Relatively rare condition that results in the uterus becoming trapped between the sacral promontory and the pubic symphysis during pregnancy.

Aetiology
Risk factors:
- Uterine retroversion
- Posterior pelvic adhesions
- Adenomyosis
- Benign & malignant neoplasms
- Uterine malformations
- Endometriosis
- Prior abdominal surgery
Pathophysiology
Uterine retroversion:
Normal variant of uterus with a prevalence of up to 15% of pregnancies in the first trimester
In most cases, retroversion can spontaneously return to a normal axial position by 14th week of gestation when the gravid uterus grows into the abdominal cavity. In rare cases, the uterus remains retroverted and becomes retroflexed between the sub-promontory sacrum and pubis in the pelvic cavity, potentially caused by uterine anomalies, fibroids, pelvic adhesions or a deep sacral cavity with a prominent promontory. Failures to timely diagnose and properly treat uterine incarceration often result in obstetric complications.
Clinical features
The most typical presentation occurs during 14-16 weeks of gestation (2nd trimester) with a variety of symptoms mimicking common gastrointestinal, genitourinary, and musculoskeletal conditions.
Common features (35-55% cases):
- Urinary manifestations (53.70%): Urinary retention, frequent micturition, dysuria, urgency and paradoxical incontinence
- Abdominal pain (35.80%)
Other features (1-10% cases):
- Constipation
- Vaginal bleeding
- Pelvic pain, back pain, perineal pain
- Tenesmus
- Pelvic organ prolapse (POP) (rare)
Diagnosis
Diagnosis remains difficult as symptoms are often non-specific and absent in early pregnancy.
USG:

MRI:

Management
Conservative management:
- Knee-chest positioning & manual reduction
Surgical management:
- Myomectomy ± abdominal hysterectomy
- Abdominal hysterectomy without myomectomy