Welcome to this glossary of terms in reproductive medicine
The glossary has been provided by Dr Carl A. Laskin, Co-Medical Director, LifeQuest Centre for Reproductive Medicine, Toronto, Ontario, Canada. Additional support was provided by Christine Clark, Karen Spitzer and Randy Rosenstein.
Use the alphabetical menu links to explore the glossary.
Retained products of conception in utero. Often requires a dilatation and curettage (D&C) to remove tissue from the uterus
A loss of pregnancy during the first trimester. See also Spontaneous miscarriage.
A pregnancy at risk of spontaneously aborting. Symptoms are cramping, spotting or bleeding during pregnancy. See also Threatened miscarriage.
Scar tissue which if found in the pelvic cavity may obstruct or impair implantation of the embryo in the uterus. Usually forms as a result of infection, endometriosis or surgery.
A hormone that stimulates cortisol secretion by the adrenal glands.
Act of sperm clumping together, often in response to anti-sperm antibodies.
A drug that bonds to a cell receptor and triggers a response by that cell.
A glycoprotein derived from fetal liver and partially from the yolk sac. High levels of AFP in the maternal circulation are associated with abnormalities in the fetus such as neural tube defects, intestinal obstruction, omphalocele and congenital nephrosis. Multiple pregnancies will also lead to elevated levels of AFP.
Lack of menstruation for 6 months or more.
A prenatal diagnostic test performed at 16-20 weeks’ gestation in which a small volume of amniotic fluid containing fetal cells is removed by needle aspiration from the amniotic sac. Fetal DNA is then examined for genetic abnormalities.
Sex hormones produced mainly by the adrenal gland which are present in much higher concentrations in men than women and are responsible for the development and maintenance of male sex characteristics. The major androgen is testosterone. An excessive amount of these hormones in women, defined as hyperandrogenism , can cause hirsutism, amenorrhea and infertility characteristic of the polycystic ovarian syndrome (PCOS).
Any deviation from the exact multiple of the haploid number of chromosomes.
Responsible for the growth, differentiation and maintenance of blood vessels.
The total absence of ovulation. Menses may still occur.
A compound which binds with the receptor of a hormone or a mediator and acts against or blocks its action.
Produced by the male fetus, this hormone inhibits development of the uterus, vagina, cervix and oviducts. In women, AMH is produced by the preantral and early antral follicles. AMH is gaining acceptance as a measure of ovarian reserve in women with infertility.
Antibodies directed against sperm which may agglutinate and destroy these cells. Both men and women can produce anti-sperm antibodies
Antibodies directed against sperm which may agglutinate and destroy these cells. Both men and women can produce anti-sperm antibodies.
Family of antibodies that includes the lupus anticoagulant (LAC) and anticardiolipin (aCL). Such antibodies may contribute to recurrent pregnancy loss.
The number of follicles in the ovary at the start of the menstrual cycle. This is used as a measure of ovarian reserve and as an indicator of responsiveness to superovulation.
Deposition of sperm in the vagina near the cervix, often used in combination with pharmaceutical ovarian stimulation to improve timing and conditions for gamete interactions. See also Intrauterine insemination (IUI) and Donor insemination (DI).
Intrauterine adhesions that typically occur after uterine surgery.
An in vitro procedure in which the zona pellucida of an embryo is perforated by chemical, mechanical, or laser-assisted methods to assist separation of the blastocyst from the zona pellucida.
An umbrella term that refers to techniques, procedures and treatments (including in vitro fertilization; gamete and embryo cryopreservation; ovum, sperm or embryo donation, and surrogacy) performed to help a woman achieve pregnancy.
Low sperm motility.
The absence of sperm in the seminal fluid. This may be due to a blockage or an impairment of sperm production.
The core body temperature. Normal body temperatures can range from 35.6 C° (96°F) to 36.7 C° (98°F) but will increase by half to one full degree when a woman ovulates.
A hormone produced by a pregnancy. Measurement of ßhCG is the blood test used to determine the presence of a viable pregnancy and follow early embryo development.
