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in vitro fertilization
in vitro fertilization n (Medicine) a technique enabling some women who are unable to conceive to bear children. Egg cells removed from a woman's ovary are fertilized by sperm in vitro; some of the resulting fertilized egg cells are incubated until the blastocyst stage, which are then implanted into her uterus. Abbreviation: IVF in vi′tro fertiliza′tion
n. a technique by which an ovum is fertilized with sperm in a laboratory dish and subsequently implanted in a uterus for gestation. Abbr.: IVF [1970–75] Translationsin vitro fertilization
in vitro fertilization (vē`trō, vĭ`trō) (IVF), technique for conception of a human embryo outside the mother's body. Several ovaovum
, in biology, specialized plant or animal sex cell, also called the egg, or egg cell. It is the female sex cell, or female gamete; the male gamete is the sperm. The study of the ovum is included in the science of embryology.
..... Click the link for more information. , or eggs, are removed from the mother's body and placed in special laboratory culture dishes (Petri dishes); sperm from the father are then added, or in many cases a sperm is injected directly into an ovum, a process known as intracytoplasmic sperm injection. If fertilization is successful, a fertilized ovum (or several fertilized ova), after undergoing several cell divisions, is either transferred to the mother's or a surrogate mother's body for normal development in the uterus, or frozen for later implantation. Eggs also can be frozen and fertilized later. In vitro maturation is when the ova are extracted and then matured in a laboratory (instead of in the mother's body) before they are fertilized. First developed by Patrick C. Steptoe and Robert G. Edwards of Great Britain (where the first "test-tube baby" was born under their care in 1978), IVF was devised for use in cases of infertilityinfertility,
inability to conceive or carry a child to delivery. The term is usually limited to situations where the couple has had intercourse regularly for one year without using birth control.
..... Click the link for more information. when the woman's fallopian tubes are damaged or the man's sperm count is low. It is also used to enable prospective parents with other reproductive problems (e.g., inability to produce eggs, poor sperm quality, or endometriosisendometriosis
, a condition in which small pieces of the endometrium (the lining of the uterus) migrate to other places in the pelvic area. The endometrial fragments may move to the fallopian tubes, ovaries, or other pelvic structures (e.g., the bladder or rectum).
..... Click the link for more information. ) to bear a child, and can be used in conjunction with embryo screeningembryo screening,
procedure (see genetic testing) in which a single cell is removed from an embryo two or three days after it has been conceived through in vitro fertilization and tested for genetic abnormalities.
..... Click the link for more information. to enable parents to have a child who is free of some inheritable defects or diseases. Embryo screening procedures have also been used to identify embryos that are generally free of abnormalities and are not likely to result in a miscarriage after implantation, thus improving the likely success of IVF. So-called three-parent or three-person IVF has been used in cases where mitochrondia in the mother's egg have genetic defects that could be passed along to a child; a number of techniques can be used to replace the mother's mitochrondria, but all involve transferring nuclear genetic material from the mother's egg to a donor's egg from which that material has been removed. In embryo donation (also called embryo adoption), frozen embryos that are not needed by the mother are donated for implantation to a woman or couple who are infertile but wish to have, and are capable of bearing, children. By 2012 the use of in vitro fertilization had resulted in the birth of more than 5 million babies worldwide. Nevertheless, the technique has raised legal, ethical, and religious issues, including concerns regarding legal custody of frozen embryos following divorce and questions regarding the appropriateness of the procedure posed by the Roman Catholic Church and other institutions. See also artificial inseminationartificial insemination,
technique involving the artificial injection of sperm-containing semen from a male into a female to cause pregnancy. Artificial insemination is often used in animals to multiply the possible offspring of a prized animal and for the breeding of endangered
..... Click the link for more information. ; fertilizationfertilization,
in biology, process in the reproduction of both plants and animals, involving the union of two unlike sex cells (gametes), the sperm and the ovum, followed by the joining of their nuclei.
..... Click the link for more information. ; reproductive systemreproductive system,
in animals, the anatomical organs concerned with production of offspring. In humans and other mammals the female reproductive system produces the female reproductive cells (the eggs, or ova) and contains an organ in which development of the fetus takes
..... Click the link for more information. ; surrogate mothersurrogate mother,
a woman who agrees, usually by contract and for a fee, to bear a child for a couple who are childless because the wife is infertile or physically incapable of carrying a developing fetus.
