MRCOG Part 1: Neonatology
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
Fetal haemoglobin: HbF has higher O2 affinity than adult HbA (curve is left-shifted) — this is fundamental and tested repeatedly.
Surfactant: phospholipid (dipalmitoyl phosphatidylcholine/lecithin) produced by Type II pneumocytes from ~24 weeks; matures at ~34–36 weeks.
Fetal circulation shunts: know all three (ductus venosus, foramen ovale, ductus arteriosus) and what they do, and when they close after birth.
Apgar score components: Appearance, Pulse, Grimace, Activity, Respiration — scored 0-2 each at 1 and 5 minutes.
Corticosteroids for fetal lung maturity: given 24+0 to 34+6 weeks gestation, reduces RDS, IVH, NEC.
Recommended Book
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