Complications of Early Pregnancy

Termination Of Pregnancy

Termination of pregnancy is the deliberate ending of a pregnancy by medical (pharmacological) or surgical means before the fetus reaches viability.

Termination of Pregnancy (TOP)

Epidemiology

This is critical because the legality directly determines clinical practice.

Anatomy and Function — Relevant Review

Understanding the anatomy is essential for appreciating both the procedures and the complications.

Etiology (Reasons/Indications for TOP)

The "etiology" of TOP is essentially the reasons women seek it. These map onto the legal grounds.

Risk Factors for Needing TOP / Risk Factors for Complications of TOP

Classification of TOP Methods

TOP methods are classified by:

  1. Timing / Gestational age
  2. Method (Medical vs. Surgical)

By Method

Clinical Features

Symptoms

These relate to the clinical presentation of women SEEKING TOP, and the expected/abnormal symptoms DURING and AFTER the procedure.

Signs

Pathophysiology of Key Processes

Pre-procedure Assessment (Clinical Approach)

Before any TOP, the following must be established:

Drugs Affecting Uterine Motility — Detailed Pharmacology

This section is derived from the lecture on "Drugs affecting uterine motility" [3].

Uterotonic Agents (Stimulate Uterine Contraction)

These are used for TOP, induction of labour, and management of PPH.

Differential Diagnosis of Termination of Pregnancy

The differential diagnosis (DDx) for TOP is a somewhat unusual framing compared to a typical "disease" DDx. In clinical practice, the DDx operates at two distinct levels:

  1. Before TOP: When a woman presents requesting TOP or with a positive pregnancy test and symptoms — you must confirm the nature and location of the pregnancy and exclude conditions that mimic normal intrauterine pregnancy or that contraindicate standard TOP.
  2. After TOP: When a woman presents with complications post-TOP (bleeding, pain, fever) — you must differentiate between TOP-related complications and other gynaecological/surgical emergencies.

Let's work through both systematically, because the exam scenario is almost always a case vignette — either a woman presenting with early pregnancy symptoms (and you must formulate a prioritised DDx list) or a woman presenting post-procedure with a complication.

The Lecture's Core Teaching Point

"The most important part in this session is the ability to formulate the list of differential diagnoses and to prioritize them according to the clinical condition and NOT just to give the right diagnosis." [2][4]

This tells you the examiners want you to think broadly and systematically, not jump to a single answer.


Level 1: DDx Before TOP — "Is This Really a Normal Intrauterine Pregnancy?"

Before performing TOP, you must confirm that what you are dealing with is a viable intrauterine pregnancy (IUP). If it is NOT a normal IUP, proceeding with standard TOP is either inappropriate, dangerous, or both.

Level 2: DDx in the Woman Presenting with Early Pregnancy Symptoms

This is the more common exam scenario: a young woman (e.g., 25 years old) presents with abdominal pain and vaginal spotting [2][4]. You must think through the full DDx.

The approach is systematic — think obstetric/gynaecological first, then non-gynaecological.

Level 3: DDx After TOP — "This Post-TOP Patient Is Unwell"

When a woman presents with complications after TOP, you must differentiate between:

References

[2] Lecture slides: GCBC-OG-Gyn Emergency_Notes to students_Sep2024.pdf; Block C - Gyanecological Emergency Notes to Students.pdf [4] Lecture slides: Block C - Gyanecological Emergency Notes to Students.pdf [5] Lecture slides: GC 223. Complications of Early Pregnancy.pdf [6] Senior notes: Maksim Medicine Notes.pdf (Gestational thyrotoxicosis section — hCG and molar pregnancy) [7] Senior notes: Ryan Ho GI.pdf (Appendicitis DDx section — gynaecological differentials) [8] Senior notes: Maksim Surgery Notes.pdf (Acute abdomen DDx; Paediatric surgical abdomen) [9] Senior notes: Maksim Medicine Notes.pdf (Secondary amenorrhoea — Asherman syndrome)

Diagnostic Criteria, Algorithm, and Investigations for Termination of Pregnancy

Unlike many medical conditions, TOP does not have "diagnostic criteria" in the traditional sense (e.g., there is no set of criteria to diagnose "TOP" the way you diagnose SLE or rheumatic fever). Instead, the diagnostic workup for TOP serves three interlocking purposes:

  1. Confirming the diagnosis of intrauterine pregnancy — is there a pregnancy, where is it, and is it viable?
  2. Establishing gestational age — this determines the method of TOP and legality
  3. Assessing maternal fitness — are there conditions that would affect the safety of the procedure?

