Fertility Glossary: Medical Terms Explained Simply

Fertility medicine comes with its own language. Walking into a consultation and hearing terms like "antral follicle count," "blastocyst transfer," or "hysterosalpingogram" can feel like learning a foreign language while simultaneously processing some of the most emotionally significant news of your life.

We created this glossary because you deserve to understand what your doctors are talking about. When you understand the terminology, you can participate more fully in your own care. You can ask better questions, understand your test results, and feel more in control of your journey.

This is not meant to replace conversations with your medical team. Rather, it is a reference guide you can return to whenever you encounter an unfamiliar term. Bookmark this page, print it out, or save it to your phone for easy access during appointments.

We have organized the terms alphabetically so you can quickly find what you need. For each term, we explain not just what it means but why it matters for your fertility journey. This glossary accompanies our Understanding Fertility guide, where you can learn more about each topic in depth.

A

Adhesions

Bands of scar tissue that can form between organs or structures in the pelvis. Adhesions can result from previous surgeries, infections, or conditions like endometriosis. They can affect fertility by distorting the position of the fallopian tubes or ovaries, or by creating barriers to normal function.

AMH (Anti-Mullerian Hormone)

A hormone produced by cells in developing ovarian follicles. AMH levels in the blood provide information about ovarian reserve, or the quantity of eggs remaining in the ovaries. Higher AMH generally indicates more eggs; lower AMH suggests diminished ovarian reserve. AMH testing can be done at any point in the menstrual cycle.

Anovulation

The absence of ovulation. Women who do not ovulate regularly will have difficulty conceiving because no egg is released for fertilization. Anovulation is common in conditions like PCOS and can often be treated with ovulation-inducing medications.

Antral Follicle Count (AFC)

The number of small follicles visible on the ovaries during an ultrasound early in the menstrual cycle. Like AMH, AFC provides information about ovarian reserve. A higher count generally indicates more eggs available for stimulation during fertility treatment.

Assisted Hatching

A laboratory technique where a small opening is made in the outer shell (zona pellucida) of an embryo before transfer. This is sometimes used to help embryos implant, particularly for women who have had previous implantation failures or whose embryos have thick outer shells.

Assisted Reproductive Technology (ART)

A category of fertility treatments that involves handling eggs, sperm, or embryos outside the body. IVF is the most common form of ART. The term does not include simpler treatments like IUI or ovulation induction.

Azoospermia

The complete absence of sperm in the ejaculate. Azoospermia can be obstructive (sperm are produced but cannot exit due to a blockage) or non-obstructive (sperm production is severely impaired). Treatment depends on the cause and may include surgical sperm retrieval or donor sperm.

B

Basal Body Temperature (BBT)

Body temperature taken first thing in the morning before getting out of bed. BBT rises slightly after ovulation due to progesterone, so tracking BBT over time can help identify when ovulation has occurred. However, BBT only confirms ovulation after the fact, making it less useful for timing intercourse.

Beta hCG

A blood test measuring human chorionic gonadotropin (hCG), the hormone produced by a developing pregnancy. The "beta" refers to the specific subunit of the hormone being measured. This test is used to confirm pregnancy and monitor early pregnancy development. Rising beta hCG levels over time indicate a developing pregnancy.

Biochemical Pregnancy

A pregnancy that is detected by a positive pregnancy test but ends before anything can be seen on ultrasound, typically before the fifth week of pregnancy. Also called a chemical pregnancy, this represents a very early pregnancy loss.

Blastocyst

An embryo that has developed for about five to six days after fertilization. At this stage, the embryo has differentiated into two types of cells: those that will become the fetus and those that will become the placenta. Blastocyst transfers may have higher success rates than earlier-stage transfers because embryos have demonstrated their ability to develop further.

C

Cervical Mucus

The fluid produced by the cervix that changes throughout the menstrual cycle. Around ovulation, cervical mucus becomes clear, stretchy, and slippery, which helps sperm travel to the egg. Hostile or inadequate cervical mucus can be a factor in some cases of infertility.

Clomiphene Citrate (Clomid)

An oral medication commonly used to induce ovulation. It works by blocking estrogen receptors in the brain, causing the pituitary gland to produce more FSH and LH, which stimulate the ovaries. Clomid is often a first-line treatment for women who do not ovulate regularly.

