Built from the two abortion lecture decks (the Department's "Abortions" slides and the "Abortion and Miscarriage" slides). Doses are left out on purpose: use your hospital protocol.
The reasoning chain: bleeding in early pregnancy → is the pregnancy still alive → is the cervix open → has tissue passed → is she infected or bleeding heavily → empty the uterus safely if needed → look for the cause, especially if this is not the first loss → give anti-D and counselling.
1. Definitions
Abortion is the loss of a pregnancy between conception and viability. The cut-off differs: WHO uses 20–22 weeks (or a fetus under 500 g); Kenya uses 28 weeks. It may be spontaneous (miscarriage) or induced.
- Miscarriage is common: 10–20% of clinically recognised pregnancies, and about 75% occur before 16 weeks.
- Recurrent miscarriage (habitual abortion) is three or more consecutive spontaneous losses, affecting about 1–2% of couples (the lecture quotes 2–5%).
Classification
- Spontaneous: threatened, inevitable, incomplete, complete, missed, septic, recurrent.
- Induced: legal (therapeutic, under the law) or illegal/unsafe.
2. Causes of spontaneous abortion
| Group | Examples |
|---|---|
| Fetal (about half of early losses) | Chromosomal abnormalities (50% of early miscarriages): trisomies (the commonest is trisomy 16), triploidy, monosomy X; structural defects; multiple pregnancy; degeneration of villi |
| Maternal: endocrine and metabolic (10–15%) | Poorly controlled diabetes, thyroid disease, luteal phase defect, PCOS (raised LH) |
| Maternal: anatomical (10–15%) | Müllerian anomalies (septate, bicornuate, double uterus), submucous fibroids, polyps, intrauterine adhesions (Asherman syndrome), cervical incompetence |
| Infections (about 5%) | TORCH (toxoplasma, rubella, CMV, herpes), HIV, syphilis, malaria, Ureaplasma, Chlamydia, brucellosis, listeria |
| Immunological (5–10%) | Antiphospholipid syndrome (lupus anticoagulant, anticardiolipin antibodies), alloimmune factors |
| Environmental and lifestyle | Smoking, alcohol, drugs, heavy caffeine, some drugs, radiation |
| Other maternal illness | Cyanotic heart disease, haemoglobinopathies (sickle cell), kidney disease, SLE |
| Advancing maternal age | The risk rises from under 2% below 30 to above 10% over 40 and about 50% at 45 (more chromosomal errors) |
| Unexplained | 40–60% |
3. The five types and how to tell them apart
| Type | Bleeding and pain | Cervical os | Tissue passed | Ultrasound | Plan |
|---|---|---|---|---|---|
| Threatened | Small bleed, little or no pain | Closed | None | Viable pregnancy (heartbeat) | Rest and reassure; 80% reach term |
| Inevitable | Heavy bleed, colicky pain | Open | None yet | Pregnancy in the uterus, may be failing | Empty the uterus |
| Incomplete | Persistent bleeding and pain | Open | Some tissue passed, some retained | Retained products | Evacuate |
| Complete | Pain and bleeding settle | Closed | All passed | Empty uterus | Observe, support |
| Missed | Often none, or old brown spotting; symptoms of pregnancy fade | Closed | None | No heartbeat, or an empty sac | Medical or surgical evacuation |
| Septic | Fever, pain, foul discharge | Open, purulent | May be retained | Retained products | Antibiotics then evacuate |
Threatened abortion
Definition: the process has started, but recovery is still possible. History: small, often painless bleeding (mild back or lower abdominal ache), pregnancy symptoms still present. Examination: uterus size equals dates, cervix soft with a closed os.
Ultrasound is diagnostic (a live intrauterine pregnancy); avoid a pelvic examination when ultrasound is available. Differentials: cervical ectopy, polyp, cervical cancer, ectopic pregnancy, molar pregnancy.
Management and outlook: rest until the bleeding stops, simple pain relief, reassurance, and anti-D if she is rhesus-negative. About 80% of threatened abortions continue to term; with a live fetus on ultrasound, over 95% continue. Pregnancies that continue carry more preterm labour, placenta praevia and growth restriction.