Think of the diagnostic process as building a pre-operative assessment — you are confirming that what you plan to treat is actually what you think it is, and that the patient is safe to undergo the procedure.


Diagnostic Criteria — What Must Be Confirmed Before TOP

There are no formal "diagnostic criteria" published by ILAE-type bodies, but in practice every reputable guideline (WHO, RCOG, NICE, Hong Kong HA protocols) requires the following to be established:

Investigation Modalities — Detailed Breakdown

Let's now go through each investigation systematically, explaining what it is, why we do it, key findings, and interpretation — from first principles.

References

[2] Lecture slides: GCBC-OG-Gyn Emergency_Notes to students_Sep2024.pdf; Block C - Gyanecological Emergency Notes to Students.pdf [4] Lecture slides: Block C - Gyanecological Emergency Notes to Students.pdf [5] Lecture slides: GC 223. Complications of Early Pregnancy.pdf [6] Senior notes: Maksim Medicine Notes.pdf (hCG homology with TSH section) [7] Senior notes: Ryan Ho GI.pdf (Acute abdomen investigations) [8] Senior notes: Ryan Ho Fundamentals.pdf (Obstetric examination and imaging) [10] Senior notes: Ryan Ho Radiology.pdf (Obstetric imaging — USS landmarks) [11] Senior notes: Ryan Ho Haemtology.pdf (DIC — obstetric causes including septic abortion) [12] Senior notes: Ryan Ho Rheumatology.pdf (Antiphospholipid syndrome — Sapporo criteria)

Management of Termination of Pregnancy

Management of TOP is a structured, stepwise process. The overarching framework is:

  1. Pre-procedure preparation (counselling, legal, investigations — covered in prior sections)
  2. Choosing the method (medical vs surgical, based on gestational age, patient factors, and preference)
  3. Performing the procedure
  4. Post-procedure care (confirm completion, manage pain, start contraception, follow-up)
  5. Managing complications (covered in the next section)

The key decision point is which method to use and when. Let me walk through the entire management algorithm, then discuss each treatment modality in depth with indications, contraindications, protocols, and the pharmacological reasoning behind every drug.


Treatment Modality 1: Medical TOP

Medical TOP uses pharmacological agents to induce expulsion of the pregnancy — essentially "inducing a miscarriage" in a controlled setting.

The Standard Regimen: Mifepristone + Misoprostol

This is the gold-standard combination used worldwide (WHO, RCOG, NICE, FIGO all endorse it). Let me explain the pharmacology from first principles, then the protocols.

Treatment Modality 2: Surgical TOP

Surgical TOP physically removes the pregnancy from the uterus. The specific technique depends on gestational age.

Cervical Priming — A Detailed Overview

Cervical priming deserves its own section because it is the single most important step in reducing surgical complications. Think of the cervix as a gatehouse — trying to force it open damages the gate.

Perioperative Care

Management of Specific Scenarios

References

[2] Lecture slides: GCBC-OG-Gyn Emergency_Notes to students_Sep2024.pdf; Block C - Gyanecological Emergency Notes to Students.pdf [3] Lecture slides: Block C - The woman needs that drug_ Oral contraceptives, Drugs affecting uterine motility.pdf [4] Lecture slides: Block C - Gyanecological Emergency Notes to Students.pdf [10] Senior notes: Ryan Ho Radiology.pdf (Obstetric imaging) [11] Senior notes: Ryan Ho Haemtology.pdf (DIC — obstetric causes) [13] Senior notes: Ryan Ho Diagnostic Radiology.pdf (Uterine artery embolisation for PPH)

Complications of Termination of Pregnancy

Complications of TOP can be organised by timing (immediate, early, late) and by method (medical vs surgical). Understanding the pathophysiology of each complication is the key to recognising, preventing, and managing them. Overall, TOP is a safe procedure when performed correctly — the complication rate for first-trimester TOP is very low (< 1% for serious complications). However, complications rise substantially with increasing gestational age, and some are life-threatening if missed.

