1. Investigations for primary amenorrhoea
2. Subinvolution
3. Assisted breech delivery

1. Station zero
2. Myomectomy
3. Classical vs lower segment caesarean scar
4. Disclosure to relatives of a terminally ill gynae patient

1. Pathophysiology of PCOS
2. Hirsutism in women
3. APGAR score
4. Caput succedaneum vs cephalhematoma

1. Endometriosis as estrogen-dependent disease
2. Tubal patency tests in post-menstrual period
3. Is moulding essential during fetal delivery?
4. COCs contraindicated in puerperium
5. Low-dose aspirin in pregnancy-related hypertension risk

1. Investigations for primary amenorrhoea
2. Subinvolution
3. Assisted breech delivery

1. Station zero
2. Myomectomy
3. Classical vs lower segment caesarean scar
4. Disclosure to relatives of a terminally ill gynae patient

1. Pathophysiology of PCOS
2. Hirsutism in women
3. APGAR score
4. Caput succedaneum vs cephalhematoma

1. Endometriosis as estrogen-dependent disease
2. Tubal patency tests in post-menstrual period
3. Is moulding essential during fetal delivery?
4. COCs contraindicated in puerperium
5. Low-dose aspirin in pregnancy-related hypertension risk

Part F: Scenario-Based MCQs (1 mark each)

• Answer: d) 4 mg
• Rationale: WHO and most guidelines recommend 4-5 mg daily for women with previous NTD-affected pregnancy (high-risk group), vs 400 mcg for general population.

• Answer: d) Cervical
• Rationale: Cervical fibroids cause pressure symptoms like dyspareunia, vaginal mass sensation, difficulty in intercourse. Intramural fibroids cause bulk symptoms; submucosal cause bleeding; subserosal are often asymptomatic.

• Answer: c) 31
• Rationale: Quadrivalent HPV vaccine covers types 6, 11, 16, 18 (NOT 31). The 9-valent vaccine added types 31, 33, 45, 52, 58.

• Answer: c) Total motility >=32%
• Rationale: WHO 2021 lists total motility >=42% as normal. The others (volume >=1.4 mL, sperm count >=16 million/mL, normal morphology >=4%) are correct.

• Answer: b) Dry, warm and stimulate
• Rationale: ABC-D = Airway, Breathing, Circulation, Drugs. First: dry/warm baby, clear airway gently if needed, stimulate. Epinephrine and intubation come later if needed.

• Answer: d) Osteoporosis prevention
• Rationale: HRT is indicated for vasomotor symptoms, genitourinary symptoms, and bone health/osteoporosis prevention. It's contraindicated for thromboembolic prevention (increases VTE risk).

• Answer: a) Non-stress test (already done; likely answer is c) Induction of labour)
• Rationale: At 38 weeks with reduced liquor and borderline NST, induction of labour is appropriate after confirming fetal maturity.

• Answer: d) Uterine fibroid (MUSA = Morphological Uterus Sonographic Assessment)
• Rationale: MUSA is a standardized scoring system for fibroid burden and location, not for adenomyosis or endometriosis alone.

• Answer: a) Endometrial carcinoma
• Rationale: In the context of a clinical exam, endometrial carcinoma (malignancy) is the most concerning diagnosis. Atrophy and polyps are more common benign causes, but as a "most important to rule out" — endometrial cancer is the answer.

• Answer: d) 47,XXY (likely c) 46,XX is more common)
• Rationale: Most complete moles are 46,XX (diploid, entirely paternal origin). 46,XY occurs in ~10%, 47,XXX and 47,XXY are rare.

• Answer: b) Ultrasound pelvis
• Rationale: Initial workup for AUB includes history, pelvic exam, and ultrasound to rule out structural causes (fibroids, polyps, adenomyosis) before considering endometrial biopsy.

• Answer: b) Diagonal conjugate
• Rationale: The diagonal conjugate (sacral promontory to lower border of symphysis pubis, ~12.5-13 cm) is the only AP diameter measured clinically. True conjugate, obstetric conjugate, and oblique diameter require imaging.