Inevitable abortion
Bleeding is heavier, pain colicky, and the internal os is open with products felt at it. The pregnancy cannot continue. Aims: speed up the expulsion and keep strict asepsis. Under 12 weeks: suction evacuation. Over 12 weeks: oxytocin or prostaglandin to induce expulsion. Control heavy bleeding with uterotonics, give fluids and blood as needed.
Incomplete abortion
Some tissue has passed, some remains. Bleeding and pain persist, the uterus is smaller than dates and the os is open. Retained products cause bleeding, sepsis and placental polyp. Treatment: evacuate the retained products (suction curettage or manual vacuum aspiration, MVA; misoprostol is an alternative in early cases), give prophylactic antibiotics, and send tissue for histology.
Complete abortion
All the tissue has gone. Pain stops, bleeding becomes trace or absent, the os is closed, and ultrasound shows an empty uterus. Be sure it was not an ectopic pregnancy with a pseudosac.
Missed abortion
The fetus is dead and retained. The uterus is smaller than dates, the os is closed, pregnancy symptoms fade and the pregnancy test turns negative. Ultrasound: a crown-rump length of 7 mm or more without a heartbeat, or an empty sac above 25 mm (an anembryonic pregnancy). Complications: sepsis and rarely DIC, especially over 16 weeks. Treatment: misoprostol (expulsion in about 48 hours) or suction evacuation / D&E; later in pregnancy, repeated misoprostol with antibiotics.
Septic abortion
Any abortion with clinical infection of the uterus and its contents: fever (38 °C or more for 24 hours), offensive purulent discharge, lower abdominal pain and tenderness. Commonest cause: an unsafe induced abortion by an untrained person; spontaneous cases are usually mild.
| Grade | Spread |
|---|---|
| I | Infection confined to the uterus (commonest, usually spontaneous) |
| II | Spread to the parametrium, tubes, ovaries or pelvic peritoneum |
| III | Generalised peritonitis, endotoxic shock, jaundice or acute kidney injury |
Clues to spread: a pulse above 100 to 120 matters more than fever. Examination: tender uterus, open os, foul discharge; guarding means peritonitis.
Investigations: full blood count, urea, creatinine and electrolytes, high vaginal swab, blood cultures, pelvic ultrasound (retained products), abdominal X-ray if bowel injury is suspected (free air), chest X-ray for breathing difficulty.
Complications: haemorrhage, injury to the uterus, bowel and bladder, **peritonitis, endotoxic shock (often E. coli), DIC, acute kidney injury**, thrombophlebitis and death.
Management: resuscitate (oxygen, IV crystalloid, blood), broad-spectrum IV antibiotics (a combination such as ampicillin, gentamicin and metronidazole is typical), and evacuate the uterus within 4 to 6 hours of starting antibiotics. Laparotomy for bowel injury or uncontrolled sepsis. Give tetanus prophylaxis after an unsafe abortion and counsel on contraception.
4. Investigations: tie each to a question
| Test | The question it answers |
|---|---|
| Transvaginal ultrasound | Is the pregnancy in the uterus, alive, and complete? |
| β-hCG (serial) | Is the level rising or falling appropriately? (Ectopic or molar pregnancy?) |
| Full blood count, group and crossmatch, rhesus | How much blood lost? Does she need anti-D? |
| Blood cultures, high vaginal swab, urea and creatinine | Septic abortion and its effect on the kidneys |
| Chromosomes of the products | Recurrent loss: was it a chromosomal error? |
5. Recurrent miscarriage: find the cause
Three or more consecutive losses. No cause is found in about 50%. Work it up:
- Genetic (3–5%): parental balanced translocation (risk of loss over 25%; the commonest cause of first-trimester loss). Karyotype both parents.
- Antiphospholipid syndrome (about 15%): lupus anticoagulant, anticardiolipin and anti-β2 glycoprotein antibodies on two occasions 12 weeks apart. Treat with low-dose aspirin and heparin in the next pregnancy.
