Morning Sickness: Symptoms of NAUSEA and VOMITING in pregnant women that usually occur in the morning during the first 2 to 3 months of PREGNANCY. Severe persistent vomiting during pregnancy is called HYPEREMESIS GRAVIDARUM.Doxylamine: Histamine H1 antagonist with pronounced sedative properties. It is used in allergies and as an antitussive, antiemetic, and hypnotic. Doxylamine has also been administered in veterinary applications and was formerly used in PARKINSONISM.Antiemetics: Drugs used to prevent NAUSEA or VOMITING.Motion Sickness: Disorder caused by motion, as sea sickness, train sickness, car sickness, air sickness, or SPACE MOTION SICKNESS. It may include nausea, vomiting and dizziness.Altitude Sickness: Multiple symptoms associated with reduced oxygen at high ALTITUDE.Hyperemesis Gravidarum: Intractable VOMITING that develops in early PREGNANCY and persists. This can lead to DEHYDRATION and WEIGHT LOSS.Surrogate Mothers: Women who allow themselves to be impregnated with the understanding that the offspring are to be given over to the parents who have commissioned the surrogate.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Pregnancy Complications: Conditions or pathological processes associated with pregnancy. They can occur during or after pregnancy, and range from minor discomforts to serious diseases that require medical interventions. They include diseases in pregnant females, and pregnancies in females with diseases.Encyclopedias as Topic: Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)Pimpinella: A plant genus in the family APIACEAE (Umbelliferae) that is used in SPICES and is a source of anethole.Pesticide Synergists: Chemicals that, while not possessing inherent pesticidal activity, nonetheless promote or enhance the effectiveness of other pesticides when combined.Smell: The ability to detect scents or odors, such as the function of OLFACTORY RECEPTOR NEURONS.Sick Leave: An absence from work permitted because of illness or the number of days per year for which an employer agrees to pay employees who are sick. (Webster's New Collegiate Dictionary, 1981)Serum Sickness: Immune complex disease caused by the administration of foreign serum or serum proteins and characterized by fever, lymphadenopathy, arthralgia, and urticaria. When they are complexed to protein carriers, some drugs can also cause serum sickness when they act as haptens inducing antibody responses.Circadian Rhythm: The regular recurrence, in cycles of about 24 hours, of biological processes or activities, such as sensitivity to drugs and stimuli, hormone secretion, sleeping, and feeding.Therapeutic Misconception: Misunderstanding among individuals, frequently research subjects, of scientific methods such as randomization and placebo controls.Citrus: A plant genus of the family RUTACEAE. They bear the familiar citrus fruits including oranges, grapefruit, lemons, and limes. There are many hybrids which makes the nomenclature confusing.Citrus sinensis: A plant species of the genus CITRUS, family RUTACEAE that provides the familiar orange fruit which is also a source of orange oil.Nephrolithiasis: Formation of stones in the KIDNEY.Beverages: Liquids that are suitable for drinking. (From Merriam Webster Collegiate Dictionary, 10th ed)Mothers: Female parents, human or animal.Abortion, Induced: Intentional removal of a fetus from the uterus by any of a number of techniques. (POPLINE, 1978)Odors: The volatile portions of substances perceptible by the sense of smell. (Grant & Hackh's Chemical Dictionary, 5th ed)Heartburn: Substernal pain or burning sensation, usually associated with regurgitation of gastric juice into the esophagus.Promethazine: A phenothiazine derivative with histamine H1-blocking, antimuscarinic, and sedative properties. It is used as an antiallergic, in pruritus, for motion sickness and sedation, and also in animals.Metoclopramide: A dopamine D2 antagonist that is used as an antiemetic.Codeine: An opioid analgesic related to MORPHINE but with less potent analgesic properties and mild sedative effects. It also acts centrally to suppress cough.Ipomoea: A plant genus in the family CONVOLVULACEAE best known for morning glories (a common name also used with CONVOLVULUS) and sweet potato.Foxes: Any of several carnivores in the family CANIDAE, that possess erect ears and long bushy tails and are smaller than WOLVES. They are classified in several genera and found on all continents except Antarctica.Pregnancy Trimester, First: The beginning third of a human PREGNANCY, from the first day of the last normal menstrual period (MENSTRUATION) through the completion of 14 weeks (98 days) of gestation.Pregnant Women: Human females who are pregnant, as cultural, psychological, or sociological entities.Women, Working: Women who are engaged in gainful activities usually outside the home.Prince Edward Island: An island in the Gulf of St. Lawrence constituting a province of Canada in the eastern part of the country. It is very irregular in shape with many deep inlets. Its capital is Charlottetown. Discovered by the French in 1534 and originally named Ile Saint-Jean, it was renamed in 1799 in honor of Prince Edward, fourth son of George III and future father of Queen Victoria. (From Webster's New Geographical Dictionary, 1988, p981 & Room, Brewer's Dictionary of Names, 1992, p433)Intelligence: The ability to learn and to deal with new situations and to deal effectively with tasks involving abstractions.Intelligence Tests: Standardized tests that measure the present general ability or aptitude for intellectual performance.Ginger: Deciduous plant rich in volatile oil (OILS, VOLATILE). It is used as a flavoring agent and has many other uses both internally and topically.Candy: Sweet food products combining cane or beet sugars with other carbohydrates and chocolate, milk, eggs, and various flavorings. In the United States, candy refers to both sugar- and cocoa-based confections and is differentiated from sweetened baked goods; elsewhere the terms sugar confectionary, chocolate confectionary, and flour confectionary (meaning goods such as cakes and pastries) are used.Constipation: Infrequent or difficult evacuation of FECES. These symptoms are associated with a variety of causes, including low DIETARY FIBER intake, emotional or nervous disturbances, systemic and structural disorders, drug-induced aggravation, and infections.Ondansetron: A competitive serotonin type 3 receptor antagonist. It is effective in the treatment of nausea and vomiting caused by cytotoxic chemotherapy drugs, including cisplatin, and has reported anxiolytic and neuroleptic properties.Vomiting: The forcible expulsion of the contents of the STOMACH through the MOUTH.Homeopathy: A system of therapeutics founded by Samuel Hahnemann (1755-1843), based on the Law of Similars where "like cures like". Diseases are treated by highly diluted substances that cause, in healthy persons, symptoms like those of the disease to be treated.Materia Medica: Materials or substances used in the composition of traditional medical remedies. The use of this term in MeSH was formerly restricted to historical articles or those concerned with traditional medicine, but it can also refer to homeopathic remedies. Nosodes are specific types of homeopathic remedies prepared from causal agents or disease products.Dreams: A series of thoughts, images, or emotions occurring during sleep which are dissociated from the usual stream of consciousness of the waking state.Hunger: The desire for FOOD generated by a sensation arising from the lack of food in the STOMACH.Hyoscyamus: A plant genus of the family SOLANACEAE which contains TROPANES.Reproductive Techniques, Assisted: Clinical and laboratory techniques used to enhance fertility in humans and animals.Infertility: Inability to reproduce after a specified period of unprotected intercourse. Reproductive sterility is permanent infertility.Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.