Assessment of key parameters of normal uterus in women of reproductive age

Currently, the precise and detailed anatomical data of the normal uterus, especially the myometrium thickness in various parts of the uterus, are lacking. This study aims to provide normal references for uterine size in healthy reproductive-aged Chinese women to facilitate the application of hysteroscopic surgery. A total of 298 women of reproductive age with normal uterine were included. Parity was significantly correlated with uterine measurements (P < 0.05), and age impacted several measurements (P < 0.05). At each uterine site examined, the myometrium was thinner in nulliparous women than in parous or primiparous women (P < 0.001). Similarly, the extrauterine measurements for parous or primiparous women were larger than those for nulliparous women. Weight affected some external measurements but not myometrial thicknesses, while height did not affect uterine measurements (P > 0.05). There was a positive correlation between body mass index (BMI) and extrauterine measurements as well as myometrial thickness (P < 0.05). The mathematical model of the uterine size for women of reproductive age was constructed stratified by parity. The study is the first to provide a detailed statistical description of the accurate anatomical parameters of the uterus in Chinese reproductive-aged women and has great significance for improving the safety and effectiveness of hysteroscopic surgery for patients.