Glossary of Terms

A/B/C/D/E/F/G/H/I/J/K/L/M/N/O/P/Q/R/S/T/U/V/W/XYZ

A

Abortion
Spontaneous or induced termination of pregnancy.

Acrosome
A small “cap” overlaying the head of a sperm.

Acrosome reaction
The loss of the acrosome necessary for successful fertilisation.

Adhesion
The sticking of ovaries, tubes, uterus, bowel and abdominal lining to one another. Adhesions affect the normal movement of these organs and can cause infertility. They can be due to pelvic surgery, tubal infections or endometriosis.

AI
Artificial insemination

Amenorrhoea
Absence of periods, usually taken as fewer than 2 periods per year.

Amniocentesis
A test where amniotic fluid is aspirated to test the foetus for chromosomal abnormalities.

Androgens
Male sex hormones.

Anovulation
The absence of ovulation.

Antibodies
Chemicals produced by the body to fight or attack foreign substances entering the body. Normally they prevent infection. However, if they attack the sperm or foetus, they cause infertility. Sperm antibodies may be made by either the man or the woman.

ART
Assisted Reproductive Technology, includes all types of infertility treatment that involves medical intervention such as donor sperm, insemination, ovulation induction, IVF, GIFT, ICSI etc.

Azoospermia
The absence of sperm in the ejaculate.

B

Basal body temperature
Body temperature taken orally, upon waking in the morning, before any activity.

Blastocyst
A stage in the development of the early human embryo. The blastocyst forms four days after fertilisation and is a sphere of cells containing a fluid-filled cavity.

Blastomere
One of the cells in an early embryo.

C

Cervical mucus
Mucus produced by the cervix which permits passage of sperm to the uterus and fallopian tubes. This mucus changes in volume and quality at the time of ovulation.

Cervix
Lower section of the uterus that protrudes into the vagina.

Conception
Fertilisation of a woman’s egg by a man’s sperm.

Chorion villus sampling (CVS)
A procedure where cells are taken during a pregnancy at about 10 weeks to assess the normality of the chromosomes.

Chromosome
A thread-like structure of DNA which makes up all the genes. A normal human body cell has 46 chromosomes whereas eggs and sperm have 23.

Cleavage arrest
The failure of an embryo to continue through to the next stage of development during cleavage.

Clomiphene
A drug used to stimulate the ovaries to produce follicles.

Congenital
Existing before birth.

Cryopreservation
Storage by freezing, used for embryos and eggs.

Cytogenetics
The study of the chromosomes.

D

DI
See Donor Insemination

Dispermy
The fertilisation of an egg by two sperm instead of one as normally occurs.

Donor eggs
Eggs taken from one woman and donated to another for pregnancy.

Donor insemination (DI)
Insemination of a woman using donor sperm.

E

Ectopic pregnancy
A pregnancy that implants outside the uterus, for example, in the Fallopian tube.

Ejaculate
Semen ejected from the penis during orgasm.

Embryo
The fertilised egg and the subsequent stages of early human development.

Embryo biopsy
The removal of one or two cells from an early embryo for diagnosing chromosomal or genetic abnormalities.

Embryo transfer (ET)
The placement of embryos into the uterus using a fine catheter.

Endometrium
Lining of the uterus or womb.

Endometriosis
The presence of endometrial tissue (the normal uterine lining) in abnormal locations such as the Fallopian tubes, the ovaries and the peritoneal cavity.

Epididymis
A cord-like structure in the testes where sperm are stored.

F

Fallopian tubes
Pair of narrow tubes that carry the ovum (egg) from the ovary to the uterus.

Fertilisation
Penetration of the egg by the sperm and the joining of genetic materials to result in the development of an embryo.

Fibroid
A benign tumor of fibrous tissue in the uterus, may contribute to infertility.

Folic Acid
Folic Acid is a vitamin supplement which women are recommended to take before conceiving and in early pregnancy as it reduces the risk of neural tube defects in the foetus (spina bifida).

Foetus
The developing human from the end of the eighth week of development from fertilisation (when all major structures have begun to develop) until birth.

