Obstetrics and Gynaecology: Pregnancy, Labour and Gynaecological Care
Obstetrics and Gynaecology: what is tested
This domain tests antenatal care, hypertensive disorders, diabetes in pregnancy, labour, postpartum haemorrhage, contraception and gynaecological cancer screening. The exam expects safe prioritisation of mother and fetus.
Core rules
- Gravidity is the number of pregnancies; parity is the number of births after 24 weeks (or 20 weeks in some definitions). Dating uses last menstrual period and early ultrasound.
- Preeclampsia is new hypertension after 20 weeks with proteinuria or maternal organ dysfunction. Severe features include blood pressure at least 160/110 mmHg, headache, visual disturbance, raised liver enzymes and low platelets.
- Magnesium sulphate prevents and treats eclampsia; monitor reflexes, respiratory rate and urine output. Calcium gluconate reverses toxicity. Delivery is the definitive treatment.
- Postpartum haemorrhage causes are tone, trauma, tissue and thrombin. Uterine atony is commonest; give oxytocin, massage the uterus and escalate to tranexamic acid and surgery.
- Contraception: combined oestrogen-progestogen methods are avoided in migraine with aura, uncontrolled hypertension and previous venous thromboembolism.
Worked example. A woman at 32 weeks has blood pressure 165/110 mmHg, headache and proteinuria. Reasoning: severe preeclampsia. Give magnesium sulphate as a 4 g intravenous loading dose over 15-20 minutes, then 1 g/h, and an antihypertensive such as labetalol, hydralazine or nifedipine. Delivery is indicated after stabilisation. ACE inhibitors and ARBs are contraindicated in pregnancy.
Traps that cost marks
- Diagnosing preeclampsia before 20 weeks without another cause.
- Using ACE inhibitors for pregnancy hypertension.
- Forgetting calcium gluconate for magnesium toxicity.
- Treating postpartum haemorrhage with oxytocin alone when the uterus is already contracted and trauma is the cause.