Tay Sachs Disease

An inherited disorder 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 skill 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 amauroticfamilial idiocy, ganliosidosis type I and infantile cerebral sphingolipidosis.

Telangiectasias

A form of telangiectasis, the swelling of small blood vessels are commonly associated with elevated estrogen levels. Also called vascular spiders or spider angiomas.

Telemetry

A method used to measure the unborn baby's heartbeat, the mother's heartbeat, and contractions of the mother's uterus.

To measure the baby's heartbeat, an ultrasound transducer is placed on the mother's abdomen, close to the baby's heart.

To monitor contractions of the mother's uterus, a pressure sensor is placed on the mother's abodomen. Amplitude, frequency and duration are monitored with an interuterine catheter.

Monitoring of the baby's heartbeat can also be accomplished internally by placing an electrode through the cervix onto the baby's scalp. Also known as internal monitoring, or external fetal monitoring.

Teratogen

A term used to describe any agent, process or substance that interferes with normal fetal development. Teratogens can act either on the fetus directly or some supplemental structure such as the placental or maternal systems.

The period of highest risk occurs between weeks 3 and 12 when internal organs and systems are developed. Teratogens include drugs, alchohol, infectious agents such as the rubella virus, radiation including x-rays and environmental factors such as maternal age and general health.

Teratogenic

A general term used to describe any substance or agent that is a teratogen and may cause physical defects in the embryo.

Teratology

The study of agents, processes or substances that lead to abnormal fetal development.

Term

An infant born between 37 and 43 weeks of gestation. Size of term infants are between 19 - 21 inches (48 to 53 cm) and weigh between 6 and 9 lbs (2,700 - 4,000 g).

Termination

The death of a fetus in utero. Termination can either been spontaneous (natural miscarriage) or induced abortion.

Test Weighing

A method used to determine how much breast milk a baby is consuming by weighing it immediately before and immediately after feeding.

Testosterone

Considered a male sex hormones, testosterone is the primary natural androgen in humans. It is produced by the interstitial cells of the testes when stimulated by luteinizing hormone.

Tetracycline

A wide ranging group of antibiotics.

Thalassemia

A gentically transmitted hemolytic anemia caused by deficient hemoglobic synthesis that primarily affects people of Mediterranean origin.

Of the two forms, thalassemia major is evident in infancy and is characterized by anemia, fever and failure to thrive. Confirmation involved microscopic examination of the red blood cells.

Red blood cells are destroyed leaving large amounts of iron to be deposited in the skin. Iron is also deposited in the heart, liver and pancreas which may become fibrotic. Frequent blood transfusions are necessary to maintain the bloods ability to transport oxygen. There is currently no cure.

Threatened Miscarriage

A condition prior to the 20th week of gestation characterized by uterine bleeding and cramping that suggests a miscarriage may result. It can generally be managed with complete rest and medical observation.

Thrombosis

An abnormal condition of the veins in which a blockage occurs due to the aggregation of platelets, fibrin and cellular elements of the blood attaching to the interior walls of a vein or artery. Also called blood clot.

Thrush

Thrush, sometimes called candida albicans, is a common microscopic fungal organism normally present in the mucus membranes of the mouth, intestines and vagina. Under certain circumstances it may become superficially infected, and rarely seriously infected. Also known as Candida.

Thyroid Disease

An abnormal condition of the thyroid gland and its ability to produce the thyroid hormone.

Thyroid Gland

A vascular organ at the front of the neck consisting of two lobes connected in front of the windpipe. Larger in women than men, it increases in size during pregnancy, secreting the hormones thyroxine into the blood. It is activated by the pituitary thyrotropbic hormone and elaborated with iodine. It is essential to maintain normal body growth during infancy and childhood.

Thyroid Hormone

A compound secreted by the thyroid gland containing iodine. Thyroid hormones increase the rate of the metabolism, regulate body temperature, protein, fat and carbohydrate catabolism, control secretion of growth hormone, the maturation of the skeleton, cardiac rate, force and output, stimulate enzyme synthesis and are necessary for muscle tone and vigor.

