How IVF works?
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 the hormone FSH that a woman produces naturally. With IVF, the goal is to keep the level of FSH constant, and thus to encourage more of the recruits 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, or rarely two embryos are transferred back into the woman’s uterus. If there are additional embryos, they may be frozen and stored for later use. The steps in an IVF cycle are: • Preventing premature ovulation (the LH surge) by shutting down communication between the brain and the ovaries, so that the eggs are not lost before they can be collected • Stimulating the ovaries with injections of FSH • Triggering ovulation by replacin
