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A comprehensive glossary of frequently used terms in infertility and assisted reproduction.

Glossary of terms A to C

Welcome to the glossary aspect of the site. Here we have included a list of all the terms that have been used in the site with an accompanying definition or explanation.

Abandoned cycle An IVF cycle cancelled after drug administration has begun and before egg collection.
Abortion Pregnancy lost before the fetus can survive independently.
Acrosome Cap-like structure that surround the sperm head and contains enzymes that help penetration of the egg.
Acrosome reaction Chemical changes that enable a sperm to penetrate an egg.
Adhesions Bands of fibrous scar tissue that may bind the pelvic organs or loops of bowel together.
Adrenal gland A pair of hormone producing glands located above the kidneys.
Agglutination Clumping sperm together due to infection, inflammation or antibodies.
AID Artificial Insemination by Donor.
AIDS Acquired immune-deficiency syndrome; a fatal disease caused by HIV that destroys the immune system's ability to fight infection.
AIH Artificial Insemination by Husband.
Amenorrhoea Absence of menstrual cycles for six months or longer.
Amniocentesis A procedure which is usually carried out at around 15-16 weeks of pregnancy. It involves aspirating a small amount of the fluid which surround the baby in the womb. This fluid contains cells from the baby which can then be cultured and tested to determine the baby's chromosome. The procedure is usually performed under ultrasound scan using a fine needle. The risk of causing miscarriage by this procedure is between 0.5 - 1%. The results often take two to three weeks.  
Androgens Male sex hormones that are present in both men and women but in different quantities and producing different effects.
Andrologist A specialist in male infertility.
Anomaly Malformation or abnormality in any part of the baby.
Anovulation Absence of ovulation (failure to ovulate).
Antigen An antigen is any substance capable of eliciting immune response.
Antisperm antibodies Antibodies produced by the immune system against sperm. It adversely affects sperm function by inhibiting movement of sperm and fertilization. It can be present in males and females.
Artificial insemination Is placing sperm into the female reproductive tract.
Aspermia Absence of semen.
ASRM The American Society for Reproductive Medicine.
Assisted hatching The mechanical, chemical or laser breaching of the gelatinous coating of the egg (zona pellucida).
Asthenozoospermia Low sperm motility.
Asymptomatic Without any symptoms.
Atresia Degeneration and resorption of a follicle before it reaches maturity and ruptures.
Azoospermia The complete absence of sperm in the ejaculate, is present in about 1% of all men and in 10-15% of infertile men.
Basal body temperature (BBT) chart Charting BBT is used to predict the time of ovulation.
Beta hCG test A blood test used to detect very early pregnancy and evaluate development.
Biochemical pregnancy When the patient’s pregnancy test is positive but no pregnancy is visible on ultrasound scan.
Biopsy The removal of a piece of tissue for microscopic examination.
Blastocyst An advanced stage of embryo development, the embryo consists of an outer thin layer of cells, which later develops to placenta and an inner cell mass later develops to fetus.
Blastocyst transfer The transfer of one or more embryos at the blastocyst stage into the uterine cavity.
Blighted ovum (anembryonic pregnancy) Fertilized egg that failed to develop properly after implantation. Gestation sac develops in the absence of an embryo.
Bromocriptine (Parlodel) Tablets used to reduce prolactin production and reduce tumor when present.
Buserelin Is a GnRh agonist drug used as a nasal spray or by daily injection.
Cerebral palsy Describes a physical impairment that affects movement. The disease varies from barely noticeable to extremely severe.
Cervicitis Inflammation of the cervix.
Cervix Neck of womb. It acts as a reservoir for sperm and secretes an alkaline mucus which protect sperm from the acidity of the vagina.
Cervical mucus The secretion in the cervical canal. The amount and texture changes during the menstrual cycle.
Cervical smear (PAP smear) A screening test for cancer of the neck of the womb.
Chemotherapy The use of anticancer drugs to treat or control cancer.
Chlamydia A sexually transmitted disease, it is a common cause of pelvic infection and subsequent tubal damage and infertility.
Chocolate (endometriosis) cyst A cyst inside the ovary filled with old blood. It occurs in endometriosis.
Chorionic villus sampling (CVS) A procedure which involve taking a biopsy from the placenta to test the fetus for genetic abnormalities. It is usually carried out under ultrasound scan at about eleven weeks of pregnancy. The placenta has the same genetic make-up as the baby. There is a 2-3% risk of the procedure causing a miscarriage. 
Chromosomes Thread like structures that lie inside the nucleus of a cell. A human cell contains 23 pairs of chromosomes. Chromosomes are packed up with genes which carry all the information needed for the human body. The 23 pairs of chromosomes include a pair of sex chromosomes that determine the sex of the embryo. There are two types of sex chromosomes, X and Y - the Y is smaller than the X and contain all the essential genes for sex determination. The presence of a Y chromosome ensures a male (XY), its absence ensures a female (XX).
Cilia Hairlike projections from the cells lining the Fallopian tubes. They play a part in guiding the fertilized egg into the uterus.
Clinical pregnancy A pregnancy confirmed by increasing levels of hCG and the presence of a gestational sac detected by ultrasound scan or a fetus.
Clomiphene (clomid) A fertility drug (anti estrogen tablet) used to stimulate ovulation.
Clone A group of embryos or individuals that are genetically identical.
Congenital A defect existing since birth.
Cornua The horns of the uterus where the Fallopian tubes join the uterine cavity.
Cryopreservation The storage of the sperm, embryos or eggs by freezing at a low temperature (-196°C).
Cryptorchidism Failure of one or both testicles to descend into the scrotum.
Cyst Sac filled with fluid.
Cystic fibrosis A common genetic disease. If both partners carry the gene, there is a 25% chance that the child will have the disease. This is unpleasant and currently there is no cure. It affects the lungs, bowels, pancreas, sweat glands etc.
Cytokines Cytokines are messenger molecules produced by lymphocytes. They communicate with other cells of the immune system and recruit them to fight off infection or reject foreign tissue from the body.
Cytomegalovirus infection Infection caused by the cytomegalovirus. Primary infection of the mother during pregnancy may result in the death of the fetus or serious generalized disease of the newborn. More commonly, congenital infection follows a benign course though about 10% of affected children may subsequently be mentally retarded.
Cytotoxic Cytotoxic refers to a toxic effect on cells.

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