In Vitro Fertilization

In vitro fertilization (IVF), which literally means "fertilization in glass", is a treatment for infertility that has failed to respond to other medical and surgical interventions. The world's first IVF baby, Louise Brown, was born in 1978 in England. Since then, approximately 1,000,000 babies have been born as a result of IVF.

An IVF cycle has 6 phases:

Pituitary Suppression
In a natural menstrual cycle, hormones from the pituitary gland (LH & FSH) cause the growth of an egg within a fluid-filled space, or follicle, within the ovary. Although several follicles start to grow each month, in a natural cycle only one will become mature enough to ovulate following a surge of the hormone LH at midcycle.

In contrast, during an IVF cycle it is desirable for several eggs to mature simultaneously. At the same time we do not want an LH surge to trigger early release of these eggs. We therefore use a medication known as a GnRH agonist to temporarily turn off your own LH and FSH secretion. This medication is usually started around day 22 of the menstrual cycle and continues through the stimulation phase. It is given daily, usually by nasal spray or occasionally by injection. Other GnRH agonist regimens or protocols may also be used in specific cases.

Ovarian Stimulation
After about 2 weeks of pre-treatment with the GnRH agonist, we add daily injections of FSH & LH (known as Pergonal, Puregon or Gonal F). The injections continue for about 12-14 days. The amount of FSH & LH used is somewhat higher than you would produce on your own. This is what stimulates the growth of several follicles, instead of just one. The response of the ovaries is monitored with frequent blood tests and ultrasounds. These are done between 8:00 and 9:00 each morning. Most women learn to give their own injections in order to reduce the number of clinic visits.

Although each woman and each cycle is different, this is an example of a treatment cycle schedule:

Egg Retrieval

Once the blood tests and ultrasounds indicate a reasonable size and number of follicles, an injection of hCG is given. This hormone causes the final maturation of the egg and loosening of the egg from the wall of the follicle. The egg retrieval occurs on the second morning after this final injection (34-36 hours later).

The egg retrieval is performed by an ultrasound guided needle puncture through the top of the vagina. Local anesthetic (freezing) is placed in the top of the vagina. A short-acting intravenous medication is given for pain control. Relaxation techniques can also be helpful. Your partner is encouraged to be with you during the egg retrieval. The fluid is drained from each follicle and examined under a microscope. Not every follicle contains an egg, but at least half of the large follicles will usually yield eggs.

Fertilization

The sperm sample is washed and concentrated, then added to the eggs a few hours after retrieval. The eggs are examined the next day for signs of fertilization. Not all of the eggs will fertilize, but we expect about 70-80% of the eggs to fertilize if the sperm sample looks normal. The fertilized eggs are kept in the incubator for an additional 48 hours. Not every follicle will contain an egg, not every egg will fertilize, and not every egg that fertilizes will go on to form a good quality embryo.

Embryo Transfer

Three days following egg retrieval, the fertilized eggs (embryos) are transferred to the uterus using a fine plastic tube (transfer catheter). The exact number transferred will depend on a woman's age and embryo quality. This procedure takes only a few minutes and is usually not uncomfortable. Everyone involved with IVF treatment will be offered the option of cryopreservation. Many couples, however, will not have enough extra embryos suitable for freezing. The best quality embryos (those most likely to result in pregnancy) are usually transferred in the treatment cycle. To be selected for freezing, embryos must not show any signs of fragmentation (cell breakdown) or abnormal development. Obviously, not all embryos will meet these criteria.

Luteal Phase and Pregnancy

You will be encouraged to limit your activity for 24 hours after the embryo transfer. Your activity can be gradually increased over the next few days to non-strenuous, non-aerobic activity. Many women return to work after a few days if their jobs are not strenuous. After a 16-days, a blood test will determine whether a pregnancy occurred.

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