| Assisted hatching | The mechanical, chemical or laser breaching of the gelatinous coating of the eggs. Also known as zona drilling. |
|---|---|
| Blastocyst | A hollow ball of 50 to 100 cells reached after about five days’ embryonic development just before implantation in the uterus. |
| Cell line | Cells of common descent and type cultured in the laboratory. |
| Cell nuclear replacement | (Also called somatic cell nuclear transfer) the procedure of replacing the cell nucleus of an egg with the nucleus from another cell. |
| Cell type | One of over 200 different types of cells in the body, for example blood cells, liver cells, neural cells. Each of these cell types has a different subset of genes switched on (“expressed”) and therefore specific characteristics which allow it to serve a specific function in the body. |
| Chromosome | Small bodies within the nucleus of every cell in the body. They contain the genes. |
| Clinical pregnancy | Ultrasound evidence of a fetal heart. |
| Clinical pregnancy rate | This is a calculated as a proportion of pregnancies with beating heart for every 100 treatment cycles commenced. |
| Clone | A cell or organism derived from and genetically identical to another cell or organism. |
| Congenital | Malformations, deformities, diseases etc., are those which are either present at birth, or which, being transmitted direct from the parents, show themselves soon after birth. |
| Congenital abnormalities | Deformities or diseases which are either present at birth or show themselves soon after birth. |
| Counselling | All licensed clinics are required to offer patients counselling. Such counselling aims to enable the patient to understand the implications of treatment, to give emotional support and to help the patient cope with the consequences of treatment. |
| Cryopreservation | The freezing of oocytes, spermatozoa, eggs or embryos and their storage in liquid nitrogen. |
| Cystic fibrosis | A disorder of the mucus-secreting glands of the lungs, the pancreas, the mouth, and the gastro-intestinal tract. The commonest serious genetic disease in Caucasian children. |
| Cytoplasm | A jelly-like substance, which together with the nucleus which it surrounds, forms the cell. |
| Dedifferentiation | The process of inducing a specialised cell to revert towards pluripotency. |
| Differentiation | The process by which less specialised cells develop into more specialised cell types. |
| Diploid | A cell containing the full complement (two sets) of chromosomes. |
| DNA | Deoxyribonucleic acid—the cell’s and the body’s genetic material. |
| Donor | The woman who gives eggs to help another woman become pregnant or for use in research, or a man who gives sperm for the same purpose. |
| Donor insemination | The insemination of donor sperm into (DI) the vagina, the cervix or the womb itself. |
| Egg collection | Procedure by which eggs are collected from the woman’s ovaries by using an ultrasound guided needle. Also known as egg retrieval. |
| Embryo | A fertilized egg up to eight weeks of development. At two weeks it is approximately 1 – 1.5mm in diameter. |
| Embryo freezing | Embryos not required for treatment in a cycle can be frozen and stored for future use. Freezing is also known as cryopreservation. |
| Embryo storage | The storage of one or more frozen embryos for future use. |
| Embryo transfer | Transfer of one or more embryos to the uterus. |
| Embryologist | A scientist who creates, cultures and studies embryos in a clinical or research laboratory. |
| Endometriosis | A female condition in which endometrial cells, which normally line the uterus, implant around the outside of the uterus and/or ovaries, causing internal bleeding, pain and reduced fertility. |
| Enrichment | Increasing the proportion of stem cells in a tissue sample by removing some of the non-stem cell material. |
| Enucleated | From which the nucleus has been removed (usually of an egg). |
| Epididymis | Coiled tubing outside the testicles which store sperm. |
| Fallopian tube(s) | The tubes between the ovaries and the uterus. After release of the egg from one of the ovaries, the tube transports the egg to the uterus. |
| Foetus | The term used for an embryo after the eighth week of development until birth. |
| Follicle(s) | A small sac in the ovary in which the egg develops. |
| FSH | Follicle Stimulating Hormone (may be called Metrodin or Puregon or gonalf) can be given also to stimulate egg follicles. |
| Gamete | The male sperm or female egg. |
| Gamete intrafallopian transfer (GIFT) | A procedure in which eggs are removed from a woman’s ovaries, combined with washed sperm, and then both eggs and sperm are placed into the woman’s fallopian tube(s) through a small incision in her abdomen |
| Gene | A section of a chromosome which provides the code for the construction of proteins. |
| Genetic counselling | A process by which information is imparted to those affected by. Or at risk of a genetic disorder. It includes information on the nature of the disorder, the size and extent of genetic risks, the options, including genetic testing, that may help clarify the risks, and the available preventative, supportive and therapeutic measures. In the context of genetic testing it may include responding to the concerns of individuals referred and their families, discussing the consequences of a test, and help choose the optimal decision for themselves, but not determining a particular course of action. |
| Genetic testing | Testing to detect the presence or absence of, or change in, a particular gene or chromosome. |
