Purpose of review: Luteal phase support (LPS) is an integral part of the IVF cycles treated by gonadotropin-releasing hormone analogues. There is a worldwide controversy concerning the type of hormones used for LPS, its dose, duration, when to start and when to stop. This review will cover original as well as recent data on this topic.
Recent findings: There is a consensus in the literature among IVF centers that LPS is necessary for IVF cycles. Human chorionic gonadotropin is less commonly used than progesterone for LPS because of ovarian hyperstimulation syndrome risk. Several studies suggested that intramuscular progesterone is superior to vaginal progesterone for LPS; however, the majority of centers use vaginal progesterone to avoid side effects of intramuscular injection. There is no difference in pregnancy rate whether LPS is started on day of human chorionic gonadotropin, oocyte retrieval or embryo transfer. There is a strong evidence that LPS should be stopped either on the day of pregnancy test or the first ultrasound (6-7 weeks pregnancy). There is no evidence that addition of estrogen will improve pregnancy rate.
Summary: Progesterone is the preferred option for LPS. It should start within 2 days from triggering ovulation and should end on day of beta human chorionic gonadotropin or the day of the first ultrasound (6-7 weeks pregnancy).