Risk factor analysis and predictive model for the alleviation of postpartum stress urinary incontinence: a retrospective cohort study

Stress urinary incontinence (SUI) is characterized by involuntary urine leakage during activities that increase intra-abdominal pressure, such as coughing, sneezing, or laughing 1. As one of the most common forms of urinary incontinence, SUI affects a significant proportion of women, with global prevalence rates ranging from 5% to 72%, depending on population characteristics and diagnostic criteria 2 3. Postpartum women are particularly vulnerable, with elevated SUI incidence during the critical recovery period of one to six months after childbirth 4. A cohort study in China reported that approximately 25.9% of women experience persistent SUI at 12 months postpartum 5. This high prevalence underscores postpartum SUI as a major public health issue impacting women's physical and psychological well-being, necessitating urgent attention. Although postpartum SUI is not typically life-threatening, it can substantially impair daily functioning, social participation, emotional well-being, and overall quality of life. From a rehabilitation perspective, even conditions often perceived as relatively "mild" may still lead to persistent functional limitations if they are not recognized and managed in a timely manner. Therefore, early screening and early intervention are clinically important to prevent symptom persistence and reduce future treatment burden 6. Key risk factors for SUI include advanced maternal age, vaginal delivery, obesity, gestational diabetes, macrosomia, constipation, higher parity, and increased birth weight [7][8][9]. These factors can compromise pelvic floor structures, innervation, or muscle function, heightening SUI susceptibility. Older age, higher body mass index (BMI), and multiple vaginal deliveries are consistently linked to increased SUI risk and severity 10 11. often hindering postpartum recovery 11. Beyond its physiological impact, SUI affects women's mental health, sexual relationships, and overall quality of life 12. leading to embarrassment, social isolation, and psychological issues such as depression and anxiety, which further exacerbate socioeconomic burdens. 13. Therefore, timely early intervention and comprehensive rehabilitation are crucial for improving health outcomes in postpartum women.Pelvic floor muscle training (PFMT), particularly Kegel exercises, is a cornerstone of SUI treatment and prevention 14 15. Studies indicate that about 60% of women who perform PFMT correctly experience significant symptom improvement within one year 16. Combining PFMT with biofeedback or electrical stimulation can enhance outcomes, especially for those with weakened pelvic floor muscles or difficulty contracting them voluntarily 17. However, research on PFMT's effectiveness often focuses on overall symptom improvement, with limited exploration of risk factors for persistent SUI in women undergoing basic PFMT. This gap is particularly critical in resource-limited settings where advanced interventions like biofeedback are less accessible. Consequently, identifying women who are less likely to respond to basic PFMT and may require alternative or intensified treatment is clinically important. At present, predictive models for SUI remission, particularly those designed to support early intervention in postpartum women, remain limited. A clinically applicable prediction model may help identify high-risk women at an early postpartum stage and support individualized rehabilitation strategies, including closer follow-up, intensified pelvic floor rehabilitation, and timely referral when necessary. This study aims to evaluate the outcomes of basic PFMT in women with SUI at one month postpartum, followed up at six months, to identify key risk factors for persistent SUI and develop a predictive model to guide early clinical interventions and improve quality of life.This retrospective cohort study included women who delivered at Wuhan Central Hospital between January 2020 and December 2024 and completed postpartum follow-up visits at 1 and 6 months.Eligible participants were aged 18 years or older, had complete medical records, and attended both follow-up visits. Exclusion criteria were incomplete labor or follow-up data, twin or higher-order pregnancies (n=95), pre-existing SUI (n=68), previous pelvic floor surgery (n=15), and loss to follow-up or missing critical data (n=126). In total, 1,538 women were included in the final analysis (Figure 1). The study was approved by the Ethics Committee of Wuhan Central Hospital (Approval No. WHZXKYL2024-251) and was conducted in accordance with the Declaration of Helsinki. Because this was a retrospective study without patient identification or intervention, the requirement for written informed consent was waived 18.Data were extracted from the hospital's electronic medical records. Demographic variables included age, medical history, and gestational age at delivery. Pre-delivery height and weight were measured with participants wearing light clothing and no shoes, and BMI was calculated as weight in kilograms divided by height in meters squared (kg/m²). Postpartum BMI loss was defined as the difference between BMI at 1 month postpartum and pre-pregnancy BMI. Waist circumference was measured at the midpoint between the lower rib margin and the iliac crest, and abdominal circumference was measured at the level of the umbilicus; both were recorded to the nearest 0.1 cm. Uterine height was measured from the pubic symphysis to the uterine fundus. Neonatal weight and head circumference were measured using standard scales and measuring tapes. Blood pressure was measured using an automated sphygmomanometer (Omron HBP-9020). The average of two readings from the arm with the higher initial value was recorded, and a third reading was obtained if the difference exceeded 5 mmHg. Fasting blood glucose and glycated hemoglobin were measured after an 8-hour fast.Hypertensive disorders of pregnancy were defined according to the American College of Obstetricians an