Thin-walled hollow structure in early embryonic development before implantation; the embryo consists of a cluster of cells at one side.
One of the cells produced by cleavage of a fertilized ovum.
A fertilized ovum that fails to survive after implantation in the uterus.
Produced by the immune system of a pregnant woman to block the foreign antigens on the developing embryo, thereby preventing “rejection” of the pregnancy.
A gonadotropin-releasing hormone (GnRH) agonist.
An ART cycle in which ovarian stimulation or monitoring has been carried out with the intent of undergoing ART but which did not proceed to follicular aspiration or, in the case of a thawed embryo, to transfer.
The change that sperm cells undergo as they travel through the woman's reproductive tract, enabling the sperm to penetrate the oocyte.
Secretions produced by the cervix, which vary in viscosity according to the phase of the menstrual cycle, and become penetrable by sperm in the days preceding ovulation.
A sample of the cervical mucus examined microscopically to assess the presence of estrogen and white blood cells, indicating possible infection.
A stricture or scarring of the cervical canal.
See gonadotropin releasing hormone antagonist.
A ßhCG level in the blood, suggestive of a pregnancy, that fails to continue to rise and does not lead to a clinical pregnancy
A microorganism that may be transmitted by sexual contact. Chlamydia can exist in the reproductive tract without symptoms and may cause infertility. If present, both partners must be treated. The test for chlamydia involves obtaining a sample of cervical cells (similar to a pap smear).
A prenatal test that detects chromosomal abnormalities such as Down's syndrome by examination of placental tissue that is removed by a needle inserted through the abdomen into the placenta. Its main advantage over amniocentesis is that it can be performed earlier - between the 10th and 12th weeks of pregnancy.
The division of a fertilized ovum. The embryo size remains unchanged; the cleavage cells become smaller with each division.
Clinical evidence of pregnancy including increasing ßhCG levels and either an ultrasound examination showing an intrauterine gestational sac or in cases of abnormal pregnancies, examination of tissue confirming an ectopic pregnancy or miscarriage.
A fertility drug that stimulates ovulation through the release of gonadotropins from the pituitary gland.
Sexual intercourse.
A technique used in pre-implantation genetic diagnosis (PGD).
Medical treatment to induce the development of multiple ovarian follicles to obtain multiple oocytes at follicular aspiration.
The special gland that forms on the ovary at the site of the released oocyte and produces the hormone progesterone during the second half of the menstrual cycle. If pregnancy occurs, the corpus luteum persists and produces the progesterone necessary to support pregnancy.
Freezing embryos, ova or sperm in liquid nitrogen to keep them viable.
'Hidden testis'. Occurs when a testis is abnormally positioned high in the scrotum, often elevated into the abdomen
An androgenic hormone produced by the adrenal gland in both sexes.
The number of deliveries expressed per 100 initiated cycles, aspiration cycles, or embryo transfer cycles. The denominator (initiated, aspirated, or embryo transfer cycles) must be specified. It includes deliveries that resulted in a live birth and/or stillbirth.
A procedure whereby the cervix is dilated and the uterine lining is scraped to remove fetal tissue, polyps or fibroids, and for diagnostic purposes.
Ova that are removed from the ovaries of one woman for use by another.
Deposition in the vagina near the cervix of sperm from a donor other than the partner. The sperm may also be deposited intrauterine. Often used in combination with pharmaceutical ovarian stimulation to improve timing and conditions for gamete interactions.
Sperm collected from a man who is not the woman's partner, to be used for insemination. The sperm is usually obtained in a frozen state from a commercial sperm bank.
Abnormal pain during menstruation.
Difficult or painful intercourse.
An embryo implanting and developing outside the uterus, usually in a fallopian tube, on an ovary, or in the abdominal cavity.
Surgical removal of an ovum from one woman for in vitro fertilization (IVF). The resulting embryo is then transfered into another woman.
A surgical procedure to obtain ova from follicles in the uterus for use in IVF. Usually involves ultrasound and a small needle passed though the vaginal wall.
