Fertility language.
Made understandable.

Abstinence before a semen test

The time since your last ejaculation before collecting a semen sample. It includes ejaculation through sex or masturbation.

Also searched as: ejaculatory abstinence, semen test preparation

Adenomyosis

A condition in which tissue from the womb lining grows within the muscular wall of the womb. It is different from endometriosis.

AMH (anti-Müllerian hormone)

A hormone made by cells around small follicles in the ovaries. An AMH blood test gives information about ovarian reserve and likely response to ovarian stimulation.

Also searched as: anti mullerian hormone, AMH blood test, low AMH

Anovulation

A menstrual cycle in which an ovary does not release an egg. Bleeding can still occur without ovulation.

Also searched as: not ovulating, no ovulation

Antisperm antibodies

Immune proteins that can attach to sperm. Some laboratory reports describe IgA or IgG antibodies or use a mixed antiglobulin reaction (MAR) test.

Also searched as: IgA, IgG, MAR test

Antral follicle count (AFC)

The number of small fluid-filled follicles seen in the ovaries during an ultrasound scan. Each follicle may contain an immature egg.

Also searched as: AFC scan

Azoospermia

No sperm were found in the semen sample examined by the laboratory. This differs from having a low sperm count.

Also searched as: no sperm found

Basal body temperature (BBT)

Your resting body temperature, usually recorded after waking and before getting up. A small sustained rise can follow ovulation.

Also searched as: BBT chart, temperature tracking

BFN and BFP

Informal TTC abbreviations: BFN means a negative pregnancy test and BFP means a positive pregnancy test. They describe a result, not a medical diagnosis.

Also searched as: big fat negative, big fat positive

Blastocyst

An embryo at a later early-development stage, commonly reached around five or six days after fertilisation.

Cervical mucus

Fluid produced around the cervix that changes during the menstrual cycle. Around ovulation it may become clearer, wetter and more slippery.

Also searched as: egg white cervical mucus, EWCM

Cycle day (CD)

A way of counting days from the start of a period. Day 1 is usually the first day of proper menstrual bleeding, rather than light spotting.

Also searched as: CD1, day 1, cycle day 2–5

DPO (days past ovulation)

The number of days since ovulation. The day after an egg is released is described as 1 DPO.

Also searched as: days post ovulation, 1DPO, 14DPO

Ectopic pregnancy

A pregnancy that implants outside the womb, most often in a fallopian tube. It cannot continue safely and needs medical assessment.

Egg freezing

Collecting eggs after ovarian stimulation and freezing them for possible use in future fertility treatment.

Also searched as: oocyte cryopreservation, oocyte freezing

Egg quality

A broad way of describing an egg’s potential to support fertilisation and development into an embryo and, eventually, a baby.

Embryo

The developing group of cells formed after an egg is fertilised. In IVF, embryos are observed in the laboratory before transfer or freezing.

Endometriosis

A condition where cells similar to the womb lining grow elsewhere, such as around the ovaries or elsewhere in the pelvis.

Fertile window

The days in a cycle when sex can result in pregnancy: generally the five days before ovulation and the day of ovulation.

Also searched as: fertile days, fertility window

Fertilisation

The joining of an egg and a sperm. In unassisted conception this usually happens in a fallopian tube; in IVF it happens in a laboratory.

Also searched as: fertilization, conception

Fibroids

Non-cancerous growths in or around the womb. They vary in size and location, and many cause no symptoms.

Also searched as: uterine fibroids, myomas

Finger-prick blood test

A blood sample collected from a fingertip using a small lancet, rather than from a vein in the arm.

Also searched as: capillary sample, at home blood test, capillary blood test

Folic acid

A form of vitamin B9 recommended when planning a pregnancy to reduce the risk of neural tube defects in a developing baby.

Also searched as: folate, vitamin B9

Follicle

A small fluid-filled structure in an ovary that contains a developing egg. Follicles grow and change during a menstrual cycle.

Also searched as: ovarian follicle

Free androgen index (FAI)

A calculation using total testosterone and SHBG that can help assess androgen excess in some women. It is not a separate hormone.

Also searched as: FAI

Free T3 (FT3)

The unbound portion of the thyroid hormone triiodothyronine measured in blood. Thyroid hormones help regulate many body functions.

Also searched as: free triiodothyronine, FT3

Free T4 (FT4)

The unbound portion of thyroxine, a hormone produced by the thyroid gland. A blood test measures how much is circulating.

