IVF and Infertility Definitions
Every travel guide requires a list of terms and phrases that are necessary to communicate along the way. This is true of the ART journey as well. Although we’ve gone to great lengths to minimize the terms that you’ll need to learn, we have provided this handy guide to make it easier to communicate with your medical team and the IVF community.
Assisted Reproductive Technology Glossary
acid tyrodes digestion A form of assisted hatching in which the embryo is introduced into a chemical solution that partially erodes the zona (egg covering) in order to promote hatching.
acrosome The protective structure around the head of the sperm. The acrosome contains enzymes that enable the sperm to penetrate the egg.
adenomyosis A condition in which the endometrial glands grow into the uterine wall, creating a sponge-like effect; can be associated with poor uterine linings. This condition is sometimes associated with heavy, painful periods and uterine enlargement.
antral follicle count (AFC) Ultrasound count of the number of small early follicles in a woman’s ovaries early in her cycle. Used to measure ovarian reserve.
Anti-Mullerian Hormone (AMH) A hormone measured early in a woman’s cycle to determine her ovarian reserve.
antiphospholipid antibodies (APA) Antibodies to some of the chemical substances that coat the root system of the placenta as it grows into the uterine wall. Women with high concentrations of these substances may have a higher incidence of miscarriages or may fail to conceive after repeated attempts.
antisperm antibodies Substances in the man’s or woman’s blood and in reproductive secretions (semen, uterine, tubal secretions, and cervical mucus) that reduce fertility by causing sperm to stick together, coating their surface or killing them.
assisted hatching A technique in which the zona pellucida (outer shell of the egg) is chemically or mechanically thinned prior to embryo transfer in order to improve the likelihood of subsequent hatching.
assisted reproductive technology (ART) Procedures involving retrieval of eggs and the enhancement of eggs and sperm outside the body. It includes procedures such as gamete intrafallopian transfer (GIFT), in vitro fertilization (IVF), and zygote intrafallopian transfer/tubal embryo transfer (ZIFT/TET).
autoantibodies Antibodies that are formed against the proteins of the individual’s own body.
blastocyst An advanced stage of embryo development during which a cavity develops within the young embryo.
blastomere Cell within the developing embryo. Each blastomere is capable of developing into an identical embryo until the embryo reaches about the 30 cell stage, after which the cells begin to differentiate into specific tissues.
capacitation The process by which sperm are prepared for fertilization as they pass through the woman’s reproductive tract (in vivo capacitation); sperm may also be capacitated in the laboratory (in vitro capacitation).
cervical canal The connection between the outer cervical opening and the uterine cavity.
cervical mucus Mucus produced by glands in the cervical canal; it plays an important role in transporting sperm into the uterus and in initiating capacitation.
cervix Lowermost part of the uterus, which protrudes like a bottleneck into the upper vagina; the cervix opens into the uterus through the narrow cervical canal.
chemical pregnancy Biochemical evidence of a possible developing pregnancy based on a positive blood or urine pregnancy test; at this point, pregnancy is presumptive until confirmed by ultrasound (see also clinical pregnancy).
Chlamydia Bacteria responsible for a sexually transmitted infection that may damage the fallopian tubes and/or the male reproductive ducts, thereby causing infertility.
chromosomes Structures in the nuclei of cells, such as the egg and sperm, on which the hereditary or genetic material is arrayed.
cleavage The process of cell division.
climacteric The hormonal change that precedes the menopause by a number of years and is associated with a progressive loss of fertility, an increased incidence of abnormal or absent ovulation, hot flashes, irregular menstruation, a progressive rise in blood FSH and LH levels and mood changes. The climacteric usually represents an important stage in a woman’s life.
clinical pregnancy A pregnancy that has been confirmed by ultrasonic examination or through pathologic assessment of a surgical specimen obtained either from a miscarriage or from an ectopic pregnancy. A clinical pregnancy should be distinguished from a chemical pregnancy, which through a positive blood pregnancy test merely suggests the possibility that a pregnancy has occurred.
clomiphene citrate A synthetic hormone that is used alone or in combination with other fertility drugs to induce the ovulation of more than one egg. When marketed in the United States, Clomiphene citrate is also known as Clomid or Serophene.
