Medical Approaches to Ovarian Stimulation for Infertility

Ovarian stimulation has become the cornerstone of many infertility and fertility preservation treatments. This encompasses more conservative approaches for restoration of ovulation in anovulatory women, to more rigorous regimens for empiric ovarian stimulation (often combined with intrauterine insemination), to aggressive regimens for in vitro fertilization (IVF). There has been increased attention given to achieving a proper risk/benefit ratio in the use of ovarian stimulation with the goal of avoiding ovarian hyperstimulation syndrome (OHSS) and iatrogenic multiple pregnancy, rendering ovarian stimulation more affordable while optimizing (singleton) pregnancy and healthy live birth rates. Multiple well-designed randomized controlled trials have helped provide a solid evidence base for methods of ovulation induction in polycystic ovary syndrome (PCOS) as well as the treatment of unexplained infertility. In everyday practice, ovulation induction in anovulatory women is often ignored in favor of IVF, although no direct comparative trials establishing the superiority of IVF have been reported to date. Ovulation induction with the goal of monofollicular ovulation is often contrasted with ovarian stimulation, which encourages multiple follicular recruitment. However, empiric ovarian stimulation in couples with unexplained infertility (with or without insemination of sperm) has led to high multiple pregnancy rates and diminished enthusiasm for its widespread use. Moreover, cost and access issues limit the universal utilization of IVF. Adjuvant therapies are often used to enhance ovarian response to stimulation, especially in women with diminished ovarian reserve or previous poor ovarian response, although the overall improvement in pregnancy rates is generally disappointing. These adjuvant treatment modalities have often been promulgated with insufficient evidence of safety and efficacy. The most important clinical challenge is to find the right balance between improving chances for success (birth of a healthy child) with reasonable cost, acceptable patient discomfort, and a minimal complication rate..