What is In Vitro Fertilization?
In vitro fertilization (IVF) is the most complex and successful treatment for infertility. This technology, first developed in the late 1970s, was originally designed to treat women with blocked or damaged Fallopian tubes. Today IVF is an option for all causes of infertility.
The IVF process involves several steps:
- The patient is treated with injectable fertility drugs to enable her to release a number of eggs at the time of ovulation.
- Just prior to ovulation, the eggs are removed through the vagina under ultrasound guidance while the patient is under sedation.
- The eggs are then fertilized in the laboratory.
- The fertilized eggs (embryos) are allowed to develop in the laboratory for three to five days.
- Usually one or two embryos are transferred back to the patient’s uterus with a small catheter. If more embryos are available than will be transferred, they can be frozen for later use.
Additional IVF techniques include:
Intracytoplasmic sperm injection (ICSI)
ICSI is performed in cases where the number of sperm or eggs available is extremely low. A single sperm is injected directly into each egg.
Assisted hatching is the creation of a hole in the zona pellucida, which is the outer shell that surrounds the embryo. It is believed that, for a select group of patients, creating a hole in the zone makes it easier for the embryo to undergo the normal hatching process. This may improve the likelihood of pregnancy in these patients.
Preimplantation genetic diagnosis (PGD)
For PGD, cells are removed from the embryo and genetic analysis of the biopsied cell(s) is done. This procedure is offered to those couples who have documented chromosomal abnormalities or specific single gene mutations.
Embryo freezing and frozen embryo transfer cycles (FET)Any extra high-quality embryos that are not transferred during the IVF cycle may be frozen and saved for a future frozen embryo transfer. Not all patients will have extra embryos of sufficient quality to allow embryo freezing.
The advantages to freezing embryos and undergoing FET cycles include:
- Avoiding the need to undergo a separate stimulation cycle and egg retrieval
- The cost of thawing and transferring embryos produced in a prior cycle is significantly lower than that incurred for a fresh IVF cycle
- Avoiding the need for injectable medications and the frequent monitoring required in a fresh cycle
We have a busy oocyte donation program at our center. The most common condition motivating couples to seek egg donation is decreased ovarian reserve, often related to age. It can also be used to treat infertility from congenitally or surgically absent ovaries, or from ovaries that have stopped functioning.
Egg donors are carefully screened for infectious diseases and for common genetic diseases that can be passed on to offspring. Egg donors undergo the usual IVF treatment with hormonal injections and the recipient partner’s sperm is used to create embryos. The resulting embryos are transferred into the recipient after her uterus is prepared using hormonal therapy.
The use of a gestational carrier may be offered to patients with disorders that preclude them from becoming pregnant. Patients who choose this treatment option undergo standard IVF treatment and the resulting embryos are transferred into the gestational carrier.
Who benefits from IVF?
- IVF is most commonly used for couples and individuals with infertility.
- IVF allows women to store embryos before receiving chemotherapy or radiation therapy for the treatment of cancer or other diseases.
- IVF combined with preimplantation genetic diagnosis can be used to treat individuals and couples with a family history of a genetic disease or individuals and couples at risk for having eggs with an abnormal number of chromosomes.
Success rates of IVF
Many factors may influence a couple's chance for success, including the age of the woman, the couple’s diagnosis, the quality of the sperm and the response of the woman's ovaries to medication.
It is difficult to compare data from one IVF program to another as many factors may influence the outcomes. Northwestern Medicine treats some of the most difficult cases. Still, our pregnancy rates are at or above the national average.
The Northwestern Medicine Center for Fertility and Reproductive Medicine unit reports its success rates to the Centers for Disease Control and Prevention (CDC) each year. As a member of the Society for Assisted Reproductive Technology (SART), we only publish the most recent statistics available to the CDC. You can review these statistics at SART CORS.