On the second day of menstruation when estradiol is 193 pmol/L, it is within the normal range, at which point the down-regulation treatment in IVF can be performed. The purpose of IVF down-regulation is to prevent spontaneous ovulation from occurring, thus promoting synchronized development of multiple eggs to obtain more follicles. On the second day of menstruation, which is in the follicular phase, estradiol of 193 pmol/L is normal, and down-regulation is needed to reduce the level of estrogen to less than 50 pmol/L before the next step of ovulation stimulation treatment can be performed. If a woman needs to undergo the down-regulation treatment in IVF, she needs to consult a doctor in time to have the results of this estrogen interpreted by a professional reproductive medicine doctor, and under the doctor’s guidance, she can carry out specific treatment to reduce the estrogen to a reasonable level and improve the success rate of IVF.