Glossary

Refer to this guide whenever the biology of conception or infertility terms becomes too muddled with initials and acronyms and uncommon words.

amenorrhea – the complete absence or suppression of menstrual periods 

American Fertility Association (AFA) – a non-profit organization focusing on infertility, reproductive and sexual health, and family building by providing information, serving as a national adviser and offering a range of services that are free to consumers

American Society of Reproductive Medicine (ASRM) – an organization of health care specialists and scientists interested in reproductive medicine

amniocentesis – a procedure that removes a small amount of amniotic fluid through a needle from the fetal sac at about 16 weeks into a pregnancy to explore chromosomal abnormalities

androgens – compounds that stimulate or control the development and maintenance of masculine characteristics, including the activity of sex organs and the development of secondary sex characteristics

andrology – the specialty dealing with male health, particularly relating to the reproductive system and urology

antisperm antibodies – antibodies produced by the immune system of either the male or female partner that mistake sperm for an invading substance and begin attacking them, often causing the sperm to clump together, lose motility or lose the ability to fertilize an egg

artificial insemination – see intrauterine insemination 

assisted hatching – opening of the zona pellucida (or shell of an embryo) mechanically or with enzymes prior to transferring into the uterus to assist the embryo in escaping from its shell before implantation

assisted reproductive technology (ART) – any treatments that involve handling human eggs, sperm or resulting embryos outside the body in a laboratory

asthenospermia – sperm with poor motility or movement

azoospermia – no measurable level of sperm in the semen 

basal body temperature – resting temperature measured immediately after awakening and before any physical activity has been undertaken 

blastocyst – an embryo that has grown to roughly 100 cells, typically five days after fertilization and prior to implantation

cervix – the lower narrow end of the uterus that connects the uterine cavity to the vagina

chorionic villus sampling – a procedure in which a small sample of cells is taken from the placenta early in a pregnancy for chromosomal testing

chromosomes – rod-shaped structures located in the nucleus of a cell which contain hereditary or genetic material. Humans have 23 pairs including two sex chromosomes.

cleavage – the division of a fertilized egg in which the egg size remains unchanged while the cells become smaller with each division

clinical pregnancy – a pregnancy confirmed by an increasing level of hCG and the presence of a gestational sac detected by ultrasound without evidence of a fetal heartbeat

clomiphene citrate challenge test (CCCT) – a blood test to measure follicle stimulating hormone (FSH) taken on days 3 and 10 of the menstrual cycle. Clomiphene citrate (also called Clomid) is given on days 5 through 9 to induce ovulation prior to this test.

cryopreservation – freezing and storage at an extremely low temperature, such as liquid nitrogen (-196° C), to keep embryos or sperm viable until being thawed for transfer or fertilization months or years later

donor egg – an egg from a fertile woman that is donated to an infertile woman to be used in an assisted reproduction procedure

donor sperm – sperm donated by a fertile man who is not the recipient's partner

ectopic pregnancy – a pregnancy in the fallopian tube or elsewhere outside the endometrial cavity

egg donation – the process of fertilizing eggs from a donor and transferring the resulting embryos to a recipient's uterus 

egg retrieval – the outpatient procedure of inserting a needle into an ovarian follicle within the uterus and removing the fluid and the eggs by suction, typically done using transvaginal ultrasound guidance while a patient is under sedation. Retrieved eggs are then combined with sperm under incubation in a laboratory to allow embryonic development to be observed closely for up to a week.

embryo – a fertilized egg up to 14 days after fertilization

embryologist – a laboratory specialist who handles sperm, eggs and embryos from the time of egg retrieval until embryo transfer or cryopreservation

embryology – the study of the development of an embryo 

embryo transfer (ET) – placement of an embryo into the uterus through a vaginal catheter during a non-surgical, non-sedated procedure performed with ultrasound guidance

endocrine system – an integration of small organs which release hormones to regulate metabolism, growth and development, puberty, tissue function and mood. The hypothalamus links the nervous system to the endocrine system via the pituitary gland. The key endocrine glands are the pituitary, thyroid and adrenal which release into the bloodstream specific chemical messengers called hormones to affect the heart, skin, stomach, duodenum, liver, pancreas, kidneys and reproductive organs.

