PVED GLOSSARY

Assisted Hatching- A small hole is made in the outer shell around the embryo (the zona pellucida) before transfer to the uterus
ART (Assisted Reproductive Technology) - A term used to describe advanced scientific interventions, such as IVF, which are used to treat infertility
Basic research– studies limited to the laboratory or to animals and aimed at understanding the human body and its diseases at the most fundamental level
Blastocyst- A stage of embryo development approximately 5 or 6 days after egg collection. It is the last stage of development an embryo must reach before it implants itself into the uterine wall. Transferring blastocyst stage embryos can produce the same pregnancy rates with the transfer of fewer embryos, and therefore lower the multiple pregnancy rate.
Blastomere - A single cell within a pre-implantation embryo up to the morula stage of development. Each blastomere is totipotent and has the ability to develop into a whole embryo if it was removed and grown on its own.
Blighted ovum - A non-viable pregnancy which shows a gestational sac with no fetus on ultrasound.
Beta hCG test - A blood test used to detect early pregnancy and to monitor progress of the pregnancy during the first weeks
Canceled cycle - An ART cycle in which ovarian stimulation was carried out but was stopped before eggs were retrieved. Cycles are canceled for many reasons: there may be too few or too many eggs developing; the uterine lining may not be optimal for embryo replacement; the patient may become ill; or the patient may choose to stop treatment.
Chromosome - A thread-like strand of DNA and protein the nucleus of the cell that carries genetic information. Humans have 23 pairs of chromosomes in each cell of their bodies (apart from a mature egg and sperm which have 23 single chromosomes)
Compaction - A stage of early embryo development between the 8-cell and the blastocyst stage. Around Day 4 of in vitro culture, when the embryo consists of approximately 8 cells, the cells merge together and this is called compaction. At this stage the embryo is referred to as a morula.
Corpus Luteum- After ovulation, the follicle from which the egg was released is referred to as a Corpus Luteum. The Corpus Luteum produces progesterone, which is responsible for preparing and supporting the uterine lining for implantation.
Cryopreservation - Freezing embryos from a couple's ART cycle.
Cumulus Oophorus - A protective layer of cells surrounding the egg.
Dominant follicle- the largest ovarian follicle that develops during each menstrual cycle. It is the follicle that will ovulate.
Estradiol - one of the three major estrogen hormones women produce. This estrogen dominates from puberty to menopause and is by far the most powerful estrogen. The ovarian follicle produces it as it develops during the first half of the menstrual cycle and by the corpus luteum after ovulation.
D & C (Dilation & Curettage) - is a minor surgical procedure in which the physician first dilates or opens the cervix and then inserts a thin spoon shaped instrument and uses it to remove material from the internal lining of the uterus. Dilation therefore stands for opening the cervix and curettage means the scraping of the uterine wall.
DHEA – Dehydroepiandrosterone (pronounced dee-hi-dro-epp-ee-ann-dro-stehr-own), or DHEAas it is more often called, is a steroid hormone produced in the adrenal gland. It is the most abundant steroid in the bloodstream and is present at even higher levels in brain tissue. DHEA levels are known to fall 90% from age 20 to age 90. DHEA is known to be a precursor to the numerous steroid sex hormones (including estrogen and testosterone) which serve well-known refunctions, but the specific biological role of DHEA itself is not completely understood as of yet.
Donor egg cycle- An embryo is formed from the egg of one woman (the donor) and then transferred to another woman who is unable to use her own eggs (the recipient). The donor relinquishes all parental rights to any resulting offspring.
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. Ectopic pregnancy is a dangerous condition that must receive prompt treatment.
Egg - A female reproductive cell, also called an oocyte or ovum.
Egg Donation - See donor egg cycle.
Egg retrieval- (oocyte retrieval) A surgical procedure to collect the eggs contained in the ovarian follicles.
Ejaculate - Semen discharged during the process of ejaculation.
Ejaculation- The expulsion of seminal fluid form the urethra of the penis during orgasm.
Embryo- An egg that has been fertilized by a sperm and undergone one or more divisions.
Embryologist- A highly trained scientist specializing in reproductive laboratory procedures.
Embryo transfer- Placement of embryos into a woman's uterus through the cervix after in vitro fertilization.
Endocrinology- The study of the body's hormone secreting glands.
Endometrium- The lining of the uterus that grows thick each month and is lost through menstruation or remains intact to nurture an embryo if conception takes place.
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, which may contribute to infertility.
Estrogen- Female sex hormone produced by the ovary.
Fallopian Tubes - Ducts through which eggs travel to the uterus from the ovary after they are released from a follicle. This is where fertilization normally occurs inside the body when sperm swims up the tube and meets the egg.
Fibroid - A fibrous non-malignant tumor in the uterus. May affect fertility.
Fertilization - The penetration of the egg by the sperm and the resulting combination of genetic material before an embryo is formed.
Fetus - The unborn offspring from the eighth week after conception to the moment of birth.
Follicle- A fluid-filled structure in the ovaries that contains a developing egg.
Follicle Stimulating Hormone (FSH) - A hormone produced by the pituitary gland that stimulates egg maturation in the ovaries.
Fragmentation (of embryos) - Sometimes when a cell divides in the pre-implantation embryo it is not a clean split and small fragments of cell are lost. Microscopically, this gives the embryo a poorer appearance, leading to a lower grade. Fragmented embryos are less likely to implant than those without any fragmentation. We will always choose the least fragmented embryos for transfer.
Frozen embryo cycle- An ART cycle in which frozen (cryopreserved) embryos are thawed and transferred to the woman.
Gamete - A reproductive cell and either a sperm or an egg.
Galactosemia - a rare genetic metabolic disorder. A gene for Galactosemia must be inherited from both parents who are carriers. It is an autosomal recessive condition. Normally when a person consumes a product that contains lactose (for example, milk), the body breaks galactose down into galactose and glucose. Glucose is the sugar used by the body for energy. Galactosemia means too much galactose in the blood caused by the individual missing the enzyme to convert galactose into glucose. Men with Galactosemia have normal gonadotropin function. In women it is still unclear if the POF is due to follicle depletion or follicle dysfunction.
Gestation -The period of time from conception to birth.
Gestational carrier - (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.
Gonads - in women these are the ovaries.
Gonadotropins – the hormones produced by the pituitary gland that regulate the gonads. In women they regulate the development of the eggs. The most important ones are follicle stimulating hormone (FSH) and Luteinizing hormone (LH).
Gonadotropin releasing hormone (GnRH) - a hormone which is produced by the hypothalamus in the brain. It stimulates the pituitary gland to produce and release both LH and FSH.
Gonadotropins - Hormones that control reproductive function. Human menopausal Gonadotropin (HMG), Follicle stimulating hormone (FSH) and Luteinizing hormone (LH).
Gonadotropin Releasing Hormone (GnRH) - A substance released from the hypothalamus in a pulsatile manner approximately every 90 minutes. This hormone acts on the pituitary gland enabling it to secrete LH and FSH, which stimulate the gonads.
Hatching (of embryos) - Before an embryo can implant in the uterus, it must first escape from its outer shell (zona pellucida); this process is called hatching.
Health Management Organization (HMO) - is a form of health insurance combining a range of coverage’s in a group basis. A group of doctors and other medical professionals offer care through the HMO for a flat monthly rate with no deductibles. However, only visits to professionals within the HMO network are covered by the policy. All visits, prescriptions and other care must be cleared by the HMO in order to be covered. A primary physician within the HMO handles referrals.
Hirsutism - Overabundance of hair growth often found in woman with excess androgens.
Host uterus (Gestational Carrier or Surrogate) - A couple's embryo may be transferred into another woman's uterus who then carries the pregnancy to term and returns the baby to the genetic parents immediately after birth.
Human chorionic gonadotropin (hCG) – This hormone is produced during early pregnancy and keeps the corpus luteum producing progesterone. hCG is also used to trigger ovulation during fertility treatments.