The mnemonic "CHIPS" can help you remember the major complications:

  • C — Cervical laceration
  • H — Haemorrhage
  • I — Infection (endometritis / septic abortion)
  • P — Perforation (uterine)
  • S — Sequelae (long-term: Asherman syndrome, cervical incompetence, psychological, Rh sensitisation)

1. Haemorrhage

Incidence: ~1 in 1,000 for first-trimester TOP requiring transfusion; higher in second-trimester procedures

2. Uterine Perforation

Incidence: 1–4 per 1,000 surgical TOPs (higher in second-trimester D&E)

Exam question stem: "A 24-year-old woman, G1P0, was referred from the Family Planning Association one day after suction evacuation for an unplanned and unwanted pregnancy. Intraoperatively, there was a 'give-way' sensation by the surgeon. The patient complained of mild vaginal bleeding but was otherwise well. Her BP was 120/80 mmHg, and her pulse was 80 bpm. The MOST LIKELY diagnosis is uterine perforation." [14]

3. Infection (Endometritis / Septic Abortion)

Incidence: ~3% without antibiotic prophylaxis; < 1% with prophylactic antibiotics

4. Cervical Laceration

Incidence: < 1% for first-trimester TOP; higher for second-trimester D&E

5. Incomplete Abortion / Retained Products of Conception

Incidence: 2–5% for medical TOP; < 1% for surgical TOP

6. Haematometra (Post-abortal Syndrome)

Incidence: ~1% of surgical TOPs

7. Failed TOP (Continuing Pregnancy)

Incidence: 2–5% for medical TOP (first trimester); < 0.5% for surgical TOP

8. Asherman Syndrome (Intrauterine Adhesions)

Incidence: Estimated 2–22% after surgical evacuation for miscarriage/TOP (varies by technique and number of procedures)

9. Cervical Incompetence (Cervical Insufficiency)

10. Rh Isoimmunisation

11. Psychological Sequelae

12. Venous Thromboembolism (VTE)

References

[2] Lecture slides: GCBC-OG-Gyn Emergency_Notes to students_Sep2024.pdf; Block C - Gyanecological Emergency Notes to Students.pdf [3] Lecture slides: Block C - The woman needs that drug_ Oral contraceptives, Drugs affecting uterine motility.pdf [4] Lecture slides: Block C - Gyanecological Emergency Notes to Students.pdf [5] Lecture slides: GC 223. Complications of Early Pregnancy.pdf [9] Senior notes: Maksim Medicine Notes.pdf (Secondary amenorrhoea — Asherman syndrome) [11] Senior notes: Ryan Ho Haemtology.pdf (DIC — obstetric causes including septic abortion) [13] Senior notes: Ryan Ho Diagnostic Radiology.pdf (Uterine artery embolisation; Hysterosalpingography) [14] Lecture slides: OBGYN Clinical Test By Topic.pdf (TOP exam question — uterine perforation) [15] Senior notes: Ryan Ho Haemtology.pdf (VTE risk factors — OCP, pregnancy); Ryan Ho Respiratory.pdf (PE risk factors — OCP)

High Yield Summary

Definition: TOP = deliberate ending of pregnancy before viability; legal in HK under Cap. 212 with specific conditions.

Legal Requirements (HK):

  • ≤ 24 weeks; 2 doctors' opinions; approved institution; specified grounds (maternal health, fetal anomaly)
  • No gestational limit if immediately necessary for maternal life/grave permanent injury

Methods:

  • Medical: Mifepristone (anti-progestogen) + Misoprostol (PGE1 analogue) — works by decidual necrosis + uterine contractions
  • Surgical: Vacuum aspiration (1st trimester), D&E (2nd trimester); cervical priming recommended

Key Pharmacology:

  • Mifepristone → blocks progesterone → decidual necrosis, cervical softening, sensitizes myometrium to prostaglandins
  • Misoprostol → PGE1 agonist → uterine contractions + cervical ripening
  • Gemeprost → PGE1 (vaginal, needs cold storage)
  • Oxytocin → adjunct in 2nd trimester

Pre-procedure Must-Dos:

  • Confirm IUP (exclude ectopic!)
  • Gestational age (USS)
  • Blood group + Rh status (anti-D if Rh-negative)
  • STI screening
  • Counselling + consent (2 doctors)

Key Complications: Haemorrhage, incomplete abortion, uterine perforation, infection/sepsis, cervical laceration, failed TOP, Asherman syndrome

High Yield Summary

Pre-TOP DDx — The 3 Must-Excludes:

  1. Ectopic pregnancy — empty uterus + positive β-hCG; treat with laparoscopic salpingectomy, NOT uterine evacuation
  2. Molar pregnancy — snowstorm USS, very high β-hCG; requires suction evacuation + β-hCG surveillance, NOT standard medical TOP
  3. Cornual/interstitial pregnancy — eccentric sac; suspected if no products obtained at suction TOP

