Why should IVF treatment be performed with downregulation and then ovulation? During IVF treatment, both downregulation and ovulation drugs are used in order to increase the number of eggs that the patient can retrieve. The drugs are used to lower the hormone levels in the body so that the FSH is below the recruitment level of the sinus follicles in the body, and then the ovulation drugs are used to grow this group of follicles together to retrieve a larger number of synchronized eggs. During the ovulation process, we monitor the follicle growth and hormones in real time to determine the timing of follicle maturation by the size of the follicles and the level of hormones, hence the term “controlled ovulation”. Will the follicles ovulate early during ovulation? During ovulation, as the follicles increase, the estrogen increases and some patients notice an increase in vaginal discharge and worry about early ovulation. For patients who are using hypoglycemic injections, there is no need to worry because the hypoglycemic drugs can control the increase of LH and the follicles usually will not ovulate early. Can I get my eggs without ovulation medication? Some patients feel that they are ovulating normally and can retrieve their eggs directly at ovulation without medication. If you don’t use the lowering medication, during the natural cycle, the follicles will mature, the LH level will rise and early ovulation will occur, and if the timing is not good, you will not be able to retrieve the mature eggs. Why are estrogen levels different in ovulation promotion? Each patient’s ovarian function is different and the number of small follicles collected each month is also different. After ovulation, the number of mature follicles is also different, so naturally the amount of estrogen secreted will be high or low. Why HCG injection and at night? HCG is equivalent to 20 times of LH. When the follicles reach about 18mm in diameter, HCG is needed to induce egg maturation, and eggs are retrieved 36-38 hours after HCG injection. The injections are given at night and the eggs are retrieved the morning after, which is good for timing.