Acid reflux: A condition in which acid flows back up from the stomach into the upper intestines and the esophagus.
Acupressure: Manual pressure to parts of the body to relieve stress and pain.
Acupuncture: Insertion of needles into particular parts of the body to relieve stress and pain.
Aerobic exercise: Workouts like running or swimming that condition the heart and lungs by increasing the efficiency of the body's oxygen use.
Alpha-fetoprotein: A protein manufactured by the fetal yolk sac, and later by the fetus' gastro-intestinal tract and liver. A test for levels of AFP in the mother's blood can help detect Down's syndrome, spina bifida, and other abnormalities.
Amniocentesis: A prenatal test to detect birth defects that is performed after the 15th week of pregnancy. It involves inserting a needle through the abdomen to retrieve fluid that contains placental cells.
Amniotic fluid: The liquid within the uterus in which the fetus lives until birth.
Anencephaly: A neural tube defect involving severe structural defects of the brain and skull. Fetuses with anencephaly do not survive.
Anesthesia: Loss of sensation, or general insensibility to pain, induced by an anesthetic.
Antibodies: Specialized proteins created in response to the presence of antigens in the body.
Antigen: A protein, toxin, or other substance that makes the body react by producing antibodies.
Antihypertensive medication: Drugs used to prevent or control high blood pressure.
Areola: Darker skin that surrounds the nipple of the breast.
Artificial insemination: Impregnating a female with male semen using methods other than intercourse.
Bacteria: Single-cell microorganisms that may be capable of causing disease.
Carrier: A person who carries an infectious agent but shows no symptoms of infection.
Cervical opening: The opening at the lower part of the uterus that leads to the vagina.
Chorionic villus sampling: A prenatal test to detect birth defects that is performed at an early stage of pregnancy. It involves using a needle to retrieve placental cells for testing.
Choroin: The outer layer of the membranes that enclose the fetus. It helps with the development of the placenta.
Cone biopsy: A surgical procedure in which a cone-shaped piece of the cervix is removed. It is a treatment for cervical dysplasia (precancerous cells in the cervical tissue).
Corticosteroid: A steroid produced by the adrenal glands. It acts as an anti-inflammatory and helps maintain blood sugar levels, blood pressure, and muscle strength and controls salt and water balance.
Cytomegalovirus: A group of viruses that cause enlargement of various organs and may cause birth defects if acquired prenatally.
DES: Diethylstilbestrol: A synthetic estrogen hormone that some pregnant women were once prescribed to prevent miscarriage; the female offspring of mothers who took DES during pregnancy have a higher rate of vaginal cancer and malformed cervix. Male children of these women have a higher rate of genitourinary abnormalities and infertility. DES is no longer prescribed to pregnant women.
Diuretic: A substance that increases the amount of fluid that leaves the body.
DNA (Deoxyribonucleic acid): A nucleic acid that forms the chromosomes in human cells.
Down syndrome: Also known as Down's syndrome. A congenital disorder that is usually caused by the presence of an extra 21st chromosome. The affected child will have mild to moderate mental retardation.
Eclampsia: Convulsions or seizures brought on by seriously high blood pressure in pregnancy (pre-eclampsia). Untreated, eclampsia can lead to coma or death.
Ectopic pregnancy: A pregnancy in which the fertilized egg grows outside the uterus, usually in one of the fallopian tubes.
Enzyme: A protein that speeds up chemical processes and reactions in the body.
Estriol: A female sex hormone that increases during pregnancy.
Estrogen: The female sex hormone that controls the course of the menstrual cycle.
Fallopian tube: Either of two thin tubes that carry the egg from the ovaries to the uterus.
Fetus: An unborn child from the eighth week after conception until the moment of birth. From conception to eight weeks it is called an embryo.
Genital herpes: An inflammatory skin disease on the genitals, caused by the herpes virus.
Gestation: The nine-month period of pregnancy from conception to birth.
Gestational diabetes: A disease characterized by high blood sugars during pregnancy.
Glucose: The human body converts most dietary carbohydrates into a sugar called glucose. Glucose is a major source of energy for most cells of the body.
HELLP syndrome: A group of symptoms that occur in pregnant women who have (H) hemolytic anemia, (EL) elevated liver enzymes, and (LP) low platelet count.
Hemolytic anemia: A type of anemia in which the red blood cells die faster than they can be replaced.
Hemorrhage: Massive, heavy bleeding.
