Antepartum Haemorrhage

Antepartum haemorrhage (APH) is bleeding from or into the genital tract after the period of viability (24 weeks in most modern texts; 28 weeks in older Indian texts) and before delivery of the baby. It is an obstetric emergency complicating 3–5% of pregnancies and is dominated by two heavyweights — placenta praevia (painless bleeding) and placental abruption (painful bleeding) — whose differentiation, grading, and management algorithms are the single most repeated APH theme in NEET PG.

High-yield: APH is bleeding after viability and before delivery. The two major causes are placenta praevia and abruptio placentae. The classic exam discriminator is painless (praevia) versus painful (abruption) bleeding.

Definition & Classification

APH is defined as bleeding from the genital tract after 24 (or 28) weeks of gestation up to the birth of the baby. Causes are grouped as:

Category	Conditions	Contribution
Placental (major)	Placenta praevia (~35%), Abruptio placentae (~35%)	~70%
Unexplained / indeterminate	"Marginal" / unclassified bleeds	~20–25%
Local (extra-placental)	Cervical polyp, cervical ectropion, carcinoma cervix, vaginal trauma, vulvovaginal varicosities, "show"	~5%
Vasa praevia	Fetal vessels crossing the os	<1% (but catastrophic)

High-yield: Two-thirds of APH is due to placenta praevia and abruptio placentae together. Always exclude these two before labelling a bleed as "local" or "indeterminate".

Placenta Praevia

Definition & Grading

Placenta praevia (PP) is implantation of the placenta partly or wholly in the lower uterine segment (over or near the internal os). The traditional 4-grade clinical/anatomical classification:

Grade	Type	Description
I	Low-lying	Placenta in lower segment, lower margin does not reach the os
II	Marginal	Lower margin reaches but does not cover the internal os
III	Incomplete (partial) central	Placenta covers os when closed, not when dilated
IV	Complete (total) central	Placenta completely covers the internal os

Modern (RCOG/ultrasound) terminology simplifies this to: low-lying placenta (edge <20 mm from os) versus placenta praevia (placenta covers the os). Grades I–II are "minor"/"lateral"; grades III–IV are "major"/"central".

High-yield: Type IV (complete central) praevia is the most dangerous, bleeds earliest and heaviest, and is an absolute indication for caesarean section regardless of fetal viability.

Etiology / Risk Factors

The unifying theme is defective decidua forcing the placenta to spread/implant low.

• Previous caesarean (scar) — strongest modifiable risk; also the key link to placenta accreta spectrum.
• Multiparity, advanced maternal age (>35 y).
• Previous PP, previous D&C / repeated abortions, previous myomectomy.
• Multiple pregnancy (large placenta), smoking, cocaine.
• Prior endometritis / Asherman.

Clinical Features

• Painless, causeless, recurrent, apparently external bright-red bleeding in the latter half of pregnancy. The first bleed ("warning haemorrhage") is usually not fatal.
• Uterus soft, relaxed, non-tender; fundal height corresponds to dates.
• Malpresentation common (breech, transverse, unstable lie) — placenta blocks descent of head.
• Stallworthy's sign: slowing of fetal heart on pressing the head into the pelvis (cord/placental compression), recovering on release.
• Fetal condition usually good unless massive maternal bleed (blood lost is maternal).

High-yield: Bleeding in praevia is maternal in origin and proportionate to revealed loss → maternal shock matches visible blood; the fetus is relatively spared unless the mother decompensates.

Diagnosis & Investigation of Choice

Transvaginal ultrasound (TVS) is the investigation of choice — safe, more accurate than transabdominal scan, and the gold standard for localising the placenta and measuring os-to-edge distance.

High-yield: Never do a per-vaginal (digital) examination in suspected praevia outside an operating theatre fully prepared for caesarean ("double set-up examination"). A speculum may be used cautiously to exclude local causes.

A low-lying placenta on a mid-trimester anomaly scan migrates upward in most women as the lower segment forms; rescan at 32 weeks (and 36 weeks if still low). Add colour Doppler / MRI when placenta accreta spectrum is suspected (anterior praevia + previous CS).

Management — stepwise approach

Admit → resuscitate (IV access, group & cross-match, FBC) → assess gestation, bleeding severity, fetal status → decide expectant vs active.

1. Expectant (McAfee–Johnson regimen): for a preterm fetus (<37 wks), mother haemodynamically stable, bleeding settled. Hospitalise, bed rest, correct anaemia, keep blood ready, give antenatal corticosteroids (24–34 wks) and anti-D if Rh-negative. Aim to prolong pregnancy to ~37 weeks.
2. Active / delivery: if ≥37 weeks, or active heavy bleeding, or maternal/fetal compromise at any gestation.
3. Mode of delivery:
   • Caesarean for all major degrees (Type III–IV) and any os-covering placenta; for accreta, plan an elective LSCS at ~34–36 weeks with senior team ± planned caesarean hysterectomy.
   • Vaginal delivery may be attempted only in Type I (and selected Type II anterior) with cephalic presentation, minimal bleeding, and placental edge >20 mm from os.

