Comprehensive Analysis of Risk Factors for Recurrence in Women of Reproductive Age Undergoing Hysteroscopic Polypectomy

Endometrial polyps, benign neoplastic lesions arising from focal hyperplasia of the endometrial stroma and glands, represent a frequently underrecognized gynecological entity, with a prevalence of 20% to 40% in reproductive aged women [ 1 , 2 ]. They are clinically significant pathological entities associated with a spectrum of gynecological morbidity. Patients present with substantial gynecological manifestations, including abnormal uterine bleeding, which adversely affects daily functioning, as well as infertility and implantation failure, contributing to adverse reproductive health outcomes [ 1 – 3 ]. The risk of malignancy associated with endometrial polyps has been reported to range from 1.5% to 7.2%, with this risk increasing by a factor of 1.5 to 7 times in individuals presenting with abnormal uterine bleeding [ 4 – 6 ]. Hysteroscopic resection is widely recognized as the gold standard therapeutic intervention for endometrial polyps in clinical practice, owing to its precision and efficacy in preserving endometrial integrity [ 1 – 3 , 7 – 9 ]. Nevertheless, recurrence rates following complete surgical resection exhibit considerable variability, ranging from 2.5% to 43.6%, as reported in the literature [ 5 , 10 – 12 ]. Postoperative recurrence of endometrial polyps poses significant clinical concern, driven by their symptomatic burden and potential for malignant transformation. Consequently, it is imperative to both elucidate modifiable risk factors associated with posttreatment recurrence and implement targeted preventive strategies, thereby optimizing long-term patient outcomes. Several medical therapies have been investigated as adjunctive treatments to reduce the risk of recurrence following hysteroscopic resection of endometrial polyps. Among these, the levonorgestrel-releasing intrauterine system (LNG-IUS) has shown promising results by inducing endometrial atrophy and providing sustained local progestin release, which may help prevent the regrowth of polyps. Combined oral contraceptives (COCs) and cyclic progestins have also been used, particularly in reproductive-age women, to regulate the endometrial cycle and suppress hyperplastic changes that contribute to polyp formation [ 13 , 14 ]. A recent randomized controlled trial found that the LNG-IUS substantially decreased recurrence rates at 6 and 12 months, compared with oral progestins and COC therapy [ 13 ]. Additionally, gonadotropin-releasing hormone agonists can be considered in select cases, particularly when polyp recurrence is associated with estrogen-dependent conditions, such as adenomyosis [ 15 , 16 ]. Although surgical removal remains the definitive treatment, these medical options offer potential benefits in reducing recurrence, especially in patients with a high risk of relapse or contraindications to repeated surgical interventions. The best therapeutic strategy is still an subject of debate. The use of prophylactic treatment to reduce the risk of recurrence remains controversial and should be individualized based on factors such as the patient’s age, severity of symptoms and their impact on quality of life, and reproductive intentions. Current evidence on endometrial polyp recurrence following hysteroscopic resection remains scarce, and clinical guidelines acknowledge the need for robust empirical investigations to elucidate recurrence mechanisms and establish evidence-based protocols for standardized therapeutic strategies [ 3 , 8 ]. Studies have identified several risk factors associated with the recurrence of endometrial polyps following hysteroscopic resection procedures; these investigations have incorporated clinical, histopathological, and surgical variables, including polyp morphology, hormonal status, completeness of resection, and concurrent endometrial pathologies (eg, hyperplasia, chronic endometritis), to elucidate independent risk factors and their underlying mechanisms. Hyperplastic polyps without atypia have been shown to exhibit a higher recurrence rate than benign functional polyps, likely due to their intrinsic proliferative potential [ 17 ]. Premalignant or malignant changes in polyps, incomplete resection, excessive estrogen stimulation without progesterone counterbalance (including that associated with obesity, hormone replacement therapy, or anovulatory cycles), tamoxifen use, and concurrent endometrial pathologies, such as chronic endometritis and endometrial hyperplasia, can facilitate the recurrence of endometrial polyps following hysteroscopic resection. Postmenopausal women – particularly those on hormone therapy – as well as individuals with obesity, multiple polyps, genetic predisposition, or insulin resistance and hyperinsulinemia, are also at increased risk of recurrence [ 10 , 12 , 17 – 27 ]. However, since many risk factors, including obesity, hormonal therapies, and chronic inflammation, are interrelated, it is challenging to isolate independent predictors. Therefore, studies on this issue have provided conflicting reports [ 11 , 17 ]. In this retrospective cohort study, based on histopathological confirmation of primary and recurrent endometrial polyps, we aimed to investigate the factors associated with polyp recurrence following hysteroscopic resection in premenopausal women, a population considered to be at higher risk for recurrence. Various clinical, hormonal, histopathological, and procedural variables can influence the likelihood of recurrence. By identifying and analyzing these factors, we aim to better stratify recurrence risk and contribute to the development of more personalized follow-up strategies and preventive approaches. Ultimately, a clearer understanding of recurrence-related determinants could lead to improved long-term outcomes and reduced need for repeated surgical intervention in women undergoing hysteroscopic polypectomy.