The seminal fluid and sperm released through the penis during orgasm.
When an oocyte and sperm join together, they create an embryo which may develop into a fetus.
A procedure during which an embryo is placed into the uterus after IVF with the goal of implantation and pregnancy.
A procedure whereby a small sample of the uterine lining is removed and sent to pathology for microscopic evaluation.
Growth of endometrial tissue outside the uterus (e.g. peritoneum, bowel surface, etc.) causing irritation, pain, adhesions, infertility and other pelvic abnormalities.
A narrow, convoluted tube responsible for the maturation of sperm prior to ejaculation, connecting the efferent ducts from the rear of each testicle to its vas deferens.
The repeated inability to get or keep an erection firm enough for sexual intercourse. Sometimes used interchangeably with impotence, even if the latter is a more comprehensive definition.
The generic term for the primary steroid hormones produced by the ovaries from puberty to menopause.
Either of a pair of tubes that conduct ova from the ovary to the uterus. Normal fertilization takes place within this structure.
The probability of achieving a pregnancy within one menstrual cycle.
The capacity of a man, woman or couple to achieve a pregnancy within one menstrual cycle, which results in a live birth.
The process during which a sperm penetrates an oocyte, fusion of genetic material occurs, and an embryo develops.
The developing human organism after the embryo stage from the 9th week of pregnancy to the moment of birth.
A non-cancerous smooth muscle tumor found within the wall of the uterus. Also known as a myoma.
The delicate ends of the fallopian tubes that help pick up the released oocyte from the ovary.
A cyto-genetic technique used to detect chromosomal abnormalities. Fluorescent-stained probes are used to identify the presence or absence of specific DNA sequences on chromosomes. Used in pre-implantation genetic diagnosis (PGD). Often used for pre-natal genetic counseling when a specific disease may be carried by a parent.
Fluid-filled structure in the ovary which contains the oocyte and from which the oocyte is released at ovulation or retrieved during the treatment cycle.
Hormone secreted by the pituitary gland responsible for stimulating follicular development during the first half of the menstrual cycle. Pharmaceutical forms of FSH (both urinary and recombinant) are used in ovarian stimulation cycles.
Fluid inside the follicle that cushions and nourishes the ovum.
The first half (pre-ovulation) portion of the woman's menstrual cycle. Marked by growth of the endometrial lining of the uterus, maturing of ova in follicles and elevated estrogen levels.
A reproductive cell, either a sperm or oocyte/ovum.
A procedure similar to IVF except that washed sperm and harvested ova are placed inside a catheter, separated by an air bubble, and then transferred inside a woman's fallopian tube, where fertilization takes place. This can be done only in women with at least one normal tube and requires a laparoscopy. It is now rarely used as pregnancy rates with IVF are the same or higher, and with the latter no laparoscopy is required.
A woman who carries a pregnancy to term for a couple. The embryo formed from the ovum and sperm of the couple who are the intended parents. The carrier has no genetic relation to the child.
Molecules located on the cell membrane that bind gonadotropins and activate the cell’s response. The variability in gonadotropin receptors, on a genetic basis, influences reproductive function physiology and response to ovarian stimulation in ART.
A hormone released from the hypothalamus that controls the synthesis and release of the pituitary hormones FSH and LH that stimulate the ovaries.
Synthetic compounds that interact with the GnRH receptor to stimulate the release of FSH and LH from the pituitary gland. Usually administered to control ovarian stimulation during IVF cycles. When administered over a 10-14 day period, GnRH agonists lead to the shedding of the GnRH receptors on the pituitary gland, thereby preventing spontaneous ovulation. This is essential during an IVF cycle to ensure harvesting of the oocytes from the unruptured follicles. Examples include leuprolide and buserilin.
Synthetic compounds that compete with natural GnRH and block the release of LH and FSH. Typically administered mid-luteal phase to prevent LH surge and endogenous ovulation as well as preventing arrest of follicle maturation and asynchrony of maturation. They act within a few hours of administration and can therefore be used only when there is a risk of LH surge. Examples include ganirelix and cetrorelix.
