PLAB 1 Obstetrics and Gynaecology 2

Question 1

A 22-year-old woman presents with heavy, regular periods (menorrhagia) but no structural abnormality on ultrasound. She does not wish to conceive. According to NICE, what is the first-line treatment?

Accepted Answer

Levonorgestrel intrauterine system (Mirena IUS)

Answer

NICE guidelines (NG88) recommend the levonorgestrel intrauterine system (LNG-IUS/Mirena) as first-line treatment for heavy menstrual bleeding. It reduces blood loss by up to 96% and provides contraception. If declined, alternatives include tranexamic acid, NSAIDs, or combined hormonal contraception.

Question 2

A woman at 28 weeks' gestation has a routine blood test showing she is Rhesus D negative. What is the recommended prophylactic management?

Accepted Answer

Routine antenatal anti-D immunoglobulin prophylaxis at 28 weeks

Answer

NICE recommends routine antenatal anti-D prophylaxis (RAADP) at 28 weeks for all RhD-negative women (single dose of 1,500 IU or two doses at 28 and 34 weeks). This prevents sensitisation and haemolytic disease of the newborn. Additional anti-D is given after sensitising events.

Question 3

A 40-year-old woman presents with a 3 cm complex ovarian cyst found incidentally on ultrasound. Her CA-125 is 85 U/mL (normal <35). Using the Risk of Malignancy Index (RMI), which factors are included in the calculation?

Accepted Answer

Ultrasound score, menopausal status, and CA-125 level

Answer

The Risk of Malignancy Index (RMI) = Ultrasound score (U) x Menopausal status (M) x CA-125 level. An RMI ≥250 warrants referral to a specialist gynaecological oncology centre. This woman's elevated CA-125 and postmenopausal status increase her RMI significantly.

Question 4

A primigravida at 41+3 weeks' gestation is offered a membrane sweep. She asks about the evidence. What should you tell her about the purpose of a membrane sweep?

Accepted Answer

It can help stimulate the onset of spontaneous labour by releasing prostaglandins, reducing the need for formal induction

Answer

Membrane sweeping involves separating the membranes from the lower uterine segment, which stimulates local prostaglandin release. NICE recommends offering sweeps from 40 weeks in nulliparous women and 41 weeks in multiparous women to reduce the need for formal induction of labour.

Question 5

A 32-year-old woman in established labour has a cervical dilatation rate of 0.3 cm/hour after 4 hours despite adequate contractions. According to NICE intrapartum care guidelines, what is this called and what is the next step?

Accepted Answer

Delay in the first stage — consider amniotomy if membranes are intact, and/or oxytocin augmentation

Answer

NICE defines delay in the first stage as cervical dilatation of less than 0.5 cm/hour over 4 hours. Management includes amniotomy (ARM) if membranes are intact, followed by oxytocin augmentation if progress remains slow. Caesarean section is considered if these measures fail.

PLAB 1 Practice Test

PLAB 1 Practice Test

PLAB 1 Obstetrics and Gynaecology 2