Follicular development during hormone replacement therapy in patients with premature ovarian insufficiency

PURPOSE: To provide information about the relationship between follow‐up period and follicular development in patients with infertility due to premature ovarian insufficiency (POI) who are undergoing hormone replacement therapy (HRT). It is necessary to detect follicle development for artificial insemination or in vitro fertilization. METHODS: This retrospective cohort study was conducted at a university hospital in Tokyo, Japan, from April 2014 to February 2019 in 20 patients [follicular development group, 11 women (55%); non‐follicular development group, 9 women (45%)] with POI; their follicular development was followed up weekly. Background characteristics, including age, follicle‐stimulating hormone (FSH) and anti‐Mullerian hormone levels (AMH), the period from the last spontaneous menstruation to hormone replacement therapy initiation, and follow‐up period during HRT were investigated. The period without follicular development was tabulated, and the subsequent cumulative follicular development detection rate was calculated. RESULTS: At least 1‐year follow‐up, the cumulative follicular development rate was 70%; follicular development was observed with a probability of 49.1% at 3 months, 33.4% at 6 months, and 8.3% at 12 months in the follow‐up period. CONCLUSIONS: The results show that the longer the non‐follicle development period, the lower the probability of subsequent follicular development in patients with POI during HRT.