Technically, “in vitro fertilization” only refers to the process of fertilizing an egg outside the body. However, the term IVF is generally used to describe the entire treatment cycle. This involves three phases:
Phase 1 – Egg RecruitmentThe patient receives a series of hormone injections over a period of several weeks. These hormones stimulate a number of her existing eggs to develop and become ready for fertilization. The eggs are then retrieved through the vaginal wall using a needle in a quick, outpatient procedure.
Phase 2 – Egg Fertilization
Fresh or frozen sperm can be used to fertilize several of the patient’s eggs in an IVF dish. The eggs are observed to ensure that fertilization is successful. Then, the embryos are allowed to grow for 3-5 days. At this point, they are ready for transfer back into the patient’s body. Excess embryos can be frozen for later use.
Phase 3 – Embryo Transfer
A fertilized embryo is delivered into the patient’s uterus via a narrow, flexible catheter. Rather than simply being released into the womb, the embryo is precisely placed on the wall of the uterus to increase its chances of survival. Within two weeks, a pregnancy test can be used to confirm successful implantation. Progesterone hormone treatment is continued through the first trimester. This keeps the lining of the uterine wall thick enough to nurture the implanted embryo properly.
Some patients achieve a pregnancy after just one round of in vitro fertilization while others require multiple treatment cycles. Additional options may be explored for patients who do not respond to IVF.