IVF (In Vitro Fertilization)

IVF can be broken down into the following steps:

Birth control pills or estrogen

Before you start IVF treatment, your healthcare provider may prescribe birth control pills or estrogen. This is used to stop the development of ovarian cysts and control the timing of your menstrual cycle. It allows your healthcare provider to control your treatment and maximize the number of mature eggs during the egg retrieval procedure. Some people are prescribed combination birth control pills (estrogen and progesterone), while others are given just estrogen.

Ovarian stimulation

During each natural cycle in a healthy person of reproductive age, a group of eggs begins to mature each month. Typically, only one egg becomes mature enough to ovulate. The remaining immature eggs in that group disintegrate.

During your IVF cycle, you’ll take injectable hormone medications to encourage the entire group of that cycle’s eggs to mature simultaneously and fully. This means, instead of having just one egg (like in a natural cycle), you may have many eggs. The type, dosage and frequency of medications prescribed will be tailored to you as an individual based on your medical history, age, AMH (anti-mullerian hormone) level and your response to ovarian stimulation during previous IVF cycles.

The other steps in the ovarian stimulation process include:

• Monitoring: Your ovaries’ response to the medications is monitored by ultrasounds and blood hormone levels. Monitoring can occur daily or every few days over two weeks. Most stimulations last between eight and 14 days. At monitoring appointments, healthcare providers use ultrasound to look at your uterus and ovaries. The eggs themselves are too small to be visible with ultrasound. But, your healthcare providers will measure the size and number of growing ovarian follicles. Follicles are little sacks within your ovaries that should each contain a single egg. The size of each follicle indicates the maturity of the egg it contains. Most follicles greater than 14 millimeters (mm) contain a mature egg. The eggs contained within follicles less than 14 mm are more likely be immature and won’t fertilize.
• Trigger shot: When your eggs are ready for final maturation (determined by your ultrasound and hormone levels), a “trigger shot” is given to finalize the maturation of your eggs in preparation for egg retrieval. You’ll be instructed to administer the trigger shot exactly 36 hours before your scheduled egg retrieval time.

Egg retrieval

• Your healthcare provider uses an ultrasound to guide a thin needle into each of your ovaries through your vagina. The needle is connected to a suction device used to pull your eggs out of each follicle.
• Your eggs are placed in a dish containing a special solution. The dish is then put in an incubator (controlled environment).
• Medication and mild sedation are used to reduce discomfort during this procedure.
• Egg retrieval is done 36 hours after your last hormone injection, the “trigger shot.”

Fertilization

The afternoon after your egg retrieval procedure, the embryologist will try to fertilize all mature eggs using intracytoplasmic sperm injection, or ICSI. This means that sperm will be injected into each mature egg. Immature eggs cannot have ICSI performed on them. The immature eggs will be placed in a dish with sperm and nutrients. Immature eggs rarely finish their maturation process in the dish. If an immature egg does mature, the sperm in the dish can then attempt to fertilize the egg.

On average, 70% of mature eggs will fertilize. For example, if 10 mature eggs are retrieved, about seven will fertilize. If successful, the fertilized egg will become an embryo.

If there are an exceedingly large number of eggs or you don’t want all eggs fertilized, some eggs may be frozen before fertilization for future use.

Embryo development

Over the next five to six days, the development of your embryos will be carefully monitored.

Your embryo must overcome significant hurdles to become an embryo suitable for transfer to your uterus. On average, 50% of fertilized embryos progress to the blastocyst stage. This is the stage most suitable for transfer to your uterus. For example, if seven eggs were fertilized, three or four of them might develop to the blastocyst stage. The remaining 50% typically fail to progress and are discarded.

All embryos suitable for transfer will be frozen on day five or six of fertilization to be used for future embryo transfers.

Embryo transfer

There are two kinds of embryo transfers: fresh embryo transfer and frozen embryo transfer. Your healthcare provider can discuss using fresh or frozen embryos with you and decide what’s best based on your unique situation. Both frozen and fresh embryo transfers follow the same transfer process. The main difference is implied by the name.

A fresh embryo transfer means your embryo is inserted into your uterus between three and seven days after the egg retrieval procedure. This embryo hasn’t been frozen and is “fresh.”

A frozen embryo transfer means that frozen embryos (from a previous IVF cycle or donor eggs) are thawed and inserted into your uterus. This is a more common practice for logistical reasons and because this method is more likely to result in a live birth. Frozen embryo transfers can occur years after egg retrieval and fertilization.

As part of the first step in a frozen embryo transfer, you’ll take oral, injectable, vaginal or transdermal hormones to prepare your uterus for accepting an embryo. Usually, this is 14 to 21 days of oral medication followed by six days of injections. Typically, you’ll have two or three appointments during this time to monitor the readiness of your uterus with ultrasound and to measure your hormone levels with a blood test. When your uterus is ready, you’ll be scheduled for the embryo transfer procedure.

The process is similar if you’re using fresh embryos, except embryo transfer happens within three to five days of being retrieved.

The embryo transfer is a simple procedure that doesn’t require anesthesia. It feels similar to a pelvic exam or Pap smear. A speculum is placed within the vagina, and a thin catheter is inserted through the cervix into the uterus. A syringe attached to the other end of the catheter contains one or more embryos. The embryos are injected it the uterus through the catheter. The procedure typically takes less than 10 minutes.

Pregnancy

Pregnancy occurs when the embryo implants itself into the lining of your uterus. Your healthcare provider will use a blood test to determine if you’re pregnant approximately nine to 14 days after embryo transfer.

If donor eggs are being used, the same steps are taken. The egg donor will complete ovarian stimulation and egg retrieval. After fertilization takes place, the embryo is transferred to the person who intends to carry the pregnancy (either with or without various fertility medications).

There are many factors to take into consideration before starting IVF treatment. To get the best understanding of the IVF process and what to expect, it’s important to consult with your healthcare provider.