Obstetrics: Summative Revision Notes

A screening test (NT scan, biochemistry, NIPT) gives a probability, never a yes/no answer — a "high risk" or "positive" result always requires a diagnostic test (CVS, amniocentesis) for confirmation before any irreversible decision. No screening test, however high its reported accuracy, substitutes for diagnostic confirmation.

Dependent ankle oedema (resolves overnight, no HTN/proteinuria) — normal. Dilutional anaemia (plasma volume rises faster than RBC mass) — expect Hb to dip, not pathological alone. Supine hypotensive syndrome (IVC compression by gravid uterus, relieved by lateral position) — textbook benign, no cardiology workup needed for the classic picture.

CBC · blood group/Rh + antibody screen · urine R/M · universal HIV/syphilis/HBsAg screening (not risk-factor-gated) · TFT · blood glucose · folic acid/iron counselling. Done early — not deferred to 20 weeks.

Must cover: purpose/accuracy, procedure-specific risks (miscarriage risk for invasive tests), voluntary nature with no coercion, the range of possible results, and that the decision to continue or end the pregnancy remains the patient's alone — never framed as an obligation. A strong medical indication never substitutes for the consent process itself.

Screening = probability, never diagnosis NIPT positive still needs CVS/amniocentesis Universal infection screening, not risk-gated Decision after diagnosis stays the patient's own

▶ Open Quiz 01

BP ≥160/110 · platelets <100,000 · impaired LFTs/RUQ pain · rising creatinine · pulmonary oedema · severe headache/visual symptoms. Severe features → MgSO₄ + BP control + deliver after brief stabilisation, not prolonged expectant care, regardless of gestational age. Proteinuria amount alone does not define "severe."

First-line for both treatment and prevention of seizures — superior to phenytoin/diazepam, which are not first-line. Started empirically once severe features/seizure occur — never delayed for neuroimaging. Toxicity monitoring: deep tendon reflexes, respiratory rate, urine output; antidote is IV calcium gluconate. Delivery, not seizure control alone, is the definitive treatment for eclampsia — stabilise first, then proceed.

Haemolysis (schistocytes, ↑LDH) + ELevated liver enzymes + Low Platelets — a severe preeclampsia variant. No safe platelet threshold to justify watchful waiting; risk of hepatic rupture/DIC drives prompt delivery after stabilisation. Platelet transfusion is not mandatory in every case — reserved for bleeding risk or specific low counts before cesarean.

Once a unit's documented protocol criteria for ICU referral are met, failure to escalate is a deviation from that unit's own standard of care — carries independent medico-legal weight regardless of eventual outcome.

Severe features = deliver after stabilising, not "wait it out" MgSO₄ first-line, started empirically HELLP: no safe platelet "wait" number

▶ Open Quiz 02

Vaginal examination avoided in suspected previa until placental location is confirmed sonographically. Complete (type IV) previa = absolute contraindication to vaginal delivery, bleeding status notwithstanding. A settled bleed in known previa still means admission, not discharge.

Never tocolyse in abruption. Visible loss underestimates true loss when concealed — resuscitate beyond the visible volume. Fetal bradycardia with abruption needs urgent action, not an hour of observation.

Antenatal diagnosis (colour Doppler) changes management even when asymptomatic: third-trimester hospitalisation, elective cesarean before labor/membrane rupture (~34–36 wks). Amniotomy is contraindicated — it is the dangerous act, not a diagnostic step. Vaginal delivery is never the plan, regardless of FHR reassurance.

Doctrine of necessity: incapacitated patient + necessary life-saving intervention + no time for consent → proceed with the full necessary treatment, document reasoning; no waiting for next-of-kin or an ethics committee. Competent refusal (e.g. transfusion refusal on religious grounds) must be respected even if fatal — pursue non-blood alternatives, document thoroughly; distress alone ≠ incapacity; family cannot override a competent patient's own refusal.

Previa: never vaginal exam without imaging confirmation Abruption: visible loss ≠ true loss Vasa previa: amniotomy is the danger, not the test Necessity doctrine: full treatment, no delay for consent-seeking

▶ Open Quiz 03

Alert line crossed = heightened surveillance + consider transfer to a centre capable of operative delivery; not itself an indication for cesarean. Action line crossed (alert + 4 hrs) = the actual threshold for reassessment and intervention. Never augment blindly before assessing the cause of delay (power vs mechanical obstruction).

Safe instrumental delivery needs full dilatation and adequately low station — "fully dilated" alone is not sufficient. Many OP positions rotate spontaneously in a well-conducted second stage; persistent OP at full dilatation is not, by itself, an absolute indication for either instrumental delivery or cesarean.

Offer ECV around 36–37 wks before defaulting to either vaginal breech trial or elective cesarean — skipping ECV is a recognised standard-of-care omission. Spontaneous cephalic conversion becomes progressively less likely closer to term.

Plateaued dilatation despite adequate contractions + worsening caput/moulding + FHR changes = obstruction (often CPD) → cesarean. Augmenting with oxytocin here is dangerous, not just unhelpful — risks uterine rupture. Instrumental delivery is not an option before full dilatation.

Late starts, missing dilatation entries, and unmonitored FHR stretches are treated as significant adverse markers in litigation — independent of the actual care given, because the contemporaneous record is the primary evidence that monitoring was adequate. "Not statutorily mandated" ≠ legally inconsequential.

