Glossary/ Dictionary

In Vitro Fertilization (IVF) comes with many new terms with which you may not be familiar. Here is a partial dictionary of some of those terms. 

Adhesions: Scar tissue that attaches to the surface of organs.

American Society for Reproductive Medicine (ASRM): A professional society whose affiliate organization, the Society for Assisted Reproductive Technology (SART), reports annual fertility clinic data to the Centers for Disease Control and Prevention (CDC).

Androgens: Sex hormone that is present in much higher concentrations in men than women.

Andrologist: A specialist in the study of male reproduction.

Anovulation: The total absence of ovulation. Menses may occur.

Antisperm Antibody testing: Testing to determine if a man’s sperm or a woman’s blood harbors substances that cause sperm to ‘clump’ together, lose motility or lose the ability to fertilize an egg.

ART (Assisted Reproductive Technology): All treatments or procedures that involve surgically removing eggs from a woman’s ovaries and combining the eggs with sperm to help a woman become pregnant. The types of ART are in vitro fertilization (IVF), zygote intrafallopian transfer (ZIFT) and frozen embryo transfer (FET). 

ART cycle: A process in which 1) an ART procedure is carried out, 2) a woman has undergone ovarian stimulation or monitoring with the intent of having an ART procedure, or 3) frozen embryos have been thawed with the intent of transferring them to a woman. A cycle begins when a woman begins taking fertility drugs or having her ovaries monitored for follicle production.

Assisted Hatching: Making a small hole in the zona pellucida (gel-like covering of embryo) to facilitate implantation of the developing embryo in the uterine wall.

Azoospermia: The absence of sperm in the seminal fluid. This may be due to a blockage or an impairment of sperm production.

Beta HCG (hCG): A hormone, human chorionic gonadotropin, produced by a pregnancy. Measurement of a beta hCG is the blood test used to determine pregnancy to follow its progression.

Canceled cycle: An ART cycle in which ovarian stimulation was carried out but which was stopped before eggs were retrieved, or in the case of frozen embryo cycles, before embryos were transferred. 

Centers for Disease Control and Prevention (CDC): A government agency within the U.S. Department of Health and Human Services responsible for publishing annual fertility clinic success rates. 

Cervical Mucus: 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 proceeding ovulation.

Chemical Pregnancy: A positive hCG level in the blood that fails to continue to rise and does not lead to a clinical pregnancy.

Clinical Pregnancy: Clinical evidence of pregnancy including increasing hCG levels and either ultrasound examination showing an intrauterine gestational sac or in cases of abnormal pregnancies, examination of tissue confirming an ectopic pregnancy or miscarriage.

Clomiphene Citrate (Clomid/Serophene):  A synthetic drug used to stimulate the body’s own production of FSH and LH.

Corpus Luteum: A gland that forms on the ovary at the site of the released egg 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 the pregnancy.

Cryopreservation: The freezing of excess embryos from an IVF cycle. The embryos are preserved for future transfer by storing them at very low temperatures.

Donor egg cycle (DE): An embryo formed from the egg of one woman (the donor) and then transferred to another woman who is unable to conceive with her own eggs (the recipient). The donor relinquishes all parental rights to any resulting offspring.

Donor Embryo Transfer (DET): A procedure that involves a woman who is using embryos that another couple has created from a previous ART procedure and are frozen. The couple has donated them for use by other patients after deciding not to use the embryos.  The embryos are matched with a recipient, thawed and transferred at the appropriate time in the cycle.

Donor Sperm: Sperm collected from a man who is not the woman’s spouse to be used to artificially inseminate her. Usually this sperm is obtained in a frozen state from a commercial sperm bank.

Ectopic pregnancy: A pregnancy in which the fertilized egg implants in a location outside of the uterus usually in the fallopian tube, the ovary, or the abdominal cavity.

Egg retrieval (also called oocyte retrieval): A procedure to collect the eggs contained in the ovarian follicles.  

Embryo: An egg that has been fertilized by a sperm and undergone one or more divisions. A term used to describe the early stages of fetal growth.

Embryo transfer: Placement of embryos into a woman’s uterus through the cervix after in vitro fertilization with the goal of implantation and pregnancy.

Endometriosis: A medical condition involving the presence of tissue similar to the uterine lining in locations outside of the uterus, such as the ovaries, fallopian tubes, and abdominal cavity.

Endometrial Biopsy: A small sample of tissue removed from the lining of the uterus for microscopic examination to determine the presence or absence of progesterone stimulation. This diagnostic test, which can be performed in a doctor’s office helps determine whether a woman ovulates or has hormonal imbalances.

Estrogen: The primary steroid hormone produced by ovaries from puberty to menopause.

Estradiol Level (E2 Level): The principal form of estrogen in reproductive age women. Its level is measured in the blood to determine follicular maturation prior to ovulation.

Fallopian Tube: Either a pair of tubes that conduct eggs from the ovary to the uterus. Normal fertilization takes place within this structure.

Fertility: The ability to conceive a pregnancy.

Fertilization: The penetration of the egg by the sperm and the resulting combining of genetic material that develops into an embryo.

Fetus: The developing human organism after the embryo stage from the ninth week of pregnancy to the moment of birth.

Fibroid: A non-cancerous smooth muscle tumor found within the walls of the uterus, also known as a myoma.

Follicle: A structure in the ovaries that contains a developing egg.

Follicle Stimulating Hormone (FSH): A hormone produced in the pituitary gland that stimulates the ovary to ripen a follicle for ovulation. In the male, FSH stimulates sperm production.

Follicular Phase: The portion of the menstrual cycle when ovarian follicle development takes place.

Fresh eggs, sperm, or embryos: Eggs, sperm, or embryos that have not been frozen. However, fresh embryos may have been conceived using fresh or frozen sperm.

Frozen cycle: A cycle in which embryos are preserved through freezing (cryopreservation) for transfer at a later date.

Frozen Embryo Transfer (FET): Embryos that were cryopreserved from fresh IVF cycle are thawed and transferred into the uterus.

Gamete: A sperm or an egg.

Gamete Intrafallopian Tube Transfer (GIFT): A procedure similar to IVF except that the sperm and eggs 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.

Gestational carrier (also called a gestational surrogate): A woman who carries an embryo that was formed from the egg of another woman. The gestational carrier usually has a contractual obligation to return the infant to its intended parents.

Gestational sac: A fluid-filled structure that develops within the uterus early in pregnancy. In a normal pregnancy, a gestational sac contains a developing fetus.

Gonadotropin Release Hormone (GnRH):  A hormone released from the hypothalamus that controls the synthesis and release of the pituitary hormones FSH and LH.

Gonadotropin: A hormone capable of stimulating the testicles or the ovaries to produce sperm or an egg, respectively. FSH and LH are gonadotropins. Drugs which are gonadotropins include Gonal-F and Follistim.

Hormonal Assay: Also known as hormone tests. These include FSH, LH, Prolactin, Estradiol, Testosterone, and Progesterone. If hormones are not in balance, fertility can be affected.

Human Chorionic Gonadotropin (HCG): A hormone secreted by the placenta that prolongs the life of the corpus luteum beyond its usual  fourteen day life span, resulting in the production of sufficient progesterone to support a pregnancy. It may be injected following HMG or FSH to trigger ovulation and ensure adequate luteal function. This hormone is the basis of most pregnancy tests.

Human Menopausal Gonadotropin (HMG): A natural product containing both FSH and LH. The hormones are extracted from the urine of postmenopausal women. The drug is used to treat both male and female infertility and to stimulate the development of multiple oocytes.

Hysterosalpingogram (HSG): An x-ray procedure (sometimes called a “dye test”) during which dye 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.

Hysteroscopy: Fiber optic visualization of the inside of the uterus through the cervix with a telescope-like device. This procedure is performed to evaluate and treat abnormalities inside the uterine cavity. This procedure can be performed in the office or in conjunction with a laparoscopy.

ICSI (intracytoplasmic sperm injection): A procedure in which a single sperm is injected directly into an egg; this procedure is most commonly used to overcome male infertility problems.

Idiopathic Infertility (unexplained Infertility): The term used when no reason can be found to explain the cause of a couple’s infertility.

Infertility: Difficulty achieving conception. In many studies, infertility is defined as the failure of a couple to conceive, despite unprotected intercourse, after a certain amount of time (usually 6 – 12 months).

Implantation: The embedding of the fertilized egg or embryo in the lining of the uterus.

IUI (intrauterine insemination): A medical procedure that involves placing sperm into a woman’s uterus to facilitate fertilization. IUI is not considered an ART procedure because it does not involve the manipulation of eggs.

IVF (in vitro fertilization): An ART procedure that involves removing eggs from a woman’s ovaries and fertilizing them outside her body. The resulting embryos are then transferred into the woman’s uterus through the cervix.

Laparoscopy: A surgical procedure in which a fiber optic instrument (a laparoscope) is inserted through a small incision in the abdomen to view the inside of the pelvis.

LH Surge: A spontaneous release of large amounts of Luteinizing Hormone (LH). This normally results in the release of a mature egg (ovulation). The LH surge does not usually occur spontaneously in women treated with injectable gonadotropins. For this reason a similar hormone, HCG is given to stimulate the final steps in maturation.

Luteal Phase: The days of a menstrual cycle following ovulation and ending with menstruation. During this 12 to 16 day period, the hormone progesterone is produced.

Luteinizing Hormone (LH): A hormone produced and released by the pituitary gland. It is responsible for triggering ovulation. In the male, LH stimulates testosterone production.

Male factor: Any cause of infertility due to deficiencies in sperm quantity or factors that make it difficult for a sperm to fertilize an egg under normal conditions.

Micromanipulation: Microscopic procedures such as ICSI or assisted hatching involving the eggs, sperm or embryos.

Miscarriage (also called spontaneous abortion): A pregnancy ending in the spontaneous loss of the embryo or fetus before 20 weeks of gestation.

Multiple birth: A pregnancy that results in the birth of more than one infant.

Multiple gestation: A pregnancy with multiple fetuses.

Myomectomy: The surgical removal of fibroid tumors from the wall of the uterus.

Oligospermia: A condition in which the number of sperm in semen sample is abnormally low.

Oligo-ovulation: Irregular ovulation.

Oocyte: The female reproductive cell, also called an egg.

Ovarian Hyperstimulation Syndrome (OHSS): A medical complication that may occur with gonadotropin use. In its severe form, OHSS is characterized by ovarian enlargement and a buildup of fluid in the abdomen, chest cavity, or around the heart. It affects blood electrolytes, liver, kidney function and puts the patient at greater risk for blood clots. Patients may experience abdominal discomfort, nausea, vomiting, weight gain, and decreased urine production, shortness of breath, difficulty breathing, and pelvic pain. If you experience these symptoms or have any concerns, always contact your physician immediately.

Ovarian monitoring: The use of ultrasound and/or blood or urine tests to monitor follicle development and hormone production.

Ovarian stimulation: The use of drugs to stimulate the ovaries to develop follicles and eggs.

Ovarian dysfunction: A cause of infertility due to problems with egg production by the ovaries.

Ovulation: Release of a mature egg from the surface of the ovary.

Ovulation induction: The use of hormone therapy to stimulate egg development.

Papanicolaou Smear (PAP test): Screening test to evaluate cells of the cervix to determine if they are normal.

Postcoital Test (PCT): Microscopic study of samples of vaginal and cervical secretions taken several hours after sexual relation and examined for live, moving sperm.

Pregnancy (clinical): Pregnancy documented by the presence of a gestational sac on ultrasound. For ART data collection purposes, pregnancy is defined as a clinical pregnancy rather than a chemical pregnancy (i.e., a positive pregnancy test).

Primary infertility: Infertility in persons who have never had children.

Progesterone (P4): Hormone produced and released by the corpus luteum. Progesterone is necessary to prepare the lining of the uterus for the implantation of the fertilized egg. During pregnancy it is produced by the placenta.

Secondary infertility: Infertility in persons who have already had children.

Semen Analysis (SA): Freshly ejaculated semen is evaluated under a microscope to count the number of sperm (count), the percentage of moving sperm (motility) and to assess the size and shape of the sperm (morphology).

Society for Assisted Reproductive Technology (SART): An affiliate of the American Society for Reproductive Medicine composed of clinics and programs that provide ART. SART reports annual fertility clinic data to CDC.

Sonohystogram (SHG): Injection of sterile saline into the uterine cavity during an ultrasound examination to assess for irregularities of the cavity.

Spermwash: Technique for separating sperm from seminal fluid.

Stimulation: Administration of hormones which induce development of multiple ovarian follicles.

Testicular Biopsy: A small surgical excision of testicular tissue to determine the ability of cells to produce normal sperm.

Testosterone: The most potent male sex hormone; produced in the testes but also present in women in lower amounts.

TDI: Therapeutic or artificial insemination. During this procedure, sperm from a donor is placed into a woman’s vagina or cervix. Also known as AID: artificial insemination by donor.

Tubal factor: Structural or functional damage to one or both fallopian tubes that reduces fertility.

Ultrasound: A technique used in ART for visualizing the follicles in the ovaries and the gestational sac or fetus in the uterus.

Uterine factor: A disorder in the uterus (e.g., fibroid tumors) that reduces fertility.

Vaginal ultrasound: Visualization of soft tissue by projecting sound waves through a probe that is inserted into the vagina. A baseline ultrasound shows the ovaries in their unstimulated state. A follicular ultrasound shows egg follicle maturation. A pregnancy ultrasound shows if a pregnancy is intrauterine or tubal and measures growth if there is a fetus.

Varicocele: A collection of varicose veins in the scrotum. Blood flows in an abnormal direction in these veins towards the testicles.

ZIFT (zygote intrafallopian transfer): An ART procedure in which eggs are collected from a woman’s ovary and fertilized outside her body. A laparoscope is then used to place the resulting zygote (fertilized egg) into the woman’s fallopian tube through a small incision in her abdomen.

Zygote: An embryo in the early stages of development.