The aim of treatment with a gonadotropin-releasing hormone (GnRH) agonist is elimination of the luteinizing hormone (LH) surge and fluctuating LH concentrations, which compromise outcome in cycles of ovarian stimulation for in-vitro fertilization (IVF). This chapter addresses the characteristics of the standard long-course protocol. It is most common to initiate treatment in the luteal phase to minimize the consequences of the flare effect seen in the first few days of treatment with a GnRH agonist. The down-regulation effect of agonists can be established and maintained by multiple applications of nasal spray, single daily injection, or depo formulations lasting variable lengths of time. When the patient is down-regulated at the start of follicle stimulating hormone (FSH) treatment, subsequent follicular growth and recruitment is dictated by two elements: the ovarian reserve, which dictates the number of follicles available for recruitment, and the profile of circulating FSH concentrations.

The incidence of ectopic pregnancies is increased in assisted reproductive technology (ART) due to a higher number of embryos transferred and a higher prevalence of tubal disease in patients undergoing in vitro fertilization (IVF). The incidence of heterotopic pregnancies increased with increasing number of embryos transferred. Ectopic pregnancy occurs usually within the fallopian tubes. Abdominal pain is the most common clinical manifestation. Other symptoms and signs include vaginal spotting, amenorrhea, and a pelvic mass. The recent advances in ultrasound technology and the higher expertise of sonographers have improved the early diagnosis of ectopic pregnancies. The beta sub-unit of human chorionic gonadotropin (hCG) has been used to differentiate a developing viable intrauterine pregnancy from an abnormal pregnancy. Vascular endothelial growth factor (VEGF) is elevated in ectopic pregnancies. Methotrexate and mifepristone are used in the treatment of ectopic pregnancy. Laparoscopy, laparotomy and salpingectomy are the surgical options for treating ectopic pregnancies.