A total of 1488 patients of reproductive age who underwent hysteroscopic polypectomy were initially identified from the institutional database between January 1, 2010, and January 1, 2024. Following the application of predefined exclusion criteria, 467 patients were excluded, resulting in a final analytical cohort of 1021 eligible participants. The median age of the cohort was 42 years (IQR: 36–46 years), with a median follow-up duration of 31 months (IQR: 17–48 months). Endometrial polyp recurrence was histopathologically confirmed in 82 patients (8.0%) with a median time to recurrence of 42.5 months. A detailed comparison of baseline demographic and clinical characteristics between patients with and without endometrial polyp recurrence is presented in Table 1 . Normality assessment using the Kolmogorov-Smirnov and Shapiro-Wilk tests revealed that continuous variables were not normally distributed ( P <0.05). Therefore, non-parametric tests were used for statistical comparisons. Baseline characteristics were compared between groups using the Mann-Whitney U test for continuous variables and chi-square test for categorical variables.There were no significant differences in median age, gravidity, or parity between the 2 groups. However, patients who experienced recurrence had a higher prevalence of obesity (BMI ≥30 kg/m 2 ), PCOS, adenomyosis, leiomyoma uteri, and tamoxifen use than did with those without recurrence. Variables with P <0.1 in univariate analysis were considered for inclusion in the multivariate model. The following variables met this threshold: obesity (BMI ≥30 kg/m 2 ; P <0.001), infertility ( P <0.1), PCOS ( P <0.001), diabetes mellitus ( P <0.1), tamoxifen use ( P <0.001), adenomyosis ( P <0.001), and leiomyoma uteri ( P <0.001). These variables were subsequently included in the multivariable logistic regression analysis. Variable selection for the final multivariable logistic regression model was performed using the forward likelihood ratio method. The final model demonstrated adequate fit, with a Hosmer-Lemes-how test P value of 0.704, indicating no significant deviation between predicted and observed outcomes. Variance inflation factors were <2.0 for all covariates, confirming the absence of multicollinearity. The multivariable analysis identified 5 independent risk factors for endometrial polyp recurrence: adenomyosis (OR=10.297, 95% CI=5.251–20.188, P <0.001), PCOS (OR=8.990, 95% CI=2.855–28.312, P <0.001), BMI ≥30 kg/m 2 (OR=8.698, 95% CI=4.521–16.736, P <0.001), tamoxifen use (OR=6.088, 95% CI=1.936–19.140, P= 0.002), and leiomyoma uteri (OR=4.012, 95% CI=2.143–7.509, P <0.001), as shown in Table 2 . LNG-IUS treatment was associated with a significant reduction in endometrial polyp recurrence risk (adjusted OR=0.043, 95% CI=0.019–0.097, P <0.001). The median duration of LNG-IUS therapy was 36 months, compared with 3 months for oral progesterone and combined estrogen-progestin regimens. Kaplan-Meier survival analysis was performed to evaluate recurrence-free survival probabilities over time for variables identified as independent predictors in the multivariate analysis. Log-rank tests were used to compare survival curves between groups. Patients treated with LNG-IUS exhibited significantly improved recurrence-free survival outcomes than did those receiving alternative treatments or no adjuvant therapy. Conversely, individuals diagnosed with adenomyosis, uterine leiomyomas, PCOS, or obesity (BMI ≥30 kg/m 2 ), or those undergoing tamoxifen therapy demonstrated significantly reduced recurrence-free survival, as evidenced by Kaplan-Meier survival curve analysis ( Figure 1 ). The primary hypothesis that specific clinical factors would predict endometrial polyp recurrence was confirmed through multivariable analysis. The secondary hypothesis regarding the protective effect of LNG-IUS treatment was validated with a significant odds ratio of 0.043 (95% CI: 0.019–0.097, P <0.001), representing an approximately 23-fold reduction in recurrence risk, compared with other treatment modalities.