..... Click the link for more information. . Bibliography See L. Andrews, The Clone Age (1999); R. M. Henig, Pandora's Baby (2004). in vitro fertilization
In Vitro Fertilization DefinitionIn 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.PurposeIVF 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 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.PrecautionsThe 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 throughout the process.DescriptionIn 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's ovaries using a long, thin needle. The physician gains 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. A 2004 study from the Mayo Clinic found that frozen sperm was as effective as fresh sperm for IVF.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).PreparationOnce 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.AftercareAfter 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.RisksThe 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.Normal resultsSuccess rates vary widely between clinics and between physicians performing the procedure and implantation does not guarantee pregnancy. Therefore, the procedure may have to be repeated more than once to achieve pregnancy. However, success rates have improved in recent years, up from 20% in 1995 to 27% in 2001.Abnormal resultsAn ectopic or multiple pregnancy may abort spontaneously or may require termination if the health of the mother is at risk. The number of multiple pregnancies has decreased in recent years as technical advances and professional guidelines have led to implanting of fewer embryos per attempt.ResourcesPeriodicals"Frozen, Fresh Sperm Both Effective for In Vitro Fertilization." Obesity, Fitness & Wellness Week June 5, 2004: 1059."Multiple Births Via In Vitro Fertilization Are Declining." Women's Health Weekly May 6, 2004: 16.OrganizationsAmerican Society for Reproductive Medicine. 1209 Montgomery Highway, Birmingham, AL 35216-2809. (205) 978-5000. 〈asrm@asrm.com〉 http://www.asrm.com.Center for Fertility and In Vitro Fertilization Loma Linda University. 11370 Anderson St., Loma Linda, CA 92354. (909) 796-4851. http://www.llu.edu/llumc/fertility.Resolve. 1310 Broadway, Somerville, MA 02144-1731. (617) 623-0744. http://www.resolve.org.Other"Infertility." HealthWorld Online Page. http://www.healthy.net."In vitro Fertilization: A Teacher's Guide from Newton's Apple." PBS Page. http://www.pbs.org/ktca/newtons/11/invitro.html.fertilization [fer″tĭ-lĭ-za´shun] in human reproduction, the process by which the male's sperm unites with the female's oocyte, creating a new life. The sex and other biologic traits of the new individual are determined by the combined genes and chromosomes that exist in the sperm and oocyte. See also conception and reproduction. Called also fecundation and impregnation.
After injection into the vagina, millions of sperm cells (spermatozoa) make use of their whiplike tails to swim through the cervix toward the uterus. Most are destroyed along the way by secretions in the vagina, but some reach the uterus and a few may enter the fallopian tubes. A very small number may survive as long as 48 hours. If during this period only one sperm succeeds in entering a fallopian tube and meeting there an oocyte ready to be fertilized, conception can occur. This event is possible only during a period of about 4 days of the month. After the sperm lodges in the oocyte, the tail disappears, but the head unites with the oocyte to form the zygote.in vitro fertilization the process by which conception takes place in a laboratory medium; the term literally means fertilization “in glass.” A lay term for the product of in vitro fertilization is “test tube baby.”
The treatment cycle involves the following steps: (1) Induction of ovulation with fertility drugs, such as clomiphene citrate, injectable follicle-stimulating hormone/luteinizing hormone, or both, to produce multiple ovarian follicles. When the largest follicle reaches 20 mm in diameter the patient is given an injection of human chorionic gonadotropin to induce expulsion of the oocyte from the follicle. (2) Laparoscopy and follicular aspiration for the harvesting of oocytes. (3) Maturation of retrieved oocytes and inoculation with the husband's or donor's sperm. (4) Incubation of the resulting embryos until they reach the two- to six-cell stage. (5) Transfer of an embryo via catheter into the patient's uterus; at this point intensive intervention ceases, the pregnancy is considered normal, and no further manipulation is required.in vivo fertilization union of the sperm and ovum within the reproductive tract of the female; usually taken to mean insemination" >artificial insemination in which the sperm is artificially introduced into the vagina, cervix, or uterine cavity to overcome the problem of infertility.in vit·ro fer·til·i·za·tion (IVF), a process whereby (usually multiple) ova are placed in a medium to which sperm are added for fertilization, the zygote thus produced then being introduced into the uterus with the objective of full-term development.in vitro fertilization Reproduction medicine A procedure that bypasses some causes of infertility, by removing eggs from the ovaries and fertilizing them ex vivo; the resulting early embryo is then transferred into the uterus via the cervix. See Assisted–'artificial' reproduction, Infertility, Surrogate motherhood, Test tube baby. in vi·tro fer·til·i·za·tion (IVF) (in vē'trō fĕr'til-ī-zā'shŭn) A process in which (usually multiple) oocytes are placed in a medium to which sperm are added for fertilization. The zygote thus produced is then introduced into the uterus and allowed to develop to term. in vitro fertilization Fertilization of an egg that has been withdrawn from the body, by sperms that have been obtained by masturbation. The procedure is done by adding semen to the eggs in a glass receptacle. A successfully fertilized ovum may then be artificially implanted into the womb (uterus) so that the pregnancy may continue. Fertilization can also be achieved by intracytoplasmic sperm injection. Recently cytoplasm containing known mitochondrial genetic defects has been eliminated by a process in which a fertilized nucleus is transferred into another ovum. Babies born from such a procedure can be said to have three parents.in vitro fertilization (IVF) a technique used in animal and human science, whereby an OVUM is fertilized with SPERM outside the body, before IMPLANTATION in the UTERUS. Freezing of the reproductive components, such as the ova, permits long-term storage in order for IVF to be carried out at a later date.See IVF
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