1. Part A - Management of a 30-yr primigravida, 35 weeks, BP 150/100 + proteinuria (severe pre-eclampsia) - 15 marks
2. Part B.1 - Investigations for primary amenorrhoea - 6 marks
3. Part B.2 - Subinvolution - 6 marks
4. Part B.3 - Assisted breech delivery - 6 marks
5. Part C.1 - Station zero - 5 marks
6. Part C.2 - Myomectomy - 5 marks
7. Part C.3 - Classical vs lower segment caesarean scar - 5 marks
8. Part C.4 - Disclosure to relatives of a terminally ill gynae patient - 5 marks
9. Part D.1 - Pathophysiology of PCOS - 5 marks
10. Part D.2 - Hirsutism in women - 5 marks
11. Part D.3 - APGAR score - 5 marks
12. Part D.4 - Caput succedaneum vs cephalhematoma - 5 marks
13. Part E.1 - Endometriosis as estrogen-dependent disease (justify) - 3 marks
14. Part E.2 - Tubal patency tests best in post-menstrual period (reasons) - 3 marks
15. Part E.3 - Is moulding essential during fetal delivery? - 3 marks
16. Part E.4 - COCs contraindicated in puerperium (justify) - 3 marks
17. Part E.5 - Low-dose aspirin in pregnancy at risk of hypertensive disorder (justify) - 3 marks

1. Investigations for primary amenorrhoea
2. Subinvolution
3. Assisted breech delivery

1. Station zero
2. Myomectomy
3. Classical vs lower segment caesarean scar
4. Disclosure to relatives of a terminally ill gynae patient

1. Pathophysiology of PCOS
2. Hirsutism in women
3. APGAR score
4. Caput succedaneum vs cephalhematoma

1. Endometriosis as estrogen-dependent disease
2. Tubal patency tests in post-menstrual period
3. Is moulding essential during fetal delivery?
4. COCs contraindicated in puerperium
5. Low-dose aspirin in pregnancy-related hypertension risk

Part F: Scenario-Based MCQs (1 mark each)

• Answer: d) 4 mg
• Rationale: WHO and most guidelines recommend 4-5 mg daily for women with previous NTD-affected pregnancy (high-risk group), vs 400 mcg for general population.

• Answer: d) Cervical
• Rationale: Cervical fibroids cause pressure symptoms like dyspareunia, vaginal mass sensation, difficulty in intercourse. Intramural fibroids cause bulk symptoms; submucosal cause bleeding; subserosal are often asymptomatic.

• Answer: c) 31
• Rationale: Quadrivalent HPV vaccine covers types 6, 11, 16, 18 (NOT 31). The 9-valent vaccine added types 31, 33, 45, 52, 58.

• Answer: c) Total motility >=32%
• Rationale: WHO 2021 lists total motility >=42% as normal. The others (volume >=1.4 mL, sperm count >=16 million/mL, normal morphology >=4%) are correct.

• Answer: b) Dry, warm and stimulate
• Rationale: ABC-D = Airway, Breathing, Circulation, Drugs. First: dry/warm baby, clear airway gently if needed, stimulate. Epinephrine and intubation come later if needed.

• Answer: d) Osteoporosis prevention
• Rationale: HRT is indicated for vasomotor symptoms, genitourinary symptoms, and bone health/osteoporosis prevention. It's contraindicated for thromboembolic prevention (increases VTE risk).

• Answer: a) Non-stress test (already done; likely answer is c) Induction of labour)
• Rationale: At 38 weeks with reduced liquor and borderline NST, induction of labour is appropriate after confirming fetal maturity.

• Answer: d) Uterine fibroid (MUSA = Morphological Uterus Sonographic Assessment)
• Rationale: MUSA is a standardized scoring system for fibroid burden and location, not for adenomyosis or endometriosis alone.

• Answer: a) Endometrial carcinoma
• Rationale: In the context of a clinical exam, endometrial carcinoma (malignancy) is the most concerning diagnosis. Atrophy and polyps are more common benign causes, but as a "most important to rule out" — endometrial cancer is the answer.

• Answer: d) 47,XXY (likely c) 46,XX is more common)
• Rationale: Most complete moles are 46,XX (diploid, entirely paternal origin). 46,XY occurs in ~10%, 47,XXX and 47,XXY are rare.

• Answer: b) Ultrasound pelvis
• Rationale: Initial workup for AUB includes history, pelvic exam, and ultrasound to rule out structural causes (fibroids, polyps, adenomyosis) before considering endometrial biopsy.

• Answer: b) Diagonal conjugate
• Rationale: The diagonal conjugate (sacral promontory to lower border of symphysis pubis, ~12.5-13 cm) is the only AP diameter measured clinically. True conjugate, obstetric conjugate, and oblique diameter require imaging.

