A Prediction Model for Pelvic Floor Recovery After Vaginal Birth With Risk Factors.

Importance: Although parturients report few postpartum symptoms, birth is clearly associated with future symptom development. The ability to identify asymptomatic at-risk women would facilitate prevention.

Objective: The aim of the study was to develop a model predicting abnormal recovery in women at risk for childbirth-associated pelvic floor injury.

Study design: Women undergoing first vaginal birth at high risk of pelvic floor injury underwent examinations and ultrasound imaging and completed 6-week and 6-month postpartum questionnaires. We defined "abnormal" recovery as having ≥1 of the following 3 findings: (1) levator ani injury, (2) decreased objective pelvic floor strength, and (3) Pelvic Organ Prolapse Quantification point Bp ≥0. Descriptive statistics and bivariate analyses compared "normal" and "abnormal" recovery. Birth characteristics, 6-week examinations, and questionnaires potentially predicted abnormal recovery at 6 months. Significant variables were included as candidates in the multivariable logistic regression predicting "abnormal" recovery after birth.

Results: Fifty-four women (63.5%) had normal and 31 (36.5%) had abnormal recovery at 6 months. At 6 weeks, women with abnormal recovery had decreased pelvic floor strength by Oxford scores (3 [2-5], 6 [2-8]; P = 0.002), lower point Bp (-1 [-3 to 0], -2 [-3 to -1]; P = 0.02), larger genital hiatus (4 [3 to 4], 3 [3 to 3.5]; P = 0.02), and higher levator ani injury rate (76.7%, 22.4%; P < 0.001). Between-group questionnaire differences were not clinically significant. Our final model included postpartum examination findings or birth characteristics: Oxford Scale, 6-week Pelvic Organ Prolapse Quantification GH strain, infant head circumference, and second stage ≥120 minutes. The area under the curve for predicting abnormal recovery at 6 months was 0.84, indicating a good sensitivity and specificity balance.

Conclusion: The model identifies women at risk for an abnormal recovery trajectory.