ABSTRACT
Historically, monitoring of ovarian response, by means of measuring estrogen, came into the use for ovulation induction owing to the complications of gonadotrophin treatment. In ovulation induction cycles with gonadotrophins Klopper and co-workers showed that success rates and complication rates were not dependent on monitoring as such, but on the treatment protocol used. If more gonadotrophins are given, successes increase, as do complications. Monitoring merely gives us the possibility to descide how far we want to go.1 This is probably true for ovulation induction cycles but not for ovarian stimulation with gonadotrophins in ART cycles where the mature oocytes should not be ovulated. In these cycles the method for monitoring should be a clinically useful method to identify the optimal time for retrieving the mature oocytes.