1. Part A - Management of a 30-yr primigravida, 35 weeks, BP 150/100 + proteinuria (severe pre-eclampsia) - 15 marks
2. Part B.1 - Investigations for primary amenorrhoea - 6 marks
3. Part B.2 - Subinvolution - 6 marks
4. Part B.3 - Assisted breech delivery - 6 marks
5. Part C.1 - Station zero - 5 marks
6. Part C.2 - Myomectomy - 5 marks
7. Part C.3 - Classical vs lower segment caesarean scar - 5 marks
8. Part C.4 - Disclosure to relatives of a terminally ill gynae patient - 5 marks
9. Part D.1 - Pathophysiology of PCOS - 5 marks
10. Part D.2 - Hirsutism in women - 5 marks
11. Part D.3 - APGAR score - 5 marks
12. Part D.4 - Caput succedaneum vs cephalhematoma - 5 marks
13. Part E.1 - Endometriosis as estrogen-dependent disease (justify) - 3 marks
14. Part E.2 - Tubal patency tests best in post-menstrual period (reasons) - 3 marks
15. Part E.3 - Is moulding essential during fetal delivery? - 3 marks
16. Part E.4 - COCs contraindicated in puerperium (justify) - 3 marks
17. Part E.5 - Low-dose aspirin in pregnancy at risk of hypertensive disorder (justify) - 3 marks

PART A: Long Essay (15 marks)

A 30-year-old primigravida, 35 weeks gestation, BP 150/100 mmHg, proteinuria — Management

• BP >=140/90 on two occasions 4 hrs apart after 20 weeks + proteinuria (>=300 mg/24 hr or dipstick >=1+) = Pre-eclampsia.
• Classify severity:
  • Non-severe (mild): BP 140/90 to 159/109, no severe features.
  • Severe: BP >=160/110, or any of - headache, visual disturbance, epigastric pain, oliguria, pulmonary edema, HELLP, thrombocytopenia, deranged LFT/RFT, fetal growth restriction.
  • Given BP 150/100, this patient is currently non-severe pre-eclampsia, but must be monitored closely as it can progress.

• Headache, blurring of vision, epigastric/right hypochondrial pain, decreased fetal movements, edema.
• BP in both arms, fundal height, fetal heart sound, reflexes (hyperreflexia/clonus), signs of impending eclampsia.

• Urine: dipstick + 24-hr urinary protein or spot protein:creatinine ratio.
• Blood: CBC (platelet count), LFT (AST/ALT), RFT (urea, creatinine, uric acid), coagulation profile if severe.
• Fetal: USG for growth/liquor/biophysical profile, umbilical artery Doppler, NST/CTG.

• Admit for BP >=150/100 or any severe feature, or if outpatient monitoring is not feasible. Bed rest in left lateral position.

• Oral Labetalol (100-400 mg TDS) or Nifedipine (10-20 mg retard BD/TDS) or Methyldopa (250-500 mg TDS/QID) as first-line for non-severe.
• If severe/uncontrolled: IV Labetalol or IV Hydralazine (5 mg bolus) or oral Nifedipine.

• Magnesium sulphate (MgSO4) indicated if progresses to severe pre-eclampsia or impending eclampsia.
• Pritchard regimen: 4 g IV loading + 10 g IM (5 g each buttock), maintenance 5 g IM 4 hourly, or Zuspan regimen (4 g IV loading, 1-2 g/hr infusion).
• Monitor for toxicity: check patellar reflex, respiratory rate (>=16/min), urine output (>=30 mL/hr); antidote = 10% calcium gluconate 10 mL IV.

• Daily fetal movement count, NST, serial growth scans, Doppler (umbilical artery, MCA).
• Corticosteroids (Betamethasone 12 mg IM x 2 doses 24 hrs apart) for fetal lung maturity since <37 weeks and delivery may be needed soon.

• At 35 weeks with non-severe pre-eclampsia: continue expectant management with close monitoring (BP, symptoms, labs twice weekly, fetal surveillance) until 37 weeks, UNLESS severe features/deterioration develop -> then deliver regardless of gestational age.
• If it progresses to severe pre-eclampsia, eclampsia, HELLP, non-reassuring fetal status, or growth restriction with abnormal Doppler -> deliver promptly after stabilization.
• Mode: vaginal delivery preferred if favorable Bishop score and no contraindication; induction of labour with continuous fetal monitoring. Caesarean for obstetric indications, deteriorating maternal/fetal condition, or unfavorable cervix requiring urgent delivery.

