Complete Miscarriage

Complete miscarriage is the spontaneous passage of all products of conception before 24 weeks, with the cervix closing and bleeding settling. Most are caused by chromosomal abnormality of the embryo. It affects about 15 to 20 percent of clinically recognised pregnancies and matters because retained tissue, haemorrhage and sepsis must be excluded before the patient is reassured.

• Risk factors: maternal age above 35 years, previous miscarriage, smoking, alcohol, uncontrolled diabetes, thyroid disease, uterine anomalies.
• Most losses occur before 12 weeks.
• A complete miscarriage needs no evacuation if confirmed on ultrasound.

There is a history of vaginal bleeding with cramping lower abdominal pain and passage of tissue or clots, after which pain and bleeding settle and pregnancy symptoms fade. The cervical os is closed, the uterus is small and non-tender, and bleeding is light.

• Bleeding that reduces markedly after passage of tissue.
• Cervical os closed on speculum examination.
• Pregnancy test may stay positive for 2 to 4 weeks.
• Differential diagnosis: incomplete miscarriage, ectopic pregnancy, pregnancy of unknown location, molar pregnancy, cervical or vaginal bleeding of other cause.
• Complications: retained tissue, secondary haemorrhage, infection, anaemia, Rhesus alloimmunisation, psychological distress.

The diagnosis is confirmed when a prior intrauterine pregnancy is documented, or tissue is passed, and a transvaginal ultrasound shows an empty uterus with a thin endometrium.

• Urine pregnancy test, haemoglobin and blood group with Rhesus status.
• Transvaginal ultrasound: empty uterine cavity, endometrial thickness below 15 mm, no ectopic mass, no free fluid.
• If no previous scan proved an intrauterine pregnancy, check serum hCG at 0 and 48 hours; a steady fall to negative supports complete miscarriage.
• Send passed tissue for histology where possible to exclude molar change.
• Where ultrasound is unavailable, use clinical findings: closed os, minimal bleeding, small uterus, and a negative urine test after 3 weeks.

Treatment is reassurance, analgesia, Rhesus prophylaxis where needed and safety netting, with no surgical evacuation.

• Supportive: explain the diagnosis and counsel on grief; advise rest as needed and avoidance of tampons and intercourse for 2 weeks; treat anaemia.
• Pharmacological: paracetamol 1 g oral 6-hourly as needed (maximum 4 g in 24 hours); ibuprofen 400 mg oral 8-hourly with food for up to 3 days if no contraindication; if haemoglobin is below 11 g/dL give ferrous sulphate 200 mg oral 8-hourly for 3 months; folic acid 400 micrograms oral daily if planning a further pregnancy; start the chosen contraceptive method at once if pregnancy is not wanted.
• Procedures: none.
• Special groups: Rhesus negative women after 12 weeks of gestation or with heavy bleeding give anti-D immunoglobulin 250 IU IM within 72 hours of the bleed.
• Red flags: heavy bleeding soaking more than 2 pads in an hour, fever above 38 degrees Celsius, offensive discharge, severe or one sided pain, fainting, shoulder tip pain; these need urgent review.
• Follow-up: review at 1 to 2 weeks; repeat urine pregnancy test at 3 weeks and return if still positive; offer investigation after 3 consecutive losses.