endocrinology – the branch of medicine dealing with disorders of the endocrine system and its hormone secretions

endometriosis – a condition characterized by the uterine lining growing outside the uterus, on or in other areas of the abdominal cavity. The misplaced endometrium is usually unable to exit the body, possibly resulting in internal bleeding, degenerated blood and tissue shedding, inflammation of the surrounding areas, pain and the formation of scar tissue.

endometrium – the lining of the uterus

estradiol – the major estrogen in both men and women which has a critical impact on reproductive and sexual functioning as well as other organs in the human body. From first period to menopause, women have more estradiol than any other estrogen.

estrogen – three naturally occurring estrogens (or sex hormones) in women are estradiol, estriol, and estrone. Each is produced from androgens (such as testosterone) through actions of enzymes to significantly impact the reproductive system, among other body functions. These hormones are largely responsible for stimulating the uterine lining to thicken.

fallopian tubes – a pair of tubes attached to the uterus, one on each side, where sperm and eggs meet in normal conception. The tubes also are responsible for nourishing the embryo during the first few days after fertilization.

follicle – the fluid-filled cyst or sac in which an egg matures, lying just under the ovary surface

follicle stimulating hormone (FSH) – a hormone produced by the pituitary gland that stimulates the growth of the follicle surrounding an egg. FSH also can be given by injection.

frozen embryo – an embryo that has been cryogenically preserved

frozen embryo transfer (FET) – an embryo that is thawed after cryogenic preservation and placed into the uterus through a vaginal catheter during a non-surgical, non-sedated procedure performed with ultrasound guidance

gamete – an egg or a sperm

gamete intrafallopian transfer (GIFT) – the placing of sperm and egg directly into the fallopian tube, where fertilization takes place. This procedure is no longer performed by the Fertility Center's doctors due to better success rates with intrauterine transfers following in vitro fertilization (IVF).

genetic – inherited conditions, usually due to genes located on chromosomes 

gestational carrier or surrogate – a woman who carries a pregnancy in utero for another woman but does not provide a genetic contribution  

gestational sac – a fluid-filled structure that develops within the uterine cavity early in a pregnancy and contains an embryo

gonadotropin releasing hormone (GnRH) – a hormone secreted by the hypothalamus (an area of the brain that controls reproduction among other functions) which prompts the pituitary gland to release follicle stimulating hormone (FSH) and luteinizing hormone (LH) into the bloodstream. Synthetic analogs are available.

habitual or spontaneous abortion – the occurrence of repeated pregnancies that end in miscarriage of the fetus, usually before 20 weeks of gestation. Affects about one-third of women who conceive.  Also known as recurrent pregnancy loss.

human chorionic gonadotropin (hCG) – a hormone produced by the placenta that is detected and measured by most pregnancy tests. This hormone also can be given by injection to stimulate ovulation and trigger maturation of eggs.

hormone – a substance secreted from organs of the body (such as the pituitary gland, adrenal gland or ovaries) which is carried by blood or another bodily fluid to organs and tissues to exert a specific action

hyaluronan binding assay (HBA) – a test to determine the maturity of sperm in a fresh semen sample. This qualitative analysis evaluates the ability of mature sperm to bind to the substance hyaluronan, which is a major component of the external coating of eggs. The ability to bind to hyaluronan is not present in immature sperm and is necessary for proper sperm function.

hyperstimulation – see ovarian hyperstimulation syndrome

hysterosalphingogram (HSG) – an x-ray procedure while the uterus and fallopian tubes are filled with dye to determine if the tubes are open and whether there are uterine abnormalities or blockages

hysteroscopy – an operative procedure done through the cervix which allows a surgeon to inspect and treat the uterine cavity with a visual scope and instruments while the cavity is expanded with fluid or gas. This intervention typically is done under anesthesia for therapeutic purposes, but a diagnostic procedure can be performed without anesthesia.

implantation – embedding of an embryo into the uterine lining

infertility – the inability to conceive after one year of unprotected intercourse. Also the inability to carry a pregnancy to term. This definition is reduced to six months for women over age 35 or for those with a history of painful periods, irregular cycles, pelvic inflammatory disease and miscarriages as well as for men with a low sperm count.

intracytoplasmic sperm injection (ICSI) – a procedure in which a single sperm cell is injected with an ultrafine needle directly into a single mature egg to help spur fertilization. This procecure is used primarily with male-factor infertility cases.