comparative genomic hybridization (CGH) A genetic test that evaluates a cell for all of its chromosomes (full karyotyping).
conception Creation of a zygote by the fertilization of an egg by a sperm.
conceptus A term used to describe the developing implanted embryo and/or early fetus.
controlled ovarian hyperstimulation (COH) In response to the administration of fertility drugs, the maturation of several follicles simultaneously, which results in the production of an exaggerated hormonal response.
corpus luteum A term for a follicle after an egg has been extruded. After ovulation, the follicle collapses, turns yellow, and is transformed biochemical and hormonally. The corpus luteum produces progesterone and estrogen, and has a life span of about 10 to 14 days, after which it dies unless a pregnancy occurs. If the woman becomes pregnant, the life span of the corpus luteum is prolonged for many weeks. A synonym for the corpus luteum is the yellow body.
cryopreservation The process of freezing (in liquid nitrogen) and storing eggs, sperm, and embryos for future use.
diethylstilbestrol(DES) A drug previously taken by women during pregnancy that may cause infertility and/or pathologic conditions in the reproductive tracts of both male and female offspring.
diagnostic hysteroscopy A procedure usually performed under local or general anesthesia in the office setting or in the operating room. A thin telescope like instrument is inserted via the vagina and cervix into the uterine cavity. Carbon dioxide gas or a liquid is injected to distend the cavity and allow direct visualization of its structure.
ectopic pregnancy A pregnancy that occurs when the embryo implants in a location other than the uterus; the most likely site for such implantation is the fallopian tube (in which case the term ectopic pregnancy is used synonymously with tubal pregnancy). If undetected, an ectopic pregnancy may rupture and cause life threatening internal bleeding. Ectopic pregnancies almost always require surgical intervention.
egg The female gamete, which develops in the ovary; also known as an egg or oocyte. An egg is the largest cell in the human body.
egg retrieval The retrieval of eggs from the ovarian follicles prior to ovulation; the eggs are aspirated from the follicles through a needle either during ultrasound guidance or laparoscopy.
embryo The term for a fertilized egg from the time of initial cell division through the first six to eight weeks of gestation. Thereafter, the embryo begins to differentiate and take on a human organic form; at this point it is traditionally referred to as a fetus.
embryo adoption The donation of an embryo by the original intended parents to another person/couple to aid in conception through IVF. This generally occurs when the original intended parents have completed their family and have remaining embryos frozen, or when they have decided not to continue pursuing parenthood through IVF (in the case of medical issues that preclude it, a successful adoption, etc.).
embryo co-culturing The addition of cells derived from the growth of other tissue (from the lining of human or bovine fallopian tubes, or human follicular lining) to the culture medium in which the zygote is being nurtured in the laboratory. This is thought to enhance growth and promote the development of healthier embryos.
embryo transfer The process whereby embryos that have been grown in vitro are transferred into the uterus.
endometriosis A condition in which the endometrium grows outside the uterus, causing scarring, pain, and heavy bleeding, and often damaging the fallopian tubes and ovaries in the process. Endometriosis is a common organic cause of infertility.
endometrium The lining of the uterus, which grows during the menstrual cycle under the influence of estrogen and progesterone. The endometrium grows in anticipation of nurturing an implanting embryo in the event of a pregnancy; it sloughs off in the form of menstruation if implantation does not occur.
epididymis Tubular reservoir that contains and transfers sperm to the vas deferens and subsequently through the urethra and penis at the time of ejaculation.
estradiol (E2) A female hormone produced by ovarian follicles. The concentration of estrogen in the woman’s blood is often measured to determine the degree of her response to controlled ovarian hyperstimulation with fertility drugs. In general, the higher the estradiol response, the more follicles are likely to be developing and, accordingly, the more eggs are likely to be retrieved.
estradiol valerate A preparation of natural estradiol taken orally or by injection.
estrogen A primary female sex hormone, produced by the ovaries, placenta, and adrenal glands. fallopian tubes Narrow, 4 inch long structures that lead from either side of the uterus to the ovaries.