This longitudinal cohort study retrospectively analyzed risk factors for endometrial polyp recurrence in reproductive-aged women presenting with abnormal uterine bleeding who underwent hysteroscopic polypectomy, using histopathologically confirmed diagnoses at baseline and recurrence. Endometrial polyp recurrence was observed in 8% of the study cohort. Adjuvant treatment with LNG-IUS demonstrated a profound protective effect against endometrial polyp recurrence. Conversely, a BMI ≥30 kg/m 2 , adenomyosis, PCOS, leiomyoma uteri, and tamoxifen use increased the recurrence of endometrial polyps in these patients. The widely accepted theory states that factors contributing to recurrence stem from shared pathophysiological mechanisms underlying polyp pathogenesis and recurrence, suggesting an overlapping molecular etiology. Endometrial polyp pathogenesis is mediated by hormonal dysregulation and chronic inflammatory processes, characterized by local hyperestrogenism, dysregulated estrogen to progesterone receptor ratios, impaired apoptotic mechanisms, and aberrant overexpression of angiogenic and mitogenic growth factors [ 28 – 32 ]. Hormonal dysregulation and chronic inflammatory processes also underlie the pathophysiology of adenomyosis and uterine leiomyomas [ 33 , 34 ]. The observed correlation between adenomyosis and multiple endometrial polyps raises the possibility that adenomyosis can influence the intrauterine environment through increased secretion of cytokines or other bioactive mediators, thereby facilitating polyp development [ 35 ]. Additionally, patients with adenomyosis can exhibit an intrinsic hypersensitivity of the endometrial stroma to estrogens, potentially due to increased constitutive expression of estrogen receptor beta [ 36 ]. This heightened sensitivity may contribute to polyp formation independently of cytokine and growth factor expression. Given the shared etiological factors among endometrial polyps, adenomyosis, and leiomyomas, all patients should undergo thorough preoperative evaluation, such as transvaginal ultrasonography, to identify coexisting lesions. Early detection allows for comprehensive management of multiple pathologies in a single surgical session, thereby optimizing treatment outcomes and reducing the need for repeat interventions. Consistent with prior evidence, our analysis demonstrated a significantly elevated risk of endometrial polyp recurrence in patients with adenomyosis and uterine leiomyomas. Evidence from longitudinal cohort studies indicates that PCOS and obesity are independent risk factors for endometrial polyp development, mediated by chronic anovulation, hyperinsulinemia, and estrogen-progesterone receptor dysregulation [ 27 , 37 – 40 ]. Lu et al demonstrated that PCOS confers a 2.75-fold increased risk of endometrial polyp development in premenopausal women [ 27 ]. Furthermore, obesity is associated with a 3.2- to 4.4-fold elevated risk of endometrial polyp formation, attributable to adipose-derived hyperestrogenism and insulin resistance [ 4 , 37 ]. Our results corroborate those of the existing literature, demonstrating concordance in the observed relationships between these risk factors and endometrial polyp recurrence. The elevated risk of endometrial polyps in women with PCOS and obesity is mediated by shared etiopathological mechanisms [ 4 , 27 , 37 – 40 ]. Lu et al postulated that PCOS-associated endometrial polyp development arises from a dysregulated estrogen-progesterone receptor ratio, favoring estrogen dominance [ 27 ]. Similarly, in obesity, adipose tissue-derived peripheral aromatization amplifies systemic estrogen levels, promoting endometrial hyperplasia and polypogenesis. Insulin resistance, a hallmark of PCOS and obesity, further exacerbates this risk through hyperinsulinemia-driven cellular proliferation and inhibition of apoptosis [ 38 , 40 ]. Endometrial polyps represent the most prevalent endometrial pathology identified in patients undergoing tamoxifen therapy, particularly among breast cancer survivors [ 40 ]. Abnormal uterine bleeding and recurrent endometrial polyps can heighten anxiety in patients receiving tamoxifen therapy, compounded by their elevated risk of endometrial malignancy. Tamoxifen, via its selective estrogen receptor modulator activity, exerts an estrogen agonist effect on estrogen-sensitive tissues, such as the endometrium, thereby elevating the risk of endometrial hyperplasia and malignancy [ 