Also searched as: free thyroxine, FT4

FSH (follicle-stimulating hormone)

A hormone released by the pituitary gland. It supports follicle development in ovaries and sperm production in testes.

Also searched as: follicle stimulating hormone, FSH blood test

hCG (human chorionic gonadotrophin)

A hormone detected by pregnancy tests. It can be measured in urine or in blood, where a numerical result may be reported.

Also searched as: beta hCG, beta-hCG, pregnancy hormone

Hormone profile

A group of blood tests selected to answer a particular hormonal question. Different fertility profiles contain different markers.

Also searched as: fertility blood tests, hormone panel, fertility hormone test

HSG (hysterosalpingogram)

An X-ray examination using contrast dye to assess the outline of the womb cavity and whether dye passes through the fallopian tubes.

Also searched as: hysterosalpingography

HyCoSy

An ultrasound-based examination in which contrast passes through the womb and fallopian tubes to assess whether the tubes appear open.

Also searched as: hysterosalpingo contrast sonography, HyFoSy, tubal ultrasound test

Hysteroscopy

An examination of the inside of the womb using a thin camera passed through the cervix.

ICSI (intracytoplasmic sperm injection)

A laboratory technique used within IVF in which an embryologist injects one sperm directly into an egg.

Also searched as: intracytoplasmic sperm injection

Implantation

The process in which an embryo attaches to and begins embedding in the lining of the womb. It happens after fertilisation.

IUI (intrauterine insemination)

A treatment in which prepared sperm is placed directly into the womb around ovulation. It can use a partner’s or a donor’s sperm.

Also searched as: artificial insemination, intrauterine insemination

IVF (in vitro fertilisation)

A treatment in which eggs are collected and fertilised with sperm in a laboratory. An embryo may then be transferred into the womb.

Also searched as: in vitro fertilization, in vitro fertilisation

Laparoscopy and dye test

Keyhole surgery that allows a surgeon to examine the pelvis. Dye may also be used to assess whether it passes through the fallopian tubes.

Also searched as: keyhole surgery, lap and dye

LH (luteinising hormone)

A pituitary hormone involved in egg release and in signalling testosterone production in the testes. An LH rise can occur before ovulation.

Also searched as: luteinizing hormone, LH surge

Luteal phase

The part of a menstrual cycle after ovulation and before the next period. Progesterone usually rises during this phase.

Menstrual cycle

The time from the first day of one period to the first day of the next. It is not the number of days that bleeding lasts.

Also searched as: cycle length, period cycle

Oestradiol (E2)

A form of oestrogen produced mainly by the ovaries before menopause. Its level changes as follicles develop and across the menstrual cycle.

Also searched as: estradiol, estrogen, oestrogen

Ovarian reserve

The concept of the remaining egg supply. Tests such as AMH and antral follicle count give indirect information rather than an exact count.

Also searched as: egg reserve, egg count, diminished ovarian reserve

Ovulation

The release of an egg from an ovarian follicle. Ovulation timing can vary between people and between cycles.

Also searched as: egg release

Ovulation predictor kit (OPK)

A urine test that detects a rise in luteinising hormone. Some devices also measure another hormone to estimate potentially fertile days.

Also searched as: LH test, ovulation test, OPK

PCOS / PMOS

A hormonal and metabolic condition that can affect ovulation, periods and androgen-related symptoms. PCOS is the familiar name; newer NHS information also uses PMOS.

Also searched as: polycystic ovary syndrome, polycystic ovarian syndrome, PMOS

Pelvic ultrasound

A scan that uses sound waves to look at pelvic structures such as the womb and ovaries. A transvaginal scan uses a slim probe placed in the vagina with consent.

Also searched as: transvaginal ultrasound, TVUS, fertility scan

Pregnancy test

A urine or blood test that checks for hCG, a hormone associated with pregnancy. Home tests should be read exactly as the instructions describe.

Also searched as: home pregnancy test, urine pregnancy test

Premature ovarian insufficiency (POI)

Reduced or disrupted ovarian function before age 40. It may cause absent or irregular periods and symptoms linked to lower oestrogen.

Also searched as: premature menopause, early menopause, POI

Progesterone

A hormone that usually rises after ovulation and supports the womb lining. A correctly timed blood test can provide evidence that ovulation has occurred.

