Endometritis

Endometritis refers to inflammation or infection involving the endometrium. Endometritis can be acute or chronic and may arise in an obstetric setting, such as following delivery or miscarriage, or in a non-obstetric setting due to pelvic inflammatory disease (PID) or endometrial instrumentation.

Epidemiology

Endometritis complicates 2-3% of vaginal deliveries as well as up to 27% of cesarean sections ⁵. It is the most common cause of fever in a postpartum patient ⁶.

Associations

Recognized associations include ³:

• prolonged labor
• premature rupture of membranes
• retained intrauterine clots
• retained products of conception

Clinical presentation

The typical presentation is with fever and lower abdominal pain. While imaging features can be helpful, the diagnosis is clinical as imaging can be normal, particularly in uncomplicated cases.

Radiographic features

Endometritis is a clinical diagnosis and caution should be taken due to the overlap of expected postpartum imaging findings and the ones related to the inflammatory process.

Ultrasound

While the sonographic appearance of the uterus and endometrium may be normal in early stages, findings may include:

• thickened and heterogeneous endometrium
• intracavitary/cul-de-sac fluid
• increased vascularity on Doppler ultrasound
• intrauterine air
• loss of a well defined interface between the endometrium and myometrium
  • described in cases occurring in the puerperal setting ⁷
  • may be associated with the development of a thin, hypoechoic layer in a subserosal distribution ⁸

MRI

• T2: the uterus may be enlarged with overall high signal intensity
• T1 C+ (Gd): can show intense enhancement of the uterus

Treatment and prognosis

Complications

• progression to a pyometrium
• pelvic septic thrombophlebitis

Differential diagnosis

Differential considerations include:

• retained products of conception: echogenic material in the endometrial cavity showing intrinsic vascularity
• endometrial carcinoma: can have overlapping sonographic features but will occur in a different clinical context ¹
• intrauterine blood clot: no associated vascularity

See also

• pelvic inflammatory disease