Ovulation takes place when a mature egg, or ovum, is released from the ovary. The egg begins as an immature egg, within a follicle of the ovary. Before ovulation can occur, the ovaries are first stimulated by the follicle-stimulate hormone (FSH), encouraging several follicles to develop, each of which contains an oocyte (or immature egg). Normally, only one of the follicles will fully develop a mature egg. Luteinizing hormone (LH) surges just before ovulation, speeding up the maturation process and triggering the follicle to release, or ovulate, the egg.
During normal ovulation, just one follicle matures fully, and one egg is ovulated. Fertility drugs, however, may result in more than one follicle developing a mature egg. This is called "superovulation."
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