Alert line = watch; action line = act Station, not just dilatation, decides instrumental safety Breech: offer ECV before either delivery route Augmenting adequate contractions in CPD = rupture risk

▶ Open Quiz 04

Call for help + IV access + first uterotonic + bimanual massage → add second uterotonic (ergometrine/carboprost) → balloon tamponade + crossmatch → B-Lynch/uterine artery ligation → hysterectomy (last resort). Each rung moves fast, in parallel with resuscitation — no single rung gets a prolonged "wait and watch."

Tone (atony, commonest) Tissue (retained placenta/products) Trauma (lacerations, rupture) Thrombin (coagulopathy)

Risk markers: prior cesarean(s) + anterior low-lying placenta over scar + loss of retroplacental clear space + lacunae. Plan: confirm (USS/MRI), deliver at a tertiary centre with multidisciplinary team, consent covering possible hysterectomy. Never attempt manual removal when accreta is suspected — that is the dangerous act, not the fallback.

Genital tract infection any time from labor/ROM up to 42 days postpartum (not a 24-hour window) — fever + pelvic pain/foul discharge/delayed involution. Clinical diagnosis; positive blood culture not required.

Maternal death: during pregnancy or within 42 days of termination. Late maternal death: 42 days–1 year (captures cases like peripartum cardiomyopathy deaths). Direct cause = obstetric complication itself; indirect = pre-existing/pregnancy-aggravated disease (e.g. peripartum cardiomyopathy is indirect, a frequent misclassification).

Missing timestamps/vitals create independent medico-legal exposure regardless of whether care was actually appropriate — the record, not testimony after the fact, is what defends care.

4 Ts: Tone, Tissue, Trauma, Thrombin Accreta: never manual removal if suspected antenatally Puerperal sepsis: 42-day window, clinical diagnosis Late maternal death: 42 days–1 year

▶ Open Quiz 05

DIPSI (India): 75 g glucose, non-fasting, single 2-hr value ≥140 mg/dL = diagnostic, no confirmatory test needed — this is the entire design of the test. IADPSG (international): fasting OGTT, any one of fasting ≥92 / 1-hr ≥180 / 2-hr ≥153. Management: MNT first; insulin, not oral agents, is the standard Indian step-up.

Hb 7.8 with exertional-only symptoms at 32 wks → IV iron, not oral (too slow) and not transfusion (threshold not yet met). Parenteral iron is safe in 2nd/3rd trimester, not teratogenic.

Mechanical valve + warfarin + pregnancy: switch to therapeutic LMWH for weeks 6–12 (peak warfarin embryopathy window), with documented discussion of the LMWH-vs-warfarin trade-off. Never stop anticoagulation outright regardless of prior exposure.

Pregnancy increases levothyroxine requirement (↑TBG, ↑clearance, fetal demand) — increase dose ~25–30%, target TSH <2.5 in 1st trimester (trimester-specific, tighter than non-pregnant range). Maternal T4 crosses the placenta and matters for early fetal neurodevelopment; no role for T3 supplementation.

Never stop valproate abruptly (seizure/status risk); refer urgently for a supervised switch. No dose of valproate is established "safe" — disclosure obligation applies regardless of dose.

DIPSI: single non-fasting 2-hr value ≥140 Pregnancy increases, never decreases, levothyroxine need Valproate: no safe dose, no abrupt stop Mechanical valve: LMWH in weeks 6–12

▶ Open Quiz 06

"Married woman" → "any woman or her partner" — marital status is not a bar to any ground, including contraceptive failure (confirmed in X v. Union of India, 2022). Guardian consent applies only to minors/unsound mind, not to competent unmarried adults.

Liability extends to both the discloser (sonologist) and the seeker of sex-determination information (e.g. a relative) — not the doctor alone. Section 24 presumes the pregnant woman not guilty unless proven she compelled the disclosure.

Anti-D 300 mcg IM at 28 weeks regardless of a negative ICT (negative ICT means prophylaxis will still work, not that it's unnecessary), repeated within 72 hrs postpartum if baby is Rh-positive. Additional doses after any sensitising event (APH, amniocentesis, ECV, trauma).

Falls within the MTP Act's "termination of pregnancy" definition when done by a registered RMP with consent — follows ordinary gestational-band rules. PCPNDT Act applies on top only if the reduction is sex-selective; a Medical Board is not required for routine early MFPR.

MTP bands: 1 RMP / 2 RMPs / Medical Board PCPNDT: discloser + seeker both liable Anti-D at 28 wks regardless of ICT MFPR ≠ PCPNDT unless sex-selective

▶ Open Quiz 07

Doctrine of necessity: emergency treatment without consent when incapacitated + life-threatening + no time Section 24 (PCPNDT): pregnant woman presumed not guilty unless proven she compelled disclosure Supine hypotensive syndrome: relieved by lateral position, not a cardiology workup DIPSI: single-step, non-fasting, no confirmatory test needed Late maternal death: 42 days–1 year, recorded separately for audit

Combined screening: 11–13+6 wks Anomaly scan: 18–20 wks Anti-D: 28 wks antenatal + within 72 hrs postpartum Severe preeclampsia BP: ≥160/110 Warfarin embryopathy window: 6–12 wks Puerperal sepsis window: up to 42 days postpartum Elective delivery, complete previa: ~36–37 wks DIPSI cut-off: 2-hr value ≥140 mg/dL

Eclampsia: stabilise (MgSO₄ + BP) before delivery, never the reverse Breech: offer ECV before defaulting to vaginal trial or cesarean Screening before diagnostic invasive testing, never the reverse Abruption: resuscitate, never tocolyse Suspected accreta: planned multidisciplinary delivery, never manual removal Valproate in pregnancy: supervised switch, never an abrupt stop