Exclusion criteria
First, each patient’s history was reviewed. Patients who met one of the
following criteria were excluded: (1) a previous history of total or
subtotal hysterectomy or cervical excision; (2) previous pelvic floor
surgery for prolapse or urinary incontinence; (3) a history of prolapse
or urinary or faecal incontinence; (4) pregnancy with a gestational age
≥ 8 weeks or within 12 months after delivery; and (5) malformation of
the female genital tract, such as Mayer-Rokitansky-Küster-Hauser
syndrome, although uterine mediastinum was not excluded. Then, the MR
images and MRI reports were reviewed. Patients who met one of the
following criteria were excluded: (1) a maximum uterine diameter ≥ 7 cm,
such as multiple uterine fibroids or adenomyosis; (2) any mass or cysts
in the pelvis with a diameter ≥ 6 cm, such as fibroids, ovarian cysts,
or hydrosalpinx; (3) any mass or cysts in the cervix or
the cervical canal with a diameter ≥ 2 cm; (4) any mass or cysts on the
vaginal wall, in the vaginal lumen, or in the area around the vagina
with a diameter ≥ 2 cm; (5) a maximum diameter of the rectum ≥ 3 cm or
maximum bladder diameter ≥ 6.5 cm on any sagittal images; and (6) poor
visibility of the anatomic structures of the landmarks. Finally, the
pelvic examination records were carefully reviewed, and any patients
with POP were excluded. If surgical treatment was conducted in our
hospitals, the corresponding record was also reviewed. Patients with
dense, extensive adhesions between the uterus and abdominal wall
suggestive of an obvious change in the position of the uterus were
excluded.