Our blueprint estimate puts 15–20 of the 200 questions in physiology, about 8.8% of the paper, spread across both papers. It is our estimate, not a figure published by the RCOG. One of the heaviest-weighted areas on the paper.
15–20
of 200
9
in our syllabus map
cell_function
2 other areas
Physiology questions ask what the body does normally, so that you can tell when it is not doing it. In obstetrics that means two bodies: the menstrual cycle and its feedback loops, and the adaptations of pregnancy, each of which shifts a reference range you would otherwise trust.
The 9 syllabus topics we map to Physiology for Part 1.
GnRH has to arrive in pulses; continuous exposure suppresses gonadotrophins rather than driving them. Know which cells respond to LH and which to FSH, why oestradiol feedback is negative for most of the cycle and positive at mid-cycle, and which phase of the cycle is variable in length (the follicular phase) and which is fixed (the luteal phase).
Plasma volume rises by more than red cell mass, which produces the physiological anaemia of pregnancy. The state is also pro-coagulant. Questions tend to give you a value and ask whether it is normal for the gestation, so learn the direction of each change before the size of it.
Glomerular filtration rises, so serum creatinine falls and a value that looks normal in a non-pregnant adult can be abnormal here. Ventilation increases, leaving a compensated respiratory alkalosis with a low carbon dioxide level. Glycosuria alone does not diagnose diabetes in pregnancy.
hCG maintains the corpus luteum until the placenta can produce progesterone itself. Be able to say what the corpus luteum is doing at each point, and when the placenta takes over steroid production.
Build one page per system rather than one per topic: for each, write the direction of change in pregnancy, the mechanism, and one consequence for interpreting a result. Then draw the menstrual cycle with the hormones, the follicle and the endometrium aligned on a single time axis. Test yourself by covering the labels and rebuilding the diagram from memory.
Part 1 is 200 single best answer questions across two papers with no negative marking, so an informed guess always beats a blank. Physiology is the foundation under endocrinology, pharmacology and data interpretation. A pregnancy-adjusted blood result in a data question is a physiology question wearing a different label, so revising this area first makes the neighbouring ones faster.
Every question is original and written from published RCOG and NICE guidance, and every explanation cites the guideline it came from. Free: 5 days full access, then 50 questions. No card.
Published RCOG and NICE guidance summarised for revision, with the source cited on every page.
MRCOG AI is an independent educational tool. It is not affiliated with, endorsed by, or connected to the Royal College of Obstetricians and Gynaecologists (RCOG).