Uterine inversion

Definition

• In uterine inversion the fundus descends into the uterine cavity, through the cervix or beyond the introitus; about 85 per cent of cases occur postpartum, typically in the third stage of labour.

Classification

• Puerperal (obstetric) inversion, which may be acute or chronic, is distinguished from non-puerperal inversion, which is mostly chronic and related to uterine tumours, most commonly leiomyomas (56%) and less often malignancies (32%).

Occurrence & epidemiology

Epidemiology

• Puerperal uterine inversion is a rare, life-threatening obstetric emergency; a higher incidence has been reported after caesarean section.

Aetiopathogenesis

Aetiology and risk factors

• The commonest cause is excessive cord traction during birth of the placenta; contributing factors are excessive fundal pressure in the third stage, uterine atony and placenta accreta.

Clinical features

Clinical features and complications

• Puerperal inversion is closely associated with postpartum haemorrhage; blood loss often requires transfusion and may progress to hypovolaemic shock and maternal death.
• On abdominal examination the fundus is not palpable or lower than expected, and the inverted fundus may be visible at or beyond the introitus.

Diagnosis

• The diagnosis of puerperal inversion is clinical.
• Ultrasound shows a U-shaped configuration in the sagittal plane and a target sign in the transverse plane; in the non-puerperal form, ultrasound and MRI enable the diagnosis, and distinguishing it from tumours or prolapse can be difficult.

Keep learning in the app

Further reading (selection)

1. StatPearls: Uterine Inversion (NCBI Bookshelf)
2. MSD Manual Professional Edition: Uterine Inversion
3. Obstet Gynecol Int 2020: Nonpuerperal Uterine Inversion – What the Gynaecologists Need to Know? (PMC, open access)

Cross-references