Glossary of Terms

  • Abortion: Pregnancy loss by any cause before 20 weeks of gestation.
  • Adhesion: Scar tissue attaching abnormally connecting, covering or distorting organs, such as the tubes, ovaries or other internal organs, limiting their movement and possibly causing infertility and pain.
  • American Society of Reproductive Medicine (ASRM): (formerly the American Fertility Society or AFS) Large multidisciplinary organization serving as a platform for new ideas, education and advocacy in fertility and reproductive medicine issues.
  • Amniocentesis: Sampling a small quantity of the fluid that surrounds the fetus that permits detection of certain abnormalities.
  • Aspiration: Removal of fluid and cells by suction through a needle.
  • Assisted Hatching: An in vitro procedure in which the zona pellucida of an embryo is either thinned or perforated by chemical, mechanical, or laser methods to assist separation of the blastocyst.
  • Assisted Reproductive Technologies (ART): A group of therapies that employ manipulation of the egg and/or sperm and/or early conceptus in order to establish a pregnancy.
  • Basal Body Temperature (BBT): The body temperature at rest. It is taken orally each morning immediately upon awakening and recorded on a calendar chart. The readings are studied to help identify the time of ovulation.
  • Biochemical Pregnancy: A pregnancy diagnosed only by the detection of hCG in serum or urine and that does not develop into a clinical pregnancy.
  • Blastocyst: An embryo, 5 or 6 days after fertilization, with an inner cell mass, outer layer of trophectoderm, and a fluid-filled blastocele cavity.
  • Canceled Cycle: An ART cycle in which ovarian stimulation or monitoring has been carried out with the intention to treat, but which did not proceed to follicular aspiration or, in the case of a thawed embryo, to embryo transfer.
  • Capacitation: A process the sperm must undergo that enables fertilization.
  • Cervical Factor: Infertility due to previous surgery or structural abnormality of the cervix. Also applied when there are factors associated with the cervix which inhibit sperm function.
  • Cervical Mucus: The secretion of the cervix which changes in volume and consistency throughout the menstrual cycle. Its quality is a reflection of hormonal stimulation.
  • Cervix: The lower section of the uterus which protrudes into the vagina and serves as a reservoir for sperm.
  • Chemical Pregnancy: A positive pregnancy test, but with levels of pregnancy hormone too low for ultrasound documentation of a pregnancy.
  • Cleavage: Division of one cell into 2, 2 into 4, 4 into 8, etc.
  • Clinical Pregnancy: A pregnancy in which the beating fetal heart has been identified by ultrasound.
  • Clinical Pregnancy Rate: The number of clinical pregnancies expressed per 100 initiated cycles, aspiration cycles, or embryo transfer cycles. Note: When clinical pregnancy rates are given, the denomination (initiated, aspirated, or embryo transfer cycles) must be specified.
  • Clinical Pregnancy with Fetal Heart Beat: Pregnancy diagnosed by ultrasonographic or clinical documentation of at least one fetus with heart beat. It includes ectopic pregnancy.
  • Clomiphene Citrate (Clomid TM or Serophene TM): An oral medication used to stimulate the ovary and/or synchronize an ovarian follicle development.
  • Congenital Anomaly: A non-hereditary characteristic, or defect, developing before birth.
  • Controlled Ovarian Stimulation (COS) for ART: Pharmacologic treatment in which women are stimulated to induce the development of multiple ovarian follicles to obtain multiple oocytes at follicular aspiration.
  • Controlled Ovarian Stimulation (COS) for non-ART Cycles: Pharmacologic treatment for women in which the ovaries are stimulated to ovulate more than one oocyte.
  • Corpus Luteum: A special gland that forms on the surface of the ovary at the site of ovulation. It produces progesterone during the second half of the cycle which is necessary to prepare the uterine lining for implantation.
  • Cumulus: The cloud-like collection of supportive follicle cells that surround the oocyte.
  • Cryopreservation: Controlled freezing and storage of gametes, zygotes, embryos, or gonadal tissue.
  • Cyst: A fluid filled structure that may be normal or abnormal depending on circumstances.
  • Donor Embryo Transfer: The transfer of a fertilized egg from a volunteer (may be paid or unpaid) donor to an otherwise infertile recipient.
  • Donor Insemination: The introduction of sperm from a volunteer donor into a women’s vagina, cervix or uterine cavity, in order to achieve a pregnancy.
  • Ductus Deferens (vas): A thick walled tubular structure running from each testis into the ejaculatory duct. These structures carry sperm from the epididymis to the penis.
  • Ectopic Pregnancy: A pregnancy implanted outside the uterus; most often in the Fallopian tube (tubal pregnancy).