falloposcopy A procedure performed at the time of laparoscopy or hysteroscopy, in which a thin telescope like instrument is introduced into the fallopian tube to evaluate its condition.
fertility drugs Natural or synthetic hormones that are administered to a woman to stimulate her ovaries to produce as many mature eggs as possible, or to a man to enhance sperm function or production.
fertility preservation (FP) Preserving a woman’s fertility by banking her eggs or embryos for later use. fertilization The fusion of the sperm and egg to form a zygote (See also zygote, conception).
fetus Once the embryo differentiates and begins to take on identifiable humanlike organic form, it is termed a fetus; the fetal stage of development usually begins around the eighth week of pregnancy.
fibroid tumor A benign tumor in the uterus, which may prevent the embryo from properly implanting into the endometrium or cause pain, bleeding, miscarriage, and symptomatic enlargement of the uterus.
fibrous Scar tissue that may distort the interior of the uterus and prevent the embryo from implanting properly.
fimbriae Fingerlike protrusions from the ends of the fallopian tubes that retrieve the egg or eggs at the time of ovulation.
fluid ultrasonography (FUS) A procedure whereby saline is injected via the cervix into the uterus, allowing ultrasound evaluation of the uterine cavity and fallopian tubes.
follicles Blister-like structures within the ovary that contain eggs and that produce female sex hormones.
follicle stimulating hormone (FSH) A gonadotropin that is released by the pituitary gland to stimulate the ovaries or testicles. FSH, when marketed in the United States, is also known as Follistim, Gonal-F or Bravelle follicular phase insufficiency or defect An abnormal pattern of estrogen production.
menstrual cycle, which could result in infertility or recurrent miscarriages.
follicular phase of the menstrual cycle See proliferative phase of the menstrual cycle.
gamete The female egg and the male sperm.
gastrulation The stage of embryonic development in which blastomeres are dedicated to the development of specific organs and structures.
gestational surrogacy The performance of in vitro fertilization using the prospective parents’ gametes and the subsequent transfer of the embryos into the uterus of a third party who thereupon would carry the baby to term.
gonadotropin releasing hormone agonists (GnRHa) GnRH like hormones that cause the release of virtually all FSH and LH production by the pituitary gland, GnRH agonists cause FSH and LH blood levels to fall to very low levels. In the United States, GnRH agonists are also known as Lupron, Synarel, and Nafarelin.
gonadotropin releasing hormone antagonists Hormones that block the release of both FSH and LH by the pituitary gland, causing blood levels of FSH and LH to drop to very low concentrations. In the United States, GnRH Antagonists are sold under the names Ganirelix and Cetrotide.
gonadotropin releasing hormone (GnRH) A “messenger hormone” released by the hypothalamus to influence the production of gonadotropins by the pituitary gland.
gonadotropins The gonad stimulating hormones LH and FSH, which are released by the pituitary gland to stimulate the testicles in the man and the ovaries in the woman.
gonads The ovaries and testicles.
gonococcus A bacterium producing gonorrhea, a common venereal disease occurring in both men and women that may cause sterility.
heparin A drug that may be added to the solution used to flush eggs out of ovarian follicles during egg retrieval; its purpose is to prevent blood clotting within the fluid that harbors the egg.
human chorionic gonadotropin (hCG) A hormone, produced by the implanting embryo (and subsequently also by the placenta), whose presence in the woman’s blood indicates a possible pregnancy; hCG may also be administered to women undergoing stimulation with HMG alone or in combination with other fertility drugs in order to trigger ovulation. Injections of hCG may also be administered to encourage the production of progesterone by the corpus luteum in the hope of promoting implantation following embryo transfer and thereby reducing the incidence of spontaneous miscarriage in a pregnancy resulting from IVF. The hormone hCG is derived from the urine of pregnant women.
hysterosalpingogram (HSG) A procedure used to assess the interior of the fallopian tubes and uterus; it involves injecting a dye into the uterus via the vagina and cervix, and tracking the dye’s pathway by a series of X-rays.
hysteroscope A lighted, telescope like instrument that is passed through the cervix into the uterus, enabling the surgeon to examine the cervical canal and the inside of the uterus for defects or disease.
