MRCOG Part 1 Subject Guide

MRCOG Part 1: Neonatology

~40 questionsLower priority

Neonatology covers fetal physiology and the physiological transition at birth, as well as neonatal conditions relevant to obstetric practice. Approximately 40 questions, with strong overlap with Physiology.

Topics Covered

Fetal Physiology

  • Fetal circulation — ductus venosus, foramen ovale, ductus arteriosus; right-to-left shunting
  • Fetal haemoglobin (HbF) — higher oxygen affinity than adult HbA (left-shifted O2 dissociation curve)
  • Fetal oxygen delivery — lower PO2 compensated by higher HbF affinity
  • Placental gas exchange — CO2 transfer and Bohr effect

Neonatal Adaptation

  • Physiological changes at birth — lung fluid clearance, surfactant, first breath
  • Transition of circulation — closure of ductus arteriosus (prostaglandins), foramen ovale
  • Neonatal thermoregulation — brown adipose tissue, surface area:volume ratio
  • Apgar score — components, timing, interpretation
  • Physiological jaundice — bilirubin production, UDP-glucuronosyltransferase immaturity

Neonatal Conditions

  • Respiratory distress syndrome (RDS) — surfactant deficiency, preterm; corticosteroid prevention
  • Neonatal sepsis — GBS, Listeria; early vs late onset
  • Hypoxic-ischaemic encephalopathy (HIE) — grades, therapeutic hypothermia
  • Necrotising enterocolitis (NEC) — preterm, presentation, management
  • Haemolytic disease of the newborn — Rh incompatibility, kernicterus risk

Exam Tips for Neonatology

1

Fetal haemoglobin: HbF has higher O2 affinity than adult HbA (curve is left-shifted) — this is fundamental and tested repeatedly.

2

Surfactant: phospholipid (dipalmitoyl phosphatidylcholine/lecithin) produced by Type II pneumocytes from ~24 weeks; matures at ~34–36 weeks.

3

Fetal circulation shunts: know all three (ductus venosus, foramen ovale, ductus arteriosus) and what they do, and when they close after birth.

4

Apgar score components: Appearance, Pulse, Grimace, Activity, Respiration — scored 0-2 each at 1 and 5 minutes.

5

Corticosteroids for fetal lung maturity: given 24+0 to 34+6 weeks gestation, reduces RDS, IVH, NEC.

Recommended Book

Robertson's Textbook of Neonatology or neonatology chapters in O&G textbooks.

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AceMRCOG has 40 Neonatology SBA questions with detailed explanations. Start with 50 questions free — no credit card needed.

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