The use of lead follicle diameter to initiate gonadotropin-releasing hormone antagonist does not affect in vitro fertilization clinical pregnancy, implantation, or live birth rates: a prospective, randomized study.

In this prospective, randomized study, waiting for the lead follicle to reach 14 mm before initiating GnRH antagonist administration effectively prevents an LH surge and ovulation during an IVF cycle. Furthermore, delaying GnRH start until the dominant follicle reaches 14 mm neither impacts the clinical pregnancy, implantation, or live birth rates nor increases the incidence of severe ovarian hyperstimulation syndrome.