Also searched as: day 21 blood test, mid luteal progesterone

Prolactin

A pituitary hormone important in milk production. When raised outside the expected setting, it can be relevant to menstrual, ovulatory or reproductive symptoms.

Also searched as: prolactin blood test

Reference range

The interval or comparison values a laboratory supplies to help interpret a result. Units, methods and the population used to set the range matter.

Also searched as: normal range, reference interval, borderline result

Round cells in semen

A laboratory description for cells that look round in a semen sample. They may include immature sperm-producing cells or white blood cells.

Also searched as: leukocytes, white blood cells in semen, immature germ cells

Semen analysis

A laboratory examination of semen that can report sperm numbers, movement, shape and other characteristics. Semen is the fluid; sperm are the reproductive cells within it.

Also searched as: sperm test, male fertility test, sperm analysis

Semen liquefaction and viscosity

Liquefaction describes semen becoming more fluid after ejaculation. Viscosity describes how thick or stringy the sample remains.

Also searched as: thick semen, liquefaction time, semen viscosity

Semen pH

A measure of how acidic or alkaline the semen is. It describes the sample fluid, rather than how many sperm are present.

Also searched as: seminal pH

Semen volume

The amount of semen in the collected sample, usually reported in millilitres. It is different from sperm concentration or total sperm count.

Also searched as: ejaculate volume, low semen volume

SHBG (sex hormone-binding globulin)

A protein made by the liver that carries hormones, including testosterone, in the blood.

Also searched as: sex hormone binding globulin

Sperm agglutination

Motile sperm sticking to one another, for example by their heads or tails. It is a particular observation on a semen report.

Also searched as: sperm sticking together

Sperm concentration

The number of sperm in each millilitre of semen. It is usually expressed as millions per millilitre.

Also searched as: sperm per ml, million per millilitre

Sperm count

Usually the total number of sperm in the entire ejaculate. In everyday conversation, sperm count is sometimes used loosely to mean concentration.

Also searched as: total sperm number, total sperm count, low sperm count

Sperm DNA fragmentation

Damage or breaks in sperm genetic material assessed using specialised tests. It is different from the appearance of sperm under a microscope.

Also searched as: DNA fragmentation index, DFI, SDF

Sperm freezing

Storing sperm at very low temperatures for possible future use in fertility treatment.

Also searched as: sperm cryopreservation, sperm banking

Sperm morphology

An assessment of sperm shape using defined laboratory criteria. Reports commonly give the percentage meeting those criteria.

Also searched as: normal forms, teratozoospermia, sperm shape

Sperm motility

How sperm move. Progressive sperm travel forwards; non-progressive sperm move without useful forward travel; immotile sperm do not move.

Also searched as: progressive motility, non-progressive, immotile

Sperm vitality

The proportion of sperm assessed as alive, usually using a test of cell membrane integrity.

Also searched as: sperm viability, live sperm

Testosterone

An androgen hormone made mainly in the testes in men, with smaller amounts made elsewhere and in people with ovaries.

Also searched as: total testosterone, male hormone blood test, low testosterone

Treatment add-ons

Optional extra tests or treatments offered alongside established fertility treatment. Their purpose and supporting evidence vary.

Also searched as: IVF add-ons, fertility add ons

TSH (thyroid-stimulating hormone)

A pituitary hormone that signals the thyroid gland to produce thyroid hormones. It is a common starting point when assessing thyroid function.

Also searched as: thyroid stimulating hormone, thyroid test

TTC (trying to conceive)

A common abbreviation for trying to become pregnant. It can describe different routes, including sex, donor conception or fertility treatment.

Also searched as: trying for a baby, trying to get pregnant

Tubal patency

Whether the fallopian tubes are open so that fluid can pass through them. These tubes are where egg and sperm usually meet in unassisted conception.

Also searched as: tubal latency, open fallopian tubes, blocked tubes

Two-week wait (TWW)

An informal description of the time between ovulation or fertility treatment and the recommended pregnancy test date. It is not always exactly two weeks.

Also searched as: 2WW, TWW

Unexplained infertility

A term used when a standard fertility assessment has not identified an explanation for difficulty conceiving. It does not mean that the experience is imagined.

Also searched as: normal tests but not pregnant

Venous blood test

Blood collected from a vein, usually in the arm, by an appropriately trained professional.

Also searched as: venepuncture, phlebotomy, blood draw

Vitamin D

A nutrient important for bone and muscle health. It is often discussed during preconception and pregnancy planning.