6 , 41 ]. This risk is further amplified in patients with concurrent endometrial polyps, which can serve as precursors to atypical hyperplasia and malignant transformation [ 6 ]. In a meta-analysis encompassing 21 007 cases of endometrial polyps, Sasaki et al demonstrated a 3.4% prevalence of premalignant or malignant transformation, with tamoxifen exposure associated with a 1.53-fold elevated risk of such progression [ 6 ]. In a retrospective cohort study of 34 637 tamoxifen users compared with matched controls, Ryu et al demonstrated that tamoxifen therapy was associated with a 3.80-fold increased risk of endometrial polyp development [ 41 ]. Consistent with prior literature, our analysis demonstrated that tamoxifen use was associated with a 6.088-fold increased risk of endometrial polyp recurrence. Furthermore, endometrial polyps were histopathologically confirmed in 24.1% (7/29) of tamoxifen-treated women in our cohort. Current clinical guidelines highlight the paucity of robust clinical evidence examining the efficacy of pharmacological interventions in preventing endometrial polyp recurrence. Consequently, these guidelines emphasize the necessity for further investigation into therapeutic modalities, such as LNG-IUS and alternative medical treatments, to be validated through rigorously designed randomized controlled trials [ 8 ]. The findings of the present study provide empirical evidence that postoperative administration of LNG-IUS following hysteroscopic endometrial polyp resection confers a significant reduction in recurrence risk, demonstrating an approximately 23-fold risk reduction. A recent study demonstrated that LNG-IUS is significantly superior to dydrogesterone and drospirenone/ethinylestradiol tablets in terms of reducing postoperative recurrence rates, decreasing endometrial thickness, minimizing menstrual disturbances, and improving patient compliance [ 13 ]. A meta-analysis indicated that the LNG-IUS group was associated with lower recurrence rate of endometrial polyps than was the oral progestin group [ 42 ]. These findings suggest that LNG-IUS is a highly effective option and supports its broader clinical use and promotion. Chowdary et al reported evidence that the LNG-IUS was associated with endometrial polyp regression in patients, even in the absence of concurrent surgical resection [ 43 ]. Estrogen has been shown to stimulate proliferative activity within the endometrial epithelium. In contrast, exogenous progesterone administration via the LNG-IUS induces stromal decidualization and glandular atrophy, thereby establishing a hormonally quiescent endometrial state refractory to endogenous ovarian steroid signaling [ 28 ]. This estrogen antagonistic mechanism, mediated through localized progesterone-dominated pathways, has been mechanistically linked to the suppression of pathological endometrial polyp formation [ 44 ]. Our findings provide translational validation that LNG-IUS treatment exhibits a protective effect against polyp recurrence, whereas oral progesterone monotherapy and COCs demonstrated no statistically significant risk reduction in comparative analysis. The therapeutic superiority of the LNG-IUS over oral progestin regimens in endometrial polyp prevention may be attributed to its capacity for sustained therapeutic exposure, as the risk of endometrial polyps increases over time [ 12 ]. In the present study, the median duration of LNG-IUS treatment was 36 months, whereas oral progesterone and COCs regimens demonstrated a median duration of 3 months. These findings underscore the necessity of implementing long-term therapeutic strategies to mitigate the risk of disease recurrence. The findings suggest that elevated progesterone concentrations localized to the endometrial epithelium in LNG-IUS users can confer superior therapeutic efficacy, compared with systemic oral administration, likely attributable to the sustained pharmacokinetic profile of intrauterine delivery. Wang et al conducted a retrospective analysis of 451 premenopausal patients undergoing hysteroscopic resection and demonstrated a 5-fold reduction in recurrence risk among those using the LNG-IUS, compared with alternative therapies [ 44 ]. However, methodological distinctions exist between their study and the present investigation. Wang et al used ultrasonography for recurrence diagnosis, with follow-up intervals predominantly limited to a 1-year period. In contrast, our protocol used