目的·通过超声检查探究有宫颈机能不全（cervical incompetence，CIC）史的孕妇早、中孕期盆底结构的变化特点。方法·收集2022年8月至2023年1月在同济大学附属第一妇婴保健院建卡的早、中孕期孕妇，所有孕妇均有且仅有1次早产，或者中孕流产、引产史，按照前次妊娠有无CIC病史将其分为CIC组和对照组。比较2组孕妇的年龄、体质量指数（BMI）、孕周、尿道内口漏斗形成率、尿失禁发生率。运用二维、三维及四维盆底超声对静息状态、盆底肌收缩（pelvic floor muscle contraction，PFMC）状态和瓦尔萨尔瓦动作（Valsalva maneuver，VM）状态下2组女性盆底结构进行测量；测量参数包括：膀胱颈位置、尿道倾斜角、尿道旋转角、膀胱后角、膀胱颈移动度、宫颈位置、直肠壶腹部位置、肛提肌裂孔面积（area of urogenital hiatus，HA）、肛提肌裂孔左右径、肛提肌裂孔前后径。采用一般线性回归模型校正混杂因素影响，分析CIC病史与盆底结构差异指标的相关性。结果·共纳入早、中孕期孕妇76例，其中CIC组39例，对照组37例。2组孕妇年龄差异无统计学意义，CIC组BMI、孕周均显著大于对照组，差异均有统计学意义（均P<0.05）。静息状态和PFMC状态下，2组孕妇盆底结构参数差异均无统计学意义（均P>0.05）；VM状态下，CIC组HA（P=0.016）和肛提肌裂孔前后径（P=0.014）显著增大，其他指标差异无统计学意义。一般线性回归模型校正2组孕妇的孕周及BMI后发现，CIC病史与VM状态下HA（P=0.038）和肛提肌裂孔前后径（P=0.049）均存在相关性。CIC组和对照组尿道内口漏斗形成率分别为10.25%和0，压力性尿失禁发生率分别为23.07%和13.51%，差异均无统计学意义（均P>0.05）。结论·有CIC病史的孕妇VM状态下，HA和肛提肌裂孔前后径明显增大，肛提肌裂孔的形态改变以纵轴增加更为明显。

Objective ·To explore the changes of pelvic floor structure in the early and middle pregnant women with the history of cervical incompetence (CIC) by ultrasound. Methods ·The pregnant women during early and middle trimesters were collected from Shanghai First Maternity and Infant Hospital, Tongji University School of Medicine from August 2022 to January 2023. All the pregnant women had only one history of premature delivery, abortion or induced labor in the middle trimester, and were divided into CIC group and control group according to whether having the history of CIC in the previous pregnancy. Age, body mass index (BMI), gestational age, the prevalence of funneling of internal urethral orifice and the prevalence of urinary incontinence were compared between the two groups. Two-dimensional, three-dimensional, and four-dimensional pelvic floor ultrasound was used to measure the pelvic floor structures of the women in the states of resting, pelvic floor muscle contraction (PFMC) and Valsalva maneuver (VM). The parameters of pelvic floor structure included bladder neck position, urethral inclination angle, urethral rotation angle, posterior angle of bladder, bladder neck mobility, cervix position, position of ampulla of rectum, area of urogenital hiatus (HA), hiatal transverse diameter, and hiatal anteroposterior diameter. General linear regression model was used to correct the influence of confounders and to analyze the association between the history of CIC and the different indexes of pelvic floor structure. Results ·A total of 76 pregnant women in early and middle trimesters were collected, including 39 women in the CIC group and 37 women in the control group. There was no significant difference in the age between the two groups, while BMI and gestational age in the CIC group were significantly greater than those of the control group, and the differences were significant (both P<0.05). At the states of resting and PFMC, there were no significant differences in structural parameters (all P> 0.05); at the state of VM, HA (P=0.016) and hiatal anteroposterior diameter (P=0.014) increased in the CIC group, while other parameters did not change significantly. It was found that the CIC history was associated with HA (P=0.038) and hiatal anteroposterior diameter (P=0.049) at VM after adjusting gestational age and BMI by the general linear regression model. The incidence rates of funneling of internal urethral orific in the CIC group and the control group were 10.25% and 0, respectively; the incidence rates of stress incontinence were 23.07% and 13.51%, respectively. Neither of the differences were significant (both P>0.05). Conclusion ·In the pregnant women with the history of CIC, HA and hiatal anteroposterior diameter at VM increase, and the morphological change of the levator ani hiatus is more obvious with the increase of the vertical axis.