Controlled Ovarian Hyperstimulation (COH)

The use of fertility medications to stimulate the ovaries to produce multiple eggs in a single cycle. This is a key component of IVF treatment, where having multiple eggs increases the chances of successful fertilization and embryo development.

Corpus Luteum

The structure that remains on the ovary after an egg is released. The corpus luteum produces progesterone, which prepares the uterine lining for implantation and supports early pregnancy. If pregnancy does not occur, the corpus luteum breaks down and menstruation begins.

Cryopreservation

The process of freezing biological material (eggs, sperm, or embryos) for future use. Modern vitrification techniques have made cryopreservation highly effective, with frozen embryos achieving success rates comparable to fresh transfers in many cases.

D

Day 3 Embryo

An embryo that has been developing for three days since fertilization, typically containing six to eight cells. Some clinics transfer embryos at this stage, while others culture embryos to the blastocyst stage (day 5).

Diminished Ovarian Reserve (DOR)

A condition where the ovaries have fewer eggs than expected for a woman's age. This is typically diagnosed through AMH testing, FSH levels, and antral follicle count. Women with DOR may need modified treatment approaches and should often proceed to treatment without delay.

Donor Eggs

Eggs provided by another woman for use in fertility treatment. Donor eggs may be recommended when a woman's own eggs are unlikely to result in pregnancy due to age, low ovarian reserve, or genetic concerns. Success rates with donor eggs are primarily determined by the donor's age.

Donor Sperm

Sperm provided by another man for use in fertility treatment. Donor sperm may be used by single women, same-sex female couples, or heterosexual couples where the male partner has severe sperm abnormalities or carries a genetic condition.

E

Ectopic Pregnancy

A pregnancy that implants outside the uterus, most commonly in a fallopian tube. Ectopic pregnancies cannot continue normally and can be life-threatening if not treated. Risk factors include previous ectopic pregnancy, tubal damage, and endometriosis.

Egg Retrieval

The procedure during IVF where eggs are collected from the ovaries. Using ultrasound guidance, a needle is passed through the vaginal wall to reach the ovaries, and fluid is aspirated from each follicle to collect the eggs. The procedure is typically done under sedation.

Embryo

The early stage of development after fertilization, from the fertilized egg (zygote) through the first eight weeks of development. In the context of IVF, embryos are typically cultured in the laboratory for three to six days before transfer.

Embryo Grading

A system used by embryologists to evaluate embryo quality based on appearance. Grading considers factors like cell number, symmetry, and fragmentation. While higher-grade embryos generally have better success rates, embryo grading is not perfectly predictive, and lower-grade embryos can still result in healthy pregnancies.

Embryo Transfer

The procedure where embryos are placed into the uterus. A thin catheter is passed through the cervix, and embryos are deposited in the uterine cavity. The procedure is typically painless and does not require anesthesia.

Endometriosis

A condition where tissue similar to the uterine lining grows outside the uterus. Endometriosis can cause pain, inflammation, and scarring, and is associated with reduced fertility. Treatment may include surgery and/or fertility treatment.

Endometrium

The lining of the uterus. The endometrium thickens each month in preparation for a potential pregnancy and sheds during menstruation if pregnancy does not occur. A healthy, appropriately thick endometrium is important for embryo implantation.

Estradiol (E2)

The primary form of estrogen produced by the ovaries. During fertility treatment, estradiol levels are monitored to assess how the ovaries are responding to stimulation. Each developing follicle produces estradiol, so levels rise as follicles grow.

F

Fallopian Tubes

The two tubes connecting the ovaries to the uterus. In natural conception, fertilization occurs in the fallopian tube, and the embryo travels through the tube to reach the uterus. Blocked or damaged tubes are a common cause of infertility.

Fertilization

The fusion of an egg and sperm, resulting in an embryo. Fertilization can occur naturally in the fallopian tube or in a laboratory dish during IVF.

Follicle

A fluid-filled sac in the ovary that contains an egg. Multiple follicles begin developing each month, but typically only one releases a mature egg during natural ovulation. During IVF stimulation, medications encourage multiple follicles to develop.

Follicle-Stimulating Hormone (FSH)

A hormone produced by the pituitary gland that stimulates the ovaries to develop follicles. FSH levels measured early in the menstrual cycle provide information about ovarian function. Elevated FSH can indicate diminished ovarian reserve.

