Infertility Definitions and Terminology

Aneuploidy: this is an issue with the number of chromosomes. The normal complement in a male is 46 chromosomes, 2 of which are sex chromosomes (X and Y). Examples: Klinefelter's is an example of aneuploidy involving an extra X chromosome - 47 XXY. Down Syndrome have an extra copy of chromosome 21.

Azospermia: no sperm in the ejaculate (i.e. concentration is 0 million/mL)

Concentration: the number of sperm in a specific volume of semen fluid. Usually expressed as million per milliliter (M/ml); this is the same as giga per litre (billion/litre).

Cryptospermia: concentration of sperm less then 0.5 million/mL (500,000 per mL)

Deletions: portion of a chromosome is missing.

Fertility: defined by the production of offspring. Note that a couple which conceives anytime after 1 year of unsuccesful attempted conception would strictly be defined as both infertile and fertile.

First pregnancy planners: a term used to describe young couples less than about 30 years of age with no prior fertility history (i.e. no known prior pregnancies) and with no known impediments to a pregnancy. Not previously evaluated for fertility status. This is a group which most represents those in the general population of reproductive age. Usually not a good reference group when evaluating outcomes in the couples presenting with fertility issues.

Infertility: a disease defined by the failure to achieve a pregnancy after 12 month or more of regular, unprotected intercourse. Being defined as infertile does not preclude the possibility of having children through intercourse.

Inversions: portion of a chromosome is broken off, turned upside down and reattached.

Isolated teratospermia: when the only out of 'reference range' value on a semen analysis report is the morphology.

Karyotype: genetic test which determines the number and type of chromosomes.

Morphology: the appearance of the sperm. Abosolute size of different components such as the head, midpiece, and tail are measured against a standard

Motility: a measure of sperm movement

Retrograde ejaculation: failure of the ejaculate to move forward through the urethral to the tip of the penis. It goes backwards in to the bladder

Sterility: the absence of the capacity to reproduce. There is no possibility for pregnancy by intercourse. For example, the absence of sperm in the ejaculate or bilateral obstruction of the fallopian tubes.

Teratospermia: appearance of the sperm shape and proportions does not meet a particular definition.

Translocations: when a segment of one chromosome is transferred to another chromosome. Sometimes information from one chromosome is 'swapped' with information for another. As long as all the information is there, the individual does not usually have a problem. If offspring can be conceived, they may have major congenital defects because they do not have a full 'instruction set'.