MCRM Term Glossary

The MCRM glossary includes many terms you’ll hear during your journey. If there is a term you don’t see here, please ask us!

IVF and Fertility Terms

Assisted Reproductive Technology. All treatments or procedures that include the handling of human eggs or embryos to help a woman become pregnant. ART includes but is not limited to in vitro fertilization (IVF), gamete intrafallopian transfer (GIFT), zygote intrafallopian transfer (ZIFT), tubal embryo transfer, egg and embryo cryopreservation, egg and embryo donation, and gestational surrogacy.

Antral Follicle Count, a procedure completed utilizing transvaginal ultrasound that evaluates the number of follicles produced per ovary during a cycle.

Antimulerrian Hormone, a hormone produced which can be measured and the value obtained utilized to assist in knowing how many eggs one has within their ovaries. Often utilized in conjunction with an AFC to evaluate female fertility potential

An embryo with the incorrect number of chromosomes.

Another term for Intrauterine Insemination.

The removal of fluid and cells by suction through a needle.

The placement of a small opening in the zona pellucida ,"shell", surrounding an embryo usually with the application of an acid or laser. This process assists the embryo in being able to break through the shell to better implant. Also, utilized in order to be able to complete an embryo biopsy for the process of PGD/PGS

The absence of sperm in an ejaculate.

Birth Control Pills.

Blood test utilized to confirm pregnancy.

An embryo which is 5 or 6 days of age and clearly displays an inner cell mass and trophectoderm.

Body Mass Index

Basic Sperm Analysis. Includes the evaluation of sperm count and motility.

An ART cycle in which ovarian stimulation was performed but the cycle was stopped before eggs were retrieved or, in the case of frozen embryo cycles, before embryos were transferred. Cycles are canceled for many reasons: eggs may not develop, the patient may become ill, or the patient may choose to stop treatment.

Cycle Day, i.e. CD9 = Cycle Day Nine

A pregnancy diagnosed by the detection of hCG in a blood or urine sample and does not develop into a clinical pregnancy.

The division of a single cell to 2, then to 4, then to 8, …., etc. A term often utilized with regards to embryo development.

A pregnancy documented by ultrasound visualization of one or more gestational sacs or definitive signs of pregnancy.

The practice of freezing sperm, eggs or embryos from a patient's ART cycle for potential future use.

Sperm DNA Fragmentation Index

This diagnosis means that the ability of the ovary to produce eggs is reduced. Reasons include congenital, medical, or surgical causes or advanced age.

Sperm DNA Fragmentation Assessment.

An embryo is formed from the egg of one woman (the donor) and then transferred to another woman (the recipient).

An embryo that is donated by a patient or couple who previously underwent ART treatment and had extra embryos available.

Diminished Ovarian Reserve

Bloodwork measuring the level of Estradiol

A pregnancy in which the fertilized egg implants in a location outside of the uterus-usually in the fallopian tube, the ovary, or the abdominal cavity. Ectopic pregnancy is a dangerous condition that must receive prompt medical treatment.

A female reproductive cell, also called an oocyte or ovum.

A procedure to collect the eggs contained in the ovarian follicles.

An ART cycle started with the intention of freezing (cryopreserving) all resulting eggs or embryos for potential future use.

Elective single embryo transfer is a procedure in which one embryo, selected from a larger number of available embryos, is placed in the uterus . The embryo selected for eSET might be a frozen (cryopreserved) embryo from a previous IVF cycle or a fresh embryo selected from a larger number of fresh embryos yielded during the current fresh IVF cycle.

An egg that has been fertilized by a sperm and has then undergone one or more cell divisions.

Placement of embryos into a woman's uterus through the cervix after IVF.

The study of hormones and their function and the organs that produce them and how they are produced.

The removal of a small amount of endometrium tissue for examination.

A medical condition that involves the presence of tissue similar to the uterine lining in abnormal locations.

Inner lining of the uterus and the location for where implantation occurs.

Egg Retrieval

Endometrial Receptivity Assay, tests the endometrial "receptivity" on the day of a woman's cycle that is the same as that of a planned embryo transfer. The uterus is prepared as it would for an ET or FET but instead a endometrial biopsy is performed. The ERA provides whether it was "receptive" or "not receptive".

Elective Single Embryo Transfer

The principle hormone produced by the growing ovarian follicle. It is frequently measured to evaluate the development of follicle during one's cycle.

Fresh Embryo Transfer

An embryo with the correct number of 46 chromosomes.

Infertility due to ovulatory disturbances, diminished ovarian reserve, pelvic abnormalities affecting the reproductive tract, or other abnormalities of the reproductive system. 

The controlled freezing of sperm, eggs or embryos to preserve for future fertility treatment.

Is the union of an egg and sperm.

Frozen Embryo Transfer

A structure in the ovaries that contains a developing egg.

A hormone produced by the pituitary gland which stimulates ovarian follicles to grow and develop.

The first of two phases of a woman's menstrual cycle. This phase occurs from the onset of menses to ovulation, approximately a period of 14 days.

An ART cycle in which frozen (cryopreserved) embryos are thawed and transferred to the woman.

Follicle Stimulating Hormone

A reproductive cell, either a sperm or an egg.

The deviation of time from estimated last LMP to birth. LMP is estimated using the date of retrieval or transfer.

Another term for Gestational Surrogate

A fluid-filled structure that develops within the uterus early in pregnancy. In a normal pregnancy, a gestational sac contains a developing fetus.