Hyperstimulation - The stimulation of multiple ovulations with fertility drugs.
Hyperthyroidism – Over production of thyroid hormone by the thyroid gland. This leads to an increase in metabolism and can cause estrogen to ‘burn up' too rapidly, thereby interfering with ovulation.
Hypothalamus - A part of the brain that is the “hormonal regulation center.” The hypothalamus is located adjacent to and just above the pituitary gland.
Hypothyroidism – Under production of thyroid hormone by the thyroid gland. The resulting lowered metabolism can interfere with the normal breakdown of hormones and may lead to lethargy. Women may suffer from elevated levels of prolactin and estrogen, which can interfere with fertility.
Hysterectomy - Surgical removal of the uterus.
Hysterosalpingogram - A procedure used to assess the anatomy of the cavity of the uterus and the fallopian tubes.
Hysteroscopy - A thin telescope is passed through the cervix and is used to visualize the inside of the uterus.
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.
Induced or therapeutic abortion - A surgical or other medical procedure used to end a pregnancy.
IUI (intrauterine insemination) - A type of fertility treatment in which sperm is washed and injected directly into the uterus around the time of ovulation.
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.
Karyotyping - A test performed to analyze chromosomes for the presence of genetic defects.
Klinefelter's Syndrome - A genetic abnormality characterized by having one Y (male) chromosome and two X (female) chromosomes. This condition may cause a fertility problem.
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.
Live birth - The delivery of one or more babies with any signs of life.
Luteal Phase - Post-ovulatory phase of a woman's cycle. The corpus luteum produces progesterone, which cause the uterine lining to thicken to support the implantation and growth of the embryo.
Luteal Phase Defect - (or deficiency) A condition that occurs when the uterine lining doe snot develop adequately due to inadequate progesterone stimulation or because of the inability of the uterine lining to respond to progesterone stimulation.LPD may prevent embryonic implantation or cause an early abortion.
Luteinizing hormone (LH) - A pituitary hormone that stimulates the ovary. When estrogen reaches a critical peak, the pituitary releases a surge of LH (the LH spike) that releases an egg from the follicle.
Luteinizing hormone (LH) - Surge The mid-cycle release of LH that causes an egg to be ovulated. Ovulation detection kits detect the sudden increase in LH signaling that ovulation is about to occur, usually within 24-36 hours.
Male factor - Any cause of infertility due to low sperm count or problems with sperm function that make it difficult for a sperm to fertilize an egg under normal conditions.
Miscarriage (also called spontaneous abortion) - A pregnancy ending in the spontaneous loss of the embryo or fetus before 20 weeks of gestation.
Morula - A stage of embryo development after 4 days of culture in vivo (inside the body). Between the 8-cell stage and the blastocyst stage of development, all the cells of the embryo merge together, this is referred to as a morula.
Motility (of sperm) - The ability of sperm to move and swim normally.
Multi-fetal pregnancy reduction - A procedure used to decrease the number of fetuses a woman carries and improve the chances that the remaining fetuses will develop into healthy infants. Multi-fetal reductions that occur naturally are referred to as spontaneous reductions.
Multiple-infant birth - A pregnancy that results in the birth of more than one infant.
Multiple-fetus pregnancy - A pregnancy with two or more fetuses.
Oocyte - The female reproductive cell, also called an egg.
Ovarian Cyst - A persistent fluid-filled sac inside the ovary. Cysts can produce hormones that interfere with ART cycles.
Ovarian Hyper Stimulation Syndrome (OHSS) - A potentially life-threatening condition following ovulation induction treatment. OHSS arises when too many follicles develop and hCG is given to release the eggs. This condition may be prevented by withholding hCG when ultrasound monitoring indicates that there are a large number of follicles in the ovaries. IF OHSS is evident during an IVF cycle, all the embryos may be frozen at the pro nuclear stage (the day after the egg collection) and replaced at a later date when the condition has subsided as pregnancy can exacerbate the symptoms of OHSS.
