AnSWeR  > Glossary

Affected Pregnancy: a pregnancy with a foetus affected by a genetic condition.

Amniocentesis: a diagnostic test, usually carried out between 15 - 20 weeks of pregnancy, in which a needle is inserted through the abdomen to remove a sample of amniotic fluid containing cells from the developing baby for testing. Ultrasound is used to guide the needle. The procedure carries a risk of miscarriage of about 1%.

Amniotic Fluid: the fluid contained in the amniotic sac which surrounds the baby.

Anencephaly: a defect in the closure of the neural tube during foetal development. The neural tube is a narrow channel that folds and closes between the 3rd and 4th weeks of pregnancy to form the brain and spinal cord of the embryo. Anencephaly occurs when the "cephalic" or head end of the neural tube fails to close, resulting in the absence of a major portion of the brain, skull, and scalp. Infants with this disorder are born without a forebrain (the front part of the brain) and a cerebrum (the thinking and coordinating part of the brain) and do not survive for long after birth.

Autoimmune: a condition where the body's immune system is unable to distinguish between foreign particles and the body's own cells and as a result attacks normal body tissue.

Conception: the union of the male's sperm and the female's ovum, or egg. This is the process of fertilisation. The product of this union is a cell called the zygote.

CVS (Chorionic Villus Sampling): a diagnostic test normally performed between 11 - 13 weeks of pregnancy. A needle is inserted through the mother's abdomen or cervix and is used to remove a small piece of the placenta (afterbirth). Ultrasound scanning is used to guide the needle. The procedure carries a miscarriage risk of 1-2%

Dilatation and Evaculation: medical procedure for termination of pregnancy (abortion).

Eugenics (from the Greek for "well born"): the early twentieth century policy which aimed to improve the quality of the population by preventing "unfit" people from reproducing and encouraging "fit" people to reproduce. Such ideas were popular in many countries, and were widely implemented in US, the Nordic countries, Germany and other states. The eugenic philosophy was discredited by association with Nazi abuses, and most US and UK geneticists have actively dissociated themselves from eugenics since 1945.

False negative: when a screening test suggests that a baby has a low risk of a condition which it later turns out to have.

False positive: when a screening test suggests that a baby has a high risk of a condition which it later turns out not to have.

Foetus: the name used for the unborn baby from the end of the 8 th week after conception (when the major structures have formed) until birth. Up until the eighth week, the developing offspring is called an Embryo.

Genetic Screening: genetic testing, when performed in populations known to have an increased risk of a specific genetic mutation or condition.

Genetic Testing: any procedure performed on chromosomes, genes, or gene products to determine whether a DNA mutation is causing or may cause a specific condition.

Gene: instructions carried on the chromosomes which enable cells to grow and function. Genes are passed on from one generation to the next one. One set of 23 chromosomes is inherited from the father, and one set from the mother, making 23 pairs.

Hormones: a biochemical substance that is produced by a specific cell or tissue and causes a change or activity in a cell or tissue located elsewhere in an organism.

Informed consent: when appropriate information is provided in order to enable patients to make decisions which reflect their own values. Health professionals subscribe to the values of non-directive counselling and informed consent, in order that patients can make decisions which are best for them, on the basis of full and balanced information. Relevant information might include: the purpose, risk, and benefits of testing; the reasons why the patient might participate in or decline testing; any available alternative procedures, interventions and treatment; decisions which may have to be made after receiving test results.

Invasive: procedures which involve passing a needle into the womb to collect a sample of the amniotic fluid.

Miscarriage: the spontaneous termination of a pregnancy before the foetus has developed enough to survive outside the uterus.

Neural tube: A structure in early foetal life that develops into the brain, spinal cord, spinal nerves and spine.

Non-directive counselling: when a health professional discusses options and choices with a patient, without imposing their own views or values about what the patient should do.

Nuchal Translucency: a technique for using ultrasound to measure fluid behind the neck of the foetus, usually at 10 to 14 weeks of pregnancy, which can contribute to a diagnosis of Down's syndrome.

Protein: a molecule made up of amino acids that are needed for the body to function properly. Proteins are the basis of body structures such as skin and hair and of substances such as enzymes, cytokines, and antibodies.

Screening: a test or scan which provides a risk factor of the foetus having a genetic or developmental condition, for example serum tests or ultrasound. Screening tests do not provide a conclusive diagnosis, and further tests may be required.

Termination: medical term for abortion. The premature exit of the products of conception (the foetus, foetal membranes, and placenta) from the uterus. It is the loss of a pregnancy and does not refer to why that pregnancy was lost.

Truthfulness and Disclosure: health practitioner's obligation to give reliable and accurate information to patients, to avoid withholding negative and distressing information, and to refrain from sharing information with family members without the patient's permission.

Uterus: the womb, the pear-sized female reproductive organ that nourishes the foetus until birth. The uterus is a hollow, thick-walled organ about the size of a fist. It is composed of the uterine body and the cervix. The muscular wall of the uterus is called the myometrium and the inner lining the endometrium. The Fallopian tubes serve to deliver the ova to the uterus.

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Page created: 7 September, 2004
Last updated: 20 July, 2005 3:58 PM
By: Alan Leeder