A woman who gestates, or carries, an embryo that was formed from the egg of another woman with the expectation of returning the infant to its intended parents.

Gestational Sac

Human Chorionic Gonadotropin

High DNA Stainability Index obtained from Sperm DNA Fragmentation Assessment

It is a hormone utilized as an injection to induce ovulation and maturation of oocyte(s) during ovarian stimulation protocols. It is also a hormone of early pregnancy which is monitored for pregnancy viability.

A minimally invasive surgical procedure in which a small telescopic camera is utilized to visualize the endometrium.

Intracytoplasmic Sperm Injection

Intramuscular, within the muscle

The attachment of an embryo into the lining of the uterus

An ART procedure that involves removing eggs from a woman's ovaries and fertilizing them outside her body. The resulting embryos are then transferred into a woman's uterus through the cervix.

In general, infertility refers to the inability to conceive after 12 months of unprotected intercourse. Women aged 35 and older unable to conceive after 6 months of unprotected intercourse generally are considered infertile for the purpose of initiating medical treatment.

A procedure in which a single sperm is injected directly into an egg; this procedure is commonly used to overcome male infertility problems.

A medical procedure that involves placing sperm into a woman's uterus to facilitate fertilization. IUI is not considered an ART procedure because it does not involve the manipulation of eggs.

Intrauterine Insemination

In Vitro Fertilization

An IVF cycle begins when the patient begins taking fertility medications and/or when the baseline ultrasound occurs for the monitoring of follicle production. If eggs are produced, the cycle progresses to an egg retrieval. Retrieved eggs are combined with sperm to create embryos. Fertilized embryos will be allowed to mature and grow for a period of five or six days. The heathy embryos will then either be cryopreserved for future transfer or a fresh embryo transfer will be completed.

Last Menstrual Period

The second phase of a woman's menstrual cycle occurring from the time of ovulation to the onset of menses. However, it is prolonged during pregnancy. It is associated with the production of progesterone to facilitate implantation and support early pregnancy

Any cause of infertility due to low sperm count or problems with sperm function that makes it difficult for a sperm to fertilize an egg under normal conditions.

A "Period".

A pregnancy ending in the spontaneous loss of the embryo or fetus before 20 weeks of gestation.

Embryo growth stage between cleavage stage and blastocyst development. The embryo becomes a cluster of cells and it is difficult to distinguish individual cells.

Magnified Semen Analysis. Includes the evaluation of sperm count, motility and morphology

A cleavage stage embryo. At this stage, the embryo increases in cell number without increasing in size. The age of the embryo during this stage is from day 2 until day 4.

A diagnostic category used when one or more female cause of infertility and male factor infertility are diagnosed.

A surgical procedure to remove fibroids from the uterine wall

Ovarian Hyper stimulation Syndrome

Low sperm count

Another term for Egg Retrieval

A possible complication of ovarian stimulation or ovulation induction that can cause enlarged ovaries, a distended abdomen, nausea, vomiting or diarrhea, fluid in the abdominal cavity or chest, breathing difficulties, changes in blood volume or viscosity, and diminished kidney perfusion and function.

The use of ultrasound, or blood or urine tests to monitor follicle development and hormone production.

The use of drugs (oral or injected) to stimulate the ovaries to develop follicles and eggs.

A diagnostic category used when a woman's ovaries are not producing eggs normally. It is usually characterized by irregular menstrual cycles reflective of ovaries that are not producing one mature egg each month. It includes polycystic ovary syndrome and multiple ovarian cysts.

Polycystic Ovaries

Polycystic Ovarian Syndrome

Preimplantation Genetic Diagnosis

Preimplantation Genetic Screening

A common endocrine system disorder among women of reproductive age. It can lead to infrequent or prolonged menstrual cycles, ovulation dysfunction, infertility, weight gain, excess hair growth, acne, pre-diabetes and an increase in testosterone.

Technique performed on embryos prior to transfer. PGD is for detecting specific genetic conditions to reduce the risk of passing inherited diseases to children.

Technique performed on embryos prior to transfer. PGS screens embryos for an abnormal number of chromosomes, which is of special value for women with advanced age, recurrent miscarriages, or failed IVF.

When a woman experiences two or more miscarriages

Recurrent Pregnancy Loss

Semen Analysis

The male reproductive cell.

A qualitative assessment of male factor fertility. It is a simple test completed either independently or in conjunction with a semen analysis.

The shape of sperm.

A process completed within the laboratory utilized to isolate sperm from debris within an sperm sample

An ART cycle in which a woman receives oral or injected fertility drugs to stimulate her ovaries to develop follicles that contain mature eggs.

Testicular Epididymal Sperm Aspiration. It is a minor surgical procedure utilized to collect sperm directly from the testis or the epididymis using a needle for aspiration. The procedure is utilized for men who have had a previous vasectomy or for men who have zero sperm in their ejaculate.

A diagnostic category used when the woman's fallopian tubes are blocked or damaged, making it difficult for the egg to be fertilized or for an embryo to travel to the uterus.

A technique used in ART for visualizing the follicles in the ovaries, the gestational sac, or the fetus.

An ART cycle in which the woman does not receive drugs to stimulate her ovaries to produce more follicles and eggs. Instead, follicles and eggs develop naturally.


A structural or functional disorder of the uterus that results in reduced fertility.

A fertilized egg before it begins to divide.