Presence of excessive body and/or facial hair, commonly observed in women with polycystic ovarian syndrome (PCOS).
A combination of estrogen and progesterone for the alleviation of menopausal symptoms.
A hormone that is produced in early pregnancy to keep the corpus luteum producing progesterone. The presence of the beta subunit (beta-hCG) in the blood or urine indicates a positive pregnancy test. Administration of pharmaceutical preparations of hCG, (either urinary or recombinant) in infertility treatment during a stimulated cycle, triggers ovulation and enhances the production of progesterone.
Their presence indicates exposure to HIV. Both partners are often screened for these antibodies as part of a routine infertility, pre-pregnancy work-up.
Also called menotropin, it is a pharmaceutical product containing human FSH and LH. It is extracted from the urine of post-menopausal women. HMG is used for ovarian stimulation cycles. Highly purified preparations of HMG have been introduced to reduce presence and effects of urine-derived proteins not associated with the gonadotropins.
A swelling in the testes containing fluid.
A disorder affecting men and women that can lead to infertility. It is caused by a lack of GnRH and therefore a lack of sex hormones with subsequent deficiency of gametogenesis.
Low sperm production.
Surgical removal of the uterus.
An x-ray procedure during which a contrast medium is introduced into the uterus through the cervix and passed through the fallopian tubes to determine if they are open. This also shows the configuration of the uterus (any irregularities, fibroids, etc).
Minimally invasive fiber optic visualization of the inside of the uterus through the cervix with a video-endoscope to evaluate and treat abnormalities inside the uterine cavity.
The term used when no reason can be found to explain the cause of a couple's infertility.
The embedding of the embryo in the endometrium or lining of the uterus.
A comprehensive term which defines the inability of a male to have intercourse. It can be induced by both physical and psychological etiologies and causes infertility.
A procedure during which an oocyte is removed from a mature follicle and fertilized by sperm in the laboratory, then transferred to the uterus after developing to an appropriate stage in an incubator over 3-5 days. It is the treatment of choice for women with blocked, severely damaged or absent fallopian tubes. It is also indicated in cases of endometriosis and male factor infertility, and for longstanding or unexplained infertility when other treatments have failed.
A weakened cervix with an inability to stay closed for the duration of the pregnancy; a frequent cause of prematurity.
A condition defined as: inability to conceive or carry a pregnancy to term after one year of appropriately timed, unprotected intercourse.
Injection of sperm into the uterus or cervix.
Microsurgical injection of a single sperm into the cytoplasm of an oocyte ensuring that fertilization has taken place. It is indicated in ART when there is a low sperm count, absence of sperm in the ejaculate, an abnormally high percentage of morphologically atypical sperm, or after an irreversible vasectomy. If necessary, sperm can be retrieved from the testicle.
The introduction of washed sperm directly into the uterus through the cervix by means of a catheter. It is indicated in ART in cases of impotence, anti-sperm antibodies, when there is a cervical mucus problem or when there is unexplained infertility. IUI is a less expensive and less intrusive alternative to IVF and is a reasonable first choice for infertility treatment for younger couples.
Chromosome analysis that screens for the presence of genetic defects. Used in pre-implantation genetic diagnosis (PGD).
A spontaneous release of large amounts of luteinizing hormone resulting in the release of a mature oocyte (ovulation). The LH surge may not occur spontaneously in women treated with injectable gonadotropins. For this reason, hCG, which can mimic the effect of the LH surge, is given to stimulate the final steps in maturation.
A surgical procedure where a video-endoscope is inserted through a small incision near the navel in order to visualize the pelvic cavity, the ovaries, fallopian tubes and uterus.
Pregnancies are usually dated from the first day of the last monthly period.
Drug with anti-estrogen effects used in some ART procedures.
The days of a menstrual cycle following ovulation and ending with menstruation. During this 12 to 16 day period, the hormone progesterone is produced.
