sexual function problems. Currently, there is no widely used, detailed system to sub-classify these tears, which makes it harder to study their relationship with postpartum complications and to guide follow-up care. Two classification systems have been proposed: The Scandinavian classification (Macedo et al., 2022), which grades second-degree tears based on the percentage of the perineal body involved (2A: \<50%, 2B: \>50%, 2C: entire perineal body and/or large vaginal extension). The De Simone classification, which describes tears according to their extension along the vaginal wall (lower third, middle third, upper third/fornices) and muscle involvement, with specific codes for isolated locations. This prospective, single-center observational study at AOU Vanvitelli will enroll 482 women who have a spontaneous vaginal delivery and a spontaneous second-degree perineal tear. Each tear will be independently classified according to both systems, without any additional procedures beyond routine clinical care. The primary aim is to determine which classification better correlates with important postpartum outcomes: significant drop in hemoglobin levels, moderate-to-severe perineal pain (VAS ≥5), occult lesions detected by postpartum perineal ultrasound, and abnormal Female Sexual Function Index (FSFI) scores at follow-up. By directly comparing these two systems in the same population, the study seeks to identify whether a more detailed classification can improve prediction of complications, guide patient counseling, and inform postpartum follow-up. The findings may contribute to better standardization in describing these tears and improved care for women after childbirth.

Second-degree perineal tears are among the most frequent complications of spontaneous vaginal delivery, involving the perineal muscles without damage to the anal sphincter complex. Despite their high incidence, these tears vary greatly in depth, length, and anatomical involvement, which may affect postpartum pelvic floor health, pain, bleeding, and sexual function. Current standard classification systems, such as that recommended by the Royal College of Obstetricians and Gynaecologists (RCOG), do not provide subcategories for second-degree tears, potentially limiting accurate prognostic assessment. Two more detailed systems have been proposed: Scandinavian classification (Macedo et al., 2022) - subdivides second-degree tears based on the percentage of the perineal body affected: 2A: \<50% of the perineal body, with or without lower vaginal tear ≤2 cm. 2B: \>50% of the perineal body, with or without lower vaginal tear ≤2 cm. 2C: entire perineal body, with or without lower vaginal tear \>2 cm. Vaginal extensions \>4 cm from the tear margin are also documented. De Simone classification - describes second-degree tears according to their vaginal extension and muscle involvement: 2a: lower third of the vagina with muscle involvement (includes uncomplicated episiotomy). 2b: extension from the lower to the middle third of the vagina. 2bx: isolated tear of the middle third of the vagina. 2c: extension from the lower to the upper third (including fornices). 2cx: isolated tear of the upper third (including fornices). Evidence comparing these systems in terms of clinical outcome prediction is lacking. Study Design This is a prospective, single-center, observational cohort study conducted at AOU Vanvitelli - UOC di Ostetricia e Ginecologia. The study will enroll 482 women undergoing spontaneous vaginal delivery who sustain a spontaneous second-degree perineal tear. No experimental intervention is performed; classification occurs during routine postpartum examination. All eligible tears will be classified independently by two trained operators using both classification systems. Data will be collected on hemoglobin change, perineal pain, postpartum ultrasound findings, and FSFI scores. Objectives Primary Objective: Compare the diagnostic accuracy of the Scandinavian vs. De Simone classification systems in predicting postpartum complications. Secondary Objectives: Evaluate the association of each tear subtype with: Postpartum hemoglobin reduction Perineal pain (VAS ≥5) Occult lesions detected by perineal ultrasound Pathological FSFI scores Population Inclusion Criteria: Spontaneous vaginal birth at AOU Vanvitelli Spontaneous second-degree perineal tear Signed informed consent Exclusion Criteria: Episiotomy or operative vaginal delivery Obstetric conditions preventing spontaneous birth Age \<18 years Sample Size and Statistical Plan Based on Italian national data (SIGO 2024) estimating a 35% incidence of second-degree tears and internal delivery room records showing 29% incidence, a sample size of 482 women provides 80% power at α = 0.05 to detect clinically meaningful differences in outcome prediction between classifications. Analysis: Descriptive statistics for baseline and outcome variables. Tests for normality (Shapiro-Wilk) and graphical inspection. Comparisons between subtypes: t-test or ANOVA for normally distributed continuous variables (Bonferroni/Tukey post-hoc). Mann-Whitney U or Kruskal-Wallis for non-normal data. Chi-square or Fisher's exact test for categorical variables. Multivariate logistic regression to identify independent predictors of complications, adjusting for age, parity, neonatal weight, and labor duration. Multicollinearity will be assessed via VIF; model fit via Hosmer-Lemeshow; discrimination via AUC. Data Quality and Management Data will be entered into a secure electronic database with predefined value ranges and logical consistency checks. Source data verification will be performed by cross-checking electronic records with delivery notes and patient charts. Missing data will be flagged; analyses will specify handling strategies (complete case vs. multiple imputation depending on pattern/extent). Variables are coded in a standardized data dictionary; clinical classifications follow published definitions (Macedo et al., 2022; De Simone). All study personnel will follow SOPs for recruitment, consent, classification, data collection, entry, and storage. Ethics and Safety The study is non-interventional and poses no additional risk beyond routine postpartum care. All procedures comply with the Declaration of Helsinki (2008) and Good Clinical Practice (GCP). Participants incur no costs and receive no financial incentives.