Follicle Stimulating Hormone (FSH)
Hormone produced in the pituitary gland that stimulates the ovary to develop a follicle for ovulation in women and sperm production in men.

Follicle
A fluid-filled sac in the ovary which contains an egg that is released at ovulation. In healthy women, each month, an egg develops inside this follicle.

Follicular phase
First half of the menstrual cycle when ovarian follicle development takes place and the egg matures.

G

Gamete
A reproductive cell, either sperm or egg.

Gamete Intra Fallopian Transfer (GIFT)
The mixing of sperm and egg outside the body and the transfer of the mixture to the Fallopian tube, usually by laparoscopy.

Gonadotrophin
A hormone that stimulates the production of sperm or eggs.

H

Home Pregnancy test
A test a woman can use at home to test urine for the presence of human Chorionic Gonadotropin (hCG).

Hormone
A chemical substance which has a specific regulatory effect on the activity of a particular organ.

Human Chorionic Gonadotropin (hCG)
The hormone produced in early pregnancy which keeps the corpus luteum producing progesterone.

Hyperstimulation
See OHSS

I

ICSI
See Intracytoplasmic Sperm Injection

Idiopathic
When the couple is diagnosed as having “Idiopathic infertility” this means unexplained, ie none of the tests in the infertility investigation is abnormal and a cause has not been determined.

Implantation
When the embryo attaches and embeds in the endometrium. This begins about seven days after fertilisation and is complete about 14 days after fertilisation.

Impotence
Failure to achieve an erection.

Infertility
The inability of a couple to produce children in spite of repeated attempts.

Insemination
The bringing together of sperm and egg.

Intra-Cytoplasmic Sperm Injection (ICSI)
A procedure, used for severe forms of male infertility, where a single sperm is injected into the egg.

Vitro Fertilisation (IVF)
The procedure by which eggs and sperm are mixed in the laboratory and the process of fertilisation occurs
outside the body.

L

Laparoscopy
A surgical investigation using a telescope-like instrument to look at the pelvic organs, which can performed as part of an infertility investigation.

LH surge
The release of a large amount of Luteinising hormone (LH) from the pituitary which triggers ovulation.

Libido
Sexual desire

Luteal phase
Post-ovulatory phase of the menstrual cycle. The corpus luteum produces progesterone, which causes the uterine lining to thicken and this supports the implantation and growth of the embryo.

Luteinising hormone (LH)
A hormone produced by the pituitary whose function is to mature and trigger the release of the egg at ovulation.

M

Male factor
When the cause of infertility is attributed to poor sperm quality.

Menopause
The time a woman stops menstruating.

Menstruation
Shedding of the uterine lining by bleeding, which in the absence of pregnancy, normally occurs about once a month.

MESA – Micro Epidydimal Sperm Aspiration
A procedure whereby immature sperm is aspirated from the epidydimis. This is done in cases where the man has had a vasectomy or in men who are born without the vas deferens (the duct that transports sperm from the epidydimis into the ejaculate). Sperm extracted this way can only fertilize the egg if the ICSI procedure is used.

Miscarriage
Spontaneous loss of an embryo or foetus from the womb.

Mumps
Mumps is an acute viral illness and usually presents with inflammation of the salivary glands, particularly the parotid glands (salivary glands near the ears). This illness can also cause inflammation of other tissues, most frequently the covering and substance of the central nervous system (meningoencephalitis), next the pancreas (pancreatitis) and especially after adolescence, the ovary (oophoritis) and the testis (orchitis). The mature testis is particularly susceptible to damage from mumps which can lead to infertility.

O

Oestrogen
A female sex hormone produced by the ovaries. Oestrogen is responsible for the development of the secondary feminine sex characteristics, which include breasts, rounded hips, and pubic hair. Together with progesterone, oestrogen regulates the changes that occur with each monthly period and prepares the uterus for pregnancy.

OHSS – Ovarian Hyperstimulation Syndrome
A potentially dangerous condition caused by excessive response to fertility drugs.

Oligomenorrhoea
Infrequent periods, usually taken as 2-10 periods per year.

Oligospermia
A low sperm count.

Oocyte
The female reproductive cell (egg).

