In vitro fertilization (IVF) is a process by which egg cells are fertilized by sperm outside the womb, in vitro. IVF is a major treatment in infertility when other methods of assisted reproductive technology have failed. The process involves hormonally controlling the ovulatory process, removing ova (eggs) from the woman’s ovaries and letting sperm fertilise them in a fluid medium. The fertilised egg (zygote) is then transferred to the patient’s uterus with the intent to establish a successful pregnancy. The first “test tube baby”, Louise Brown, was born in 1978.
In vitro fertilization (IVF) is a procedure in which eggs (ova) from a woman’s ovary are removed. They are fertilized with sperm in a laboratory procedure, and then the fertilized egg (embryo) is returned to the woman’s uterus.
The term in vitro, from the [Latin] root meaning within the glass, is used, because early biological experiments involving cultivation of tissues outside the living organism from which they came, were carried out in glass containers such as beakers, test tubes, or petri dishes. Today, the term in vitro is used to refer to any biological procedure that is performed outside the organism it would normally be occurring in, to distinguish it from an in vivo procedure, where the tissue remains inside the living organism within which it is normally found. A colloquial term for babies conceived as the result of IVF, test tube babies, refers to the tube-shaped containers of glass or plastic resin, called test tubes, that are commonly used in chemistry labs and biology labs. However, in vitro fertilisation is usually performed in the shallower containers called Petri dishes. (Petri-dishes may also be made of plastic resins.) However, the IVF method of Autologous Endometrial Coculture is actually performed on organic material, but is yet called in vitro. This is used when parents are having infertility problems or they want to have multiple births.
IVF has been used successfully since 1978, when the first child to be conceived by this method was born in England. Over the past 20 years, thousands of couples have used this method of ART or similar procedures to conceive.
Other types of assisted reproductive technologies might be used to achieve pregnancy. A procedure called intracytoplasmic sperm injection (ICSI) uses a manipulation technique that must be performed using 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).
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. 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 chances 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 attempted before IVF.
IVF will not work for a woman who is incapable of ovulating or with a man who is not able to produce at least a few healthy sperm.
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, a 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.
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 or 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.
After the IVF procedure is performed, the woman can resume normal activities. A pregnancy test can be done approximately 12–14 days after the procedure to determine if it was successful.
Risks Factors and Complications
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.
Forin vitrofertilization, hormones are administered to the patient, and then eggs are harvested from her ovaries (A). The eggs are fertilized by sperm donated by the father (B). Once the cells begin to divide, one or more embryos are placed into the woman’s uterus to develop (C). (Illustration by GGS Inc.)
is achieved, the pregnancy carries the same risks as any pregnancy achieved without assisted technology.
The major complication of IVF is the risk of multiple births. This is directly related to the practice of transferring multiple embryos at embryo transfer. Multiple births are related to increased risk of pregnancy loss, obstetrical complications, prematurity, and neonatal morbidity with the potential for long term damage. Strict limits on the number of embryos that may be transferred have been enacted in some countries (e.g., England) to reduce the risk of high-order multiples (triplets or more), but are not universally followed or accepted. Spontaneous splitting of embryos in the womb after transfer can occur, but this is rare and would lead to identical twins. A double blind, randomised study followed IVF pregnancies that resulted in 73 infants (33 boys and 40 girls) and reported that 8.7% of singleton infants and 54.2% of twins had a birth weight of < 2500 g. However recent evidence suggest that singleton offspring after IVF is at higher risk for lower birth weight for unknown reasons.
Another risk of ovarian stimulation is the development of ovarian hyperstimulation syndrome.
If the underlying infertility is related to abnormalities in spermatogenesis, it is plausible, but too early to examine that male offspring is at higher risk for sperm abnormalities.
The issue of birth defects has been a controversial topic in IVF. Many studies do not show a significant increase after use of IVF, and some studies suggest higher rates for ICSI, whereas others do not support this finding. In 2008, an analysis of the data of the National Birth Defects Study in the US found that certain birth defects were significantly more common in infants conceived with IVF, notably septal heart defects, cleft lip with or without cleft palate, esophageal atresia, and anorectal atresia; the mechanism of causality is unclear.
Japan’s government prohibited the use of in vitro fertilisation procedures for couples in which both partners are infected with HIV. Despite the fact that the ethics committees previously allowed the Ogikubo Hospital, located in Tokyo, to use in vitro fertilisation for couples with HIV, the Health, Labour and Welfare Ministry of Japan decided to block the practice. Hideji Hanabusa, the vice president of the Ogikubo Hospital, states that together with his colleagues, he managed to develop a method through which scientists are able to remove the AIDS virus from sperm.
Success rates vary widely among clinics and among 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.
Abnormal results include ectopic or multiple pregnancy that may abort spontaneously or that may require termination if the health of the mother is at risk.
Morbidity and Mortality Rates:
The most common cause of morbidity is ecotopic pregnancy. Pain is associated with most components of the procedure. Mortality as a result of IVF is extremely rare.
Other types of assisted reproductive technologies might be used to achieve pregnancy. A procedure called intracytoplasmic sperm injection (ICSI) utilizes a manipulation technique that must be performed using 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 in the uterus as with IVF
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