• Continue antihypertensives and MgSO4 (if started) through labour and 24 hrs postpartum (eclampsia risk persists postpartum).
• Strict monitoring of BP, urine output, fluid balance (avoid fluid overload - risk of pulmonary edema).
• Postpartum: continue BP monitoring for at least 6 weeks; counsel on recurrence risk in future pregnancy and long-term cardiovascular risk.

• Low-dose aspirin (75-150 mg) from 12-16 weeks in high-risk women reduces pre-eclampsia risk - not applicable now (already symptomatic) but important for counseling in future pregnancies.
• Calcium supplementation in low-intake populations.

PART B: Short Notes (6 marks each)

B.1 Investigations for Primary Amenorrhoea

1. History & examination: growth, anosmia (Kallmann), secondary sexual characters (Tanner staging), body habitus, virilization signs.
2. First-line:
   • Pregnancy test (rule out first)
   • Pelvic ultrasound - assess uterus and ovaries (presence/absence of uterus, Mullerian anomalies, gonadal morphology)
3. Hormonal work-up:
   • Serum FSH/LH - differentiates hypergonadotropic (gonadal failure, e.g., Turner syndrome) vs hypogonadotropic (hypothalamic-pituitary cause) hypogonadism
   • Prolactin, TSH - rule out hyperprolactinemia, thyroid dysfunction
   • Serum testosterone/DHEAS - if virilization suspected (PCOS, CAH, androgen insensitivity)
4. Karyotyping - if gonadal dysgenesis suspected (e.g., Turner 45,X; Androgen insensitivity 46,XY)
5. Imaging: MRI brain/pituitary if hypogonadotropic hypogonadism suspected (rule out prolactinoma, craniopharyngioma)
6. Progesterone challenge test - assesses estrogen status and outflow tract patency
7. HSG/sonohysterography - if outflow obstruction (imperforate hymen, transverse vaginal septum, Mullerian agenesis) suspected

B.2 Subinvolution

• Retained bits of placenta/membranes
• Endometritis/pelvic infection
• Uterine fibroid
• Full bladder or rectum
• Multiple pregnancy/hydramnios (overdistension)
• Adherent blood clots

• Uterus palpable abdominally beyond expected date, feels bulkier and softer than normal
• Persistent/excessive lochia (lochia rubra continues longer than normal)
• Backache, low abdominal discomfort
• May have low-grade fever if infective cause

• Treat the cause - antibiotics for infection, evacuation of retained products (suction/curettage) if indicated
• Ergometrine/oxytocics to promote contraction
• Supportive care

B.3 Assisted Breech Delivery

1. Delivery of buttocks and legs - spontaneous, aided by maternal pushing (Lovset's manoeuvre if legs extended)
2. Delivery of shoulders and arms:
   • Lovset's manoeuvre - rotation of trunk to bring posterior arm anteriorly under the pubic arch when arms are extended/nuchal
3. Delivery of the head (after body up to nape of neck is delivered):
   • Mauriceau-Smellie-Veit manoeuvre - jaw flexion and traction on shoulders to deliver head in flexion
   • Forceps application (Piper's forceps) as an alternative for controlled delivery of the head
4. Throughout: avoid excessive traction (risk of Erb's palsy, cervical spine injury) and prevent extension/deflexion of head (risk of tentorial tear, intracranial hemorrhage).

PART C: Short Notes (5 marks each)

C.1 Station Zero

• Station 0 = the leading bony point of the presenting part is exactly at the level of the ischial spines = engagement has occurred (in a well-flexed vertex, the biparietal diameter has passed the pelvic inlet).
• Used clinically (per vaginal examination) to assess descent of the head during labour and progress of labour on the partogram.
• Above ischial spines = negative station (e.g., -1, -2); below = positive station (+1, +2, etc.), with +3 to +5 = head visible at introitus/on perineum.

