Analysis of selected factors in pelvic organ prolapse and urinary incontinence and the differentiation of clinical forms – a pilot study

Technical Summary: Analysis of Selected Factors in Pelvic Organ Prolapse and Urinary Incontinence

Problem Statement
Pelvic floor disorders, specifically pelvic organ prolapse (POP) and stress urinary incontinence (SUI), are prevalent conditions affecting nearly half of adult women. While these conditions often coexist, they present distinct clinical challenges requiring different diagnostic and therapeutic approaches. A critical gap in clinical practice is the accurate differentiation of the primary dysfunction to optimize treatment planning. Although various risk factors are hypothesized to contribute to these disorders, the specific influence of modifiable factors—such as obstetric history (term vs. preterm births, miscarriages), body mass index (BMI), and smoking status—on the differentiation between POP and SUI remains a subject of investigation. This study addresses the need to identify whether these specific factors can differentiate clinical forms of pelvic floor dysfunction to improve prevention strategies.

Methodology
This retrospective pilot study analyzed the medical records of 398 women who underwent surgical treatment at the Gynecology Clinic of Heliodor Święcicki Clinical Hospital in Poznań. Participants were classified into two distinct groups based on clinical evaluation, imaging, and ICD-10 diagnoses:

• Group 1 (Prolapse): 225 women with uterine and/or vaginal wall prolapse (affecting medial and posterior compartments) without significant urinary incontinence symptoms. This group included patients with anterior prolapse only if occult SUI was ruled out.
• Group 2 (Urinary Incontinence): 173 women diagnosed with stress urinary incontinence (SUI) or anterior vaginal wall/urethral prolapse accompanied by occult SUI symptoms.

The diagnostic protocol involved gynecological and speculum examinations, assessment of pelvic organ support, cough stress tests, and transvaginal ultrasound to evaluate bladder, uterine, and urethral anatomy. Patients with urge incontinence, neurogenic bladder, or mixed incontinence with a dominant urge component were excluded.

The study analyzed four primary variables: age, BMI, obstetric history (term births, preterm births, miscarriages), and smoking status. Statistical analysis was performed using PQStat software. Due to non-normal data distribution (confirmed by the Shapiro-Wilk test), continuous variables were analyzed using the Mann-Whitney U test. Binary variables were assessed using the chi-square test ($\chi^2$), and odds ratios (OR) with 95% confidence intervals were calculated to determine association strength. A p-value of <0.05 was considered statistically significant.

Key Results

• Miscarriages: No statistically significant correlation was found between a history of miscarriages and the occurrence of POP or SUI. While 17.34% of the SUI group and 14.22% of the POP group reported miscarriages, the odds ratio was 0.79 (95% CI: 0.56–1.36; p=0.395). The frequency of one, two, or three miscarriages did not significantly differentiate the groups.
• Preterm Births: The incidence of preterm births was low and comparable between groups (6.54% in the SUI group vs. 4.89% in the POP group). No significant relationship was observed between preterm birth history and either condition.
• Term Births (Multiparity): The majority of participants in both groups had experienced at least two term births. While the POP group showed a slightly higher frequency of three or more births (34.67%) compared to the SUI group (28.90%), the overall difference in birth distribution was not statistically significant (p=0.5646). However, the data supports multiparity as a general risk factor for both conditions.
• Body Mass Index (BMI): A high BMI was prevalent in both groups. Although a non-significant trend suggested a higher frequency of overweight and obese women in the SUI group, the differences were not statistically significant (p=0.6399). The study notes that while BMI is a common factor, it does not statistically distinguish between the two clinical forms in this cohort.
• Smoking: Smoking rates were slightly higher in the POP group (32.44%) than in the SUI group (30.64%), but the difference was not statistically significant (OR=1.09; p=0.7006). The study observed that smoking prevalence in both groups exceeded the national average for women in Poland.

Key Contributions and Claims
The primary contribution of this pilot study is the empirical differentiation of risk factors between POP and SUI within a surgical cohort. The authors conclude that:

1. Differentiation of Risk Factors: While multiparity and high BMI are significant risk factors for pelvic floor disorders generally, they do not statistically differentiate between POP and SUI in this specific population.
2. Exclusion of Specific Factors: The study provides evidence that miscarriages and preterm births are not independent risk factors for the development of POP or SUI, aligning with certain existing literature that prioritizes the mechanics of term delivery over gestational timing or pregnancy loss.
3. Clinical Implications: The findings suggest that while modifiable factors like BMI are crucial for general prevention, the specific clinical presentation (POP vs. SUI) may depend on a complex interplay of factors not fully captured by simple obstetric history or BMI alone, such as delivery method, connective tissue quality, and the duration of the second stage of labor.

Significance
The authors position this study as a foundational step toward refining prevention strategies and treatment planning. By identifying that miscarriages and preterm births are not significant differentiators, the study directs clinical focus toward other variables, such as the mechanics of term delivery and modifiable factors like BMI. The authors acknowledge the limitations of their retrospective design and sample size, noting that future research with larger populations and additional variables (e.g., birth weight, specific delivery methods, and connective tissue characteristics) is necessary to fully elucidate the pathophysiology of these disorders. The study emphasizes that accurate pre-operative differentiation is essential for optimizing surgical outcomes and reducing recurrence risks.