| Genome | The complete genetic material of an individual. |
| Gonadotrophins | Drugs used to stimulate the ovaries similar in composition to natural follicle stimulating hormone (FSH) produced in pituitary gland. |
| Haploid | A cell, usually a sperm or an egg, that contains a single set of chromosomes. Most human cells have two and are diploid. |
| HCG | Human Chorionic Gonadotrophin (may be called Choragon, Pregnyl or Profasi) is given by injection about 34-36 hours before egg collection.It helps to ripen the eggs within the follicles. |
| Hepatitis | Refers to infection with one of the hepatitis viruses which causes acute or chronic inflammation of the liver cells. |
| HMG | Human Menopausal Gonadotrophin (may be called Merional or Menopur) stimulates the development of egg follicles. |
| Hormone | Hormones are natural chemical substances produced by the body some of which control the development and release of the egg from the ovary during each menstrual cycle.Natural and synthetic preparations of those hormones are used to increase the number of eggs produced in a cycle. |
| In vitro fertilisation (IVF) | Eggs and sperm are collected and put together to acheive fertilisation outside the body. Up to three of the resulting embryos can be transferred into the woman’s womb and a pregnancy may occur. |
| In vitro fertilisation | The fertilisation of an egg by a sperm outside the body. |
| Intra cytoplasmic sperm injection (ICSI) | A micromanipulation technique. A variation of IVF treatment where a single sperm is injected into the inner cellular structure of the egg. This technique is used for couples in which the male partner has severely impaired or few sperm. |
| Intrauterine insemination (IUI) | Insemination of sperm into the uterus of a woman. |
| Menstrual cycle | A cycle of approximately one month in the female during which the egg is released from an ovary, the uterus is prepared to receive the fertilised egg and blood and tissue are lost via the vagina if a pregnancy does not occur. |
| Micromanipulation | This term covers any technique used in IVF to bypass the zona pellucida (protein shell) which surrounds the egg, as this frequently prevents sperm which has poor motility or morphology from penetrating and fertilising the egg.ICSI is the most commonly used method of micromanipulation. |
| Miscarriage | Spontaneous complete loss of a pregnancy before 24 weeks. |
| Mitochondria | Energy-producing structures in the cytoplasm of a cell. They contain a small amount of dna (0.0006% of total in a cell – check) |
| Multiple birth | Birth of more than one baby from a pregnancy (these are counted as single live births irrespective of the number of babies born). |
| Multiple pregnancy | A pregnancy in which two or more foetal hearts are present. |
| Multipotent | Having the capacity to develop into multiple (but not all) cell types. |
| Neonatal death | The death of a baby within 27 complete days of delivery. |
| Nucleus | The central part of a cell containing the chromosomes |
| Oocyte | Another name for an egg. |
| Ovarian hyperstimulation syndrome | A rare but serious consequence of taking the drugs used to stimulate the ovaries. |
| Ovary | One of a pair of female reproductive organs which produce eggs and hormones. |
| Percutaneous epididymal sperm aspiration | Retrieving sperm directly from the coiled tubing outside the testicles that store sperm (epididymis) using a needle. |
| Perinatal death | The death of a baby either in the uterus after 24 weeks pregnancy (stillbirth) or within 28 days after the birth. |
| Plasticity | The capacity of cells to develop into different cell types. |
| Pluripotent | Having the capacity to develop into every cell type in the human body, but not the extra-embryonic tissues such as the placenta and umbilical cord. |
| Primitive streak | A collection of cells which appears at about 14 days after fertilisation from which the central nervous system eventually develops. |
| Redifferentiation | The process of inducing a dedifferentiated cell to differentiate into a (different) specialised cell type. |
| Somatic | Of any cell in the body other than reproductive cells |
| Spermatid | An immature sperm |
| Spermatocyte | A cell from which 4 spermatids develop |
| Stem cell | An undifferentiated cell whose daughter cells may differentiate into other cell types |
| Stimulation drugs | Drugs used to stimulate a woman’s ovaries to produce more eggs than usual in a monthly cycle; also known as superovulatory drugs. |
| Superovulation/stimulation | The stimulation of a woman’s ovaries with drugs to produce more eggs than usual in a monthly cycle. |
| Superovulatory drugs | Hormones given to a woman so that she produces more eggs than ususal on a monthly cycle. The drugs contain human menopausal gonadotrophin. |
| Testicular sperm extraction | Retrieving sperm directly from the testis. |
| Totipotent | Having the capacity to develop into every cell type required for human development, including extra-embryonic tissues. |
| Ultrasound | Investigation using sound waves to make a picture of the womb and ovaries appear on a television screen. Ultrasound is used in monitoring egg development and in egg collection. |
| X-linked disorders | Disorders due to a mutation on the X chromosome. X-linked disorders usually only affect males, but the disorders can be transmitted through healthy female carriers. |
| Zygote | The single cell formed when the male sperm fertilises the female egg. |