Fertility Glossary of Terminology


AB – C – DEFGHI – J – K – LM – N – OP – Q – RST – U – V – W – X – Y – Z


AMH – Anti Müllerian Hormone is produced by follicles and is one potential test for ovarian reserve

Andrologist – Doctor specialising in male infertility

Anovulation – When a woman does not ovulate

Azoospermia – When no sperm is present in semen

Basal body temperature (BBT) Your temperature, taken first thing in the morning when your body is at rest.

Births per embryo transferred – Births per embryo transferred (rather than births per cycle) are stated because fertility professionals say it’s the best measure of a clinic’s success and it allows you to make a fair comparison between clinics. It gives a fair overall view of their performance but it can’t tell you your individual chance of success (only your doctor can do that).

Births per egg collection – The chance of success from all the fresh and frozen embryo transfers within two years of one egg collection. Whilst births per embryo gives you an indication of success rates for just one embryo transfer, births per egg collection gives an overall picture of success rates for a full course of treatment (which can include one fresh and a number of frozen transfers).

Blastocyst stage – An embryo that is 5 or 6 days old following egg collection

Blighted ovum When a fertilised egg implants in the womb but sadly doesn’t develop into a baby

Bromocriptine A medicine sometimes prescribed to help with ovulation problems in women who have high levels of prolactin, a hormone that can interfere with ovulation.

Diathermy – Electrosurgery used either as a cutting modality or else to cauterize small blood vessels to stop bleeding

Embryo – Fertilised egg

Endometriosis – Cells from the endometrium appear outside the uterine cavity, generally on the ovaries and can cause distortion and adhesions

Epididymis – The organ where sperm is stored

Fallopian tubes – Tubes which join the uterus to the ovaries

Fibroids – Benign (non-malignant) tumours of the uterine wall

Folic acid Also known as vitamin B9, folic acid is vitally important for a growing baby’s nervous system.

Follicle – The sack in which the egg grows before ovulation. Not every follicle contains an egg

Follicle-stimulating hormone (FSH) Follicles are the parts of your ovaries that contain your eggs. FSH causes these follicles to ripen your eggs, ready for release when you ovulate. Available under the brand names Gonal-F and Metrodin.

FSH – Follicle Stimulating Hormone which is responsible for maturing the egg

Gametes – Reproductive cells, either female eggs or male sperm

HEP B (Anti-HBc) – Hepatitis B: first antibody produced after infection with hepatitis B virus; used to detect acute and chronic infections.

HEP B (HBsAg) – Hepatitis B: earliest indicator of acute hepatitis B and frequently identifies infected people before symptoms appear; undetectable in the blood during the recovery period; it is the primary way of identifying those with chronic infections

HCG – Human Chorionic Gonadotropin is a hormone injection that triggers ovulation

HFEA – Human Fertilisation and Embryology Authority is the regulatory body by which all fertility clinics in the UK conform to set standards

HTLV – Human T-Lymphotropic Virus (HTLV) is a retrovirus associated with a weakening of the immune system which is lifelong. Some people may carry without symptoms whilst others develop cancers and other diseases, depending on the form of HTLV with which they are infected

Hydrosalpinx – Fluid collects in the fallopian tube

Hypogonadism Also known as gonad deficiency, this is what happens when your brain doesn’t produce enough of certain hormones, known as gonadotrophins. In men, this can impair sperm production, and in women, it can prevent ovulation.

Hypothalamus – Area of the brain responsible for the control of the pituitary gland

Hysteroscopy – An inspection of the uterus using a small telescope

IVF – In Vitro Fertilisation During IVF, mature eggs are retrieved from the ovaries and fertilized by sperm in a laboratory. Then the fertilized egg (embryo) or eggs (embryos) are implanted in the uterus. One cycle of IVF takes about two weeks.

ICSI – Intra Cytoplasmic Sperm Injection involves injecting single sperm directly into a mature egg using a specially prepared needle

Impryl – Impryl is the mens & women’s fertility supplement choice of specialists across the UK that helps optimise sperm and egg quality.

IMSI – Intracytoplasmic Morphologically-selected Sperm Injection is ICSI with the difference of an extremely high-powered microscope to select the sperm cells with the best quality

Irregular cycle An irregular menstrual cycle is one that varies in length by more than a few days from month to month. In some cases, an irregular cycle can be a sign that you’re not ovulating regularly.

IUI – Intra Uterine Insemination involves injecting sperm using a fine catheter when a woman has ovulated

Laparoscopy – An inspection of the pelvis using a small telescope

LH – Luteinising Hormone which brings about ovulation

LH – RH analogue – A drug that stimulates the release of FSH from the pituitary gland

Myomectomy – Open surgery to remove large fibroids

Multiple birth rates – Having twins may seem like a wonderful thing, but multiple pregnancies are much less safe for both mother and babies. That’s why the HFEA set a target for all clinics to have a multiple birth rate of 10% or lower

Oestrogen / Oestrodiol (E2) – A female sex hormone secreted by the developing follicle

OHSS – Ovarian Hyper Stimulation Syndrome has varying degrees of severity and is a complication caused when there is an excessive response of the ovaries to fertility drugs

Ovariesv The female reproductive organs which produce female sex hormones and store and release eggs

Ovulation – The release of the egg from the ovarian follicle

Peritoneal cavity – The space that contains internal pelvic and abdominal organs

Pituitary gland – The gland which secretes the hormones that control ovulation

PCOS – Polycystic Ovarian Syndrome

PGAS – Pre-implantation Genetic Aneuploidy Screening is a chromosomal analysis of abnormal embryos

Progesterone – A female sex hormone produced by the ovaries during the release of a mature egg at ovulation

Prolactin – Hormone produced by the pituitary gland. High levels of prolactin cause anovulation

Pronuclei – Visible signs of fertilisation containing the genetic material from the male and female gametes

Rubella – Disease caused by the rubella virus. If the mother is infected, the baby will be born with a range of serious incurable illnesses

Satellite Fertility Clinic – What a satellite clinic is, is a common question. Often fertility clinics will have multiple satellite treatment clinics around the country to reduce patient travelling times, where investigations, treatment planning and scans will be carried out. Only the main procedures will require you to travel to the clinic headquarters.

Sickle cell screening – Blood test to check whether or not there is a possibility that a baby could inherit sickle cell disease

Testes – The male reproductive organs that produce sperm

Thalassaemia – A genetic condition affecting the blood. There are different types of thalassaemia. Depending on which type, thalassaemia may cause no illness at all or may be a serious lifelong condition requiring treatment

TSH – Thyroid Stimulating Hormone is produced by the pituitary gland and causes the thyroid gland to make 2 hormones: T3 and T4

Total Fertility (Rate) – The mean number of children a woman would have by age 50 if she survived to age 50 and were subject, throughout her life, to the age-specific fertility rates observed in a given year. The total fertility is expressed as the number of children per woman.

Varicocele – Varicose veins around the vas deferens

Vas deferens – The tube from each testicle which transports sperm