In Vitro Fertilization (IVF)
In Vitro Fertilization (IVF)
IVF is an assisted reproductive technique (ART). In vitro (literally “in glass”) fertilization (IVF) is a procedure in which eggs (ova) from a woman’s ovary are removed and fertilized with sperm in a laboratory procedure—hence “in vitro” fertilization. The resulting fertilized egg (embryo) is returned to the woman’s uterus in the hope that it will establish itself there and grow to term.
Human fertilization in vivo (in the living body) occurs in oviducts (fallopian tubes) of the female reproductive tract.
IVF is one of several assisted reproductive techniques (ART) used to help infertile couples to conceive a child. If after one year of having sexual intercourse without the use of birth control a woman is unable to get pregnant, infertility is suspected. IVF is used to treat couples with unexplained infertility of long duration who have failed with other infertility treatments.
Some of the reasons for infertility are damaged or blocked fallopian tubes, hormonal imbalance, or endometriosis in the woman. In the man, low sperm count or poor quality sperm can cause infertility.
IVF is one of several possible methods to increase the chance for an infertile couple to become pregnant. Its use depends on the reason for infertility. IVF may be an option if there is a blockage in the fallopian tube or endometriosis in the woman or low sperm count or poor quality sperm in the man. There are other possible treatments for these conditions, such as surgery for blocked tubes or endometriosis, which may be tried before IVF.
IVF will not work for a woman who is not capable of ovulating or a man who is not able to produce at least a few healthy sperm.
Other similar types of assisted reproductive technologies are also used to achieve pregnancy. A procedure called intracytoplasmic sperm injection (ICSI) uses a manipulation technique that uses a microscope to inject a single sperm into each egg. The fertilized eggs can then be returned to the uterus, as in IVF. In gamete intrafallopian tube transfer (GIFT) the eggs and sperm are mixed in a narrow tube and then deposited in the fallopian tube, where fertilization normally takes place. Another variation on IVF is zygote intrafallopian tube transfer (ZIFT). As in IVF, the fertilization of the eggs occurs in a laboratory dish. And, similar to GIFT, the embryos are placed in the fallopian tube (rather than the uterus as with IVF).
The screening procedures and treatments for infertility can become a long, expensive, and sometimes disappointing process. Each IVF attempt takes at least an entire menstrual cycle and can cost $5,000-$10,000, which may not be covered by health insurance. The anxiety of dealing with infertility can challenge both individuals and their relationship. The added stress and expense of multiple clinic visits, testing, treatments, and surgical procedures can become overwhelming. Couples may want to receive counseling and support through the process.
In vitro fertilization is a procedure where the joining of egg and sperm takes place outside of the woman’S body. A woman may be given fertility drugs before this procedure so that several eggs mature in the ovaries at the same time. Eggs (ova) are removed from a woman’ ovaries using a long, thin needle. The physician gets access to the ovaries using one of two possible procedures. One procedure involves inserting the needle through the vagina (transvaginally). The physician guides the needle to the location of the ovaries with the help of an ultrasound machine. In the other procedure, called laparoscopy, a small thin tube with a viewing lens is inserted through an incision in the navel. This allows the physician to see inside the patient, and locate the ovaries, on a video monitor.
Once the eggs are removed, they are mixed with sperm in a laboratory dish or test tube. (This is where the term “test tube baby” comes from.) The eggs are monitored for several days. Once there is evidence that fertilization has occurred and the cells begin to divide, they are then returned to the woman’S uterus.
In the procedure to remove eggs, enough may be gathered to be frozen and saved (either fertilized or unfertilized) for additional IVF attempts.
Once a woman is determined to be a good candidate for in vitro fertilization, she will generally be given “fertility drugs” to stimulate ovulation and the development of multiple eggs. These drugs may include gonadotropin releasing hormone agonists (GnRHa), Pergonal, Clomid, or human chorionic gonadotropin (hcg). The maturation of the eggs is then monitored with ultrasound tests and frequent blood tests. If enough eggs mature, the physician will perform the procedure to remove them. The woman may be given a sedative prior to the procedure. A local anesthetic agent may also be used to reduce discomfort during the procedure.
After the IVF procedure is performed the woman can resume normal activities. A pregnancy test can be done approximately 12-14 days later to determine if the procedure was successful.
The risks associated with in vitro fertilization include the possibility of multiple pregnancy (since several embryos may be implanted) and ectopic pregnancy (an embryo that implants in the fallopian tube or in the abdominal cavity outside the uterus). There is a slight risk of ovarian rupture, bleeding, infections, and complications of anesthesia. If the procedure is successful and pregnancy is achieved, the pregnancy would carry the same risks as any pregnancy achieved without assisted technology. However because many
Fallopian tubes —In a woman’S reproductive system, a pair of narrow tubes that carry the egg from the ovary to the uterus.
GIFT —Gamete intrafallopian tube transfer. This is a process where eggs are taken from a woman’s ovaries, mixed with sperm, and then deposited into the woman’s fallopian tube.
ICSI —Intracytoplasmic sperm injection. This process is used to inject a single sperm into each egg before the fertilized eggs are put back into the woman’s body. The procedure may be used if the male has a low sperm count.
ZIFT —Zygote intrafallopian tube transfer. In this process of in vitro fertilization, the eggs are fertilized in a laboratory dish and then placed in the woman’s fallopian tube.
IVF patients are of advanced maternal age, and therefore have an increased risk for conceiving a child with Down syndrome or other abnormalities, in IVF programs it would be better test ovocytes before implantation in order to detect potential chromosomal aneuploidies, thus avoiding the transfer of embryos affected by aneuploid oocytes.
Success rates vary widely between clinics and between physicians performing the procedure. A couple has about a 10% chance of becoming pregnant each time the procedure is performed. Therefore, the procedure may have to be repeated more than once to achieve pregnancy.
IVF has been used successfully since 1978, when the first child to be conceived by this method was born in England. Since then, thousands of couples have used IVF or other assisted reproductive technologies to conceive.
An ectopic or multiple pregnancy may abort spontaneously or may require termination if the health of the mother is at risk. There has been medical controversy over whether children conceived using IVF are more liable to suffer birth defects. A 2005 metastudy—a study of all existing studies—found a 30–40% increase in birth defects risk for IVF babies versus those conceived naturally. If this effect is real, the cause is not known.
See also Embryo and embryonic development; Embryo transfer; Embryology; Clone and cloning.
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Brenda Wilmoth Lerner