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.
Single embryo transfer (SET)
The transfer of one embryo in an ART procedure.
Slow-freezing
A cryopreservation procedure in which the temperature of the cell(s) is lowered in a step-wise fashion, typically using a computer controlled rate, from physiological (or room) temperature to extreme low temperature.
Small for gestational age
A birth weight less than the 10th centile for gestational age. When reporting results the reference criteria should be specified. If gestational age is unknown, the birth weight should be registered.
Sperm bank
Repository of cryopreserved sperm stored for future use
Sperm concentration
The (measure of the) number of spermatozoa in millions per 1 ml of semen.
Sperm density
A measure of the mass/volume ratio (specific gravity) for spermatozoa.
Sperm isolation
A procedure that involves the separation of sperm through centrifugation and resuspension in culture media. It can be used to remove seminal plasma and infectious agents before IUI and ART procedures. This procedure has been shown to be effective in the removal of HIV. It may also be effective in removing other infectious particles but clinical safety and efficacy have to be established for each particular infection. This term is sometimes referred to as ‘sperm washing’.
Sperm motility
The percentage of moving spermatozoa relative to the total number of spermatozoa.
Sperm recipient cycle
A MAR cycle in which a woman receives spermatozoa from a person who is not her sexually intimate partner. In the case of ART registry data, a sperm recipient cycle would only include data from cycles using ART procedures.
Sperm vitality
The percentage of live spermatozoa relative to the total number of spermatozoa.
Spermatogenic arrest
Failure of germ cells to progress through specific stages of spermatogenesis at onset or during meiosis.
Spermatozoon
The mature male reproductive cell produced in the testis that has the capacity to fertilize an oocyte. A head carries genetic material, a midpiece produces energy for movement, and a long, thin tail propels the sperm.
Spontaneous abortion/miscarriage
The spontaneous loss of an intra-uterine pregnancy prior to 22 completed weeks of gestational age.
Spontaneous reduction/vanishing sac(s)
The spontaneous disappearance of one or more gestational sacs with or without an embryo or fetus in a multiple pregnancy documented by ultrasound.
Sterility
A permanent state of infertility.
Stillbirth rate
The number of stillbirths per 1000 total births (stillbirths plus live births).
Subfertility
A term that should be used interchangeably with infertility.
Syngamy
The process during which the female and male pronuclei fuse.
Teratozoospermia
A reduced percentage of morphologically normal sperm in the ejaculate below the lower reference limits. When reporting results, the reference criteria should be specified.
Testicular sperm aspiration/extraction (TESA/TESE)
A surgical procedure involving one or more testicular biopsies or needle aspirations to obtain sperm for use in IVF and/or ICSI.