High-yield: Tocolytics (e.g., nifedipine) may be used cautiously in stable preterm praevia to buy time for steroids, but never with heavy active bleeding or non-reassuring fetal status.

Complications

• Antepartum: malpresentation, preterm birth, recurrent bleeds.
• Intrapartum/PPH: the lower segment contracts poorly → atonic PPH; placenta accreta spectrum → torrential bleed, hysterectomy.
• Postpartum: sepsis, anaemia; air embolism (rare).
• Increased neonatal morbidity from prematurity.

Abruptio Placentae (Accidental Haemorrhage)

Definition & Types

Premature separation of a normally situated placenta after viability, before delivery. Bleeding may be:

• Revealed (~80%) — blood escapes through the cervix.
• Concealed (~20%) — blood retained behind the placenta; the most dangerous (shock out of proportion to visible loss).
• Mixed — both.

Etiology / Pathophysiology

Primary event = rupture of maternal decidual spiral arteries → retroplacental haematoma → further separation. Risk factors:

• Hypertension / pre-eclampsia — the commonest associated cause.
• Trauma / road accident, sudden uterine decompression (e.g., after delivery of first twin, or rupture of membranes in polyhydramnios).
• Previous abruption (recurrence ~10×), advanced age/parity.
• Cocaine, smoking, thrombophilias, sudden change in uterine size.
• Short cord, folic acid deficiency (classically taught), preterm premature rupture of membranes.

High-yield: The single most important associated condition with abruption is pregnancy-induced hypertension / pre-eclampsia. Cocaine causes abruption via intense vasospasm.

Clinical Features

• Sudden, continuous, painful bleeding; blood typically dark, non-clotting.
• Tense, tender, "woody-hard" uterus; uterine height may be more than dates (concealed blood).
• Fetal distress or absent fetal heart — the fetus is directly threatened (placental gas exchange lost).
• Maternal shock out of proportion to revealed bleeding (concealed type).
• May present with idiopathic preterm labour.

High-yield: Shock out of proportion to external blood loss + tense tender uterus + fetal distress = concealed abruption until proven otherwise.

Couvelaire Uterus & DIC

• Couvelaire uterus (uteroplacental apoplexy): blood extravasates between myometrial fibres up to the serosa, giving a bluish, ecchymotic, oedematous uterus. It is a clinical/operative diagnosis, does not by itself mandate hysterectomy, and the uterus usually still contracts after delivery (managed with oxytocics; hysterectomy only for intractable atony).
• DIC is the feared coagulopathy — thromboplastin from the retroplacental clot enters circulation. Abruption is the commonest obstetric cause of DIC/consumptive coagulopathy.

High-yield: Abruptio placentae is the leading obstetric cause of acute DIC and acute renal failure (acute tubular/cortical necrosis). Couvelaire uterus is NOT an automatic indication for hysterectomy.

Diagnosis

Abruption is primarily a clinical diagnosis. Ultrasound has low sensitivity (a normal scan does NOT exclude abruption) but may show a retroplacental clot. Investigations: FBC, coagulation profile (fibrinogen, D-dimer, platelets, PT/aPTT), group & cross-match, renal function, Kleihauer–Betke (Rh-negative). Falling fibrinogen is the most useful early DIC marker.

High-yield: A normal USG does not rule out abruption — it is a clinical diagnosis. USG is far more valuable for praevia.

Management — stepwise approach

Resuscitate aggressively (two wide-bore IVs, crystalloids/blood) → correct coagulopathy (FFP, cryoprecipitate, platelets) → assess fetus → deliver.

1. Mother unstable or fetus dead: prompt vaginal delivery preferred if feasible (amniotomy ± oxytocin); CS if uncontrolled bleeding or obstruction. Aggressively replace blood/clotting factors.
2. Live fetus with distress / viable, no immediate vaginal delivery: emergency caesarean section.
3. Live fetus, no distress, mild abruption, preterm: highly selective expectant management with continuous monitoring, steroids 24–34 wks, in a setup ready for immediate delivery.
4. Monitor for PPH (deliver with oxytocics ready), renal failure (urine output, fluid balance), and DIC.

Complications

• Maternal: hypovolaemic shock, DIC, acute renal failure (cortical necrosis), PPH, Sheehan's syndrome, Couvelaire uterus, death.
• Fetal: hypoxia, IUGR, prematurity, high perinatal mortality.

