Depending on a woman’s age, anywhere between 1 and 30 follicles, known as ‘recruits’, will begin to develop in each menstrual cycle. Whatever her age, though, only one of these developing follicles will dominate and ovulate at the level of follicle stimulating hormone (FSH) that a woman produces naturally.
With in vitro fertilisation (IVF), the goal is to keep the level of FSH constant, and thus encourage more of the recruits to grow and to develop mature eggs, which are collected surgically under vaginal ultrasound guidance. The eggs are then fertilised in the laboratory, cultured for several days, and then one embryo (or rarely two) is transferred back into the woman’s uterus. If there are additional embryos, they may be frozen and stored for later use if of suitable quality.
IVF cycles include a preparation month which involves a nursing and possible counselling appointment followed by these steps: