IVF & FERTILITY GLOSSARY OF TERMS

Anovulation

A lack of ovulation – where a woman’s ovaries fail to release eggs.

Anti-Mullarian Hormone (AMH)

A protein released by the ovaries that is related to the development of follicles in the ovary.

Antral Folicles

Smaller follicles in the ovaries that produce eggs – they are a good predictor of ovarian reserve, egg supply and response to stimulation with fertility drugs.

ART

Assisted Reproductive Technologies (ART) refers to any fertility treatment that involves eggs and embryos.

Azoospermia

The complete lack of sperm cells.

Basal Body Temperature

The body’s temperature at rest.

Blocked Fallopian Tubes

When an obstruction prevents the egg from traveling down the fallopian tube – known as tubal factor infertility.

Controlled Natural Cycle IVF

Where minimal drugs are used in the treatment, for example to prevent spontaneous ovulation – see Modified Natural Cycle IVF.

Corpus Luteum

After an egg has matured and been ovulated from the follicle, the empty follicle becomes a corpus luteum.

Crown Rump Length (CRL)

A pregnancy ultrasound measurement that measures the length in centimeters from the top of the baby's head to the bottom of the buttocks.

Cryopreservation

The process of preserving tissue by freezing it with liquid nitrogen. Cryopreservation may be used to preserve eggs, sperm, embryos, or ovarian tissue for later use.

Cytoplasm

The fluid contents of the egg cell.

Doppler

A form of ultrasound scan that measures the speed of red blood cells moving along blood vessels.

Down Regulation

A part of IVF treatment that involves the use of GnRH antagonists or GnRH agonists to temporarily suppress your body's natural production of FSH and LH.

Dysmenorrhea

Pelvic pain or cramping that occurs during menstruation.

Ectopic Pregnancy

Where the embryo implants itself into the fallopian tube.

Egg Retrieval

During IVF treatment, retrieval refers to the removal of the oocytes from the ovaries.

Embryo

An organism in the early stages of development.

Endometrioma

A cyst that appears on the ovary, filled with old blood.

Endometriosis

Women’s condition in which tissue similar to the lining of the uterus grows in other parts of the body, usually the ovaries.

Endometrium

The inner lining of the uterus.

Estradiol

The most abundant of the hormones called estrogens – most often measured during fertility testing.

Estrogen

A hormone secreted primarily by the ovaries, but it is also secreted by the adrenal glands and from fatty tissues. Its main duty is to signal the lining of the uterus to grow.

Fallopian Tubes

These are two thin tubes, one on each side of the uterus, which help lead the mature egg from the ovaries to the uterus. If conception takes place, the egg is usually fertilized in the fallopian tube. Then, the fertilized egg, or embryo, makes its way through the tube, and eventually implants into the uterine lining.

Female Factor Infertility

The phrase used when the cause for infertility is from the woman’s side.

Fertile Window

The time period where sex may lead to pregnancy – technically up to six days before a woman ovulates.

Fertilisation

A series of events that take place at the penetration of the egg by the sperm.

Fertility

The ability to conceive and have children.

Fibroids

Non-cancerous tumors containing fibrous tissue - may cause infertility, pelvic pain, heavy menstruation or problems with pelvic pressure or bowel movements.

Follicle

A small fluid-containing sac within the ovary.

Follicle-Stimulating Hormone (FSH)

The hormone that triggers the development of immature eggs in the ovary.

Gamete

The egg or the sperm cell.

Gonadotropin-Releasing Hormone (GnRH)

A hormone that stimulates the pituitary gland to produce two hormones, follicle-stimulating hormone (FSH) and luteinizing hormone (LH).

GnRH Agonist

A kind of fertility drug that uses artificial hormones to mimic GnRH. At first, they lead to a rapid increase in FSH and LH production followed by a stop in production – used to prevent natural ovulation.

GnRH Antagonist

A kind of fertility drug used to suppress the production of FSH and LH hormones. They do not create an initial surge in hormone production like GnRH agonists – used to prevent natural ovulation.

Human Chorionic Gonadotropins (hCG)

A hormone produced during pregnancy. Pregnancy testing involves the detection of hCG.

Hostile Cervical Mucus

Cervical mucus that is less than ideal for achieving pregnancy.

Hysterosalpingogram (HSG)

A test that allows the doctor to evaluate the shape of the uterus and whether or not the fallopian tubes are open.