- Endocrine: diabetes (control it), thyroid antibodies and thyroid function, PCOS.
- Inherited thrombophilia: protein C and S deficiency, factor V Leiden, prothrombin mutation.
- Infections: syphilis, TORCH.
- Uterine factors: septate or double uterus (hysteroscopic resection of the septum), Asherman syndrome (hysteroscopic division of adhesions), submucous fibroids (myomectomy). Transvaginal or 3D ultrasound and hysterosalpingography or hysteroscopy make the diagnosis.
- Cervical insufficiency: see below.
Second-trimester loss and cervical insufficiency
Painless dilatation of the cervix with ballooning of the membranes into the vagina, rupture and expulsion of a live-looking fetus, usually at 16 to 24 weeks. Causes: congenital weakness and uterine anomalies; acquired (commoner) after D&C, dilatation and evacuation, difficult operative deliveries through an undilated cervix, and cone biopsy or cervical amputation; multiple pregnancy and previous preterm birth.
Diagnosis: a history of repeated painless mid-trimester losses. Outside pregnancy: a Hegar dilator (number 6 to 8) passes the internal os without resistance, or funnelling on hysterosalpingography. In pregnancy: transvaginal ultrasound shows a cervix under 25 mm with funnelling.
Treatment: cervical cerclage (a non-absorbable tape or stitch around the cervix at the level of the internal os), usually at 12 to 14 weeks, with 80–90% success.
- History-indicated: three or more previous second-trimester losses.
- Ultrasound-indicated: short cervix or funnelling after one or two losses.
- Rescue (emergency) cerclage: the cervix is already dilated.
- Methods: McDonald (purse-string, commonest and simplest), modified Shirodkar (submucosal tape, via an anterior vaginal incision), transabdominal (rare; for repeated failure).
- Contraindications: intrauterine infection, ruptured membranes, bleeding, uterine irritability, cervical dilatation over 4 cm.
6. After a miscarriage
- Anti-D immunoglobulin to every rhesus-negative woman.
- Contraception and counselling about when to try again.
- Support: grief is real and often neglected. Offer follow-up and a clear explanation: most losses are not caused by anything the mother did.
- Recurrent loss needs an investigation clinic, not just reassurance.
Examiner questions
- Classify spontaneous abortion and state the key examination finding that separates a threatened from an inevitable abortion.
- A woman has fever, offensive discharge and a pulse of 120 after an unsafe abortion. How do you manage her?
- List the causes of recurrent miscarriage and say which tests you would request.
- What is cervical incompetence and how is it treated?
Practice questions
1. A 24-year-old at 9 weeks has a small painless bleed. The cervical os is closed and ultrasound shows a fetal heartbeat. The diagnosis is: A. Missed abortion · B. Inevitable abortion · C. Threatened abortion · D. Incomplete abortion · E. Ectopic pregnancy Answer: C.
2. The commonest cause of early (first-trimester) miscarriage is: A. Cervical incompetence · B. Infection · C. Chromosomal abnormality of the fetus · D. Diabetes · E. Uterine septum Answer: C.
3. Painless dilatation of the cervix at 20 weeks with expulsion of a live-looking fetus suggests: A. Threatened abortion · B. Missed abortion · C. Cervical insufficiency · D. Placenta praevia · E. Molar pregnancy Answer: C. Treat the next pregnancy with a cervical cerclage at 12–14 weeks.
4. After an unsafe abortion a woman has fever, tender uterus, a pulse of 120 and a foul vaginal discharge. The most important management is: A. Reassurance · B. Oral antibiotics only · C. Resuscitation, IV broad-spectrum antibiotics and evacuation of the uterus · D. Hysterectomy at once · E. Bed rest Answer: C.
5. Which test is most useful in a woman with three consecutive first-trimester miscarriages and a history of a deep vein thrombosis? A. Pap smear · B. Antiphospholipid antibodies (lupus anticoagulant, anticardiolipin) · C. HIV test only · D. Ultrasound of the kidneys · E. Serum ferritin Answer: B.