Study population 
A retrospective analysis of patients seen in a reproductive endocrine clinic at St Mary’s Hospital, London, UK. 100 consecutive women with FHA were seen by three experienced endocrinologists (Dr Channa N Jayasena, Professor Stephen Franks and Miss Lisa J Webber) between January 2016 and February 2020. Due to the lack of universally accepted criteria for diagnosing FHA, FHA diagnosis was made on clinical suspicion by the three consultant physicians. Women with FHA and concurrent PCOS features were also noted. The database was also interrogated to identify 100 consecutive patients with a confirmed PCOS diagnosis between November 2014 and February 2020. PCOS was diagnosed in accordance with the Rotterdam Criteria (2003).14 Patients were excluded if taking contraceptive medication or using a contraceptive device at the time of blood testing, to reduce the influence of these on hormone levels.