Human Fertilisation and Embryology Authority (HFEA)

UK authority responsible for licensing, regulating and monitoring UK fertility clinics and research.

In Vitro Fertilisation

Fertilisation in a glass dish in the laboratory (alternatively called ‘test tube baby’ treatment).

In Vitro Maturation (IVM)

A process involving the collection of eggs, including immature eggs from smaller follicles in the ovary, which are then matured in the laboratory to produce several embryos.

Infertility

Failure to conceive after two years of unprotected sexual intercourse.

Intra-Cytoplasmic Sperm Injection (ICSI)

A specialised laboratory technique by which sperm is injected into the egg to facilitate fertilisation in male factor infertility.

Intra-Uterine Insemination (IUI)

Introduction of sperm into the uterine cavity through a tube called a catheter.

Luteinizing Hormone (LH)

A hormone that eventually triggers the release of the egg.

Male Factor Infertility

The phrase used when the cause for infertility is from the man’s side.

Menstruation

The shedding of the uterine lining (endometrium) through the vagina - also commonly called your ‘period’.

Mild/Soft IVF

Where treatment is conducted in the natural menstrual cycle and only small doses of stimulating drugs are used, with the objective of producing 2-7 eggs.

Natural Cycle In IVF

IVF without the use of fertility drugs to stimulate the ovaries to produce multiple eggs (relies on the spontaneous development of one follicle and one egg only).

Necrozoospermia

Sperm that does not move at all – sperm may be alive and not moving or dead.

Oligospermia

When very few sperm cells are produced, resulting in a low sperm count.

Oocyte

An immature egg that develops in a follicle.

Ovarian Cyst

A fluid-filled sac that develop on the ovaries. They are not uncommon in women an most cysts will go away without any treatment.

Ovarian Hyperstimulation (OHSS)

A rare but serious complication caused by the side-effects of fertility drugs. The ovaries become swollen with fluid, which can leak into the body.

Ovarian Reserve

The number of immature eggs that your ovaries contain at any time.

Ovary

The female reproductive organ that produces eggs.

Ovulation

The release of a ripe egg from the ovary.

Ovulation Induction

Stimulation of the follicles of the ovaries through the use of fertility drugs, resulting in the production of multiple eggs in one cycle.

Polycystic Ovarian Syndrome (PCOS)

A common cause of infertility in women, which may lead to irregular periods, anovulation, cystic ovaries and an increased risk of miscarriage.

Primary Infertility

Infertility without any previous pregnancy.

Progesterone

A female hormone that prepares the lining of the uterus to receive and sustain the fertilised egg.

Reproductive Endocrinologist

A doctor who specialises in treating infertility in women and men.

Retyrograde Ejaculation

A potential cause of male infertility -  when semen enters the bladder during orgasm, instead of leaving the body via the urethra.

Secondary Infertility

Infertility when there has been a previous pregnancy.

Sperm Morphology

The shape and/or form of the sperm cells.

Sperm Motility

The movement and swimming of sperm. Poor sperm motility means that the sperm do not swim properly, which can lead to male infertility.

Subfertility

Decreased fertility or a decreased chance of getting pregnant, but not a complete inability to get pregnant.

Superovulation

The drug-induced production of multiple eggs for use during assisted reproductive technologies, such as IVF.

Tubal Patency Test

An X-ray examination to check the health of the fallopian tubes and ensure there are no blockages.

Teratozoospermia

The medical term for abnormally shaped sperm.

Testicular Sperm Extraction (TESE)

A minor surgical procedure that involves the removal of a small sample of testicular tissue in order to retrieve sperm for use in an IVF treatment cycle.

Testosterone

The main male hormone, produced in the testes, which stimulates the development of male sex characteristics and is essential in the production of sperm.

Ultrasound

Involves the use of high-frequency sound waves to create an image of the internal organs. Commonly used during fertility treatment to examine the uterus, ovaries, and follicles, and to help guide instruments used during treatment. Ultrasound is also used to track the development of the growing fetus.

Vas Deferens

The thin muscular tube that carries the sperm from the testes to the urethra. Obstruction of this tube can lead to male infertility.

Vasectomy

A surgical procedure that severs or otherwise obstructs the vas deferens.

Urology

Medical specialty concerned with the urinary tracts of males and females and the reproductive system of males.

Zygote

The zygote stage refers to the moment after the sperm fertilizes the egg, but before cell division begins.