A hormone produced and released by the pituitary gland that controls the length and sequence of the female menstrual cycle, including ovulation, preparation of the uterus for implantation of a fertilized oocyte, and ovarian production of both estrogen and progesterone. In men, LH is responsible for stimulating the production of testosterone Recombinant LH is available for ovarian stimulation cycles.
Heavy or prolonged menstrual flow.
A substance extracted from human urine that contains FSH and LH.
Shedding of the uterine lining in response to estrogen and progesterone when conception has not occurred.
Microscopic procedures, such as ICSI or assisted hatching, involving the oocytes, sperm, or embryos.
Spermatozoa are obtained from the epididymis by either aspiration or surgical excision.
Spontaneous loss of an embryo or fetus from the womb.
Discomfort on one side of the lower abdomen during ovulation.
A common benign tumour in the muscular wall of the uterus, also called a fibroid.
Surgical removal of fibroid tumours from the wall of the uterus.
Infrequent menstrual periods with intervals between periods of greater than 35 days.
Abnormally low number of sperm in a semen sample.
The egg cell produced in the ovaries. Also called the ovum or female gamete.
A fluid filled sac growing in the ovaries that may lead to ovulatory disorders.
A condition involving ovarian enlargement and an acute fluid shift out of the intravascular space, most commonly seen as a complication of ovarian induction therapy.
The number and quality of oocytes in the ovaries of a woman of childbearing age.
Stimulation of follicle development and maturation via exogenous gonadotropins.
Release of a mature oocyte from the surface of the ovary.
The use of hormone therapy (injectable gonadotropins) to stimulate oocyte maturation and release.
A screen to evaluate cervical cells to determine if they are normal. Cells are collected from the cervix with a cotton swab, wooden spatula or small brush and then examined microscopically.
An infection of organs in the pelvic cavity which can lead to severe complications including tubal blockage and adhesions.
A minimally invasive surgical technique used for sperm retrieval in men with obstructive azoospermia in which sperm is aspirated from the epididymis through a fine needle.
The gland which releases several hormones that regulate the function of many endocrine cells, tissues and organs. Pituitary gland function is regulated by the hypothalamus through complex feed-back mechanisms.
Embryonic tissue that connects the developing fetus to the uterine wall; provides a mechanism for flow of nutrients and oxygen from the maternal circulatory system to the fetus, and removal of fetal waste. The fetus is connected to the placenta by the umbilical cord.
A condition characterized by multiple cysts in the ovaries frequently accompanied by elevated levels of androgens, infertility, obesity and hirsutism. The cysts are actually follicles. Sometimes referred to as Polycystic Ovary Syndrome.
An analysis of cervical mucus within a few hours of coitus to inspect interaction between sperm and cervical mucus. Also known as the Sims-Huhner Test.
Screening of a single cell from an embryo produced in an IVF cycle for genetic and/or chromosomal abnormalities prior to embryo transfer. It has two main purposes: to identify genetic diseases in the embryo and to detect anomalies that cause ART failure.
Describes a patient who has never been able to conceive a pregnancy.
A hormone produced and released by the corpus luteum of the ovary during the second half of an ovulatory cycle and by the placenta during pregnancy. Progesterone is necessary to prepare the lining of the uterus for the implantation of the fertilized oocyte. Supplemental support can be provided by injection or in vaginal or oral forms when indicated.
A hormone produced by the pituitary gland. Measurement of circulating prolactin may provide an index of a functional disorder within the hypothalamic-pituitary axis that may lead to failure of proper ovulation.
Ubiquitous molecules that are involved in myriad physiologic and pathologic processes including the contraction and relaxation of smooth muscles, control of blood pressure and modulation of inflammation.
A gland in the male reproductive system that produces a portion of the semen including a chemical that liquefies the coagulated semen 20 - 60 minutes after entering the vagina.
Produced by genetic engineering, rFSH has a similar structure and biologic activity to pituitary or urinary FSH. Also called follitropins and sometimes referred to as r-hFSH.
