In Vitro Fertilization (IVF) provides an alternative method of achieving a pregnancy for couples who have tried and have been unsuccessful with other fertility treatments. In many cases, it is the therapy of first choice. In a normal conception cycle, an egg is released from the ovary and unites with a sperm cell that has traveled through the uterus and fallopian tubes after being deposited in the vagina during intercourse. When the sperm penetrates the egg, fertilization occurs. The fertilized egg develops further as it moves through the tube into the uterus. Implantation does not occur until several days after fertilization.

The IVF procedure allows the union of the egg and the sperm and early growth of the embryo to occur in the laboratory. For a pregnancy to result through IVF, four steps must be successfully completed. Pregnancy cannot occur if even one step of the procedures fails.

These four steps are as follows:

Retrieval of the mature egg. Fertility drugs (hMG, Gonal-F, or Puregon) are used to ripen more than one egg. This process is called controlled ovarian hyperstimulation. Eggs are recovered by transvaginal ultrasound directed aspiration of the follicles. Intravenous sedation is used. Because timing of the egg collection is critical, ultrasound monitoring and hormone tests are done before egg retrieval.

Sperm collection, fertilization, and embryo development. A semen specimen is obtained and prepared at the appropriate time in relationship to the egg recovery. Meanwhile, the eggs are placed in culture medium to incubate and mature until timing is optimal for fertilization by the sperm. The resulting zygote is called a pre-embryo. In nature as well as in the laboratory, fertilization may not occur, nor does development always continue once the egg is penetrated by sperm.

Transfer of the developing embryo(s) into the uterus. On the third or fifth day after egg recovery, the embryo(s) are tranferred into a small tube through the cervix into the uterus. This process is technically much simpler than the egg retrieval in that it does not require anaesthesia and is like a regular pelvic exam.

Implantation and growth of the embryo(s). After fertilization and transfer, further development and implantation of the embryo(s) in the uterine lining is governed by hormones, receptors on the uterine lining, and other unknown factors. Blood tests will be taken to detect pregnancy. Additional hormones are given to support the early pregnancy.