11th April 2024

A 25-year-old female presents to her general practitioner with 4 months of amenorrhoea.

A 25-year-old female presents to her general practitioner with 4 months of amenorrhoea. She is concerned about her fertility. She reports one previous normal vaginal delivery and one dilatation and curettage. She has no other past medical or obstetric history. Her BMI is 19 kg/m², and her observations are normal. The examination is unremarkable. A pregnancy test is negative, and blood tests reveal gonadotrophin levels are normal, and serum prolactin is 320 mU/l (<400 mU/il. Given the likely diagnosis, what is the gold standard investigation?

Select the SINGLE most appropriate option from the list below. Select ONE option only.