Decoding The In Vitro Fertilization (IVF) Procedure
IVF involves several steps:-
Ovarian Stimulation Egg RetrievalSperm Retrieval Fertilization andEmbryo Transfer.
One cycle of IVF can take about two to three weeks. More than one cycle may be needed.
The start of an IVF cycle begins by using synthetic hormones to stimulate the ovaries to produce multiple eggs — rather than the single egg that typically develops each month. Multiple eggs are needed because some eggs won’t fertilize or develop normally after fertilization.
Several different medications may be used for:-
- Ovarian stimulation
- Oocyte maturation
- To prevent premature ovulation
- To prepare the lining of your uterus
To determine when the eggs are ready for collection either a Vaginal ultrasound or Blood tests to measure your response to ovarian stimulation medications will be done.
Sometimes IVF cycles need to be canceled before egg retrieval for one of these reasons:
- Inadequate number of follicles developing
- Premature ovulation
- Too many follicles developing, creating a risk of ovarian hyperstimulation syndrome
- Other medical issues
If your cycle is canceled, your doctor might recommend changing medications or their doses to promote a better response during future IVF cycles. Or you may be advised that you need an egg donor.
Egg retrieval can be done in your doctor’s office or a clinic 34 to 36 hours after the final injection and before ovulation.
- During egg retrieval, you’ll be sedated and given pain medication.
- Transvaginal ultrasound aspiration is the usual retrieval method. An ultrasound probe is inserted into your vagina to identify follicles. Then a thin needle is inserted into an ultrasound guide to go through the vagina and into the follicles to retrieve the eggs.
- If your ovaries aren’t accessible through transvaginal ultrasound, an abdominal ultrasound may be used to guide the needle.
- 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 egg retrieval, you may experience cramping and feelings of fullness or pressure.
- Mature eggs are placed in a nutritive liquid (culture medium) and incubated. Eggs that appear healthy and mature will be mixed with sperm to attempt to create embryos. However, not all eggs may be successfully fertilized.
If you’re using your partner’s sperm, a semen sample needs to be provided at your doctor’s office or clinic the morning of egg retrieval. Typically, the semen sample is collected through masturbation. Other methods, such as testicular aspiration — the use of a needle or surgical procedure to extract sperm directly from the testicle — are sometimes required. Donor sperm also can be used. Sperm are separated from the semen fluid in the lab.
Fertilization can be attempted using two common methods:
- Conventional insemination. During conventional insemination, healthy sperm and mature eggs are mixed and incubated overnight.
- Intracytoplasmic sperm injection (ICSI). In ICSI, a single healthy sperm is injected directly into each mature egg. ICSI is often used when semen quality or number is a problem or if fertilization attempts during prior IVF cycles failed.
In certain situations, your doctor may recommend other procedures before embryo transfer:-
- Assisted hatching. About five to six days after fertilization, an embryo “hatches” from its surrounding membrane (zona pellucida), allowing it to implant into the lining of the uterus. If you’re an older woman, or if you have had multiple failed IVF attempts, your doctor might recommend assisted hatching — a technique in which a hole is made in the zona pellucida just before transfer to help the embryo hatch and implant. Assisted hatching is also useful for eggs or embryos that have been previously frozen as the process can harden the zona pellucida.
- Preimplantation genetic testing. Embryos are allowed to develop in the incubator until they reach a stage where a small sample can be removed and tested for specific genetic diseases or the correct number of chromosomes, typically after five to six days of development. Embryos that don’t contain affected genes or chromosomes can be transferred to your uterus. While preimplantation genetic testing can reduce the likelihood that a parent will pass on a genetic problem, it can’t eliminate the risk. Prenatal testing may still be recommended.
- Embryo transfer is done at your doctor’s office or a clinic and usually takes place two to five days after egg retrieval.
- You might be given a mild sedative. The procedure is usually painless, although you might experience mild cramping.
- The doctor will insert a long, thin, flexible tube called a catheter into your vagina, through your cervix and into your uterus.
- A syringe containing one or more embryos suspended in a small amount of fluid is attached to the end of the catheter.
- Using the syringe, the doctor places the embryo or embryos into your uterus.
- If successful, an embryo will implant in the lining of your uterus about six to 10 days after egg retrieval.