Fresh Transfer

An embryo transfer that occurs in the same cycle as egg retrieval, using embryos that have not been frozen. This contrasts with a frozen embryo transfer, where embryos are cryopreserved and transferred in a later cycle.

Frozen Embryo Transfer (FET)

A transfer using embryos that were previously cryopreserved. FET allows for genetic testing results before transfer, provides flexibility in timing, and in some cases may result in better success rates than fresh transfers.

G

Gametes

The reproductive cells: eggs (ova) in women and sperm in men. Each gamete contains half the genetic material needed to create a new individual.

Gestational Carrier (Surrogate)

A woman who carries a pregnancy for another person or couple. In gestational surrogacy, the embryo is created through IVF using eggs and sperm from the intended parents or donors, so the carrier is not genetically related to the child. Note: Surrogacy regulations vary by country and are currently not permitted in the UAE.

GnRH Agonist

A medication that initially stimulates and then suppresses the release of FSH and LH from the pituitary gland. GnRH agonists are used in some IVF protocols to prevent premature ovulation.

GnRH Antagonist

A medication that immediately blocks the release of LH from the pituitary gland. GnRH antagonists are used in IVF to prevent premature ovulation and are typically given during the latter part of stimulation.

Gonadotropins

Injectable fertility medications that directly stimulate the ovaries. These include FSH and LH, either alone or in combination. Gonadotropins are more powerful than oral medications and are commonly used in IVF protocols.

H

hCG (Human Chorionic Gonadotropin)

A hormone produced during pregnancy that is detected by pregnancy tests. In fertility treatment, an hCG injection (trigger shot) is given to induce final egg maturation before retrieval.

Hydrosalpinx

A blocked fallopian tube that has become filled with fluid. Hydrosalpinx can reduce IVF success rates because the fluid may leak into the uterus and affect implantation. Treatment often involves removing or blocking the affected tube before IVF.

Hysterosalpingogram (HSG)

An X-ray procedure used to evaluate the uterine cavity and fallopian tubes. Dye is injected through the cervix, and X-rays show whether the tubes are open and whether the uterine cavity appears normal.

Hysteroscopy

A procedure where a small camera is inserted through the cervix to visualize the inside of the uterus. Hysteroscopy can diagnose and sometimes treat conditions like polyps, fibroids, or adhesions within the uterine cavity.

I

ICSI (Intracytoplasmic Sperm Injection)

A technique where a single sperm is injected directly into an egg to achieve fertilization. ICSI is used when there are concerns about sperm quality or when previous IVF cycles showed poor fertilization.

Implantation

The process where an embryo attaches to and begins growing in the uterine lining. Implantation typically occurs about six to ten days after fertilization.

Infertility

Generally defined as the inability to conceive after 12 months of regular unprotected intercourse, or after 6 months for women over 35. Infertility does not necessarily mean pregnancy is impossible; it indicates that medical evaluation and possibly treatment may be helpful.

Intrauterine Insemination (IUI)

A fertility treatment where washed and concentrated sperm are placed directly into the uterus around the time of ovulation. IUI bypasses the cervix and places sperm closer to the egg, improving the chances of fertilization.

L

Laparoscopy

A minimally invasive surgical procedure where a small camera is inserted through the abdomen to visualize the pelvic organs. Laparoscopy can diagnose conditions like endometriosis, adhesions, or tubal problems, and can often treat these conditions at the same time.

Letrozole (Femara)

An oral medication used to induce ovulation. Originally developed for breast cancer treatment, letrozole is now widely used in fertility treatment and may have fewer side effects than clomiphene for some women.

LH (Luteinizing Hormone)

A hormone produced by the pituitary gland. The surge of LH in the middle of the menstrual cycle triggers ovulation. LH is measured in ovulation predictor kits and is sometimes monitored during fertility treatment.

Luteal Phase

The second half of the menstrual cycle, from ovulation to the start of the next period. During the luteal phase, progesterone from the corpus luteum prepares the uterine lining for potential implantation. A short or inadequate luteal phase can affect fertility.

M

Miscarriage

The spontaneous loss of a pregnancy before 20 weeks. Most miscarriages occur in the first trimester and are often caused by chromosomal abnormalities in the embryo.

