Glossary of Infertility Terms


Adhesion: The scar tissue that forms around reproductive organs following a previous injury, infection or surgery.

Amenorrhea: The absence of menstruation

Androgen: Primarily a male sex hormone, found in the ovaries.

Anovulation: The total absence of ovulation.

Artificial Insemination (AI): The depositing of sperm in the vagina near the cervix or directly into the uterus, with the use of a catheter instead of by sexual intercourse. This technique is used to overcome sexual performance problems, to avoid sperm-mucus interaction problems, to maximize the potential of poor semen, and for using donor sperm.

Assisted Reproductive Technologies (ART): A variety of procedures used to bring about conception without sexual intercourse, including IVF, and GIFT.


Basal body temperature (BBT) test: The temperature of the woman taken every morning during a cycle before any activity is done that may raise her temperature. It is done to help determine if ovulation has taken place.

Baseline ultrasound: An examination conducted before starting therapy to determine the general position and condition of the ovaries.

Blastocyst transfer: A recent advance in infertility treatment, in which embryos develop for 4 or 5 days (until they reach blastocyst stage), rather than the usual 2 or 3 days in IVF.


Cervical mucus: Mucus produced by the cervix that permits passage of sperm during ovulation, and prevents infection.

Cervix: Lower section of the uterus that protrudes into the vagina, through which the sperm pass to reach the uterus.

Chemical pregnancy: The false appearance of pregnancy due to changes in hormonal levels.

Concentration (also called sperm count): This measures how many million sperm there are in each milliliter of seminal fluid. Counts of less than 20 million per milliliter (<20 million/cc) are associated with decreased fertility.

Conception: Fertilization: When the sperm meets and penetrates the egg.

Controlled ovarian hyperstimulation: Stimulation of the ovaries with various hormonal medications in order to develop as many follicles as possible, as well as to control the timing of ovulation.

Corpus luteum: A structure that forms at the site of an ovarian follicle after it releases an egg. The corpus luteum releases estrogen and progesterone, two hormones necessary for maintaining a pregnancy. If pregnancy occurs, the corpus luteum functions for five or six months. If pregnancy does not occur, it stops functioning.

Cryopreservation: Storage of organs or tissues at very low temperatures. Embryos that are not used in an ART cycle can be cryopreserved for future use.


Dysmenorrhea: Cramping and pain around the time of menstruation.

Dysmucorrhea: Poor quality or inadequate cervical mucus that can prohibit sperm passage.


Ectopic pregnancy: The implantation of an embryo in a place other than the uterus.

Egg retrieval: A procedure used to obtain eggs from ovarian follicles for use in in vitro fertilization. The procedure may be performed during laparoscopy or through the vagina by using a needle and ultrasound to locate the follicle in the ovary.

Ejaculate: As a noun, it refers to the mixture of sperm and seminal fluid that comes out of a man's penis during sexual stimulation. As a verb, it refers to the passing of this material.

Endometrial biopsy: The removal of a sample of the lining of the uterus for examination.

Endometriosis: A disease whereby cells lining the uterus (or endometrium) get outside of the uterus and stick to other organs, causing inflammation.

Endometrium: The lining of the uterus.

Epididymis: The organ in the man where sperm are stored, nourished and mature after manufacture.

Embryo: Term used to describe the early stages of fetal growth, from conception to the eighth week of pregnancy.

Embryo transfer: Placing an egg fertilized outside the womb into a woman's uterus or fallopian tube.

Estradiol: The most potent naturally occurring estrogen in humans, which is released from the ovary.

Estrogen: Hormone that stimulates secondary female sexual characteristics and controls the course of the menstrual cycle. Also produced in low quantities in males.

Estrone: One of the relatively weak estrogens, which is produced in large amounts in PCOS (polycystic ovarian syndrome) patients.


Fallopian tubes: Ducts through which eggs travel to the uterus once released from the follicle. Sperm normally meet the egg in the fallopian tube, the site at which fertilization usually occurs.

Fertility specialist: A physician specializing in the practice of fertility. The American Board of Obstetrics and Gynecology certifies a subspecialty for OB-GYNs who receive extra training in reproductive endocrinology (the study of hormones) and infertility.

Fertility treatment: Any method or procedure used to enhance fertility or increase the likelihood of pregnancy, such as ovulation induction treatment, varicocele repair (repair of varicose veins in the scrotal sac), and microsurgery to repair damaged fallopian tubes. The goal of fertility treatment is to help couples have a child.

Fertilization: The combining of the genetic material carried by sperm and egg to create an embryo. Normally occurs inside the fallopian tube (in vivo) but may also occur in a Petri dish (in vitro). (See also In Vitro Fertilization at

Fibroid tumor: Benign (not malignant or life-threatening) tumor of fibrous tissue that can occur in the uterine wall. May be totally without symptoms or may cause abnormal menstrual patterns or infertility.

Follicles: Fluid-filled sacs in the ovary, which contain the eggs released at ovulation. Each month an egg develops inside the ovary in a follicle.

Follicle Stimulating Hormone (FSH): A pituitary hormone that stimulates follicular development and spermatogenesis (sperm development). In the woman, FSH stimulates the growth of the ovarian follicle. In the man, FSH stimulates the Sertoli cells in the testicles and supports sperm production. Elevated FSH levels are associated with gonadal failure in both men and women.


