INVITED REVIEW IVF endocrinology: the Edwards era

Through pioneering human IVF as a global infertility treatment, Robert Edwards and his clinical partner Patrick Steptoe launched the field of IVF endocrinology. Following repeated failures with oocytes collected in human menopausal gonadotrophin (HMG) primed cycles timed to injection of human chorionic gonadotrophin (HCG), the first successful IVF pregnancy came from a spontaneous menstrual cycle. Intensive endocrine monitoring was used to track pre-ovulatory follicular development and collect a single ripe egg timed to the natural LH surge. Despite this groundbreaking achievement, ovulation induction was clearly required to make IVF treatment clinically robust and reliable. Ovarian stimulationwith clomiphene citratewas used to achieve the firstmaternity from a superovulated human IVF cycle in 1980. HMG/HCG regimens were then successfully introduced—including substitutionof ‘pure’ follicle-stimulating hormone as theprincipal ovarian stimulant. The application and success of IVF treatment were dramatically enhanced by the introduction of gonadotrophin-releasing hormone analogues that enabled elective control of endogenous gonadotrophin release during ovarian stimulation. Programmed gonadotrophin regimes yielding double-digit oocyte numbers became normal: ‘more is better’ was the ethos. Bob Edwards expressed increasing concern over the cost, complexity and potential long-term health risks of such high-order ovarian stimulation. In later life he repeatedly called for a return to minimalist approaches based on the natural menstrual cycle to improve oocyte quality over quantity. This article reviews the application of ovulation induction to human IVF and celebrates Edwards’ abiding impact on the field, which firmly grounds him in the reproductive endocrinology pantheon.