Abstract： Objective:To estimate risks of cervical intraepithelial neoplasia (CIN) Ⅱ or worse (CINⅡ +) on loop electrosurgical excisional procedure (LEEP) specimens with the diagnosis of endocervical curettage (ECC) CINⅠ compared with biopsy CINⅠ, and also to investigate the hierarchical management scheme of ECC CINⅠ based on the relevant factors of CINⅡ + risk. Methods:(1) A retrospective computer-based research for subjects enrolled in the Obstetrics and Gynecology Hospital, Fudan University from Jan. 2013 to Jun. 2021 was performed. The case group comprised women with an ECC CINⅠ (ECC results of CINⅠ with colposcopy-directed biopsy results ≤CINⅠ), and the control group comprised women with a biopsy CINⅠ (colposcopy-directed biopsy results of CINⅠ with negative ECC findings) were divided after LEEP surgery and diagnosis in the next three months. The clinical data of all patients before LEEP were analyzed, and the pathological diagnosis between two groups after LEEP was compared. (2) Variables, including age, cytology, high-risk human papillomavirus (HR-HPV), ECC results, cervical transformation zone (TZ) and colposcopy impression, were included to describe the characteristics and compare the incidence of LEEP CINⅡ +. (3) Univariate analysis and Multivariate logistic regression method were used to analyze the related factors that affect the LEEP CINⅡ + in CINⅠ patients. Further, the specific risks caused by related factors and conduct a stratified study in LEEP CINⅡ + were analyzed. Results:(1) Overall, 2 581 women with ECC CINⅠ or biopsy CINⅠ diagnosis who underwent LEEP participated in the study with the mean age (43.6±9.5) years old. Chi square test found that the age and cytology of patients in ECC CINⅠ group were statistically different from those of biopsy CINⅠ group (all P<0.05). There was no significant difference in HR-HPV detection, TZ type and colposcopy impression between the two groups (all P>0.05). ECC CINⅠ comprised 957 women, with LEEP histopathology results revealing 288 (30.1%, 288/957) CINⅡ +, which was significantly higher than that of biopsy CINⅠ which was comprised 1 624 women, with LEEP histopathology results showing 333 (20.5%, 333/1 624) CINⅡ + ( χ2=30.31, P<0.001). (2) Compared by LEEP CINⅡ + with LEEP ≤CINⅠ group, there were no significant difference in the age, HR-HPV, colposcopy impression (all P>0.05); but there were significantly differences in cytology, ECC CINⅠ, type Ⅲ TZ (all P<0.001). Multivariate logistic regression analysis showed that atypical squamous epithelial cells (ASC-H; OR=2.77, 95% CI: 2.04-3.77), high-grade squamous intraepithelial lesions and worse (HSIL +; OR=2.93, 95% CI: 2.24-3.81), ECC CINⅠ ( OR=1.89, 95% CI: 1.56-2.29) and type Ⅲ of TZ ( OR=1.76, 95% CI: 1.45-2.11) were independent risk factors for LEEP CINⅡ + (all P<0.05). (3) When cytology was ≤low-grade squamous intraepithelial lesion (LSIL) and ≥ASC-H, the detection rate of CINⅡ + in ECC CINⅠ was significantly higher than that of biopsy CINⅠ (all P<0.001). In ECC CINⅠ, the rate of CINⅡ + with cytology ≤LSIL was significantly lower than that in cytology ≥ASC-H (56.0% vs 25.9%; χ2=49.38, P<0.001). In type Ⅰ/Ⅱ of TZ, the detection rate of CINⅡ + between ECC CINⅠand biopsy CINⅠ had no significantly different; while in type Ⅲ of TZ, there was significantly different (72.7% vs 46.2%; χ2=4.02, P=0.045). In ECC CINⅠ, type Ⅲof TZ was significantly higher in the rate of CINⅡ + than that of type Ⅰ/Ⅱ of TZ (72.7% vs 21.7%; χ2=16.38, P<0.001). When cytology ≥ASC-H, type Ⅲ of TZ and colposcopy impression of HSIL were combined, the rate of CINⅡ + in ECC CINⅠ was 6/6 while 1/3 in biopsy CINⅠ. Conclusions:Cytology ≥ASC-H, ECC CINⅠ and type Ⅲ TZ are the risk factors of LEEP CINⅡ +. However, cytology ≥ASC-H is more valuable in predicting LEEP CINⅡ + than ECC CINⅠ. For patients with ECC CINⅠ to perform LEEP, it is recommended that cytology ≥ASC-H is taken as the first level stratification, and type Ⅲ TZ is taken as the second level stratification. The colposcopy impression of patients is recommended for a reference parameter.