Ovarian monitoring - The use of ultrasound and/or blood or urine tests to monitor follicle development and hormone production. Ovarian Reserve may be tested by checking a single FSH blood test on cycle day 3 or by the clomiphene challenge test, in which FSH is measured on day 3, clomiphene 100 mg is taken on days 5 through 9, and FSH is measured again on day 10. Both tests are utilized to predict a decline in a woman’s ability to become pregnant, independent of her age.
Ovarian stimulation - The use of drugs (oral or injected) to stimulate the ovaries to develop follicles and eggs.
Ovulation - The release of an egg from an ovarian follicle.
Ovulatory dysfunction - A cause of infertility due to problems with egg production by the ovaries.
Ovum - Another name for the egg.
Patent - The condition of being open or unblocked (as with the fallopian tubes).
Pelvic Inflammatory Disease (PID) – An infection of the pelvic organs that may lead to tubal blockage and pelvic adhesions.
Pituitary gland - The mater gland. The pituitary gland is situated in the brain by the hypothalamus and controls all hormonal functions, including the gonads, the adrenal glands and the thyroid gland.
Polar body - The discarded genetic material resulting from female germ cell division. When an egg matures it discards half of its genetic material so that the egg cell is ready to fuse with half the male genes inside a sperm. This discarded genetic material can be seen in the egg as a small round piece of cytoplasm at the edge of the egg cell. The presence of a polar body tells us whether an egg is mature or immature.
Polycystic ovaries - A condition found in women who don't ovulate, characterized by excessive production of male sex hormones (androgens) and the presence of cysts on the ovary. PCO can be without symptoms although some women who do show symptoms are said to have PCOS.
Polycystic Ovary Syndrome (PCOS) - A condition where the symptoms of having polycystic ovaries are evident. PCOS symptoms may include weight gain, acne and excessive hair growth.
Pregnancy (biochemical) - A positive pregnancy test that shows no evidence of a gestational sac or viable fetus on ultrasound. Can be classed as a very early miscarriage.
Pregnancy (clinical) - A pregnancy documented by ultrasound that shows a gestational sac containing a viable fetus in the uterus. For ART data collection purposes, pregnancy is defined as a clinical pregnancy rather than a biochemical pregnancy (i.e., a positive pregnancy test).
Pre-implantation Genetic Diagnosis (PGD) - offers the opportunity to test a single cell from an eight cell embryo for certain diseases caused by a mutation in a single gene (such as Cystic Fibrosis, Sickle Cell Anemia, and Huntington’s Chorea, to name a few ) prior to the embryo transfer procedure. This technology is beneficial when an inheritable disease is known to occur in one’s family or when DNA screening tests on the couple going through IVF are positive. It is also beneficial when recurrent miscarriages are known to be due to a Robertsonian translocation.
Premature ovarian failure (POF) - occurs when ovulation stops prior to age 40. A diagnosis of POF is correct when a woman has gone at least 4 months without periods, estrogen levels are low, and follicle stimulating hormone (FSH) is high as evidenced by two FSH tests at least one month apart. POF is often mistaken for premature menopause, however, that phrase is inappropriate since menstruation infrequently occurs in some women who have POF. Premature menopause occurs when a woman fails to menstruate for one year prior to age 40. Unfortunately, no treatment can restore normal ovarian function. Pregnancy is usually not possible for women who have POF. However, some women with POF do produce estrogen intermittently and ovulate, even with high FSH levels.
Progesterone - The hormone produced by the corpus luteum after ovulation that supports the development and maintenance of the uterine lining.
Pro nuclear Stage (2PN) - A fertilized egg (zygote). In IVF, the pronuclear stage is the morning after the egg collection.
Pronuclei (PN) - The evidence of fertilization. In a normally fertilized egg, two spherical structures (pronuclei) can be seen in the middle of the egg 16-22 hours post insemination. One of the spheres contains the female genetic material and the other contains the male genetic material before they fuse to form the genes of the embryo.