Thyroid Panel

A series of blood tests performed to evaluate the function of the thyroid gland and its ability to produce thyroid hormone.

Thyroid Stimulating Hormone

A substance secreted by the pituitary gland that controls the secretion of the thyroid hormone necessary for thyroid growth and function. Abbreviated to TSH.

Tocodynamometer

An electronic device use to monitor and record the contractions in labor. It consists of a pressure measuring transducer that is placed on the lower abdomen and held by a belt. It is attached to a machine that records the duration of the contractions and the time between them onto graph paper. The tocodynamometer forms one part of the process of electronic fetal monitor.

Tocolysis

A term used to describe the medical interruption and halting of contractions during premature labor.

Tocolytic Agents

A group of medications used to stop or prevent labor.

Touch Relaxation

A method of inducing relaxation in the patient by resting the hands on the tight muscles and drawing out the tension.

Toxemia of Pregnancy

An abnormal condition in which the mother experiences extremely high blood pressure, proteinuria and fluid retention after the twenty fourth week.

While the reasons for the disease are still unknown, it is more common in multiple pregnancies, hydatiform mole or hydramnios.

Complications include increase likelihood of placental abruption, cerebral hemorrhage, fetal malnutrition and low birth weight. Severe cases risk the onset of eclampsia which can result in maternal and fetal death. If the onset of eclampsia is possible, labor is induced or an emergency cesarean section is performed.

The risk of eclampsia can be reduced by eating a diet high in protein and essential nutrients, and ensuring plenty of rest and exercise. Treatment includes rest, sedation and medication to lower the blood pressure. Also called preeclampsia.

Toxic Strep A

A bacterial infection that can be the cause of serious damage. It usually first appears as the result of a cut on the skin and can rapidly spread to the rest of the body.

Toxoplasmosis

A common infection caused by the intracellular parasite toxoplasma gondii. If acquired by the mother it is characterized by rash, lymphdenopathy, fever, malaise, central nervous system disorders, myocarditis and pneumonitis. The cysts are commonly passed to humans who eat inadequately cooked meat, or by handling cat feces. Cats acquire the disease by eating infected birds and mice.

In severe cases it can contracted in utero by crossing the placenta where it is characterized by cerebral calcification, convulsions, blindness, microcephaly and mental retardation. Once infected, immunity is confered. Pregnant mothers who are not immune are warned not to handle cats, cat feces or litter boxes.

Tranquilizers

A series of drugs used to relax anxious or agitated patients, ideally without inducing conciousness although they all induce drowsiness. Minor tranquilizers, sometimes referred to as anti-anxiety agents, include chlordiazepoxide, dizepam and hydroxyzine. They have strong potential for addiction.

Transducer

An instrument which is placed on the mother's abdomen and transmits high frequency sound waves which are bounced off the fetus and uterus. The signals returned are sent to computer where they built up into a graphical image of the baby in the uterus. It forms part of the ultrasound scanner.

Transition

A term used to describe the phase linking the first and second stages of labor in which the cervix is dilating to between 7 and 10 centimeters.

Transverse Lie

The position of the fetus in utero in which the long axis of the infant's body lies perpendicular to the long axis of the mother's body.

Trial of Labor

A term used to describe a situation in which although a cesarean section may be indicated, labor is attempted in order to determine whether natural delivery is possible.

Trichomal Vaginitis

An infection cause by the parasite Trichomonas vaginalis. Itis characterized by itching, burning and a frothy, pale green-yellow, malodorous vaginal discharge. Infection is transmitted by sexual intercourse, or in newborns by passage through the birth canal. Treatment is by oral medication. Also called trichomoniasis.

Trichomoniasis

An infection caused by the parasite Trichomonas vaginalis. It is characterized by itching, burning and a frothy, pale green-yellow, malodorous vaginal discharge. Infection is transmitted by sexual intercourse, or in newborns by passage through the birth canal. Treatment is by oral medication. Also called trichomal vaginitis.

