Define and describe the clinical types and their management of abortion.

Cervical os status separates threatened from inevitable.

Definition

Abortion (miscarriage) is the termination of pregnancy before the period of viability — conventionally before 20 weeks (or a fetal weight under 500 g). When it occurs naturally it is a spontaneous abortion (miscarriage).

Clinical Types of Abortion (miscarriage)

Causes

• Genetic — chromosomal abnormalities of the conceptus (the commonest cause of early miscarriage).
• Maternal — endocrine (luteal-phase defect, uncontrolled diabetes, thyroid disease), uterine (septate uterus, fibroid, cervical incompetence — recurrent mid-trimester loss), infections, and antiphospholipid syndrome.
• Others — severe maternal illness, trauma and environmental factors; many remain unexplained.

Clinical Types

• Threatened — slight bleeding with a closed cervix; the pregnancy may still continue.
• Inevitable — increasing bleeding and pain with a dilated cervix; the pregnancy cannot be saved.
• Incomplete — part of the products is expelled, the rest retained (continued bleeding, open os).
• Complete — all products expelled; bleeding and pain settle and the uterus is well-contracted.
• Missed — the fetus is dead but retained in utero (no growth, brownish discharge, closed os).
• Septic — abortion complicated by infection of the uterus and its contents.

Differentiating the Types

Management

• Threatened — rest, reassurance and observation; confirm viability by ultrasound and serial β-hCG; give anti-D to Rh-negative women.
• Inevitable / incomplete — resuscitate if bleeding is heavy, then evacuate the uterus by suction/manual vacuum aspiration or medically (misoprostol); send products for histology.
• Complete — confirm an empty uterus on ultrasound; usually no intervention.
• Missed — evacuate medically (mifepristone + misoprostol) or surgically; check coagulation if retained long.
• Septic — broad-spectrum intravenous antibiotics and resuscitation, followed by evacuation of the infected products.

WHY the Type of Miscarriage Is Defined BY the Cervical Os

The classification of miscarriage looks like a list of names, but it is in fact a logical clinical sequence, and the key that unlocks it is the state of the cervical os. In a threatened miscarriage, there is bleeding but the pregnancy is still viable: the os is closed, the uterus corresponds to the dates, and the pregnancy may well continue (over half do) — so the management is expectant. Once the process becomes irreversible, the os opens: in an inevitable miscarriage there is bleeding with cramping pain and an open os, and the pregnancy cannot be saved. Thereafter the question is simply how much has come away: in an incomplete miscarriage, part of the products has been expelled and part retained — the os remains open, and the continued bleeding (which may be severe) comes from the retained products preventing the uterus from contracting, so it must be evacuated; in a complete miscarriage, everything has been expelled — the bleeding and pain subside, the uterus is well contracted and the os closes again. A missed miscarriage is the silent variant: the fetus has died but is retained, with a closed os and no pain — diagnosed on ultrasound. Recognising that the os simply reports whether the uterus is trying to expel its contents explains the entire classification.

WHY Septic Abortion Is a Killer — and a Public-health Problem

Understanding why septic abortion remains a major cause of maternal death in India gives this topic its true weight. Where safe, legal abortion is not accessible — because of ignorance of the law, stigma, cost, distance or a wish for secrecy — women resort to unsafe abortion at the hands of untrained persons, often with unsterile instruments or by the insertion of foreign bodies. The result is infection of the retained products (an ideal culture medium in a warm, vascular uterus), which is characteristically polymicrobial and includes anaerobes such as Clostridium. It escalates rapidly: endometritis → parametritis and pelvic peritonitis → septicaemia and septic shock, with acute renal failure and DIC — and there may also be uterine perforation and bowel injury from the procedure itself. Management is a true emergency: aggressive resuscitation, broad-spectrum intravenous antibiotics covering anaerobes, and — crucially — evacuation of the infected uterine contents (the source of the sepsis), with hysterectomy in extremis. But the real answer is preventive: the MTP Act exists to make abortion safe and legal, and every unsafe abortion represents a failure of access, contraception and counselling — which is why the topic belongs as much to public health as to gynaecology.

• Miscarriage = expulsion of the products of conception before 20 weeks (or <500 g); commonest cause is chromosomal abnormality (~50%).
• The cervical OS defines the type: threatened (bleeding, os closed, viable) → inevitable (pain + bleeding, os open) → incomplete (partial expulsion, os open, bleeds) → complete (all expelled, os closes).
• Missed miscarriage: the fetus has died but is retained — os closed, no pain, diagnosed on ultrasound; risk of DIC if long retained.
• Recurrent miscarriage (≥3): investigate for antiphospholipid syndrome, uterine anomalies, cervical incompetence, chromosomal and endocrine causes.
• Septic abortion is a leading cause of maternal death — resuscitate, give broad-spectrum antibiotics (covering anaerobes) and evacuate the uterus; prevented by safe, legal abortion (MTP Act) and contraception.