  • Elective Single Embryo Transfer (ESET): The transfer of one or more embryos, selected from a larger cohort of available embryos.
  • Embryo: The term used to describe the early stages of fetal growth. Strictly defined from the second to the ninth week of pregnancy but often used to designate any time after conception.
  • Embryo Donation: The transfer of an embryo resulting from gametes (spermatozoa and oocytes) that did not originate from the recipient and her partner.
  • Embryo Recipient Cycle: An ART cycle in which a woman receives zygote(s) or embryo(s) from donor(s).
  • Embryo/fetus Reduction: A procedure to reduce the number of viable embryos or fetuses in a multiple pregnancy.
  • Embryo Transfer (ET): The procedure in which one or more embryos are placed in the uterus or fallopian tube.
  • Embryo Transfer Cycle: An ART cycle in which one or more embryos are transferred into the uterus or fallopian tube.
  • Endocrinology: The study of hormones, their function, the organs that produce them and how they are produced.
  • Endometrial biopsy: The extraction of a small piece of tissue from the endometrium (lining of the uterus) for microscopic examination.
  • Endometriosis: The presence of endometrial tissue (tissue that normally lines the uterus) in abnormal locations such as the ovaries, fallopian tubes and abdominal cavity.
  • Endometrium: The inner lining of the uterus. The area of initial attachment of the conceptus. A portion of this lining is shed each month with menstruation.
  • Epididymis: Portion of the male genital tract next to the testis where sperm maturation is partially accomplished. Receives sperm from the testis and continues as the ductus deferens.
  • Estradiol: The principal hormone produced by the growing ovarian follicle.
  • Fertilization: Union of a sperm with an oocyte.
  • Fimbria: The finger like extensions from the end of the uterine tube that aid in gathering the oocyte at ovulation.
  • Follicle: A functioning ovarian “cyst” containing a wall of granulosa cells which produce estrogen and nourish the oocyte (egg). Each Follicle contains a single oocyte.
  • Follicle Stimulating Hormone (FSH): A hormone produced by the pituitary gland, which cause the ovarian follicles to grow.
  • Frozen-thawed Embryo Transfer Cycle (FET): An ART procedure in which cycle monitoring is carried out with the intention of transferring frozen-thawed embryo(s). Note: An FET cycle is initiated when specific medication is provided or cycle monitoring is started with the intention to treat.
  • Gestation: pregnancy
  • Gestational Carrier (Surrogate): A woman who carries a pregnancy with an agreement that she will give the offspring to the intended parent(s). Gametes can originate from the intended parent(s) and/or third party (or parties).
  • Gestational Sac: A fluid-filled structure associated with early pregnancy, which may be located inside or outside the uterus (in case of an ectopic pregnancy).
  • Gonadotropin: Hormone that stimulates the ovary.
  • Gonadotropin Releasing Hormone (GnRH): Hormone produced by the brain that stimulates the pituitary to secrete gonadotropins.
  • Hatching: The process by which an embryo at the blastocyst stage separates from the zona pellucida.
  • High-order Multiple: A pregnancy or delivery with three or more fetuses or neonates.
  • Human Chorionic Gonadotropin (hCG): A hormone of early pregnancy that can be monitored to determine the age and viability of the gestation. This hormone is also used as an injection in ovarian stimulation regimens to cause the final maturation of the oocyte (egg) and its follicle and eventually cause ovulation.
  • Human Menopausal Gonadotropin (HMG): A purified extract of LH and FSH, hormones secreted from the pituitary gland which stimulate the ovary. It is a commercial preparation used by injection to facilitate development of multiple follicles.
  • Hypothalamus: A portion of the brain that acts as a “pacemaker” controlling the production and periodic release of hormones from the pituitary gland.
  • Hysterosalpingogram (HSG): An x-ray procedure in which a special dye is injected into the uterus to illustrate the inner contour of the uterus and degree of openness (patency) of the uterine tubes.
  • Hysteroscope: A telescopic device, much like the laparoscope, that enables examination of the uterine cavity.
  • Infertility (clinical definition): A disease of the reproductive system defined by the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse.
  • Implantation: The embedding of the conceptus (embryo) into the lining of the uterus.
  • Insemination: Transfer of semen or sperm for the purpose of establishing a pregnancy.
  • Intracytoplasmic Sperm Injection (ICSI): Placement of a single sperm into an oocyte (egg) using a small glass needle to penetrate the outer coatings of the egg.
  • In Vitro Fertilization (IVF): A method of assisted reproduction that involves surgically removing an egg from the ovary, combining it with prepared sperm in the laboratory to permit fertilization.