histopathologically confirmed endometrial biopsy to diagnose recurrence, thereby improving diagnostic precision, particularly in identifying small or subclinical polyps that can evade detection via imaging modalities. In addition to the LNG-IUS, several medical therapies, including progestins, gonadotropin-releasing hormone agonists, and COCs, have been investigated to reduce the recurrence of endometrial polyps [ 13 , 14 , 45 ]. Preventing the recurrence of endometrial polyps through medical therapy holds significant clinical value, particularly in patients for whom repeated surgical intervention is not feasible or desirable. Long-acting progestin therapy – particularly the LNG-IUS – not only prevents post-polypectomy recurrence but also reduces adenomyotic foci and relieves dysmenorrhea, making it a cornerstone preventive strategy for women with concurrent disease, such as adenomyosis [ 16 ]. Given that adenomyosis often begins in adolescence and progresses in extent and severity, especially in cases of severe dysmenorrhea or abnormal uterine bleeding, early diagnosis using transvaginal ultrasound and magnetic resonance imaging criteria (junctional zone thickness >12 mm or difference between maximum and minimum junctional zone >5 mm) is critical. A brief course of gonadotropin-releasing hormone agonist therapy followed by LNG-IUS insertion can further enhance uterine volume reduction and symptom control while preserving fertility, offering a dual-purpose regimen for high-risk patients [ 16 ]. Recent studies have suggested that the etonogestrel-releasing implant (Implanon) can reduce the severity of adenomyosis-related symptoms by inducing endometrial atrophy and suppressing estrogen-driven proliferation [ 46 ]. Given the shared hormonal and inflammatory pathways involved in adenomyosis and endometrial polyp formation, Implanon may also contribute to a reduced risk of polyp recurrence. Therefore, it could be considered as a potential prophylactic medical treatment in selected patients at high risk of recurrence following hysteroscopic polypectomy. By maintaining symptom control, especially abnormal uterine bleeding, these therapies contribute to an improved quality of life. Additionally, reducing the need for repeated hysteroscopic procedures lowers the risk of endometrial trauma, which is especially relevant for women wishing to preserve fertility. From a broader perspective, medical prevention of polyp recurrence offers a cost-effective alternative to repeated surgery, decreasing the burden on patients and healthcare systems. Therefore, medical management should be considered not only as a therapeutic option but also as a preventive strategy in appropriately selected patients. Hysteroscopic polypectomy is widely regarded as the gold standard for the treatment of endometrial polyps, despite its relatively high recurrence rate. For small polyps, outpatient hysteroscopy offers a safe, well-tolerated, and cost-effective alternative to traditional operating room procedures, often eliminating the need for anesthesia. This office-based “see-and-treat” approach allows for direct visualization and immediate removal of the lesion in a single session. Numerous studies have demonstrated its high success rates and favorable patient satisfaction, establishing it as a first-line treatment option in appropriately selected cases [ 47 ]. Nevertheless, the risk of recurrence following polypectomy highlights the need for novel strategies or adjunctive techniques aimed at improving long-term outcomes. Currently, various hysteroscopic modalities are available for polyp removal, including electrosurgical resection, grasper- or scissor-assisted extraction, mechanical morcellation, and diode laser application, each with distinct advantages and limitations. However, recurrence rates have been shown to vary depending on the technique employed. For instance, the use of a resectoscope has been associated with lower recurrence rates than that of microscissors and grasping forceps, with reported rates of 0%, 5%, and 15%, respectively [ 20 ]. Similarly, intrauterine morcellation has been suggested to reduce recurrence more effectively than conventional hysteroscopic resection [ 48 ], while diode laser techniques have demonstrated lower relapse rates than have bipolar electrosurgical methods, regardless of lesion size or number [ 49 ]. Despite these findings, no single hysteroscopic technique or device can be universally