First successfully performed in 1978, in vitro fertilization (IVF) is probably one of the best known ART methods and quite possibly the most common form of treatment people think of when they think of infertility treatment. As a result, people often believe that IVF is the only treatment option for those experiencing fertility problems.
In reality, less than 2% of couples actually seek this option and often they have tried other methods, like fertility drugs, first. Although it can simply be explained as the process of joining an egg and sperm together in a lab, the procedure itself can be painstaking and must be perfectly timed in order to be successful.
The First Step
Because it is necessary to harvest several eggs for IVF treatment, women will first be administered hormonal medications, like clomiphene, hMG or FSH, for about ten days. These drugs will help promote the development of several follicles and therefore several eggs. By using these drugs, it is easier to determine just when ovulation will occur. However, frequent monitoring is still required.
You will have regular blood tests done to measure the levels of hormones in your blood. Additionally, an ultrasound may be used to allow your doctor to observe the development of the egg follicles. Once the eggs have matured, but before they have been released from the follicle, your doctor will harvest them.
Some women, however, will produce less than the ideal number of mature eggs even with high doses of ovulation stimulating medications. Women who find themselves in this situation are what is known as a “poor responder.” To find out if you may be a poor responder, it is a good idea to have testing done on your ovarian reserves as well as have an ultrasound done to evaluate your ovaries and the number of resting follicles.
Some women may not be suited to IVF because they are poor responders while others may just need to adjust the dosage of their medication. It is best to learn this information out beforehand so that you and your partner can avoid spending money on a procedure that may not work for you.
Now that your eggs have matured, they will be retrieved from your ovaries. Timing is everything in this process - an egg retrieval that is performed too soon may result in immature eggs that can’t be fertilized, while waiting too long may cause the eggs to be too mature or possibly even be spontaneously released by your body.
To harvest the eggs, your doctor will give you an anesthetic that will help you feel more comfortable although it won’t completely knock you out. Using an ultrasound to locate the mature follicles, a long, thin needle will be passed through your vagina to the ovaries. The needle will then suck the fluid from the mature follicle. An immediate microscopic observation of the fluid will reveal whether or not an egg was retrieved. If an egg was retrieved, it will be removed from the fluid and placed into an incubator. The process will then be repeated to retrieve several more eggs. The total number of eggs harvested can vary depending on the clinic you are using - it may be as low as five or it could be as many as 15.
Once the eggs have been harvested, you may be given progesterone supplements to help make your uterine lining ideal for implantation.
Shortly after your eggs have been harvested, your partner will be asked to provide a semen sample. You can also choose to use a sperm donor if your partner is unable to provide a semen sample. Next, the sperm is processed before being placed in a Petrie dish with the harvested eggs. Anywhere from 50,000 to one million sperm may be used to fertilize the eggs. Using an incubator that is set to simulate the same temperature as a woman’s body, the eggs and sperm are left to mix together for 14 to 18 hours.
After the incubation period, examination under a microscope will reveal which, if any, of the eggs have been fertilized. These will then be transferred to another location where they will be left to naturally advance. An embryologist will oversee their progression to assess whether or not development is taking place normally.
Once the embryos are ready for transferring, between two and five days after fertilization, your doctor will use a tube to gently release the embryos into your uterus. This is a relatively painless procedure that doesn’t require any anesthesia. Your doctor may also choose to use an ultrasound to help guide the placement of the fertilized eggs into your uterus. If all goes well, then at least one egg will implant into your uterine lining.
The total number of embryos transferred back into your womb can vary. Some clinics allow the couple to decide how many embryos they would like to transfer while others may have a standard preset number. In some cases, a couple may decide that they would like to freeze some of their embryos for future use. Factor’s like a woman’s age, the cause of infertility in the couple, as well as the woman’s past history of pregnancy can all influence the decision of how many embryos to transfer.
Most couples have between two and four embryos transferred into the woman’s uterus. There is obviously a greater chance of pregnancy occurring when more embryos are transferred. However, this practice also tends to increase the likelihood of a multiple pregnancy. Anywhere from 20% to 40% of pregnancies resulting from IVF are multiples.
The total process of IVF, from ovulation stimulating medication to embryo transfer, can take between four and six weeks.
Advancements in reproductive technologies have resulted in the development of allowing embryos to grow in the lab to the blastocyst stage. While IVF treatments are used to transfer embryos to the woman’s uterus at day two or three in development, nowadays technicians can wait about five days, when the embryo has developed into a blastocyst, before doing a transfer.
This delay means that only the strongest embryos are transferred back to the woman. As a result, there is a better chance of pregnancy occurring and therefore fewer embryos need to be transferred. In turn, this lowers a woman’s chances of having a multiple birth.
About two weeks after the transfer of the embryos, you will return to your doctor’s office for a pregnancy blood test to see if the procedure was successful. On average, about 35% of women using this fertility treatment are able to become pregnant while 29% of women will have a live birth. Your chances of success vary according to your age - a young woman in her 20s may have as much as a 50% chance of becoming pregnant while a woman in her 40s only has about a 20% chance.
In addition to the increased likelihood of a multiple pregnancy, women undergoing IVF have a greater risk of experiencing an ectopic pregnancy.
Odds and Ends
In vitro fertilization is often recommended as a suitable treatment for women with unexplained infertility, endometriosis, blockage or tubal damage, or ovulation problems. Men with low sperm counts may also find this technique useful for getting their partner pregnant.
However, this technology is not cheap. One cycle of IVF can cost anywhere between $10,000 and $17,000, possibly even more. While some couples have been successful at getting pregnant after only one cycle of IVF, others have tried three or four times with no success. Before you and your partner decide to take advantage of IVF, it is important to discuss how much you are willing to spend on the procedure and when you should call it quits. You should also discuss which alternatives you’d be willing to try in case this method does not work for you.
Revision date: June 11, 2011
Last revised: by Sebastian Scheller, MD, ScD