Reproductive Endocrinologist (RE) - has additional training, advanced knowledge and skill in the management of complex problems relating to hormone imbalances and difficulty in achieving or maintaining a pregnancy. It requires additional years of specialized, formal training with ongoing clinical competency testing after a four-year residency and board certification in obstetrics and gynecology. Many board certified Reproductive Endocrinologists are involved in clinical and basic science research.
RESOLVE - A national, nonprofit consumer organization offering education, advocacy, and support to those experiencing infertility.
Retrograde ejaculation - A male infertility problem in which sperm travel into the bladder instead of out of the penis. This is due to a failure in the sphincter muscle at the base of the bladder. Medical intervention is necessary in order to conceive.
Salpingectomy - Surgical removal of the fallopian tubes.
Semen - The fluid portion of the ejaculate consisting of secretions from the seminal vesicles and prostate gland, and several other glands in the male reproductive tract.
Semen analysis - A laboratory test to assess semen quality. Semen analysis includes, sperm count, morphology, motility, semen viscosity and volume.
Semen viscosity - The liquid flow or consistency of the semen.
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 the CDC.
Sperm - The male reproductive cell.
Sperm agglutination - Sperm clumping caused by antibodies or by infection.
Sperm antibodies - Antibodies that are made against sperm.
Sperm count - The number of sperm in the ejaculate.
Sperm morphology - The number or percentage of sperm which look microscopically normal.
Sperm motility - The ability of sperm to move and swim normally.
Superovulation - The stimulation of multiple ovulation with fertility drugs.
Stillbirth - The birth of an infant with no signs of life after 20 or more weeks of gestation.
Stimulated cycle - An ART cycle in which a women receives oral or injected fertility drugs to stimulate her ovaries to produce more follicles.
TESA - Testicular Sperm Aspiration.
Testes - The male reproductive gland; source of sperm and male sex hormones normally occurring paired in an external scrotal sac.
Testicular biopsy - A minor surgical procedure used to take a small sample of testicular tissue for microscopic examination. Sperm may be retrieved using a testicular biopsy when there is a tubal blockage which is preventing sperm from being ejaculated.
Testosterone - The male hormone.
Turner syndrome – is a chromosomal condition that exclusively affects females. It occurs when one of two ‘X’ chromosomes normally found in a female is missing or incomplete. The sex chromosomes determine whether an individual is male or female; they influence height as well as the development of sex organs. A female ordinarily has two ‘X’ chromosomes, while a man has one ‘X’ and one ‘Y chromosome. The reason for the total or partial loss of the chromosome usually cannot be found but the loss occurs soon after that baby is conceived. There is nothing either parent can do to prevent this from happening. It is a random genetic event.
Ultrasound - A technique used in ART for visualizing the follicles in the ovaries, the gestational sac, or the fetus.
Umbilical Cord - Two arteries and one vein encased in a gelatinous tube leading from the baby to the placenta. The umbilical cord is used to exchange nutrients and waste between the mother and the developing baby.
Unexplained infertility - Infertility for which no cause has been determined despite a comprehensive evaluation of both partners.
Urologist - A physician specializing in the genitourinary tract. Uterus -The hollow muscular organ in which a fetus develops during pregnancy.
Vagina - The canal leading from the cervix to the outside of a woman's body.
Varicocele - A dilation of veins that carry blood out of the scrotum which leads to elevated scrotal temperature. A major cause of male infertility.
Vas Deferens - The tubes through which sperm move from the testicles (epidermis) towards the seminal vesicles and prostate gland. These tubes are closed during a vasectomy.
Vasectomy - A surgical procedure to block sperm from being released in the ejaculate. Vasectomy is used as a form of birth control.
X Chromosome - The female chromosome. Females have two X chromosomes in their genotype.
Y Chromosome - The Male chromosome Males have one Y and one X chromosome in their genotype.
Zona Pellucida - The outer ‘shell' surrounding the egg. The Zona Pellucida serves two purposes; firstly allowing only one sperm to enter the egg for fertilization and secondly to hold the cells of the developing embryo together before compaction.
Zygote - A fertilized egg which has not yet divided.