  • Laparoscope: A thin, lighted viewing instrument with a telescopic lens through which a surgeon views the exterior surfaces of a female’s reproductive organs and abdominal cavity.
  • Lupron™: A synthetic form of gonadotropin (aluminizing hormone) releasing hormone used to suppress ovarian function.
  • Luteal Phase: The last fourteen days of an ovulatory cycle, associated with progesterone production from the corpus luteum.
  • Luteinizing Hormone (LH): A hormone produced and released by the pituitary gland. In the female it is responsible for ovulation and the maintenance of the corpus luteum. In the male it stimulates testosterone production and is important in the production of sperm cells.
  • Media: Fluid containing nutritive growth substances enabling cells to survive in an artificial environment.
  • Menses: A period. Cyclic (monthly) flow of blood (menstruation) signifying ovulation but failure to achieve pregnancy. Onset of bleeding is considered cycle day 1.
  • Micromanipulation: A method of assisted reproduction when the process is manually performed under the guidance of the microscope.
  • Oocyte: The female germ cell often called an egg.
  • Ovarian Hyperstimulation Syndrome (OHSS): An exaggerated systematic response to ovarian stimulation characterized by a wide spectrum of clinical and laboratory manifestations. It is classified as mild, moderate, or severe according to the degree of abdominal distention, ovarian enlargement, and respiratory, hemodynamic, and metabolic complications.
  • Ovary: The female sex gland with both a reproductive function (releasing oocytes) and a hormonal function (production of estrogen and progesterone).
  • Ovulation: The release of a mature egg from the surface of the ovary.
  • Ovulation Induction (OI): Pharmacologic treatment of women with anovulation or oligo-ovulation with the intention of inducing normal ovulatory cycles.
  • Ovum (ova or egg): Mature oocytes.
  • Pap test: A screening test to determine the presence of cervical cancer. It is done by gently touching a cotton swab on the cervix and then wiping the swab on a slide, which is treated and examined under a microscope. Another type of pap test, ThinPrep, replaces the conventional method by rinsing the cells into a vial filled with a solution that preserves them – a process that improves the quality and is believed to lead to more effective cervical cancer diagnosis and reduction in repeat testing.
  • Pituitary Gland: A small organ at the base of the brain that both controls and is controlled by production of hormones from the various endocrine glands including the ovary.
  • Polyspermy: Abnormal condition where the oocyte is fertilized by more than one sperm.
  • Preimplantation Genetic Diagnosis (PGD): Analysis of polar bodies, blastomeres, or trphectoderm from oocytes, zygotes, or embryos for the detection of aneuploidy, mutation, and/or DNA rearrangement.
  • Preimplantation Genetic Screening (PGS):  Analysis of polar bodies, blastomeres, or trophectoderm from oocytes, zygotes, or embryos for the detection of specific genetic, structural, and/or chromosomal alterations.
  • Progesterone: A hormone produced by the ovary, which prepares the uterus for implantation and supports the early pregnancy.
  • Pronucleus: A specialized stage of the oocyte or sperm nucleus before their union. After this union the conceptus is referred to as a zygote.
  • Pronuclear Stage Tubal Transfer (PROST or ZIFT): Oocytes are aspirated, allowed to fertilize in vitro and the conceptus transferred before cell division (cleavage).
  • Reproductive Surgery: Surgical procedures performed to diagnose, conserve, correct, and/or improve reproductive function.
  • Semen Analysis: The microscopic examination of the ejaculate to determine the number of sperm, their shapes (morphology) and their ability to move (motility).
  • Sperm Antibody Test: In some couples blood, semen and/or cervical mucus contain substances which hinder sperm action through an allergic or immune reaction.
  • Society for Assisted Reproductive Technology (SART): Voluntary regulatory and consultative organization of the American Society for Reproductive Medicine responsible for assisted reproduction.
  • Testicular/Epididymal Sperm Aspiration (TESA): The removal of sperm directly from the testis or the epididymis using a needle for aspiration. Usually associated with sperm injection into the oocyte (ICSI).
  • Transvaginal: Through the vagina.
  • Tubal Patency: Lack of obstruction of the Fallopian tubes.
  • Ultrasound: High frequency sound waves that can be used painlessly, safely, and without radiation, to view the internal portions of the body.
  • Unexplained Infertility: Inability to conceive where no cause has been found despite routine testing of semen, ovulation, and pelvic anatomy by laparoscopy.
  • Uterus: Womb. The reproductive organ that houses, protects and nourishes the developing embryo and fetus.
  • Varicocele: A varicose vein around the ductus deferens and the testes. This may be a cause of male infertility.
  • Zygote: A conceptus in which the egg and sperm genetic material (pronuclei) have united.

Source: Fertility and Sterility