Inevitable Miscarriage

Inevitable miscarriage is bleeding in early pregnancy with an open cervical os and no tissue yet expelled, so that loss cannot be prevented. The usual cause is fetal demise or detachment of the gestational sac. It matters because progression to heavy bleeding or infection is common, and the patient needs a clear plan.

• Occurs before 24 weeks, mostly before 13 weeks.
• Risk factors: older age, smoking, previous miscarriage, cervical incompetence at later gestations.
• The cervix is open and the process is under way.

Patients report vaginal bleeding with cramping lower abdominal pain, and examination shows a dilated internal os with the membranes sometimes bulging or ruptured. The uterus matches dates, and no tissue has passed.

• Bleeding is moderate to heavy.
• Cervix open to a finger.
• Pain is rhythmic, labour-like.
• Differential diagnosis: threatened miscarriage, incomplete miscarriage, ectopic pregnancy, molar pregnancy, cervical pathology.
• Complications: haemorrhage, infection, anaemia, shock, progression to incomplete miscarriage.

The diagnosis is made on speculum or digital examination showing an open os with a pregnancy still in the uterus.

• Urine pregnancy test, haemoglobin, blood group and Rhesus status.
• Transvaginal ultrasound: gestational sac low in the cervical canal or at the os, with or without cardiac activity.
• If cardiac activity is present, a threatened loss with cervical change at later gestation is possible and needs careful review.
• Monitor pulse, blood pressure and temperature.

The principle is to allow or assist completion of the miscarriage safely with attention to bleeding and infection.

• Supportive: bed rest while bleeding; IV access; Ringer's lactate 1 litre if bleeding is heavy; counselling.
• Pharmacological: misoprostol 800 micrograms vaginally or 600 micrograms sublingual, repeat once after 3 hours if no tissue passed; if infection is suspected, give ampicillin 2 g IV 6-hourly plus gentamicin 5 mg/kg IV once daily plus metronidazole 500 mg IV 8-hourly; analgesia with paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours) and ibuprofen 400 mg oral 8-hourly with food for 3 days.
• Procedures: manual vacuum aspiration up to 12 weeks size if bleeding is heavy or expulsion does not occur within 24 hours; sharp curettage with ovum forceps for larger uteri.
• Special groups: Rhesus negative women give anti-D immunoglobulin 250 IU IM within 72 hours.
• Red flags: heavy bleeding with dizziness, fever above 38 degrees Celsius, offensive discharge, severe pain.
• Follow-up: review at 1 to 2 weeks; repeat ultrasound or urine test at 3 weeks if management was conservative; offer contraception and counselling.