IVF is a meticulously-timed procedure that involves removing ripened eggs from a woman's ovaries, fertilizing them with semen, incubating the cells in a laboratory, and placing the embryos into the woman's uterus at precisely the right time. The procedure usually takes about one month from beginning to end.
Generally, a woman starts taking ovulation-inducing drugs, such as Clomid, somewhere between the first and fifth days of her menstrual cycle to stimulate the development of multiple follicles. (Several eggs are stimulated to develop at the same time so that a group of eggs will be available for fertilization.) During this period, a woman will have frequent blood tests to check her estrogen levels, and frequent ultrasounds to monitor the growth, size, and number of developing ovarian follicles.
When the follicles reach maturity, usually after seven to 10 days of medication, she'll receive an injection of hCG, a hormone that triggers egg release. About 34 to 36 hours later, the doctor will use ultrasound-guided aspiration to remove the eggs from the ovaries. The egg-retrieval procedure usually takes about 15 minutes, during which time a local anesthetic is given. At this point, the man is asked to provide a fresh sperm sample. For men with normal semen, about 50,000 to 100,000 of the most motile sperm will be incubated with each of his wife's eggs. (If a man has a very low sperm count, doctors may use a procedure called intracytoplasmic sperm injection, or ICSI, in which a single sperm is directly injected into each egg.)
Next, the sperm and eggs are combined in a petri dish, where the eggs become fertilized. If the fertilized eggs (embryos) are developing normally, the woman will return to the hospital or clinic several days later to have them transferred into her uterus. This procedure takes about 10 minutes and requires no anesthesia. About 14 days later, a pregnancy test will be done and a couple will learn whether the IVF procedure has been successful. If it hasn't, they can choose to try again during another cycle.
IVF is often recommended for women who have irreversibly blocked fallopian tubes, endometriosis, a cervical factor problem, ovulation disorders, or unexplained infertility, or for men with a very low sperm count. The success rate for IVF will vary according to a number of factors, including a woman's age. But in general, 15 to 20 percent of all women who begin an IVF cycle become pregnant and carry a baby to term.