Oocyte retrieval
When mature eggs are retrieved from the ovaries using a fine needle. This procedure is done vaginally and the needle is guided by ultrasound. Follicular fluid is aspirated and the egg is identified by an embryologist using a microscope.

Ovaries
Sexual glands of the female that produce the hormones oestrogen and progesterone, in which the eggs develop. There are two ovaries, one on each side of the pelvis.

Ovulation
Discharge of a mature egg, usually at about the midpoint of the menstrual cycle.

Ovulation induction
When fertility drugs, tablets or injections, are used to make a woman ovulate.

Ovum
The egg or reproductive cell from the ovary. This sex cell contains the female’s genetic information.

P

PCO – Poly Cystic Ovaries
A term that describes ovaries that contain lots of little follicles.

PCOS – Poly Cystic Ovarian Syndrome
A condition characterised by a number of features:
lots of little follicles in the ovaries
excessive hair growth
infrequent or no ovulation
irregular or no periods
being overweight
abnormal hormone levels
Women with PCOS often have difficulty conceiving and have increased risk of miscarriage if they do conceive.

Pituitary gland
This gland is stimulated by the hypothalamus and controls all hormonal functions. Located at the base of the brain just below the hypothalamus, it controls many major hormonal factories throughout the body, including the gonads (ovaries and testes), the adrenal glands and the thyroid gland.

Preimplantation Genetic Diagnosis (PGD)
Genetic and chromosomal analysis of a cell taken from an embryo before transfer to the uterus.
Premature Ovarian Failure

Premature ovarian failure (POF) is usually defined as menopause under the age of 40 and occurs in about 1% of women.

Primary infertility
This refers to a couple that has never been able to conceive.

Progesterone
Hormone secreted by the corpus luteum of the ovary after ovulation has occurred. It is responsible for preparing the uterus for pregnancy.

Puberty
Adolescence.

R

Rubella (German Measles)
Rubella (German measles) is a mild, febrile, highly infectious viral disease which was common in childhood prior to the advent of an effective vaccine. If contracted during early pregnancy, it could potentially cause a typical syndrome of congenital malformations

S

Secondary infertility
This means that the couple has conceived in the past, with or without this having resulted in a birth, but are unable to do so again in spite of having tried for a year or more.

Semen
The ejaculate of the male which includes the sperm and its nutrient plasma and other secretions.

STD – Sexually Transmitted Disease
A viral or bacterial infection that is passed on through sexual activity such as chlamydia, gonorrhea and HIV. STDs can lead to infertility in some cases.

Sperm
Male reproductive cells.

Sterility
Absolute infertility – inability to achieve a pregnancy without special treatment such as IVF.

Subfertility
Inability of a couple to conceive after a year of regular sexual intercourse, without using any form of contraception.

Superovulation
The use of hormonal injections to mature many eggs in the one cycle.

Surrogacy
An arrangement whereby a woman carries the child for a couple, with the intention that the child is handed over to the couple after birth.

T

TESA – Testicular Sperm Aspiration
This is the same type of procedure as MESA except the sperm is aspirated from the testicle rather than from the epididymis.

Testicle/testes
The male sex gland which produces testosterone and sperm.

Testicular biopsy
The removal of microscopic bits of the testicular tissue from men with very poor sperm production. Immature sperm are recovered from the tissue and injected into the egg using ICSI.

Testosterone
The main male hormone found in the blood stream (in both women and men).

U

Ultrasound
Use of high-frequency sound waves for creating an image of internal body parts. Used to monitor the development of follicles and to detect and monitor pregnancy.

Uterus
Womb / Hollow muscular organ in the woman that holds and nourishes the foetus until the time of birth.

V

Varicocele
Varicose vein of the testicle.

XYZ

Zona Pellucida
The outer layer of the egg that persists and surrounds the embryo until about 4-5 days after fertilisation.

ZIFT – Zygote Intra Fallopian transfer
This is similar to GIFT except the eggs are fertilized in the laboratory and replaced in the Fallopian Tube via laparoscopy the day after the sperm and eggs have been mixed.

Zygote
A fertilized egg.