Ovarian stimulation is used to increase the number of eggs in women who want to undergo assisted reproduction technique, either by artificial insemination or in vitro fertilization, because they have difficulty getting pregnant. The treatment involves placing a subcutaneous injection of a hormone prepared daily from the third day of the menstrual cycle. On the fourth day begins tracking the number and size of follicles (where the eggs will develop future) by vaginal ultrasound to determine the best day for the egg retrieval. Oocytes are extracted for several cycles to fertilize and then implanting the embryo in the uterus. Ovarian stimulation may increase the risk of a multiple pregnancy. Meanwhile, intercourse is usually applied directed, a treatment that involves sex on your most fertile days.