Vasa Praevia (don't miss)

Unprotected fetal vessels run through the membranes across the internal os, below the presenting part — classically with velamentous cord insertion or a succenturiate lobe. Rupture of membranes → sudden painless bleed with acute fetal distress / sinusoidal CTG (the blood lost is fetal). Diagnosis: antenatal TVS with colour Doppler; Apt test / Singer alkali-denaturation test distinguishes fetal (HbF, alkali-resistant, stays pink) from maternal blood. Management: planned caesarean ~34–36 weeks before labour.

High-yield: Vasa praevia = fetal haemorrhage → small blood loss but disastrous fetal death. Triad: ruptured membranes + painless bleeding + fetal bradycardia/sinusoidal pattern. Confirm fetal origin with the Apt test.

Key Differentials — Praevia vs Abruption vs Vasa Praevia

Feature	Placenta Praevia	Abruptio Placentae	Vasa Praevia
Onset	Insidious, recurrent	Sudden	At membrane rupture
Pain	Painless	Painful	Painless
Bleeding	Bright red, external	Dark, may be concealed	Bright red (fetal)
Uterus	Soft, relaxed, non-tender	Tense, woody, tender	Normal
Fundal height	= dates	May be > dates	Normal
Shock	Proportionate to loss	Out of proportion (concealed)	Maternal stable; fetus dies
Fetal heart	Usually good	Distress / absent	Acute distress / bradycardia
Presentation	Mal-presentation common	Usually normal lie	Normal
Investigation of choice	TVS	Clinical (USG low yield)	TVS + colour Doppler
Classic complication	PPH, accreta	DIC, ARF, Couvelaire	Fetal exsanguination

High-yield mnemonic — "PRAEVIA is Painless, ABRUPTION is Agonising." And for abruption complications: "DR. CAP" → DIC, Renal failure, Couvelaire uterus, Anaemia/Atonic PPH, Pre-eclampsia (cause).

Placenta Accreta Spectrum (linked, frequently tested)

Abnormally adherent/invasive placenta — accreta (attached to myometrium), increta (invades myometrium), percreta (through serosa, may invade bladder). Strongest risk = placenta praevia + previous caesarean (risk rises steeply with each repeat CS). Suspect when the placenta fails to separate. Diagnosis: USG (loss of clear zone, lacunae) ± MRI. Management: planned caesarean hysterectomy by an experienced team, leaving the placenta in situ. Major cause of massive obstetric haemorrhage and emergency hysterectomy.

High-yield: Anterior placenta praevia overlying a previous CS scar → suspect placenta accreta spectrum and plan for caesarean hysterectomy.

Recently asked / exam angle

• Single-best-answer discriminators: "Painless bleeding + soft uterus + transverse lie" → praevia; "Painful bleeding + tense tender uterus + pre-eclampsia" → abruption; "Bleeding right after ARM + fetal bradycardia" → vasa praevia.
• Investigation of choice in praevia = TVS; abruption = clinical diagnosis (USG may be normal). Repeatedly tested.
• Contraindicated step: per-vaginal digital exam in suspected praevia → done only as double set-up in theatre.
• Couvelaire uterus — image/clinical scenario; remember it does not mandate hysterectomy and uterus usually still contracts.
• Commonest obstetric cause of DIC / acute renal failure = abruption.
• Type IV praevia → absolute indication for LSCS.
• Apt test for fetal vs maternal blood (vasa praevia).
• McAfee–Johnson expectant regimen for preterm stable praevia.
• Strongest risk factor for accreta = previous CS + anterior praevia.
• Stallworthy's sign and the "warning haemorrhage" concept of praevia.

Rapid revision

1. APH = bleeding after viability (24/28 wks) before delivery; praevia + abruption ≈ two-thirds of cases.
2. Praevia = painless, bright red, recurrent; soft non-tender uterus; malpresentation; investigation of choice = TVS.
3. Abruption = painful, tense woody-hard tender uterus; fetal distress; shock out of proportion if concealed.
4. Never do a digital PV exam in suspected praevia — use a double set-up in theatre.
5. Type IV (complete central) praevia = absolute indication for caesarean.
6. Low-lying placenta on anomaly scan usually migrates up — rescan at 32 weeks.
7. Couvelaire uterus is a clinical finding of abruption; the uterus usually still contracts → it is not an indication for hysterectomy by itself.
8. Abruption is the commonest obstetric cause of DIC and acute renal failure; monitor fibrinogen.
9. Abruption USG can be normal — it is a clinical diagnosis; USG is most useful for praevia.
10. Vasa praevia = fetal bleed after membrane rupture with acute fetal bradycardia; confirm with Apt test; deliver by planned CS.
11. Previous CS + anterior praevia → suspect placenta accreta spectrum → plan caesarean hysterectomy.
12. Expectant care of stable preterm praevia = McAfee–Johnson regimen + antenatal steroids + anti-D if Rh-negative.