Produced by genetic engineering, rLH has a similar structure and biologic activity to natural LH. Sometimes referred to as r-hLH.
An ovary that fails to respond to FSH stimulation.
Sperm is diverted to the bladder during orgasm, rather than being released through the tip of the penis.
Level of protective antibodies against rubella (German measles). If immunity is not present, the patient should be advised to have a rubella vaccination before attempting pregnancy.
Injection of sterile saline into the uterine cavity during an ultrasound examination to assess for any irregularities of the cavity (polyps, fibroids, scarring, etc.).
A surgical procedure to remove one or both fallopian tubes.
The inability to conceive or carry a pregnancy after having successfully conceived and carried one or more pregnancies.
The fluid portion of the ejaculate consisting of secretions from the seminal vesicles, prostate gland, and several other glands in the male reproductive tract. May also refer to the entire ejaculate, including the sperm.
Test to assess sperm quality based upon the following characteristics: ejaculate volume, appearance, consistency, sperm morphology, sperm motility, sperm concentration and antibody presence.
A uterus divided into 2 parts by a wall of tissue (septum); it is associated with increased risk of early pregnancy loss.
Imaging of internal systems through high frequency sound waves. Used in ART to detect and count follicle growth (and disappearance) in many fertility treatments. Also used to detect and monitor pregnancy.
The male reproductive cell (gamete).
Sperm clumping caused by antibody reactions or by infection.
The concentration of sperm in ejaculate, measured as number of sperm per millimeter.
The shape of ejaculated sperm. A semen analysis factor that indicates the number or percentage of sperm in the sample that appear to have been formed normally. Abnormal morphology includes sperm with kinked, doubled, or coiled tails.
The ability of the sperm to swim. Poor motility is an indication of reduced fertilization potential as the sperm will have difficulty swimming towards the oocyte.
A technique to separate sperm from seminal fluid (semen).
The process of sperm production in the testes.
A method of collecting a semen specimen so that the first portion of the ejaculate is caught in one container and the rest in a second container. In most men, the first specimen will contain the vast majority of the sperm.
The total inability to reproduce. Not to be confused with infertility. A clinically irreversible condition that permanently prevents conception.
Death of a fetus after 20 weeks’ gestation.
Administration of hormones which induce development of multiple ovarian follicles. See ovulation induction.
When a couple asks a woman to carry a child for them. The child may be biologically related to the couple, to the male partner and the surrogate, or be conceived using a donor oocyte, sperm or embryo.
A small surgical excision of testicular tissue to determine the ability of the cells to produce normal sperm or ascertain the cause of testicular malfunction.
A surgical technique for retrieving sperm from men with azospermia. Testicular tissue is aspirated through a fine needle under local anesthesia and placed in culture media. Sperm are then dissected out from within the seminiferous tubules and released from the surrounding testicular tissue.
The male hormone responsible for the formation of secondary sex characteristics and for supporting the sex drive. Produced in the testes, it is also necessary for spermatogenesis. Produced by women in much lower amounts.
A pregnancy at risk of spontaneously aborting. Symptoms are cramping, spotting or bleeding during pregnancy.
Twisting of the testis inside the scrotum. Causes extreme pain and swelling; twists off the blood supply and causes severe damage to the testicle. Torsion of the ovary may also be a complication of ovarian hyperstimulation syndrome.
Surgery performed to remove a diseased portion of the fallopian tube and reconnect the two ends; sterilization reversal.
The most common genetic disorder causing female infertility in which women have only one X chromosome.
Technique for visualizing the follicles in the ovaries, allowing the estimation of size and number of follicles. May also be used to visualize the fetus in the uterus.
A uterine abnormality: the uterus has only one horn and is smaller in size than normal.
A collection of varicose veins that cause increased blood circulation in the testicles, leading to elevated scrotal temperatures, which in turn, may adversely affect sperm count and quality, resulting in male infertility.
The elective surgical procedure involving the separation of the vasa deferentia are then severed and either tied or sealed for permanent birth control.
An oocyte which is fertilized but has not yet begun the division process.