MRCOG Part 1: Physiology
Physiology is one of the highest-yield subjects in MRCOG Part 1, with approximately 139 questions. The majority focus on reproductive physiology and the hormonal control of the menstrual cycle, pregnancy and labour — making this the most clinically relevant basic science subject in the paper.
Topics Covered
Reproductive Physiology
- ›Menstrual cycle and hormonal regulation (FSH, LH, oestrogen, progesterone)
- ›Ovarian cycle — folliculogenesis, ovulation, corpus luteum
- ›Hypothalamic-pituitary-ovarian axis and feedback mechanisms
- ›Fertilisation, implantation and early pregnancy physiology
- ›Placental physiology and fetoplacental unit
- ›Physiology of labour and parturition — myometrial function, oxytocin
- ›Lactation and prolactin physiology
Cardiovascular Physiology
- ›Cardiac output, stroke volume, heart rate regulation
- ›Physiological changes in pregnancy — increased blood volume, CO, decreased SVR
- ›Blood pressure regulation and renin-angiotensin-aldosterone system
- ›Haemostasis and coagulation — relevant to obstetric haemorrhage
Renal Physiology
- ›GFR changes in pregnancy
- ›Fluid and electrolyte balance
- ›Acid-base physiology
Other Physiology Topics
- ›Respiratory physiology in pregnancy — increased tidal volume, hyperventilation
- ›Thyroid physiology — TBG changes, free vs total T3/T4 in pregnancy
- ›Fetal physiology — circulation, haemoglobin, oxygen delivery
- ›Neonatal transition and physiological changes at birth
Exam Tips for Physiology
The menstrual cycle and HPO axis are tested every sitting — know the hormone curves precisely.
Pregnancy physiological changes are extremely high-yield: know which parameters increase and by how much.
Fetal vs adult haemoglobin differences (oxygen affinity, P50) are a recurring question type.
Understand positive vs negative feedback — LH surge vs oestrogen negative feedback is a classic SBA trap.
Placental transfer mechanisms (simple diffusion, facilitated, active transport) are regularly tested.
Recommended Book
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