IVF is usually the treatment of choice for a woman with blocked, severely damaged, or absent fallopian tubes. IVF is also used to circumvent infertility caused by endometriosis or a male factor. Many programs also use IVF to treat couples with unexplained infertility of long duration who have failed with other infertility treatments. The resulting embryo is then transferred to the uterus to develop naturally. Usually, two to four embryos are transferred with each cycle.
Some clinics achieve even better results.
Success with IVF increases with the number of cycles attempted up to four cycles. Children resulting from IVF have the same incidence of birth defects as children who are conceived naturally. IVF was successfully used for the first time in the United States in 1981. Since then, more than 45,000 babies have been born in the U.S. as a result of this technique.