intramuscular injections – administering medication with a 1½ inch needle injected into the hip muscle

intrauterine insemination (IUI) – a form of artificial insemination in which sperm that has been washed free of seminal fluid and processed to increase concentration and activity is inserted directly into the uterus

in vitro fertilization (IVF) – a procedure in which an egg and sperm are combined in the laboratory dish to facilitate fertilization. Resulting fertilized and dividing embryos are transferred into a woman’s uterus to then develop naturally. This approach offers the highest rate of success of all infertility treatment options.

laparoscopy – an operative procedure done through a tiny incision in the belly button which allows a surgeon to inspect and treat the abdominal cavity with a visual scope and instruments while the cavity is expanded with fluid or gas. This intervention typically is done under anesthesia for therapeutic purposes but a diagnostic procedure can be performed without anesthesia.

laparotomy – a surgical procedure done through an incision into the abdomen

luteinizing hormone (LH) – produced by the pituitary gland, this hormone normally causes a woman to ovulate and her eggs to mature.

menopause – the natural and permanent stopping of the monthly female reproductive cycles, signaling the end of ovary function and the fertile phase of a woman's life

microsurgical epididymal sperm aspiration (MESA) – a procedure for collecting sperm from the organ that stores and nourishes sperm as they develop and pass from the testes. May be needed to extract sperm from men whose reproductive ducts are blocked. Performed with assistance from a urologist while patient is under anesthesia.  The doctors at the Fertility Center prefer the percutaneous (PESA) and testicular (TESA) aspiration techniques over the microsurgical, which requires additional specialized equipment.

miscarriage – the natural or spontaneous end of a pregnancy at a stage where the embryo or the fetus is incapable of surviving, generally defined at a gestation of prior to 20 weeks. Identified as the most common complication of early pregnancy.

morphology – the form, structure and shape of sperm

motility – the movement and speed of sperm

myomectomy – the surgical removal of fibroids from the uterus

oligospermia – low concentrations of sperm in the semen 

oocyte – egg

ovum or ova – female gamete or gametes

ovarian cyst – any collection of fluid surrounded by a very thin wall within an ovary. Any follicle that is larger than two centimeters is termed an ovarian cyst and can be as small as a pea or grow as large as a grapefruit.

ovarian hyperstimulation syndrome (OHSS) – a potentially life-threatening condition characterized by enlargement of the ovaries, fluid retention, weight gain and abdomen pain that may occur when the ovaries are overstimulated during assisted reproduction

ovarian reserve – a woman's fertility potential related to the number and quality of her eggs

ovaries – two female sex glands in the pelvis located on either side of the uterus that produce eggs and hormones including estrogen, progesterone and androgens 

ovulation – release of eggs from the ovaries, normally 14 days before the next menstrual cycle

ovulation induction – the administration of hormone medications that stimulate the ovaries to produce multiple eggs

pelvic adhesions – abnormal bands of abdominal tissue commonly caused by surgical procedures or endometriosis that may grow and become attached to the walls of the abdomen as well as to internal organs

pelvic inflammatory disease (PID) – a generic term for an infection of the female uterus, fallopian tubes and/or ovaries as it progresses to scar formation with adhesions to nearby tissues and organs

percutaneous epididymal sperm aspiration (PESA) – a procedure for collecting sperm from the organ that stores and nourishes sperm as they develop and pass from the testes. May be needed to extract sperm from men whose reproductive ducts are blocked. Done with assistance from a urologist while patient is under anesthesia.

perimenopause – the transition years leading up to menopause when reproductive hormone production becomes irregular, causing many women to experience hot flashes, mood changes, insomnia, fatigue, diminished fertility and other hormonal side effects during the fluctuations. Symptoms can begin as early as age 35.

polycystic ovary syndrome (PCOS) – an endocrine disorder that affects approximately one in ten women as the most common hormonal disorder among females of reproductive age and a leading cause of infertility. The most common symptoms are weight problems, lack of regular ovulation and/or menstruation and excessive amounts or effects of androgenic (masculinizing) hormones. Some cases lead to prolific endometrial cells or even cancer, among other health risks. Not all women with ovarian cysts have PCOS.

preimplantation genetic diagnosis (PGD) – one or two cells are removed from an embryo and screened for genetic abnormalities

premature ovarian failure – dysfunction of the ovaries, loss of eggs or removal of the ovaries at a young age, resulting in infertility as well as other possible health problems. This condition is defined by abnormally low levels of estrogen and high levels of FSH.

