Ovulation induction, with the aim of producing one or two ovulatory follicles for fertilization by sexual intercourse or artificial insemination Controlled ovarian hyperstimulation, which is generally part of in vitro fertilization, and the aim is generally to develop multiple follicles (optimally between 11 and 14 antral follicles measuring 2–8 mm in diameter),[medical citation needed] followed by transvaginal oocyte retrieval, co-incubation, followed by embryo transfer of a maximum of two embryos at a time.[4] Final maturation induction of follicles, also triggering a predictable time of ovulation.