Gamma Globulin

A protein based antibody made from pooled human plasma. Gamma globulin can be used to immunize many conditions including measles, poliomyelitis, chickenpox, serum hepatitis (following transfusion), hepatitis A, agammaglobulinemia, and hpogammaglobulinemia.

Gangliosidosis Type I

An inherited diorder of the nervous system caused by a deficiency of the hexosaminidase A enzyme. The recessive trait occurs predominantly in families of Ashkenazi Jewish origin.

Symptoms first appear in a baby at about 6 months of age after which no new skills are learned. Existing skills are progressively lost. The optic nerve atrophies after about 1 year along and additional symptoms include convulsions and blindness. Death often occurs between 2 and 4 years of age.

There is unfortunately no known therapy, and intervention remains symptomatic and supportive. It can be diagnosed in utero through amniocentesis. Also called Tay-Sachs disease, amaurotic familial idiocy and infantile cerebral sphingolipidosis.

GBS

One of the groups of streptococci (Lancefield's A - T). A serious infection pertaining to the mother's vagina and throat.

Gene

The part of every cell in which genetic material and inheritance is stored. Introduced by Mendel, the concept is still evolving and is a rapidly growing area of medical science.

In humans, genes occur as paired alleles. They serve numerous purposes, chiefly structural and regulative components that control diferentiation of cells and body tissues.

There are many different types of genes including complementary genes, dominant genes, lethal genes, mutant genes, operator genes, pleiotropic genes, recessive genes, regulator genes, structural genes, sublethal genes, supplementary genes and wild-type genes.

Genetic Counseling

A process through which the occurrence or risk of occurrence of a genetic disorder within a family is discussed with a specialist who will provide information about the courses of action available to the couple.

To be effective, a detailed family history is required and special biochemical or cytogenetic tests may be requested.

Genital Herpes Simplex

An infection whch is caused by the type 2 herpes simplex virus, also known as HSV-2.

Genital herpes is normally transmitted through sexual contact. It can be transmitted to the baby during pregnancy, either through the placenta to the fetus, or to the newborn baby by direct skin contact during delivery.

Symptons include painful lesions that turn into superficial ulcers and heal in a 5 - 7 day period. The disease is self-limiting and treatment is often symptomatic. Proper hygeine is recommended to prevent secondary infections. Patients may wish to contact the National Herpes Resource Center.

Gentle Birth

Some researchers believe that birthing and delivery is a shock to the baby's system. In an effort to reduce the clinical effect of delivery, alternative methods were developed. Gentle birth is a birth method developed by Frederick Leboyer, in which the shock of birth is reduced by welcoming the baby with loving hands, skin contact, soft lighting, and warm water.

German Measles

A contagious virus lasting approximately 2 or 3 days that is characterized by fever, a mild upper respiratory infection, lymph node enlargement and a fine red rash. Incubation time is bout 12 to 23 days.

During pregnancy fetal anomalies such as heart defects, cataracts, deafness and mental retardation may result if the mother contracts the disease during the first trimester.

A fetus that has been exposed to the virus in utero is immune for up to 30 months after birth. Vaccination is recommended for all children to minimize the chances of an epidemic and thus protect pregnant women.

Vaccination is not provided for mothers who are already pregnant, and pregnancy is to be avoided for three months after receiving the vaccine. Also called Rubella.

Gestation

The length of time between fertilzation and delivery of the baby. In humans the average time is 266 days, or about 280 days from the last menstrual period.

The gestational age referred to in pregnancy is the calendar time from the last menstrual period, and about two weeks longer than the fertilization age.

Gestational Age

The age of the fetus as determined from the first day of the last menstrual period (280 days till birth) rather than the date of conception, which is two weeks shorter (266 days till birth).

Gestational Diabetes

A form of diabetes occuring in pregnancy characterized by the body's inability to metabolize carbohydrate due to a lack of insulin.

Symptoms usually disappear after delivery, although in some cases may return several years later. Suggested causes include the destruction of insulin by the placenta and placental lactogen play a role.

Treatment includes insulin injections, a high protein diet and supplemental calcium and iron intake. Sometimes called pregnancy diabetes.

Gestational Trophoblastic Disease

An abnormal pregnancy with a cystic growth of the placenta. A hydatid mole develops from the trophoblastic tissue of the early embryonic stage of development.

With gestational trophoblastic disease all of the usual signs are highly exaggerated. The growth of the uterus is unusually rapid, morning sickness is often severe and there are high levels of chorionic gonadotropin as well as high blood pressure. In such cases the uterus must be evacuated to prevent the mole from developing into choriocarcinoma. Often abbreviated to GTN or called a molar pregnancy.

Globulin

A family of simple proteins from the plasma or blood serum, which is soluble, and is characterized by its size and electrophoretic mobility.

Glucose

A simple sugar which can be ingested when present in food, or created by the digestion of double sugars and starches, which is absorbed into the blood from the intestines.

Excess glucose is polymerized as glycogen and stored in the liver and muscles and is turned back into glucose when needed.

The measurement of glucose levels present in the blood is an important test for diagnosing diabetes.

Glucose Tolerance Test

A test which measures the body's ability to metabolize carbohydrates. The patient is administered a standard dose of glucose. Blood and urine and collected and tested periodically to determine the effectiveness of the metabolism.

Glucosuria

The presence of abnormally large quantities of glucose in the urine. Glucosuria can be a sign of kidney disease, diabetes melitus or some other metabolic disease.

Glycogen

The polymerized sugars derived from glucose when it is stored in the liver and muscle tissue. It is depolymerized and turned back into glucose as needed by the body.

Gonorrhea

A common sexually transmitted disease (STD) or venereal disease (VD), which most commonly affects the genitourinary tract.

The organism responsible is Neisseria gonorrhoeae, and symtpoms include urethritis, dysuria, yellowish-green urethral or vaginal discharge, itching and burning. The disease is more common in women than in men.

Gonorrhea is diagnosed by testing a smear, and can often be treated with penicillin.

Gravida I

A term used to describe a mother who is pregnant for the first time. Sometimes called primigravida.

Group-B Streptococcal Infection

One of the groups of streptococci (Lancefield's A - T). A serious infection pertaining to the mother's vagina and throat. Abbreviated to GBS.

GTN

Abbreviation for gestational trophoblastic disease, an abnormal pregnancy with a cystic growth of the placenta. A hydatid mole develops from the trophoblastic tissue of the early embryonic stage of development.

With GTN all of the usual signs are highly exaggerated. The growth of the uterus is unusually rapid, morning sickness is often severe and there are high levels of chorionic gonadotropin as well as high blood pressure. In such cases the uterus must be evacuated to prevent the mole from developing into choriocarcinoma. Also called a molar pregnancy.

Gynecologist

A doctor who practices the branch of medicine, which specializes in the female reproductive system. In the UK the word is often spelled gynaecologist.