Trimester

One of three periods in which the pregnancy is divided. Each trimester lasts approximately three months. The first trimester lasts from the first day of the last menstrual period to the end of the thirteenth week. It embraces the embryonic stage of development. The second trimester lasts from week fourteen to week twenty six and marks the period of rapid fetal growth. The third trimester lasts from the twenty eighth week through to delivery.

Triple Test Screening

A triple test screen is an advanced form of AFP test in which the levels of human chorionic gonadotropin and unconjugated estriol is measured in addition to alphafetoprotein.

Also known as the AFP3 test, it is used to identify the probability of a Down's syndrome pregnancy. Down's syndrome pregnancies usually have abnormally high levels of human chorionic gonadotropin and unusually low levels of estriol.

Trisomy 21

Better known as Down's Syndrome. A congenital abnormality in which the baby is born mentally retarded, with an average IQ of 50 - 60 and with physical deformation of the face (low set ears, sloping forehead, mongoloid eyes), and shortness of stature.

Trisomy 21 is caused by an extra chromosome 21 present in the G group. In a small percentage of cases it can be caused by the switching of chromosomes 14 or 15 in the D group or chromosome 21 or 22.

Trisomy 21 occurs in about 1 in 650 births, and is more commonly associated with children of mother's over the age of 35. Incidence in children of mothers over the age of 40 can be as high as 1 in 80.

Trisomy 21 can be detected prenatally through amniocentesis. The mortality rate is high within the first few years. The disease is also known as mongolism, Down's Syndrome or trisomy G syndrome.

Trisomy G Syndrome

Better known as Down's Syndrome. A congenital abnormality in which the baby is born mentally retarded, with an average IQ of 50 - 60 and with physical deformation of the face (low set ears, sloping forehead, mongoloid eyes), and shortness of stature.

Trisomy G syndrome is caused by an extra chromosome 21 present in the G group. In a small percentage of cases it can be caused by the switching of chromosomes 14 or15 in the D group or chromosome 21 or 22.

Trisomy G syndrome occurs in about 1 in 650 births, and is more commonly associated with children of mother's over the age of 35. Incidence in children of mothers over the age of 40 can be as high as 1 in 80.

Trisomy G syndrome can be detected prenatally through amniocentesis. The mortality rate is high within the first few years. The disease is also known as mongolism, trisomy 21 or Down's Syndrome.

Trophectoderm

The layer of tissue that forms the wall of the blastocyst in the early stages of embryonic development. The trophectoderm helps to implant the blastocyst to the uterine wall and supplies nutrients to the embryo.

During implantation, the trophectoderm differentiates into two layers. The inner layer, the cytotrophoblast forms into the chorion. The outer layer, syncytiotrophoblast, develops into the outer layer of the placenta. The trophectoderm is also known as the trophoblast.

Trophoblast

The layer of tissue that forms the wall of the blastocyst in the early stages of embryonic development. The trophoblast helps to implant the blastocyst to the uterine wall and supplies nutrients to the embryo.

During implantation, the trophoblast differentiates into two layers. The inner layer, the cytotrophoblast forms into the chorion. The outer layer, syncytiotrophoblast, develops into the outer layer of the placenta. The trophoblast is also known as the trophectoderm.

True Twins

A pregnancy in which two children are produced from the same ovum, which has split during early embryonic development.

True twins are always of the same sex, share the same genetic makeup and blood groups.

Both children resemble each other physically, mentally and psychologically.

True twins are also called Monozygotic twins, Enzygotic twins, identical twins or uniovular twins.

TSH

Abbreviation of thyroid stimulating hormone, a substance secreted by the pituitary gland that controls the secretion of the thyroid hormone necessary for thyroid growth and function.

Tubal Pregnancy

An abnormal condition in which the egg becomes fertilization outside of the uterus, usually in the fallopian tubes. The mother experiences severe pain to one side of the lower abdomen, between weeks 6 and 12. The pregnancy must then be surgically terminated. Also known as an ectopic pregnancy.