C.2 Myomectomy

• Symptomatic fibroid (menorrhagia, pressure symptoms, subfertility, recurrent pregnancy loss) in a woman wanting to preserve fertility/uterus
• Submucosal/intramural fibroid causing infertility or recurrent miscarriage

• Abdominal (open) myomectomy - for large/multiple fibroids
• Laparoscopic myomectomy - for accessible subserosal/intramural fibroids
• Hysteroscopic myomectomy - for submucosal fibroids (Type 0, 1, 2)
• Vaginal myomectomy - for prolapsing submucosal/cervical fibroid polyp

C.3 Classical vs Lower Segment Caesarean Scar

C.4 Disclosure to the Relatives Regarding a Terminally Ill Gynaecological Patient

• Patient autonomy and confidentiality are paramount - information should ideally be disclosed to the patient first, with her explicit consent sought before informing relatives (unless patient is incompetent to decide, e.g., unconscious).
• Truth-telling - the patient/family have the right to know the diagnosis and prognosis, delivered with compassion (principle of veracity).
• Beneficence and non-maleficence - information must be conveyed in a manner that minimizes psychological harm, in an appropriate private setting, using simple language, allowing time for questions.
• Breaking bad news protocol (e.g., SPIKES protocol):
  • Setting - private, uninterrupted
  • Perception - assess what patient/family already know
  • Invitation - ask how much detail they want
  • Knowledge - share information in simple terms, avoid jargon
  • Emotions - acknowledge and address emotional reactions
  • Strategy/Summary - discuss further plan, palliative care options
• Team-based approach - senior clinician should lead disclosure, ideally with a nurse/counselor present.
• Document the discussion and decisions taken (who was informed, what was disclosed, consent obtained).
• Avoid disclosure to relatives ahead of/against the competent patient's wishes - legal and ethical breach of confidentiality unless patient authorizes it or is incompetent.
• Cultural sensitivity - in Indian clinical practice, families are often closely involved; a balance between family involvement and patient's right to information/autonomy must be maintained.

PART D: Short Notes on Integrated Topics (5 marks each)

D.1 Pathophysiology of PCOS

1. Hypothalamic-pituitary dysfunction: Increased GnRH pulse frequency -> increased LH:FSH ratio (LH predominance) -> LH stimulates ovarian theca cells to overproduce androgens; relatively low FSH impairs follicular maturation.
2. Hyperandrogenism: Excess ovarian (and adrenal) androgen production -> arrests follicular growth at antral stage -> multiple small follicles ("string of pearls" appearance on USG) -> anovulation.
3. Insulin resistance/hyperinsulinemia: Present in ~50-70% of PCOS women (independent of obesity). Insulin acts synergistically with LH on theca cells to increase androgen production, and reduces hepatic SHBG synthesis -> increases free (bioavailable) testosterone -> worsens hirsutism/acne.

• Increased peripheral aromatization of androgens to estrogen in adipose tissue (especially with obesity) -> chronic unopposed estrogen -> positive feedback on LH (perpetuating the cycle) and endometrial hyperplasia risk.
• Obesity worsens insulin resistance -> vicious cycle.

D.2 Hirsutism in Women

• Ovarian: PCOS (most common, ~70-80% of cases), androgen-secreting ovarian tumors (Sertoli-Leydig cell tumor)
• Adrenal: Congenital adrenal hyperplasia (21-hydroxylase deficiency, non-classic form), adrenal tumors, Cushing syndrome
• Idiopathic hirsutism: increased peripheral 5-alpha reductase sensitivity with normal androgen levels and normal ovulation
• Drug-induced: danazol, androgenic progestins, phenytoin, anabolic steroids
• Others: hyperprolactinemia, acromegaly

• Treat underlying cause
• Combined oral contraceptives (suppress LH -> reduce ovarian androgen production, increase SHBG)
• Anti-androgens: Spironolactone, Cyproterone acetate, Finasteride
• Cosmetic measures: electrolysis, laser hair removal, topical eflornithine
• Weight reduction and insulin sensitizers (metformin) if insulin resistance present

D.3 APGAR Score

• 7-10: Normal
• 4-6: Moderate depression - may need stimulation/resuscitation
• 0-3: Severe depression - needs immediate resuscitation

D.4 Difference Between Caput Succedaneum and Cephalhematoma

PART E: Reasoning Questions (3 marks each)

E.1 Endometriosis is an estrogen-dependent disease - Justify

• Ectopic endometrial tissue (endometriotic implants) retains estrogen and progesterone receptors and behaves like eutopic endometrium, responding to cyclical hormonal changes.
• Endometriotic implants themselves express aromatase enzyme, enabling local estrogen synthesis independent of ovarian production, which sustains and promotes lesion growth and inflammation.
• Estrogen promotes proliferation of ectopic endometrial cells, angiogenesis, and prostaglandin production (causing pain), while there is often relative progesterone resistance in these implants, so unopposed estrogen effect dominates.
• Clinically confirmed by the fact that: disease occurs only after menarche (estrogen exposure begins) and regresses after menopause or with medical/surgical estrogen suppression (GnRH agonists, danazol, oophorectomy) - i.e., estrogen deprivation is a mainstay of treatment.

