Haematometra

Haematometra is the collection of menstrual blood inside the uterine cavity because the cervix, vagina or lower uterine outflow is blocked.

• Causes include cervical stenosis (after surgery, radiotherapy, atrophy or tumour), intrauterine adhesions, endometrial ablation, congenital outflow obstruction and cervical or endometrial cancer.
• It causes cyclical pain and can become infected (pyometra).
• Treatment is drainage and correction of the cause.

Lower abdominal pain that recurs monthly, amenorrhoea or scanty menses, a pelvic mass, urinary symptoms and, in girls, primary amenorrhoea with cyclical pain.

• A tender, enlarged, soft uterus; cervical stenosis or a vaginal obstruction on examination.
• Differential diagnosis: pregnancy, pyometra, fibroid, adenomyosis, ovarian cyst, endometrial cancer, Asherman syndrome.
• Complications: pyometra, retrograde menstruation, endometriosis, haematosalpinx, infertility and uterine perforation.

Diagnosis is by ultrasound, with MRI to define the level of obstruction.

• Pregnancy test.
• Transvaginal or abdominal ultrasound showing a distended cavity with ground-glass echoes.
• Pelvic MRI to define the level of obstruction, or any tumour.
• Full blood count; C-reactive protein if febrile.
• Biopsy of the cervix or endometrium for suspected malignancy, especially in postmenopausal women.

Drain the uterus, correct the cause of obstruction, and exclude cancer.

• Supportive: analgesia; hydration; observe temperature; explain recurrence risk and the need to treat the cause.
• Pharmacological: ibuprofen 400 mg oral 8-hourly with food (maximum 1.2 g in 24 hours) and paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours). Prophylactic antibiotic at drainage: doxycycline 100 mg oral 12-hourly for 5 days, or amoxicillin-clavulanate 625 mg oral 8-hourly for 5 days. Before surgery in a girl with obstruction, suppress menses with medroxyprogesterone acetate 150 mg IM every 13 weeks, or norethisterone 5 mg oral 12-hourly.
• Procedures: cervical dilatation with graduated Hegar dilators under ultrasound guidance and anaesthesia, with a Foley catheter or stent for 1 to 2 weeks; hysteroscopic resection of adhesions; incision of an imperforate hymen or transverse vaginal septum; excision of an obstructing lesion. Send tissue for histology.
• Special groups: in postmenopausal women biopsy the endometrium and cervix to exclude cancer. In girls with an obstructed hemivagina, resect the septum without delay.
• Red flags: fever with pain (pyometra), perforation, a mass with bleeding, postmenopausal haematometra.
• Follow-up: review at 2 weeks; ultrasound at 3 months to confirm drainage; review for recurrence.