Morphology (Sperm)

The shape and structure of sperm. Normal sperm morphology is assessed as part of a semen analysis. While lower morphology can affect fertility, pregnancy is still possible even with abnormal morphology.

Motility (Sperm)

The ability of sperm to move effectively. Progressive motility refers to sperm that swim forward in a relatively straight line. Good motility is important for sperm to reach and fertilize an egg.

O

Oocyte

The medical term for an egg. Oocytes are retrieved from the ovaries during IVF.

Ovarian Hyperstimulation Syndrome (OHSS)

A complication of fertility treatment where the ovaries over-respond to stimulation medications, becoming enlarged and causing fluid to accumulate in the abdomen. Mild OHSS is relatively common; severe OHSS is rare but can require hospitalization.

Ovarian Reserve

The quantity and quality of a woman's remaining eggs. Ovarian reserve is assessed through AMH testing, FSH levels, and antral follicle count. Reserve naturally declines with age and is an important factor in treatment planning.

Ovulation

The release of a mature egg from the ovary. Ovulation typically occurs once per menstrual cycle and is necessary for natural conception.

Ovulation Induction

The use of medications to stimulate the ovaries to produce and release eggs. This may be used for women who do not ovulate regularly or to enhance fertility in women with unexplained infertility.

P

PCOS (Polycystic Ovary Syndrome)

A hormonal condition affecting ovulation. Women with PCOS often have irregular periods, elevated androgens, and multiple small follicles on the ovaries. PCOS is a common cause of anovulatory infertility but often responds well to treatment.

PGT (Preimplantation Genetic Testing)

Testing performed on embryos before transfer to check for genetic or chromosomal abnormalities. PGT-A screens for chromosome number (aneuploidy), while PGT-M tests for specific genetic conditions. Testing requires embryo biopsy and adds time and cost to treatment.

Polyp

A growth of tissue projecting from a surface. Uterine polyps grow from the endometrium and can sometimes affect implantation. They are typically removed via hysteroscopy before fertility treatment.

Progesterone

A hormone produced by the corpus luteum after ovulation. Progesterone prepares the uterine lining for implantation and supports early pregnancy. Progesterone supplementation is often used during fertility treatment.

S

Semen Analysis

A test evaluating sperm count, motility, morphology, and other factors. Semen analysis is a basic part of fertility evaluation and provides important information about male factor fertility.

Sperm Count

The number of sperm in a semen sample, typically expressed as millions of sperm per milliliter. Low sperm count (oligospermia) can affect fertility but does not make pregnancy impossible.

Stimulation (Ovarian)

The use of injectable medications to encourage the ovaries to produce multiple eggs in a single cycle. Stimulation is monitored through ultrasounds and blood tests to track follicle growth and hormone levels.

T

Trigger Shot

An injection given to induce final maturation of eggs before retrieval. The trigger is typically hCG or a GnRH agonist and is given at a specific time so that egg retrieval can be precisely scheduled.

Two-Week Wait (TWW)

The approximately two-week period between embryo transfer (or ovulation) and pregnancy testing. This waiting period can be emotionally challenging as there is typically nothing to do but wait.

U

Ultrasound

An imaging technique using sound waves to visualize internal structures. In fertility treatment, transvaginal ultrasound is used to monitor follicle development, evaluate the uterine lining, and guide procedures like egg retrieval.

Unexplained Infertility

A diagnosis made when standard testing does not reveal a clear cause for infertility. This accounts for about 25 to 30 percent of infertility cases.

V

Varicocele

An enlargement of veins in the scrotum that can affect sperm production and quality. Varicoceles are a common cause of male infertility and can sometimes be treated surgically.

Vitrification

A rapid freezing technique used to cryopreserve eggs, sperm, and embryos. Vitrification has significantly improved survival rates after thawing compared to older slow-freezing methods.

Z

Zona Pellucida

The outer shell surrounding an egg and early embryo. The embryo must hatch from the zona pellucida before it can implant in the uterine lining. Assisted hatching involves creating an opening in this shell.

Zygote

A fertilized egg before it begins dividing. The zygote contains the complete genetic material from both egg and sperm.

Medical Disclaimer

This glossary provides general explanations of fertility-related terms and should not replace professional medical advice. Terms and definitions may be simplified for accessibility. Please consult with your healthcare provider for detailed explanations relevant to your specific situation.

Last updated: January 2026