progesterone – a female hormone secreted after ovulation which prepares the lining of the uterus for implantation of a fertilized egg or allows for the shedding of the lining at the time of menstruation

pronuclear stage – an early stage of fertilization where the egg and the sperm pronuclei are visible under a microscope

recurrent pregnancy loss – the occurrence of repeated pregnancies that end in miscarriage of the fetus, usually before 20 weeks of gestation. Also known as habitual or spontaneous abortion, this condition affects about one-third of women who conceive.

reproductive endocrinologist – a medical surgeon with a subspecialty of obstetrics and gynecology that addresses hormonal functioning as it pertains to reproduction and evaluates and treats infertility as well as hormonal dysfunctions in both men and women.

saline-infused ultrasound – a procedure that involves filling the uterus with saline solution through a tiny cervical catheter to evaluate the uterine cavity by ultrasound and identify any irregularities, such as fibroids, polyps or septums

secondary infertility – difficulty conceiving after already having conceived and carried a normal pregnancy

semen – fluid in which sperm are ejaculated

semen analysis (SA) – microscopic techniques to measure and study sperm. A basic analysis determines how many total sperm are present (for example, 25 million), how many sperm are moving (motility), and how fast they are moving. A strict criteria morphology shows how many sperm (reported in %) are shaped normally.

Society for Assisted Reproductive Technology (SART) – an affiliated society of the ASRM comprised of assisted reproductive technology programs that have a special interest in assisted reproductive technology (ART) and have demonstrated their ability to successfully perform in vitro fertilization procedures

sperm – the male reproductive cells produced by the testes which cannot divide, have a limited life span and are the smaller genetic gametes involved in fertilization

sperm extraction – see microsurgical (MESA), percutaneous (PESA) and testicular (TESA) epididymal sperm extractions

sperm penetration assay (SPA) – a test for sperm function that is used to determine the ability of the sperm to penetrate the egg membrane and form a pronucleus. This procedure also is known as the hamster egg penetration test, which has been replaced at the Fertility Center by the more effective hyaluronan binding assay (HBA) test. 

sperm separation – dividing sperm into two groups: the ones that will produce males after fertilizing an egg and the ones that will produce females. This expensive process can deplete the number of viable sperm and create a necessity for in vitro fertilization.

subcutaneous injections – administering medication with a ½ inch - ⅝ inch needle injected just under the surface of the skin into the fatty tissue

super ovulation cycle (SOC) – administering drugs to stimulate egg production and control the timing of ovulation to maximize the number of eggs produced. Frequent blood tests to monitor hormone levels and ultrasound scans to monitor follicle development are necessary to avoid hyperstimulation.

surrogate – see gestational carrier 

testes – the two male reproductive glands located in the scrotum which produce testosterone and sperm

testicular epididymal sperm aspiration (TESA) – needle biopsy to remove testicular tissue and collect living sperm from the testes. Typically done when other collection attempts, such as MESA or PESA, have been unsuccessful. Done with assistance from a urologist while patient is under anesthesia.

testosterone – the primary male hormone produced by the testes in men which is responsible for the development of sperm, male physical characteristics and sex drive. This hormone also is produced in small quantities by the ovaries in women. 

teratospermia – sperm with poor morphology or shape

thawed donor insemination (TDI) – a intrauterine insemination with donor sperm that is thawed after cryogenic preservation 

tubal ligation reversal – a surgical procedure that restores fertility to women after a tubal ligation by rejoining the separated segments of the fallopian tube to increase the chances of becoming pregnant again naturally 

ultrasound – technology that uses high-frequency sound waves to form an image of internal organs on a monitor screen for monitoring the growth of ovarian follicles or the presence of a gestational sac. Can be performed abdominally or vaginally.

uterus or womb – the hollow, muscular organ in the pelvis of women where an embryo implants and grows during pregnancy. The lining of the uterus (or endometrium) produces the monthly menstrual blood flow when there is no pregnancy.

zona pellucida – an egg’s outer layer that sperm must penetrate before fertilization can occur

zygote – a fertilized egg before cell division begins, also known as a single cell embryo

zygote intrafallopian transfer (ZIFT) – a procedure similar to in vitro fertilization (IVF) in which an egg is fertilized in a laboratory dish and the zygote (stage before cell division begins) is surgically transferred to the fallopian tube. This procedure is no longer performed by the Fertility Center's doctors due to better success rates with intrauterine transfers.