Letrozole oral after the vast majority of stopping about 7 days after the phenomenon of ovulation, when taking ultrasound to monitor the growth and development of follicles, due to individual differences, letrozole to promote ovulation is not 1 month or 2 months to promote ovulation successfully, also does not mean that a uniform to reach the number of days there will be ovulation, according to the ultrasound test results to determine. When the follicle reaches dominance, you can choose to have intercourse, and the chances of pregnancy will be significantly improved. Letrozole ovulation therapy must be used accordingly under the guidance of a doctor to be safer, because if the medication is not used properly, it may lead to overstimulation of the ovaries and cause serious consequences, or it may lead to premature ovarian failure, so the medication must be used carefully.