hysteroscopy Examination of the cervical canal and inside of the uterus for defects, by means of the hysteroscope. Surgery designed to correct such defects can be performed through the hysteroscope during this procedure, thereby often making more invasive abdominal surgery unnecessary.
implantation The process that occurs when the embryo burrows into the endometrium and eventually connects to the mother’s circulatory system.
inclusive pregnancy rates Pregnancy success reports that combine rates for both clinical and chemical pregnancies and do not distinguish between the two.
infertility The inability to conceive after one full year of normal, regular heterosexual intercourse without the use of contraception.
Inhibin B A hormone measured in the woman’s blood to measure her ovarian reserve.
insemination In the laboratory, the addition of a drop or two of the medium containing capacitated sperm to a Petri dish containing the egg in order to achieve fertilization. Also refers to placement of sperm into the woman’s reproductive tract.
insemination medium A liquid that bathes and nourishes the eggs and embryos in the Petri dish just as the mother’s body fluids sustain them in nature.
Intracytoplasmic sperm injection (ICSI) A form of micromanipulation whereby a single sperm is captured in a thin glass needle and injected directly into the ooplasm of the egg. Usually used to assist fertilization in couples suffering from severe sperm dysfunction.
intrauterine insemination (IUI) The injection of sperm, processed in the laboratory, into the uterus by means of a catheter directed through the cervix; enables sperm to reach and fertilize the egg more easily or to bypass hostile cervical mucus.
intravaginal insemination (IVI) The injection of semen (usually donor semen) into the vagina in direct proximity to the cervix in the hope that pregnancy will occur.
in vitro fertilization (IVF or IVF/ET) Literally “fertilization in glass,” IVF comprises several basic steps: the woman is given fertility drugs that stimulate her ovaries to produce a number of mature eggs; at the proper time, the eggs are retrieved by suction through a needle that has been inserted into her ovaries; the eggs are fertilized in a glass Petri dish, or in a test tube, in the laboratory with her partner’s or donor sperm, and subsequently the embryos are transferred into the body.
IVF surrogacy Synonym for gestational surrogacy.
laparoscope A long, thin telescope like instrument containing a high intensity light source and a system of lenses that enables the surgeon to examine the abdominal/pelvic cavity and to perform other diagnostic or surgical procedures under direct vision without necessitating major surgery.
laparoscopy A surgical procedure using the laparoscope. to enable the physician to assess tubal patency and visualize the abdominal cavity and perform surgical procedures if needed.
laparotomy A procedure in which an incision is made in the abdomen to expose the abdominal contents for diagnosis or surgery.
LH serial blood tests When this test is performed several times daily around the presumed time of ovulation, the detection of a rapidly rising blood LH (luteinizing hormone) concentration can accurately determine the time of probable ovulation. This test, which requires blood to be drawn several times and is therefore painful, time consuming, and expensive, has been virtually supplanted by serial urine LH testing.
luteal phase insufficiency or defect The inadequate production of hormones during the second phase of the menstrual cycle, which may result in infertility or miscarriage.
luteinizing hormone (LH) A gonadotropin released by the pituitary gland to stimulate the ovaries and testicles.
macrophages Cells of the immune system that destroy invading organisms or foreign proteins.
menopause The period of a woman’s life that begins with the total cessation of menstruation, usually between the ages of 40 and 55.
menstrual cycle The time that elapses between menstrual periods. The average cycle is 28 days, with ovulation usually occurring at the midpoint (around the 14th day).
menstruation The monthly flow of blood when pregnancy does not occur; the flow comprises about two thirds of the endometrium and blood.
miscarriage Spontaneous expulsion of the products of conception from the uterus in the first half of pregnancy.
morula An early phase during which the developing embryo, which contains a large number of blastomeres, and resembles a mulberry.
motility (sperm motility) The ability of sperm to move and progress forward through the reproductive tract and fertilize the egg; sperm motility can be assessed microscopically.
multiple pregnancy The presence of more than one gestation within the woman’s reproductive tract at the same time.
ooplasm The cytoplasm inside the egg.