E.2 Tubal patency tests are best performed in the post-menstrual period - Give reasons

• The post-menstrual (early proliferative) phase (day 6-11 of cycle) is preferred because:
  1. Endometrium is thin at this time, minimizing risk of dislodging any early pregnancy (rules out disrupting a possible luteal phase conception) and reduces risk of endometrial trauma/bleeding.
  2. Avoids the risk of retrograde transport of menstrual endometrial tissue/debris into the peritoneal cavity through the tubes, which could seed endometriosis or introduce infection.
  3. Cervical canal and tubal ostia are more relaxed/patent, and mucus is less viscid, giving more reliable results (less false blockage due to debris/clot).
  4. There is no risk of interrupting an early pregnancy (test is done well before ovulation, so no possibility of a recently fertilized ovum in transit).
• Hence tests like hysterosalpingography (HSG) and chromopertubation/laparoscopic dye test are conventionally scheduled in this window.

E.3 Is moulding essential during fetal delivery?

• Yes, moulding is a normal and often necessary adaptive process.
• Moulding is the overlapping/change in shape of the fetal skull bones at the sutures, allowing the head to adapt and reduce its diameters as it negotiates the maternal pelvis during labour, particularly at the pelvic inlet and mid-cavity.
• It facilitates engagement and descent through a bony pelvis that is often marginally adequate, effectively reducing the presenting diameters (e.g., reduces biparietal/suboccipito-frontal diameter).
• Mild-to-moderate moulding (grade 1-2) is physiological and reversible within days after birth.
• However, excessive/rapid moulding (grade 3) is pathological and indicates cephalopelvic disproportion or obstructed labour, and can cause intracranial injury (tentorial tear, subdural hemorrhage) - so while some moulding is essential/beneficial, it is also a clinical sign monitored on partogram to detect disproportion.
• Thus: physiological moulding is essential for successful vaginal delivery of many fetuses; pathological/excessive moulding is a warning sign requiring intervention (caesarean section).

E.4 Combined oral contraceptive pills are contraindicated in the puerperal period - Justify

• Increased risk of venous thromboembolism (VTE): the puerperium is already a hypercoagulable state (increased clotting factors, immobility, vascular injury at placental site - Virchow's triad present); estrogen in COCs further increases coagulability, compounding VTE/DVT/pulmonary embolism risk.
• Effect on lactation: estrogen component suppresses prolactin action and reduces the quantity and quality of breast milk, adversely affecting lactation and breastfeeding establishment - a major reason it's avoided, especially in the first 6 weeks (WHO MEC: category 4 in <21 days postpartum, category 3 at 21-42 days if breastfeeding).
• Neonatal exposure: small amounts of steroid hormone can be transferred via breast milk with theoretical effects on the neonate.
• Progesterone-only pills (POPs), barrier methods, LNG-IUS, or non-hormonal methods are preferred alternatives in the immediate puerperium/lactating women.

E.5 Justify the use of low-dose prophylactic aspirin in a pregnant woman at risk of developing hypertensive disorder

• Pre-eclampsia is associated with an imbalance between thromboxane A2 (vasoconstrictor/pro-aggregatory) and prostacyclin (vasodilator/anti-aggregatory), with relative thromboxane excess due to abnormal placentation and endothelial dysfunction.
• Low-dose aspirin (75-150 mg/day) selectively and irreversibly inhibits platelet cyclooxygenase (COX-1), preferentially reducing thromboxane A2 synthesis by platelets while relatively sparing endothelial prostacyclin production (which requires COX-2, less aspirin-sensitive at low doses).
• This shifts the balance toward vasodilatation and reduced platelet aggregation, improving trophoblastic invasion and placental perfusion, thereby reducing the incidence of pre-eclampsia, particularly early-onset/severe disease and its complications (FGR, placental abruption).
• Initiated ideally before 16 weeks (during the window of trophoblastic invasion/spiral artery remodeling) and continued until delivery (or up to 36-37 weeks per some protocols), in women with high-risk factors (previous pre-eclampsia, chronic hypertension, renal disease, autoimmune disease, multiple pregnancy, etc.) or combination of moderate risk factors.
• Extensive trial evidence (e.g., ASPRE trial) supports significant reduction in preterm pre-eclampsia with this regimen, with a good safety profile at low dose (no significant increase in bleeding risk).