Developmental potential of immature human oocytes aspirated after controlled ovarian stimulation.

Purpose: Intracytoplasmic sperm injection (ICSI) for initially immature oocytes that mature in vitro is controversial and practice varies widely. While it may increase the number of usable embryos, it may also be time-intensive and potentially low-yield. This study sought to elucidate which patients may benefit from ICSI of initially immature oocytes that matured in vitro.