In vitro fertilization is the general term used to describe the process of retrieving eggs and fertilizing them in a laboratory in order to create embryos for uterine transfer. The egg freezing process requires a patient to undergo egg retrieval, after which the eggs are frozen. Later, at a time determined by the patient, the egg thawing, fertilization and embryo transfer take place.
IVF is the most technologically advanced and successful form of fertility therapy available. The pregnancy rates associated with IVF are the highest of all fertility treatments across every age bracket. This is because IVF optimizes all of the steps associated with the reproductive process. In a natural cycle, only one egg is ovulated, fertilized and implanted in the uterus. IVF augments these processes by stimulating multiple eggs to grow, fertilizing them directly in the laboratory (in vitro) and placing multiple embryos into the uterus.
The IVF cycle has three phases: ovarian stimulation and egg retrieval; fertilization and embryo culture; and embryo transfer and progesterone support. Following is a brief description of these three phases.
For a description of the procedure in greater detail, please see The IVF Cycle.
Injectable fertility medications are used to stimulate the ovaries, making multiple eggs available for retrieval. An ultrasound-guided needle is inserted through the vagina to suction the fluid and the egg from the follicle. Eggs are frozen 2-4 hours following retrieval.
Following egg thawing, all surviving eggs are placed in a dish filled with culture media. Each egg is then injected with one sperm in a procedure called intracytoplasmic sperm injection (ICSI).
Once the eggs have been fertilized, the embryos are maintained in the laboratory before being transferred to the uterus. Typically, embryo transfer takes place after three days, while a blastocyst transfer is performed after five days. Embryos are placed in the uterine cavity using a catheter in a procedure similar to that used in intrauterine insemination (IUI). Prior to embryo transfer, a small hole is made in the outer shell of each embryo to help the embryo hatch (assisted hatching).
The transfer process is critical to the success of IVF. If an embryo is not placed in the correct location, or if a uterine contraction causes it to move once it has been placed inside the uterus, the embryo may fail to implant. We have a great deal of experience in this delicate process, and we utilize special catheters and ultrasound to assist us in the transfer. Additionally, the embryo transfer is practiced in advance of the actual procedure.
In most cases, progesterone supplementation is used during the second half of the cycle (the luteal phase). This assists in preparing the endometrium for embryo implantation. The most common dose is 200 mg vaginally twice daily. The progesterone is continued until the end of the first trimester if the pregnancy is successful, or until the second negative pregnancy test.
For more information on IVF and fertility, please visit Santa Monica Fertility.