Gamete: A reproductive cell. Sperm in men, the egg in women.

Gonadotropins: Hormones that control reproductive function: Follicle Stimulating Hormone and Luteinizing Hormone.

Gonadotropin Releasing Hormone (GnRH): A substance secreted every ninety minutes or so by a part of the brain called the hypothalamus. This hormone enables the pituitary to secrete LH and FSH, which stimulate the gonads.


Human Chorionic Gonadotropin (hCG): The hormone produced in early pregnancy that keeps the corpus luteum producing progesterone. Also used via injection to trigger ovulation after some fertility treatments, and used in men to stimulate testosterone production.

Hypothalamus: The gland at the base of the brain that controls the release of hormones from the pituitary glands.

Hysteroscopy: A visual examination of the uterus using an instrument called a hysteroscope, which enables the doctor to see into the organ without making a large incision.


Idiopathic infertility: The term used to explain when the cause of infertility cannot be explained.

Infertility: The inability to conceive after a year of unprotected intercourse (six months if the woman is over age 35) or the inability to carry a pregnancy to term.

Implantation (Embryo): The embedding of the embryo into tissue so it can establish contact with the mother's blood supply for nourishment. Implantation usually occurs in the lining of the uterus; however, in an ectopic pregnancy it may occur elsewhere in the body.

Intracytoplasmic Sperm Injection (ICSI): A micromanipulation (occurring under the microscope) procedure in which a single sperm is injected directly into the egg to enable fertilization with very low sperm counts or with non-motile sperm (sperm that don't swim effectively toward the egg). The embryo is then transferred to the uterus.

Intramuscular (IM) needle: A needle designed to administer medication deep into the muscle. Injections of this type are usually given in the thigh or upper buttock area.

In Vitro Fertilization (IVF): Eggs produced by administering fertility drugs are retrieved from the woman's body and fertilized by sperm in a laboratory. The resulting embryos are transferred by catheter to the uterus.


Luteal phase: Days of the menstrual cycle after ovulation when progesterone is produced by the corpus luteum.

Luteinizing Hormone (LH): A pituitary hormone that stimulates the gonads. In the man, LH is necessary for spermatogenesis and for the production of testosterone. In the woman, LH is necessary for the production of estrogen.

Luteinizing Hormone Surge (LH SURGE): The release of luteinizing hormone (LH) that causes release of a mature egg from the follicle.


Micromanipulation: A variety of techniques that can be performed in a laboratory under a microscope. Anembryologist manipulates egg and sperm to improve the chances of pregnancy. (See Intracytoplasmic Sperm Injection, ICSI at

Miscarriage: Spontaneous loss of a viable embryo or fetus in the womb.

Motility: This is the percentage of the sperm which move ("swim") normally. Ideally, at least 40% of the sperm should move in a forward, purposeful manner to facilitate timely fertilization of the egg.

Morphology: The physical structure and configuration of sperm cells. The ability of sperm to swim. Poor motility means the sperm have a difficult time swimming toward the egg.


Oligospermia: Abnormally low number of sperm in the ejaculate of the male.

Oocyte: The egg.

Ovarian hyperstimulation syndrome (OHSS): A painful condition caused when the ovaries become over stimulated by the various hormones that cause follicular development.

Ovaries: The two sexual glands of the female where the eggs are stored. The ovaries also produce the hormones estrogen and progesterone.

Ovulatory dysfunction: A problem with the ovary where the egg is not matured or released properly.

Ovum: The egg.


Pituitary gland: The gland located at the base of the brain that secretes a number of important hormones that regulate fertility, as well as normal growth and development of the body.

Polycystic ovarian syndrome (PCOS): The formation of cysts in the ovaries that occurs when the follicle stops developing. This is due to a hormonal imbalance in the ovary.

Post-coital test (PCT): A test to determine whether the sperm can move properly through the cervical mucus.

Progesterone: The hormone produced by the corpus luteum during the second half of a woman's cycle. It thickens the lining of the uterus to prepare it to accept implantation of a fertilized egg.


Sperm (spermatozoa): The microscopic cell that carries the male's genetic information to the female's egg; the male reproductive cell; the male gamete.

Sperm count: The number of sperm in an ejaculate. Also called sperm concentration and given as the number of sperm per milliliter.

Subcutaneous (SC) needle: A needle designed to administer medication just below the surface of the skin, into the fatty tissue.


Testosterone: The male hormone responsible for the formation of secondary sex characteristics and for supporting the sex drive. Testosterone is also necessary for spermatogenesis (sperm development).

Tubal pregnancy: The development and attachment of a fertilized egg in a fallopian tube.


Ultrasound: A test used instead of X-rays to visualize the reproductive organs; for example, to monitor follicular development.


Viscosity: The thickness of the semen. Abnormalities in the viscosity or consistency of the seminal fluid can be detrimental to the sperm. For example, if the semen is very thick and viscous, sperm may have difficulty traveling through the semen and into the woman's reproductive tract.

Volume: The amount of seminal fluid in a normal ejaculation should be two milliliters (2 ccs) or more. The volume may be low if a man is anxious when producing a specimen, if the entire specimen is not appropriately collected, or if there is a hormonal imbalance, obstruction, or dehydration.

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