Labor Onset: The beginning of true OBSTETRIC LABOR which is characterized by the cyclic uterine contractions of increasing frequency, duration, and strength causing CERVICAL DILATATION to begin (LABOR STAGE, FIRST ).Labor, Obstetric: The repetitive uterine contraction during childbirth which is associated with the progressive dilation of the uterine cervix (CERVIX UTERI). Successful labor results in the expulsion of the FETUS and PLACENTA. Obstetric labor can be spontaneous or induced (LABOR, INDUCED).Labor Stage, First: Period from the onset of true OBSTETRIC LABOR to the complete dilatation of the CERVIX UTERI.Labor, Induced: Artificially induced UTERINE CONTRACTION. Generally, LABOR, OBSTETRIC is induced with the intent to cause delivery of the fetus and termination of pregnancy.Myometrium: The smooth muscle coat of the uterus, which forms the main mass of the organ.Uterine Contraction: Contraction of the UTERINE MUSCLE.Amnion: The innermost membranous sac that surrounds and protects the developing embryo which is bathed in the AMNIOTIC FLUID. Amnion cells are secretory EPITHELIAL CELLS and contribute to the amniotic fluid.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Labor Pain: Pain associated with OBSTETRIC LABOR in CHILDBIRTH. It is caused primarily by UTERINE CONTRACTION as well as pressure on the CERVIX; BLADDER; and the GASTROINTESTINAL TRACT. Labor pain mostly occurs in the ABDOMEN; the GROIN; and the BACK.Placenta: A highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products. It includes a fetal portion (CHORIONIC VILLI) derived from TROPHOBLASTS and a maternal portion (DECIDUA) derived from the uterine ENDOMETRIUM. The placenta produces an array of steroid, protein and peptide hormones (PLACENTAL HORMONES).Obstetric Labor, Premature: Onset of OBSTETRIC LABOR before term (TERM BIRTH) but usually after the FETUS has become viable. In humans, it occurs sometime during the 29th through 38th week of PREGNANCY. TOCOLYSIS inhibits premature labor and can prevent the BIRTH of premature infants (INFANT, PREMATURE).Obstetric Labor Complications: Medical problems associated with OBSTETRIC LABOR, such as BREECH PRESENTATION; PREMATURE OBSTETRIC LABOR; HEMORRHAGE; or others. These complications can affect the well-being of the mother, the FETUS, or both.Trial of Labor: Allowing a woman to be in LABOR, OBSTETRIC long enough to determine if vaginal birth may be anticipated.Labor Presentation: The position or orientation of the FETUS at near term or during OBSTETRIC LABOR, determined by its relation to the SPINE of the mother and the birth canal. The normal position is a vertical, cephalic presentation with the fetal vertex flexed on the NECK.Labor Stage, Third: The final period of OBSTETRIC LABOR that is from the expulsion of the FETUS to the expulsion of the PLACENTA.Delivery, Obstetric: Delivery of the FETUS and PLACENTA under the care of an obstetrician or a health worker. Obstetric deliveries may involve physical, psychological, medical, or surgical interventions.Cesarean Section: Extraction of the FETUS by means of abdominal HYSTEROTOMY.Oxytocics: Drugs that stimulate contraction of the myometrium. They are used to induce LABOR, OBSTETRIC at term, to prevent or control postpartum or postabortion hemorrhage, and to assess fetal status in high risk pregnancies. They may also be used alone or with other drugs to induce abortions (ABORTIFACIENTS). Oxytocics used clinically include the neurohypophyseal hormone OXYTOCIN and certain prostaglandins and ergot alkaloids. (From AMA Drug Evaluations, 1994, p1157)Doulas: Trained lay women who provide emotional and/or physical support during obstetric labor and the postpartum period for mothers and their partners.Labor Stage, Second: The period of OBSTETRIC LABOR that is from the complete dilatation of the CERVIX UTERI to the expulsion of the FETUS.Obstetric Nursing: A nursing specialty involving nursing care given to the pregnant patient before, after, or during childbirth.Episiotomy: An incision of the posterior vaginal wall and a portion of the pudenda which enlarges the vaginal introitus to facilitate delivery and prevent lacerations.Gynecology: A medical-surgical specialty concerned with the physiology and disorders primarily of the female genital tract, as well as female endocrinology and reproductive physiology.Obstetrics: A medical-surgical specialty concerned with management and care of women during pregnancy, parturition, and the puerperium.Obstetrics and Gynecology Department, Hospital: Hospital department responsible for the administration and management of services provided for obstetric and gynecologic patients.Obstetric Surgical Procedures: Surgery performed on the pregnant woman for conditions associated with pregnancy, labor, or the puerperium. It does not include surgery of the newborn infant.Diagnostic Techniques, Obstetrical