As soon as the ultrasound finds an adequate number (it is different in each individual case) and size (18-20 mm) of follicles, the stimulation phase ends. It is time to make the final injection.

The injection nurse will tell you the exact time for human chorionic gonadotropin (HCG) or agonist injection. This injection contributes to oocyte maturation and separation from the inner wall of the follicle. Follicular puncture and egg extraction usually takes place 35-37 hours after the trigger injection. It is important to perform this injection in the set time.