recommended for all patients, given the variability in efficacy, safety, and cost [ 7 , 8 ]. Supporting this, a long-term follow-up study reported no statistically significant difference in the recurrence of endometrial polyps or the persistence of abnormal uterine bleeding between manual (Resectr 9 Fr) and motor-driven (TruClear) hysteroscopic tissue removal systems [ 50 ]. Furthermore, accumulating evidence suggests that performing endometrial resection following polypectomy may be a safe and effective strategy for significantly reducing recurrence, particularly in premenopausal women, when compared with hysteroscopic polypectomy alone [ 25 , 51 – 53 ]. A key methodological strength of the present investigation lies in its systematic longitudinal follow-up protocol, which facilitated comprehensive data collection across diverse clinical and patient-reported outcomes. Notable another methodological strengths of this study include its substantial cohort size and the consistent application of histopathological confirmation for primary and recurrent endometrial polyp diagnoses. While histopathological verification remains the diagnostic gold standard for endometrial polyps, clinical suspicion frequently originates from ultrasonographic findings, which often guide subsequent clinical management strategies, including surveillance or therapeutic intervention. However, the ultrasonographic identification of endometrial polyps is complicated by inherent diagnostic limitations, as malignant lesions exhibiting polypoid morphological characteristics may be erroneously classified as benign, thereby introducing the potential for diagnostic inaccuracy with significant prognostic implications. A further methodological strength of this investigation lies in the use of standardized hysteroscopic resection protocols for endometrial polyp removal, ensuring adherence to contemporary surgical guidelines. Evidence from comparative clinical studies indicates that resectoscopic en bloc resection encompassing the polyp base and vascular pedicle, with full-thickness myometrial excision to a depth of 5 mm, demonstrates significantly reduced recurrence rates relative to that of blunt avulsion techniques [ 5 , 7 ]. This study has several limitations that should be acknowledged. First, due to its retrospective design, there is a risk of selection bias and incomplete data documentation. Second, the absence of information regarding the number of endometrial polyps represents a notable limitation, as polyp multiplicity can be an important factor influencing recurrence risk [ 10 , 12 ]. Including this parameter could have provided further insight into the relationship between polyp burden and clinical outcomes. Finally, while histopathological confirmation was available, operator experience was not accounted for, which may have influenced the recurrence rates. Future studies should aim to overcome the limitations observed in the present investigation by adopting prospective, multicenter designs with larger sample sizes and extended follow-up periods. In particular, including detailed data on the number, size, and location of endometrial polyps could help clarify their potential role in recurrence risk. Moreover, type of surgical technique used can allow for more individualized risk assessment and management strategies. Randomized controlled trials comparing the efficacy of different adjunctive medical therapies, such as LNG-IUS, progestins, COCs, and gonadotropin-releasing hormone agonists, could further inform post-polypectomy treatment protocols. Ultimately, future research should aim to establish evidence-based guidelines for the prevention of polyp recurrence, particularly in high-risk populations, such as premenopausal women.

The clinical implications derived from this study can inform evidence-based counseling and therapeutic decision-making for reproductive-aged women undergoing hysteroscopic endometrial polyp resection. Particular emphasis should be placed on high-risk populations, including tamoxifen users and individuals with adenomyosis, uterine leiomyomas, PCOS, or elevated BMI, who require comprehensive preoperative counseling regarding their heightened risk of polyp recurrence. To optimize long-term outcomes, clinicians are advised to integrate LNG-IUS therapy into postoperative management protocols for eligible patients, leveraging its progesterone-mediated endometrial suppression to mitigate recurrence risk.