operative laparoscope A laparoscope that has been modified to allow passage of a double bore needle or surgical instruments through a groove or sleeve adjacent to the instrument (see also laparoscope).
outcome-based reimbursement (OBR) A financial plan whereby full payment for IVF is only made in the event of a baby being born following the transfer of all embryos (over one or more months of treatment).
ovarian stroma The ovarian tissue surrounding the follicles that produces hormones.
ovaries Two white, almond sized structures, the female counterpart of the testicles that are attached to each side of the pelvis adjacent to the ends of the fallopian tubes; the ovaries both release eggs and discharge sex hormones into the bloodstream.
ovulation The process by which an ovary releases one or more eggs.
peritoneal cavity The abdominal cavity that contains pelvic organs, bowel, stomach, liver, kidneys, adrenal glands, Spleen, and so on, and is lined by a membrane called the peritoneum.
phrenic nerve A nerve that may be irritated by trapped gas or blood during laparoscopy or following internal bleeding, resulting in subsequent pain in the shoulder, arm, and neck (most commonly on the right side).
pituitary gland A small, grape-like structure hanging from the base of the brain that, together with the hypothalamus, produces and regulates the release of many hormones in the body.
placenta The uterine factory that nourishes the fetus throughout pregnancy and is connected to the baby’s navel via the umbilical cord.
placentation Formation and attachment of the placenta to the uterine wall.
polycystic ovarian syndrome (PCOS) Condition in which the ovaries develop multiple small cysts; it is often associated with abnormal or absent ovulation and, accordingly, with infertility.
polyps (uterine) Outgrowths that protrude into the uterus and may cause pain and bleeding or prevent an embryo from implanting.
postcoital test (PCT) Assessment of the cervical mucus after intercourse to evaluate the quality of the mucus and mucus sperm interaction; also known as the Huhner Test.
preimplantation genetic diagnosis (PGD) A new diagnostic technology involving chromosome and genetic assessment of the embryo in order to determine its health and potential to develop into a healthy offspring. A procedure currently used to determine the sex of the embryo and to diagnose a variety of genetic disorders.
progesterone A primary female sex hormone produced by the corpus luteum that induces secretory changes in the glands of the endometrium. Progesterone may also be given by injection or in the form of vaginal suppositories to enhance implantation and reduce the risk of miscarriage.
progesterone blood hormone test Measuring of the concentration of progesterone in the woman’s blood during the second half of the menstrual cycle about one week prior to anticipated menstruation; indicates whether or not she is likely to have ovulated because progesterone is usually produced only by the corpus luteum, which develops after ovulation.
prolactin A hormone produced by the brain that may influence the activity of FSH on the ovaries.
prolonged coasting The discontinuation of hMG/FSH medication and deferring hCG administration for a number of days, while continuing GnRH agonist therapy in cases where severe ovarian hyperstimulation occurs following COH.
prostate gland Gland in the male reproductive tract that secretes a milky substance that nurtures and promotes survival of sperm. The combination of sperm and milky fluid that is ejaculated during erotic experiences is known as semen.
quantitative beta hCG blood pregnancy test A test that detects and measures the amount of hCG produced by an implanting embryo) in the woman’s blood. Measured nine to 11 days after embryo transfer, it can diagnose a possible pregnancy before the woman has missed a menstrual period.
salpingostomy A form of tubal surgery in which the end of the fallopian tube(s) is opened at the time of aparoscopy or laparotomy, using small surgical stitches or a laser.
scrotum Pouch in which the male’s testicles are suspended outside the body.
selective reduction of pregnancy Prior to completion of the third month of pregnancy, reduction of the number of fetuses in a large multiple pregnancy by injecting a chemical substance under ultrasound guidance; the fetus or fetuses succumb almost immediately and are absorbed by the body. It may be considered a life saving measure for the remaining fetuses in high multiple pregnancies such as quadruplets, quintuplets, or greater, and may reduce the risk of high multiple pregnancies.
semen The combination of sperm, seminal fluid, and other male reproductive secretions.
