MRCOG Part 1 High-Yield Topics: Where to Focus Your Study

Not all MRCOG Part 1 topics are created equal. Some knowledge areas contribute 15-20 questions to the exam while others contribute 5-8. If your revision time is limited (and whose is not?), you need to know where to focus. This article breaks down the approximate question distribution across the 15 knowledge areas and tells you exactly which subtopics within each area are most frequently tested.

The Question Distribution

The RCOG publishes a curriculum blueprint that indicates the approximate weighting of each domain. Based on this blueprint and analysis of the exam structure, here is the approximate distribution across the 200 SBAs:

Critical Priority Topics: Detailed Breakdown

Anatomy and Surgical Anatomy (15-20 questions)

Anatomy is the single most predictable topic in MRCOG Part 1. The same structures come up again and again, and the questions demand precision. Here are the highest-yield subtopics:

• Pelvic floor muscles and perineal body: Know the layers of the pelvic floor, the components of the urogenital diaphragm, and the perineal body composition. Questions often ask about structures damaged during delivery or episiotomy.
• Blood supply of the uterus and ovaries: The uterine artery crossing the ureter ("water under the bridge") is a classic. Know the anastomoses between uterine and ovarian arteries.
• Nerve supply to pelvic organs: The pudendal nerve (S2-S4), its course through Alcock's canal, and structures it innervates. Also know the autonomic supply to the bladder.
• Surgical anatomy of the anterior abdominal wall: Layers encountered during Caesarean section, the inguinal canal boundaries, and the course of the inferior epigastric artery.
• Brachial plexus and obstetric palsy: Erb's palsy (C5-C6) versus Klumpke's palsy (C8-T1), the muscles affected, and the clinical presentation.
• Anatomy of the breast: Lymphatic drainage, quadrants, and blood supply. This appears more frequently than you might expect.

Physiology (15-20 questions)

Physiology questions in MRCOG Part 1 are not abstract. They are almost always framed in the context of pregnancy or reproduction.

• Maternal cardiovascular changes in pregnancy: Cardiac output increases 30-50%, blood volume increases 40-50%, SVR decreases. Know the timeline of these changes across trimesters.
• Renal physiology in pregnancy: GFR increases 50%, normal creatinine in pregnancy is lower than non-pregnant values. Understand physiological hydronephrosis.
• Fetal circulation: The ductus venosus, foramen ovale, and ductus arteriosus. Know the oxygen saturations in different vessels and what happens at birth.
• Placental physiology: Gas exchange, nutrient transport, and hormone production. The placenta as an endocrine organ (hCG, hPL, progesterone, oestrogen).
• The menstrual cycle: Follicular phase, luteal phase, the LH surge, and the role of inhibin and activin. This comes up in almost every sitting.
• Haematological changes in pregnancy: Physiological anaemia (dilutional), hypercoagulable state, platelet changes, and white cell count.

Endocrinology (12-15 questions)

• Hypothalamic-pituitary-ovarian axis: GnRH pulsatility, the two-cell two-gonadotrophin theory, and feedback mechanisms.
• Thyroid function in pregnancy: hCG cross-reactivity with the TSH receptor, the shift in reference ranges, and management of hypothyroidism.
• Polycystic ovary syndrome: The hormonal profile (raised LH:FSH ratio, hyperandrogenism, insulin resistance) and the Rotterdam criteria.
• Adrenal physiology: Cortisol changes in pregnancy, congenital adrenal hyperplasia, and the steroid synthesis pathway.
• Calcium metabolism and vitamin D: Parathyroid hormone actions, calcitonin, and bone metabolism in pregnancy.

Pathology (12-18 questions)

• Cervical pathology and CIN: The transformation zone, HPV types (16, 18), the progression from CIN to invasive carcinoma, and the Bethesda classification.
• Gestational trophoblastic disease: Complete vs partial mole (genetics, histology, hCG levels), choriocarcinoma, and FIGO staging.
• Ovarian tumour classification: Epithelial, germ cell, and sex cord-stromal tumours. Know the most common subtypes and their tumour markers.
• Endometrial pathology: Hyperplasia with and without atypia, endometrial carcinoma risk factors, and the FIGO staging system.
• Placental pathology: Placenta accreta spectrum, placental abruption histology, and villitis of unknown aetiology.

Clinical Management (12-18 questions)

Although Part 1 is a "basic sciences" exam, clinical management questions are increasingly common. They test whether you can apply science to clinical scenarios.

• Pre-eclampsia: Pathophysiology (defective trophoblast invasion), diagnostic criteria, management with magnesium sulphate and labetalol.
• Ectopic pregnancy: Risk factors, diagnostic criteria for medical management (methotrexate), and surgical approach.
• Miscarriage management: Expectant, medical (misoprostol), and surgical options. NICE guidance on when to use each.
• Venous thromboembolism in pregnancy: Risk stratification (RCOG GTG 37a), LMWH dosing, and timing of thromboprophylaxis.
• Rhesus isoimmunisation: Anti-D prophylaxis, Kleihauer test, and management of Rh-negative mothers.

Data Interpretation and Statistics (12-18 questions)

• Sensitivity and specificity: How to calculate them from a 2x2 table, and their relationship to positive and negative predictive values.
• Likelihood ratios: How to calculate and interpret positive and negative likelihood ratios. Understand how pre-test probability relates to post-test probability.
• Study designs: Know the hierarchy of evidence: RCT, cohort, case-control, cross-sectional. Understand the biases inherent in each.
• Number needed to treat (NNT): Calculation and interpretation, and its relationship to absolute risk reduction.
• Screening principles: Wilson and Jungner criteria, the difference between screening and diagnostic tests.

The Priority Matrix: How to Allocate Your Time

If you have 6 months, spend the first 2 months on the critical topics (Anatomy, Physiology, Endocrinology, Pathology, Clinical Management, Statistics). These 6 areas alone account for approximately 80-110 of the 200 questions. Mastering them gives you a strong foundation and a realistic chance of passing even if your lower-yield topics are weaker.

Months 3-4 should cover the high-priority topics (Pharmacology, Biochemistry, Embryology, Genetics). These add another 30-50 questions to your coverage.

Month 5 is for the moderate-priority topics (Biophysics, Immunology, Microbiology) and for filling gaps identified by your question bank analytics.

Month 6 is for mock exams and targeted revision only. No new topics. Just consolidation and gap-filling.

Subtopics That Catch Candidates Off Guard

Beyond the obvious high-yield areas, there are several subtopics that consistently surprise candidates:

• Ultrasound physics: Piezoelectric effect, Doppler principles, and artefacts. Many candidates skip this, but 3-5 questions can make the difference.
• Drug metabolism in pregnancy: Increased GFR means faster renal clearance. Hepatic enzyme induction by progesterone. These concepts apply across pharmacology questions.
• Genetics of common conditions: The inheritance pattern of cystic fibrosis, sickle cell disease, Turner syndrome, and Klinefelter syndrome. Know the karyotypes.
• Immunology of pregnancy: How the fetus avoids rejection (HLA-G expression, regulatory T cells, decidual NK cells). This is increasingly tested.

Using This Knowledge Strategically

Knowing which topics are high-yield is only useful if you act on it. Use a question bank that tracks your performance by topic, so you can see exactly where you stand. If you are scoring 80%+ in Anatomy but 45% in Statistics, you know where your next study session should focus.

The candidates who pass are not the ones who know the most. They are the ones who know where their gaps are and have the discipline to fill them.