This study received ethics approval from the Institutional Ethics Committee of the University of Health Sciences Antalya Education & Research Hospital (approval date: August 8, 2024; approval number: 2024-217). Given the retrospective design of the study, which involved the analysis of anonymized patient data collected from electronic medical records between 2010 and 2024, it was not feasible to obtain informed consent from individual participants. The ethics committee specifically reviewed and approved the waiver of informed consent, as the research posed minimal risk to participants and all data were de-identified to ensure confidentiality. This approach is consistent with established ethical guidelines for retrospective studies utilizing existing clinical data. Following ethics approval, we retrospectively analyzed the electronic hospital records of patients who underwent hysteroscopic polypectomy at the Antalya Education & Research Hospital for abnormal uterine bleeding between January 1, 2010, and January 1, 2024. The inclusion criteria for participants were defined as follows: (1) premenopausal status, (2) histopathologically confirmed endometrial polyps via hysteroscopic examination, (3) primary diagnosis of endometrial polyps (ie, no prior history of polyps), and (4) postoperative follow-up period of at least 6 months. Exclusion criteria were (1) patients postmenopause (2) confirmed malignancy, (3) hysterectomy performed within 6 months postoperatively, and (4) pregnancy occurrence during the postoperative follow-up period. All demographic and clinical data for this study were retrospectively extracted from the institutional electronic medical record system, which contains comprehensive patient information including demographic characteristics, clinical diagnoses, surgical procedures, laboratory test results, imaging findings, and follow-up records. Data collection was performed using a standardized data abstraction form developed prior to the study, including, specifying, all variables of interest, such as age, body mass index, reproductive history, comorbidities, medication exposures, and surgical details. Two independent investigators systematically reviewed the electronic medical record system for each eligible patient and entered the data into the abstraction form, with any discrepancies resolved through consensus and, if necessary, reexamination of the original records. Both the primary and recurrent diagnoses of endometrial polyps were verified by reviewing histopathology reports, and all data were anonymized prior to analysis in accordance with institutional and ethical guidelines. These rigorous data collection and validation procedures enhance the credibility and reliability of the study’s findings. Given the retrospective nature of this cohort study, randomization and blinding were not applicable, as the analysis was based on existing clinical data. However, to minimize potential biases, we implemented rigorous methodological safeguards: (1) all histopathological evaluations for recurrence were performed by pathologists blinded to patients’ clinical characteristics and treatment histories, ensuring objective outcome assessment; (2) data abstraction followed standardized protocols with predefined variables to maintain consistency; and (3) multivariable regression models adjusted for key confounders identified a priori. A thorough history and gynecological examination were conducted on every patient. All patients underwent a preoperative gynecological evaluation, including transvaginal ultrasonography, with magnetic resonance imaging performed when clinically indicated. Pathologies, such as adenomyosis, uterine leiomyomas, and polycystic ovarian morphology, identified during gynecological evaluation and imaging modalities were methodically recorded. Cervical dilation was performed preoperatively by the clinical team on the evening prior to surgery for all patients. All surgical procedures were performed under general anesthesia. A preoperative bimanual pelvic assessment was systematically performed before commencing the surgical procedure. The cervix was identified and secured anteriorly using a single-tooth tenaculum. Subsequently, cervical dilation was performed with Hegar dilators, to accommodate the hysteroscope diameter, followed by hysteroscopic insertion. Normal saline solution (0.9% NaCl) was used as the uterine distension medium during the procedure, with a bipolar resectoscope used as the energy modality for tissue resection. All polyps identified during hysteroscopic evaluation were resected using a bipolar resectoscope, ensuring complete excision of the polyp stalk and base, along with the adjacent superficial myometrial layer. Endometrial curettage was systematically performed for all patients, with histopathological evaluation conducted on all resected tissue specimens. Clinicians emphasized the necessity of rigorous postoperative follow-up, consistent with clinical standards and responsive to patients’ fertility preservation objectives. Treatment regimens were individualized according to clinical indications, with options including oral progesterone, COCs, or insertion of a LNG-IUS. Postoperatively, hormonal therapy was tailored to individual risk profiles: LNG-IUS insertion was recommended as first-line therapy within 4 weeks after resection for eligible patients, while oral progestins (medroxyprogesterone acetate 10 mg/day) or COCs were prescribed for 3 months in select cases. Follow-up