Society for Assisted Reproductive Technology (SART) Affiliated with the American Society for Reproductive Medicine, SART provides information about IVF programs and compiles a registry of audited IVF results from participating programs.
Sonohysterogram (also called fluid ultrasound examination [FUS]) A procedure whereby a liquid is injected via the cervix into the uterus, allowing ultrasound evaluation of the uterine cavity and fallopian tubes.
sperm The male gamete; spermatozoa.
sperm antibody test A test that determines whether either partner’s blood or the woman’s cervical mucus contains antibodies to sperm.
sperm count A basic fertility assessment test of sperm function, primarily involving counting the number of sperm, assessing their motility and progression, and evaluating their overall structure and form.
Sperm DNA integrity Assay (SDIA) A test that detects occult sperm dysfunction.
Staggered IVF (St-IVF) A form of IVF which involves separating the cycle in which ovarian stimulation and egg retrieval is performed from a later cycle where the ET is performed (days, weeks, months or years later). More on Staggered IVF.
stimulation Induction of the development of a number of follicles in response to the administration of fertility drugs.
surrogacy Situation in which an infertile woman uses someone else’s uterus to carry a child to term for her. Surrogacy can be divided into (1) cases in which the surrogate mother contributes biologically to the offspring by providing her own eggs (classic surrogacy), and (2) cases in which the surrogate does not contribute biologically and therefore must undergo IVF (gestational surrogacy).
syphilis A life endangering venereal disease that in its late stages attacks most systems in the body, including the cardiovascular and central nervous systems.
testicles The male counterparts of the female ovaries; located in the scrotum, the testicles produce sperm and male hormones such as testosterone.
testicular sperm extraction (TESE) A procedure performed on an outpatient basis (usually under local anesthesia) where one or more hair-thin tissue biopsy specimens are removed from the testicle and delivered to the embryology laboratory for sperm to be removed for ICSI.
testosterone The predominant male sex hormone, which influences the production and maturation of sperm.
thyroid stimulating hormone (TSH) A hormone produced by the pituitary gland that stimulates the release of thyroid hormone by the thyroid gland.
transcervical Refers to the physiological or surgical pathway whereby secretions, organisms, sperm, or surgical instrumentation passes from the vagina into the uterus.
transmyometrial embryo transfer A procedure that transfers embryos to the uterus via a needle and/or catheter introduced through the uterine wall (myometrium) rather than through the cervix. It is used in situations where severe narrowing of the cervix negates the performance of conventional embryo transfer.
transvaginal egg retrieval An ultrasound guided egg retrieval procedure in which the needle is passed through the back or side of the woman’s vagina into her ovaries. It is the most commonly performed egg retrieval procedure today.
treatment cycle The menstrual cycle during which a particular fertility treatment such as IVF, IUI, AID, GIFT, etc. was performed.
tubal reanastomosis A surgical procedure in which the fallopian tubes are reconnected, reestablishing patency. Usually performed after a previous tubal ligation (sterilization). Also referred to as a tubal ligation reversal or simply a tubal reversal.
unexplained infertility Infertility whose cause cannot be readily determined by conventional diagnostic procedures; this occurs in about 10% of all infertile couples.
ureaplasma A microorganism that occurs in the reproductive tracts of males and females, and might interfere with sperm transport and/or embryo implantation. It might also be responsible for early miscarriages.
uterus A muscular organ that enlarges during pregnancy from its normal pear-like size to accommodate a full term pregnancy.
varicocele A collection of dilated veins around the testicles that hinders sperm function, possibly through increasing the temperature in the scrotum.
vas deferens Tube that connects the epididymis with the urethra in the male reproductive tract.
vitrification An ultrarapid freezing method of eggs and embryos that is far more effective at preserving egg viability than previous “conventional” (slow freezing) cryopreservation methods.
vasectomy Surgery to block the male’s sperm ducts for the purpose of birth control.
vulva The external portion of the female reproductive tract.
washing (sperm washing) The processing of a semen specimen in a centrifuge in order to separate the sperm cells from the seminal fluid.
zona pellucida The shell like covering of the human egg.
zygote The term for a fertilized egg until it begins to cleave, at which time it is known as an embryo.