ICMART

GLOSSARY

The International Glossary on Infertility and Fertility Care

The following glossary was developed in 2017 by a global panel of more than 100 multidisciplinary experts, professional organisations, and patient representatives to provide consensus agreement on 283 items and definitions. Published in Fertility and Sterility (FNS) and Human Reproduction (HR).
A printable version of the 2017 Glossary and more information on the methodology, and a list of previous compiled glossaries can be found here.

Leydig cell

The complete expulsion or extraction from a woman of a product of fertilization, after 22 completed weeks of gestational age; which, after such separation, breathes or shows any other evidence of life, such as heart beat, umbilical cord pulsation or definite movement of voluntary muscles, irrespective of whether the umbilical cord has been cut or the placenta is attached. A birth weight of 500 grams or more can be used if gestational age is unknown. Live births refer to the individual newborn; for example, a twin delivery represents two live births.

Live birth

The complete expulsion or extraction from a woman of a product of fertilization, after 22 completed weeks of gestational age; which, after such separation, breathes or shows any other evidence of life, such as heart beat, umbilical cord pulsation or definite movement of voluntary muscles, irrespective of whether the umbilical cord has been cut or the placenta is attached. A birth weight of 500 grams or more can be used if gestational age is unknown. Live births refer to the individual newborn; for example, a twin delivery represents two live births.

Live birth delivery rate

The number of deliveries that resulted in at least one live birth, expressed per 100 cycle attempts. In the case of ART/MAR interventions, they can be initiated cycles, insemination, aspiration cycles or embryo transfer cycles. When delivery rates are given, the denominator (initiated, inseminated, aspirated or embryo transfer cycles) must be specified.

Low birth weight

Birth weight less than 2500 g.

Luteal phase defect

A poorly defined abnormality of the endometrium presumably due to abnormally low progesterone secretion or action on the endometrium.

Luteal phase support

Hormonal supplementation in the luteal phase, usually progesterone.

Major congenital anomaly

A congenital anomaly that requires surgical repair of a defect, is a visually evident or life-threatening structural or functional defect, or causes death.

Male infertility

Infertility caused primarily by male factors encompassing: abnormal semen parameters or function; anatomical, endocrine, genetic, functional or immunological abnormalities of the reproductive system; chronic illness; and sexual conditions incompatible with the ability to deposit semen in the vagina.

Maternal spindle transfer

Transfer of the maternal spindle (including maternal chromosomes) from a patient’s oocyte into a donated oocyte in which the maternal spindle with chromosomes has been removed.

Mature oocyte

An oocyte at metaphase of meiosis II, exhibiting the first polar body and with the ability to become fertilized.

Maturing oocyte

An oocyte that has progressed from prophase I but has not completed telophase I, thus does not exhibit the first polar body.

Medically assisted reproduction (MAR)

Reproduction brought about through various interventions, procedures, surgeries and technologies to treat different forms of fertility impairment and infertility. These include ovulation induction, ovarian stimulation, ovulation triggering, all ART procedures, uterine transplantation and intrauterine, intracervical and intravaginal insemination with semen of husband/partner or donor.

Microdissection testicular sperm extraction (MicroTESE)

A surgical procedure using an operating microscope to identify seminiferous tubules that may contain sperm to be extracted for IVF and/or ICSI.

Micromanipulation in ART

A micro-operative ART procedure performed on sperm, egg or embryo; the most common ART micromanipulation procedures are ICSI, assisted hatching and gamete or embryo biopsy for PGT.

Microsurgical epididymal sperm aspiration/extraction (MESA/MESE)

A surgical procedure performed with the assistance of an operating microscope to retrieve sperm from the epididymis of men with obstructive azoospermia. In the absence of optical magnification, any surgical procedure to retrieve sperm from the epididymis should also be registered as MESE.

Mild ovarian stimulation for IVF

A protocol in which the ovaries are stimulated with gonadotropins, and/or other pharmacological compounds, with the intention of limiting the number of oocytes following stimulation for IVF.

Missed spontaneous abortion/missed miscarriage

Spontaneous loss of a clinical pregnancy before 22 completed weeks of gestational age, in which the embryo(s) or fetus(es) is/are nonviable and is/are not spontaneously absorbed or expelled from the uterus.

Modified natural cycle

An ART procedure in which one or more oocytes are collected from the ovaries during a spontaneous menstrual cycle. Pharmacological compounds are administered with the sole purpose of blocking the spontaneous LH surge and/or inducing final oocyte maturation.

Monosomy

The absence of one of the two homologous chromosomes in embryos. Autosomal monosomies in embryos are not compatible with life. Embryos with sex chromosome monosomies are rarely compatible with life.

Morula

An embryo formed after completion of compaction, typically 4 days after insemination or ICSI.
Scroll to Top