and Gynecological: Methods and procedures for the diagnosis of conditions related to pregnancy, labor, and the puerperium and of diseases of the female genitalia. It includes also demonstration of genital and pregnancy physiology.Periodicals as Topic: A publication issued at stated, more or less regular, intervals.Diagnosis-Related Groups: A system for classifying patient care by relating common characteristics such as diagnosis, treatment, and age to an expected consumption of hospital resources and length of stay. Its purpose is to provide a framework for specifying case mix and to reduce hospital costs and reimbursements and it forms the cornerstone of the prospective payment system.International Classification of Diseases: A system of categories to which morbid entries are assigned according to established criteria. Included is the entire range of conditions in a manageable number of categories, grouped to facilitate mortality reporting. It is produced by the World Health Organization (From ICD-10, p1). The Clinical Modifications, produced by the UNITED STATES DEPT. OF HEALTH AND HUMAN SERVICES, are larger extensions used for morbidity and general epidemiological purposes, primarily in the U.S.Dry Eye Syndromes: Corneal and conjunctival dryness due to deficient tear production, predominantly in menopausal and post-menopausal women. Filamentary keratitis or erosion of the conjunctival and corneal epithelium may be caused by these disorders. Sensation of the presence of a foreign body in the eye and burning of the eyes may occur.Clinical Coding: Process of substituting a symbol or code for a term such as a diagnosis or procedure. (from Slee's Health Care Terms, 3d ed.)Tears: The fluid secreted by the lacrimal glands. This fluid moistens the CONJUNCTIVA and CORNEA.Meibomian Glands: The sebaceous glands situated on the inner surface of the eyelids between the tarsal plates and CONJUNCTIVA.Receptors, Prostaglandin: Cell surface receptors that bind prostaglandins with high affinity and trigger intracellular changes which influence the behavior of cells. Prostaglandin receptor subtypes have been tentatively named according to their relative affinities for the endogenous prostaglandins. They include those which prefer prostaglandin D2 (DP receptors), prostaglandin E2 (EP1, EP2, and EP3 receptors), prostaglandin F2-alpha (FP receptors), and prostacyclin (IP receptors).Polymorphism, Genetic: The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.Receptors, Prostaglandin E: Cell surface receptors which bind prostaglandins with a high affinity and trigger intracellular changes which influence the behavior of cells. Prostaglandin E receptors prefer prostaglandin E2 to other endogenous prostaglandins. They are subdivided into EP1, EP2, and EP3 types based on their effects and their pharmacology.Dystocia: Slow or difficult OBSTETRIC LABOR or CHILDBIRTH.Parity: The number of offspring a female has borne. It is contrasted with GRAVIDITY, which refers to the number of pregnancies, regardless of outcome.Chronology as Topic: The temporal sequence of events that have occurred.Ericaceae: The heath plant family of the order Ericales, subclass Dilleniidae, class Magnoliopsida that are generally shrubs or small trees. Leaves are alternate, simple, and leathery; flowers are symmetrical with a 4- or 5-parted corolla of partly fused petals.Helminthiasis, Animal: Infestation of animals with parasitic worms of the helminth class. The infestation may be experimental or veterinary.Exercise Movement Techniques: Methods or programs of physical activities which can be used to promote, maintain, or restore the physical and physiological well-being of an individual.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Inula: A plant genus of the family ASTERACEAE. Members contain INULIN, alantol, helenin, alantic acid, and acrid resin.Faculty: The teaching staff and members of the administrative staff having academic rank in an educational institution.Cholestasis, Intrahepatic: Impairment of bile flow due to injury to the HEPATOCYTES; BILE CANALICULI; or the intrahepatic bile ducts (BILE DUCTS, INTRAHEPATIC).Cholestasis: Impairment of bile flow due to obstruction in small bile ducts (INTRAHEPATIC CHOLESTASIS) or obstruction in large bile ducts (EXTRAHEPATIC CHOLESTASIS).Bile Acids and Salts: Steroid acids and salts. The primary bile acids are derived from cholesterol in the liver and usually conjugated with glycine or taurine. The secondary bile acids are further modified by bacteria in the intestine. They play an important role in the digestion and absorption of fat. They have also been used pharmacologically, especially in the treatment of gallstones.Pruritus: An intense itching sensation that produces the urge to rub or scratch the skin to obtain relief.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.