After the preparations are completed, one cycle of
IVF can take about 2 to 3 weeks. More than one cycle may be needed. The steps in a cycle go as follows:
Treatment to make mature eggs
The start of an
IVF cycle begins by using lab-made hormones to help the ovaries to make eggs — rather than the single egg that usually develops each month. Multiple eggs are needed because some eggs won't fertilize or develop correctly after they're combined with sperm.
Certain medicines may be used to:
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Stimulate the ovaries. You might receive shots of hormones that help more than one egg develop at a time. The shot may contain a follicle-stimulating hormone (FSH), a luteinizing hormone (LH) or both.
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Help eggs mature. A hormone called human chorionic gonadotropin (HCG), or other medicines, can help the eggs ripen and get ready to be released from their sacs, called follicles, in the ovaries.
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Delay ovulation. These medicines prevent the body from releasing the developing eggs too soon.
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Prepare the lining of the uterus. You might start to take supplements of the hormone progesterone on the day of the procedure to collect your eggs. Or you might take these supplements around the time an embryo is placed in the uterus. They improve the odds that a fertilized egg attaches to the lining of your uterus.
Your doctor decides which medicines to use and when to use them.
Most often, you'll need 1 to 2 weeks of ovarian stimulation before your eggs are ready to be collected with the egg retrieval procedure. To figure out when the eggs are ready, you may need:
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Vaginal ultrasound, an imaging exam of the ovaries to track the developing follicles. Those are the fluid-filled sacs in the ovaries where eggs mature.
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Blood tests, to check on how you respond to ovarian stimulation medicines. Estrogen levels often rise as follicles develop. Progesterone levels remain low until after ovulation.
Sometimes,
IVF cycles need to be canceled before the eggs are collected. Reasons for this include:
- Not enough follicles develop.
- Ovulation happens too soon.
- Too many follicles develop, raising the risk of ovarian hyperstimulation syndrome.
- Other medical issues happen.
If your cycle is canceled, your care team might recommend changing medicines or the amounts you take, called doses. This might lead to a better response during future
IVF cycles. Or you may be advised that you need an egg donor.
Egg retrieval
This is the procedure to collect the eggs from one or both ovaries. It takes place in your doctor's office or a clinic. The procedure is done 34 to 36 hours after the final shot of fertility medicine and before ovulation.
- Before egg retrieval, you'll be given medicine to help you relax and keep you from feeling pain.
- An ultrasound device is placed into the vagina to find follicles. Those are the sacs in the ovaries that each contain an egg. Then a thin needle is inserted into an ultrasound guide to go through the vagina and into the follicles to collect the eggs. This process is called transvaginal ultrasound aspiration.
- If your ovaries can't be reached through the vagina this way, an ultrasound of the stomach area may be used to guide the needle through the stomach and into the ovaries.
- The eggs are removed from the follicles through a needle connected to a suction device. Multiple eggs can be removed in about 20 minutes.
- After the procedure, you may have cramping and feelings of fullness or pressure.
- Mature eggs are placed in a liquid that helps them develop. Eggs that appear healthy and mature will be mixed with sperm to attempt to create embryos. But not all eggs are able to be fertilized with success.
Sperm retrieval
If you're using your partner's sperm, a semen sample needs to be collected at your doctor's office or clinic the morning of egg retrieval. Or sperm can be collected ahead of time and frozen.
Most often, the semen sample is collected through masturbation. Other methods can be used if a person can't ejaculate or has no sperm in the semen. For example, a procedure called testicular aspiration uses a needle or surgery to collect sperm directly from the testicle. Sperm from a donor also can be used. Sperm are separated from the semen fluid in the lab.
Fertilization
Two common methods can be used to try to fertilize eggs with sperm:
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Conventional insemination. Healthy sperm and mature eggs are mixed and kept in a controlled environment called an incubator.
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Intracytoplasmic sperm injection (ICSI).
A single healthy sperm is injected right into each mature egg. Often,
ICSI
is used when semen quality or number is an issue. Or it might be used if fertilization attempts during prior
IVF cycles didn't work.
In certain situations, other procedures may be recommended before embryos are placed in the uterus. These include:
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Assisted hatching. About 5 to 6 days after fertilization, an embryo "hatches" from the thin layer that surrounds it, called a membrane. This lets the embryo attach to the lining of the uterus.
If you're older and you want to get pregnant, or if you have had past
IVF attempts that didn't work, a technique called assisted hatching might be recommended. With this procedure, a hole is made in the embryo's membrane just before the embryo is placed in the uterus. This helps the embryo hatch and attach to the lining of the uterus. Assisted hatching is also useful for eggs or embryos that were frozen, as that process can harden the membrane.
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Preimplantation genetic testing. Embryos are allowed to develop in the incubator until they reach a stage where a small sample can be removed. The sample is tested for certain genetic diseases or the correct number of threadlike structures of DNA, called chromosomes. There are usually 46 chromosomes in each cell. Embryos that don't contain affected genes or chromosomes can be transferred to the uterus.
Preimplantation genetic testing can lower the chances that a parent will pass on a genetic problem. It can't get rid of the risk completely. Prenatal testing may still be recommended during pregnancy.
Embryo transfer
The procedure to place one or more embryos in the uterus is done at your doctor's office or a clinic. It often takes place 2 to 6 days after eggs are collected.
- You might be given a mild sedative to help you relax. The procedure is often painless, but you might have mild cramping.
- A long, thin, flexible tube called a catheter is placed into the vagina, through the cervix and into the uterus.
- A syringe that contains one or more embryos in a small amount of fluid is attached to the end of the catheter.
- Using the syringe, the embryo or embryos are placed into the uterus.
If the procedure works, an embryo will attach to the lining of your uterus about 6 to 10 days after egg retrieval.
After the procedure
After the embryo transfer, you can get back to your usual daily routine. Your ovaries may still be enlarged, so vigorous activities or sex might cause discomfort. Ask your care team how long you should stay away from these.
Typical side effects include:
- Passing a small amount of clear or bloody fluid shortly after the procedure. This is due to the swabbing of the cervix before the embryo transfer.
- Breast tenderness due to high estrogen levels.
- Mild bloating.
- Mild cramping.
- Constipation.
Call your care team if you have moderate or severe pain, or heavy bleeding from the vagina after the embryo transfer. You'll likely to need to get checked for complications such as infection, twisting of an ovary and ovarian hyperstimulation syndrome.