Key Principles:

  • Always perform pregnancy test in any reproductive-age woman with abdominal pain
  • Always perform TVUS before TOP to confirm IUP, exclude ectopic, date pregnancy
  • Always inspect evacuated tissue for products of conception — absence suggests abnormal implantation site
  • After TOP, differentiate complications (incomplete abortion, perforation, sepsis, haematometra, failed TOP) from non-TOP causes (ectopic, appendicitis, PID, ovarian pathology)
  • Prioritise life-threatening conditions (ruptured ectopic, septic abortion, perforation) over less urgent diagnoses

High Yield Summary

Pre-TOP Investigations — The Minimum Set:

  1. Urine β-hCG — confirm pregnancy (negative rules out ectopic)
  2. TVUS — confirm IUP, site, viability, gestational age (CRL)
  3. FBC — baseline Hb, detect anaemia
  4. Blood group + Rh — anti-D if Rh-negative
  5. Group and save — prepare for possible haemorrhage
  6. STI screening or prophylactic antibiotics — prevent post-TOP infection
  7. Legal documentation — two doctors certify grounds; informed consent

Discriminatory Zone: β-hCG 1,000-2,000 mIU/mL — above this, IUP should be visible on TVUS. If not → suspect ectopic. BUT do not make irreversible decisions on a single value in stable patients.

Serial β-hCG (48h): Rising ≥ 66% = likely viable IUP; rising < 66% = abnormal (ectopic/failing); falling = resolving.

Post-TOP Confirmation: Inspect and send products for histology. No villi = suspect ectopic/cornual. Follow-up β-hCG to confirm resolution.

USS Landmarks: GS at 5 weeks → YS at 6 weeks (confirms IUP) → FH at 6-7 weeks (confirms viability).

High Yield Summary

Method Selection:

  • ≤ 9 weeks: Medical (mifepristone 200 mg PO + misoprostol 800 μg vaginal 24-48h later) OR surgical (MVA/suction aspiration) — patient choice
  • 9-14 weeks: Surgical (suction aspiration) preferred; medical also possible
  • 14-24 weeks: Medical (mifepristone + repeated misoprostol/gemeprost) preferred; D&E only by experienced operator
  • Molar pregnancy: Suction evacuation (NOT medical TOP)

Key Drugs:

  • Mifepristone: anti-progesterone → decidual necrosis, cervical softening, prostaglandin receptor upregulation
  • Misoprostol: PGE1 → uterine contractions + cervical ripening; vaginal route most effective
  • Gemeprost: PGE1 pessary; needs cold storage; second-trimester use
  • Oxytocin: adjunct in second trimester; ineffective alone in early pregnancy

Cervical Priming: Recommended for ALL surgical TOP; essential > 12 weeks, nulliparous, < 18 years

Perioperative Must-Dos: Prophylactic antibiotics + Anti-D (if Rh-negative) + Analgesia + Immediate contraception

Complication Management:

  • No products at evacuation → suspect ectopic/cornual → urgent evaluation
  • Perforation → stop procedure → laparoscopy/laparotomy (bowel injury risk)
  • Septic abortion → IV antibiotics → experienced surgical evacuation ~1h after
  • Haematometra → re-evacuation + uterotonics

High Yield Summary

Immediate complications: Haemorrhage (atony, retained products, cervical laceration, perforation), uterine perforation (→ bowel injury — always laparoscopy to exclude), vasovagal reaction

Early complications: Incomplete abortion (ongoing bleeding, elevated β-hCG, USS echogenic material → re-evacuate), endometritis/septic abortion (fever, foul discharge → IV antibiotics → evacuation 1h later by experienced surgeon), haematometra (pain + distended uterus + closed os + minimal external bleeding → re-evacuate), failed TOP (no bleeding after medical TOP → USS + β-hCG → surgical completion)

Late complications: Asherman syndrome (secondary amenorrhoea, infertility — from basalis damage by curettage → prevent by using suction not sharp curettage), cervical incompetence (second-trimester loss in future — from cervical trauma), Rh isoimmunisation (preventable with anti-D), psychological sequelae (not a "syndrome" — support and counselling)

Key Management Principles:

  • Perforation → STOP → laparoscopy (bowel damage risk)
  • Septic abortion → IV antibiotics FIRST → evacuate ~1h later
  • No products at evacuation → suspect ectopic/cornual
  • All Rh-negative women → anti-D within 72h
  • Prevention of Asherman → suction aspiration, avoid aggressive curettage

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