Introduction
The production of hormones and the development of eggs within the ovary are controlled by the pituitary gland in the brain. The pituitary gland controls ovarian function through its production of two hormones that are secreted into the blood stream and travel to the ovaries to have their effects. These hormones are FSH (follicle stimulating hormone) and LH (leuteinizing hormone). These hormones have been isolated and purified and are available for use in ovulation manipulation. Normally, only one egg is formed per cycle. COH (controlled ovarian hyperstimulation) is a term used to describe our efforts to induce the ovaries to produce more than just a single egg. Depending on the indication, several eggs can be induced to develop with FSH. With ovulation induction, we attempt to produce 1 to 3 mature eggs but with IVF we want as many as we can stimulate since with IVF we can control the number of eggs that are fertilized.

The Hormone Preparations
Gonal-F and Follistim are the most common brands of FSH used in IVF. They are given by injection only, but are given just under the skin (subcutaneously) through a very small, short needle. These injections are self administered and may be given in the abdomen or in the thigh.

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