In Vitro Fertilization (IVF)
In vitro fertilization (IVF) is a method of assisted reproduction in which eggs are retrieved from the woman’s ovaries and inseninated with the man’s sperm in a laboratory dish. The fertilized eggs are cultivated in the laboratory for a few days and then transferred to the woman’s uterus, with the hope that it will implant in the uterine lining and continue to develop. An average IVF cycle takes from 6 to 8 weeks, depending on the circumstances.
The description below is of a standard IVF cycle and is intended only for general information purposes. The medical protocol for your IVF cycle will vary depending on your IVF physician and your particular medical situation. You must discuss the details of your treatment plan with your IVF physician to understand exactly what will be involved in your IVF cycle.
In surrogacy and egg donor arrangements, every participant will not have to go through all of the treatment phases outlined below. In a surrogacy arrangement, the surrogate will not undergo the stimulation/retrieval phases but will complete an embryo transfer. By contrast, an egg donor will undergo the stimulation/retrieval phases but will not be involved in an embryo transfer.
STEP 1: MENSTRUAL CYCLE & HORMONE SUPPRESSION
The IVF cycle will start on the first day of the menstrual period closest to the patient’s scheduled IVF treatment. Once the period begins, the IVF physician will usually give the patient oral contraceptives to regulate her hormone levels and limit the development of cysts. The contraceptives are usually taken for two to four weeks. Around week two, the patient will start daily subcutaneous injections (shots) of a medication (Lupron) to complete her pre-stimulation ovarian suppression. These injections typically last about two weeks.
STEP 2: OVARIAN STIMULATION
During this phase, the patient begins taking one or more fertility medications to stimulate her ovaries to produce multiple mature eggs (typically 7 to 15) rather than the single egg that normally develops each month. Drug type and dosage will vary depending on the IVF clinic and the patient’s response to the medications. These medications are usually administered by daily subcutaneous shots for 8 to 12 days. While she is receiving her fertility injections, the patient will be monitored by ultrasound scans to see the size and number of developing follicles and by blood tests to measure estrogen levels. Ovarian follicles are small fluid-filled sacks in the ovaries where the eggs grow. Each follicle typically holds one egg. Patients will have 4 to 5 monitoring visits during this time.
STEP 3: EGG RETRIEVAL & FERTILIZATION
Once the ultrasound scans show that the follicles are large and almost mature, the patient is given a trigger shot to stimulate the eggs’ maturation. Ovulation normally occurs about 48 hours after this injection, so egg retrieval will be scheduled to take place just before ovulation occurs (typically 34 to 36 hours).
Egg retrieval is typically done using a fine, hollow needle guided by ultrasound. The retrieval is a mildly invasive procedure that is often done under light anesthesia. When mature follicles are found in the ovaries, the eggs are gently removed from the follicles through the needle by a suction device. Unless they are being frozen, the eggs are fertilized with sperm within hours of their retrieval and placed in an incubator. It takes 3 to 5 more days for the fertilized eggs to be tested for viability. Any viable embryos will either be frozen or a “fresh” embryo transfer will be scheduled.
STEP 4: EMBRYO TRANSFER
Your IVF clinic’s embryologist will monitor your embryos and, if they are developing normally, the embryo transfer will be scheduled 3 to 6 days after the egg retrieval. However, if you have requested that PGT (preimplantation genetic testing) be performed on your embryos, then the embryos will often be frozen (cryopreserved) while waiting for the test results. In that case, PGT approved embryos will be thawed and transferred at a later date.
The embryo transfer procedure is short (usually about 10 to 20 minutes) and is generally painless. The embryos are transferred to the patient’s uterus using a tiny, slender tube guided by ultrasound. Because multiple pregnancies are considered high risk, it is now common to only transfer a single viable embryo. This is especially the case with PGT screened embryos. Many fertility specialists recommend 24 to 48 hours of bed rest after the transfer.
STEP 5: PREGNANCY TESTING AND CONFIRMATION
The surrogate will take a pregnancy blood test about two weeks after the embryo transfer. During this time, she will be prescribed medications needed to provide hormonal support to a pregnancy.
A positive pregnancy blood test is usually confirmed by a second blood test. A couple weeks later, an ultrasound scan will identify a normal pregnancy and be able to detect the heartbeat of the new embryo. If all goes well, at the end of the first trimester of pregnancy the surrogate will be referred to her obstetrician for standard prenatal care. For out-of-town surrogates, this referral typically comes much earlier (upon pregnancy confirmation by ultrasound).
Although IVF success rates continue to improve, it can often take two or more IVF cycles for a healthy, full-term pregnancy to begin.
More detailed information may be found for all IVF related topics under “News and Publications” at reproductivefacts.org, provided by the American Society for Reproductive Medicine.