consisted of systematic transvaginal ultrasound and clinical evaluation at 6 months, then annually for asymptomatic patients, with prompt hysteroscopic reevaluation for recurrent abnormal uterine bleeding or sonographic abnormalities (endometrial thickness >12 mm or focal lesions). This protocol was uniformly applied across all patients, with any deviations documented and accounted for in the analysis. Endometrial assessment was conducted using various diagnostic methods, including Pipelle biopsy, dilatation and curettage, hysteroscopy, or hysterectomy, in all patients presenting with recurrent abnormal uterine bleeding, or when clinically indicated. Recurrence was defined as the histopathologically confirmed diagnosis of an endometrial polyp during follow-up biopsy obtained via Pipelle sampling, dilatation and curettage, hysteroscopy, or hysterectomy and served as the primary outcome variable in the study. Demographic and obstetric parameters, including age, gravidity, and parity, were operationalized as continuous numerical variables within the analytical framework. To address potential confounding, we implemented a rigorous analytical approach, as follows. (1) All clinically relevant variables were screened in univariate analyses ( P <0.1 threshold for inclusion); (2) the final multivariable logistic regression model incorporated both statistical significance (forward likelihood ratio method, P <0.05 retention threshold) and clinical relevance, including known polyp recurrence predictors from existing literature; (3) continuous variables were assessed for linearity using fractional polynomials; (4) model fit was verified via Hosmer-Lemeshow testing ( P =0.34), and variance inflation factors (<2.0 for all covariates) confirmed absence of multicollinearity. This comprehensive strategy optimized the balance between overadjustment and residual confounding. Distribution of these continuous variables was assessed through graphical methods (histograms and probability plots) and formal statistical tests for normality, including the Kolmogorov-Smirnov and Shapiro-Wilk tests. Non-normally distributed continuous variables were expressed as median (IQR) and subjected to Mann-Whitney U testing to assess differences between groups. Clinical and demographic variables including body mass index (BMI), history of infertility, polycystic ovary syndrome (PCOS), hypertension, diabetes mellitus, tamoxifen use, endometriosis, adenomyosis, leiomyoma, and postoperative hormonal therapies (oral progesterone, COCs, or LNG-IUS) were included as categorical variables for analytical purposes. Categorical variables were expressed as frequencies and proportions, reported as counts (n) and percentages (%). Categorical variables were compared across groups using the chi-square test. Variables demonstrating a statistical significance threshold of P <0.1 in univariate analyses were subsequently incorporated into a multiple logistic regression model to identify independent predictors of recurrence. Variable selection was conducted via the forward likelihood ratio method, with statistical significance defined as P <0.05 in the final regression model. Kaplan-Meier survival curves were generated to evaluate recurrence-free survival probabilities over time for variables independently associated with endometrial polyp recurrence, as identified through multiple logistic regression analysis. Recurrence-free survival was calculated within a time to event analysis framework, defined as the duration in months from hysteroscopic polypectomy to histopathologically confirmed recurrence. Patients without evidence of recurrence were administratively censored at the date of their last documented transvaginal ultrasonography surveillance. For all variables included in the primary analyses, cases with missing or incomplete data were excluded from the relevant statistical analyses (complete-case analysis). The proportion of missing data for key demographic and clinical variables was minimal (<2%). The pattern of missingness was assessed and determined to be random, rather than systematic. To evaluate the potential impact of missing data, sensitivity analyses were performed by comparing baseline characteristics between included patients and those excluded due to missing data, revealing no significant differences. Additionally, multivariable analyses were repeated using multiple imputation for missing values, which yielded results consistent with the primary analysis. These procedures ensured that missing or incomplete data did not introduce bias and that the study’s findings were robust and reliable. To ensure the study was adequately powered to detect clinically significant associations between predictors and endometrial polyp recurrence, a post hoc power analysis was conducted. Given the observed recurrence rate of 8% (82/1021) and the effect sizes identified in our multivariable logistic regression (eg, odds ratio [OR]=10.297 for adenomyosis, OR=8.698 for BMI ≥30 kg/m 2 ), the achieved power exceeded 99% for all significant predictors (α=0.05, two-tailed). This calculation was performed using G*Power 3.1, assuming a medium to large effect size (f 2 =0.25) based on prior literature [ 10 , 12 ]. The sample size of 1021 provided robust statistical power (>90%) to identify even modest associations (OR ≥1.8) in our adjusted model, which included 10 covariates. These results confirmed the study’s capacity to reliably address its primary aim of evaluating recurrence risk factors.