Homocysteine: A type of amino acid that forms proteins necessary for human life.
Human chorionic gonadotropin (hCG): A hormone that helps the ovaries produce progesterone and estrogen during the first trimester of pregnancy.
Hyperemesis gravidarum: Excessive vomiting in pregnancy. "Hyper" means over; "emesis" means vomiting; and gravidarum refers to a pregnant state.
Hyperglycemia: A condition of abnormally high blood sugar levels.
Hypoglycemia: A condition of abnormally low blood sugar levels.
In utero: Within the uterus; usually refers to the fetus.
Infection: Invasion of body tissue by disease-causing microorganisms, which may produce tissue injury.
Insulin: A hormone released by the pancreas that helps glucose move out of the blood and into the cells in the body, where the glucose can be used as energy and nourishment.
Intrauterine: Within the uterus.
IUD: A contraceptive device inserted in the uterus.
Jaundice: A condition in which the skin has a yellowish tone associated with a buildup of a bile pigment (bilirubin) in the bloodstream.
Karyotype: A map of the chromosomes in the nucleus of a single cell. Karotyping is also known as chromosome analysis, and it is used to diagnose some types of genetic diseases.
Ketone: A substance formed when the body breaks down fat. Uncontrolled diabetes, starvation, and sometimes alcohol use produces ketones in urine.
Macrosomia: A condition in which the fetus grows abnormally large. It often occurs when the mother had diabetes. High glucose (sugar) levels from the mother's blood reach the fetus, where the sugar is stored as fat.
Magnesium sulfate: Used to prevent seizures (eclampsia) in women with pre-eclampsia. It is also the active ingredient in most laxative wafers.
Methotrexate: Used to treat some ectopic pregnancies. It is also used in treating leukemia and various tumors.
Miscarriage: Premature expulsion of a fetus from the uterus before 20 weeks. Also called spontaneous abortion. Neural tube defect: Any of several congenital defects of the brain and spinal cord caused by the incomplete closing of the neural tube.
Molar pregnancy: An abnormally formed placenta that results in miscarriage. Also called a hydatidiform mole. Women with molar pregnancies will need blood work after they miscarry to make sure that all the abnormal placental tissue has been evacuated.
Natural childbirth: A method of childbirth in which medications and medical interventions are minimized, and the mother uses relaxation and breathing techniques to control pain and ease delivery.
Neurological: Pertaining to the neuromuscular system: the central, peripheral, and autonomic nervous systems.
Placenta previa: A condition that occurs when the placenta implants itself in the lower part of the uterus, blocking the cervical opening to the vagina.
Placenta: The organ that connects the fetus to the mother. It delivers oxygen and nutrients to - and takes waste away from - the fetus during pregnancy. It is attached to the fetus by the umbilical cord and is expelled after birth.
Pre-eclampsia: Pregnancy-induced high blood pressure that causes severe swelling and/or a high concentration of protein in the urine. It is cured when the baby is delivered.
Progesterone: A hormone that prepares the uterus for the development of a fertilized egg.
Pulmonary embolism: A potentially fatal blood clot that travels to the lungs, blocking major blood vessels. The risk for pulmonary embolism increases after surgery or prolonged bed rest.
Quickening: A woman's first experience of fetal movement. Quickening usually occurs between 16 and 20 weeks of pregnancy.
Rh factor: A group of antigens present in the red blood cells.
RNA (Ribonucleic acid): A nucleic acid that helps synthesize protein in the cells.
Spina bifida: A neural tube defect in which the fetus' backbone does not form properly. Also called open spine.
STDs: Sexually transmitted diseases.
Thiamin: One of the B complex vitamins. Also known as Vitamin B1.
Toxoplasmosis: A disease caused by the parasite Toxoplasma gondii, which may cause birth defects if acquired prenatally. Because contact with the fecal matter of domestic cats can spread the disease, caution should be used when handling litterboxes.
Ultrasound: A non-invasive imaging method using high sound frequencies that allows views of internal organs, blood flow, and tissues.
Uterine contractions: When the muscles in the uterine wall tighten and relax repeatedly.
Uterus: A hollow muscular organ located in a woman's pelvic cavity. It is where the fertilized egg attaches and the fetus develops. It is also called a womb.
Reviewed By: LaQuita Martinez, MD, Department of Obstetrics and Gynecology, Emory Johns Creek Hospital, Alpharetta, GA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.