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.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Pregnancy Outcome: Results of conception and ensuing pregnancy, including LIVE BIRTH; STILLBIRTH; SPONTANEOUS ABORTION; INDUCED ABORTION. The outcome may follow natural or artificial insemination or any of the various ASSISTED REPRODUCTIVE TECHNIQUES, such as EMBRYO TRANSFER or FERTILIZATION IN VITRO.Pre-Eclampsia: A complication of PREGNANCY, characterized by a complex of symptoms including maternal HYPERTENSION and PROTEINURIA with or without pathological EDEMA. Symptoms may range between mild and severe. Pre-eclampsia usually occurs after the 20th week of gestation, but may develop before this time in the presence of trophoblastic disease.Hypertension, Pregnancy-Induced: A condition in pregnant women with elevated systolic (>140 mm Hg) and diastolic (>90 mm Hg) blood pressure on at least two occasions 6 h apart. HYPERTENSION complicates 8-10% of all pregnancies, generally after 20 weeks of gestation. Gestational hypertension can be divided into several broad categories according to the complexity and associated symptoms, such as EDEMA; PROTEINURIA; SEIZURES; abnormalities in BLOOD COAGULATION and liver functions.Pregnancy Complications, Cardiovascular: The co-occurrence of pregnancy and a cardiovascular disease. The disease may precede or follow FERTILIZATION and it may or may not have a deleterious effect on the pregnant woman or FETUS.Pregnancy Complications, Hematologic: The co-occurrence of pregnancy and a blood disease (HEMATOLOGIC DISEASES) which involves BLOOD CELLS or COAGULATION FACTORS. The hematologic disease may precede or follow FERTILIZATION and it may or may not have a deleterious effect on the pregnant woman or FETUS.Female Urogenital Diseases and Pregnancy Complications: Pathological processes of the female URINARY TRACT, the reproductive system (GENITALIA, FEMALE), and disorders related to PREGNANCY.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.Pregnancy, Ectopic: A potentially life-threatening condition in which EMBRYO IMPLANTATION occurs outside the cavity of the UTERUS. Most ectopic pregnancies (>96%) occur in the FALLOPIAN TUBES, known as TUBAL PREGNANCY. They can be in other locations, such as UTERINE CERVIX; OVARY; and abdominal cavity (PREGNANCY, ABDOMINAL).Abortion, Spontaneous: Expulsion of the product of FERTILIZATION before completing the term of GESTATION and without deliberate interference.Pregnancy Complications, Neoplastic: The co-occurrence of pregnancy and NEOPLASMS. The neoplastic disease may precede or follow FERTILIZATION.Fetal Growth Retardation: The failure of a FETUS to attain its expected FETAL GROWTH at any GESTATIONAL AGE.Abruptio Placentae: Premature separation of the normally implanted PLACENTA from the UTERUS. Signs of varying degree of severity include UTERINE BLEEDING, uterine MUSCLE HYPERTONIA, and FETAL DISTRESS or FETAL DEATH.Premature Birth: CHILDBIRTH before 37 weeks of PREGNANCY (259 days from the first day of the mother's last menstrual period, or 245 days after FERTILIZATION).Pregnancy, Animal: The process of bearing developing young (EMBRYOS or FETUSES) in utero in non-human mammals, beginning from FERTILIZATION to BIRTH.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).Pregnancy Trimester, Second: The middle third of a human PREGNANCY, from the beginning of the 15th through the 28th completed week (99 to 196 days) of gestation.Uterine Artery: A branch arising from the internal iliac artery in females, that supplies blood to the uterus.Pregnancy Trimester, Third: The last third of a human PREGNANCY, from the beginning of the 29th through the 42nd completed week (197 to 294 days) of gestation.Civil Disorders: Deliberate and planned acts of unlawful behavior engaged in by aggrieved segments of the population in seeking social change.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Placenta Diseases: Pathological processes or abnormal functions of the PLACENTA.Pregnancy Complications, Infectious: The co-occurrence of pregnancy and an INFECTION. The infection may precede or follow FERTILIZATION.Eclampsia: Onset of HYPERREFLEXIA; SEIZURES; or COMA in a previously diagnosed pre-eclamptic patient (PRE-ECLAMPSIA).Pregnancy, Twin: The condition of carrying TWINS simultaneously.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).Infant, Newborn: An infant during the first month after birth.Placental Circulation: The circulation of BLOOD, of both the mother and the FETUS, through the PLACENTA.Gestational Age: The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated as the time from the last day of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization.Trophoblasts: Cells lining the outside of the BLASTOCYST. After binding to the ENDOMETRIUM, trophoblasts develop into two distinct layers, an inner layer of mononuclear cytotrophoblasts and an outer layer of continuous multinuclear cytoplasm, the syncytiotrophoblasts, which form the early fetal-maternal interface (PLACENTA).Diabetes, Gestational: Diabetes mellitus induced by PREGNANCY but resolved at the end of pregnancy. It does not include previously diagnosed diabetics who become pregnant (PREGNANCY IN DIABETICS). Gestational diabetes usually develops in late pregnancy when insulin antagonistic hormones peaks leading to INSULIN RESISTANCE; GLUCOSE INTOLERANCE; and HYPERGLYCEMIA.Congenital Abnormalities: Malformations of organs or body parts during development in utero.Fetal Death: Death of the developing young in utero. BIRTH of a dead FETUS is STILLBIRTH.Preconception Care: An organized and comprehensive program of health care that identifies and reduces a woman's reproductive risks before conception through risk assessment, health promotion, and interventions. Preconception care programs may be designed to include the male partner in providing counseling and educational information in preparation for fatherhood, such as genetic counseling and testing, financial and family planning, etc. This concept is different from PRENATAL CARE, which occurs during pregnancy.Pregnancy, High-Risk: Pregnancy in which the mother and/or FETUS are at greater than normal risk of MORBIDITY or MORTALITY. Causes include inadequate PRENATAL CARE, previous obstetrical history (ABORTION, SPONTANEOUS), pre-existing maternal disease, pregnancy-induced disease (GESTATIONAL HYPERTENSION), and MULTIPLE PREGNANCY, as well as advanced maternal age above 35.Pregnancy, Multiple: The condition of carrying two or more FETUSES simultaneously.Cesarean Section: Extraction of the FETUS by means of abdominal HYSTEROTOMY.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.Stillbirth: The event that a FETUS is born dead or stillborn.Prenatal Care: Care provided the pregnant woman in order to prevent complications, and decrease the incidence of maternal and prenatal mortality.Infant, Small for Gestational Age: An infant having a birth weight lower than expected for its gestational age.Uterus: The hollow thick-walled muscular organ in the female PELVIS. It consists of the fundus (the body) which is the site of EMBRYO IMPLANTATION and FETAL DEVELOPMENT. Beyond the isthmus at the perineal end of fundus, is CERVIX UTERI (the neck) opening into VAGINA. Beyond the isthmi at the upper abdominal end of fundus, are the FALLOPIAN TUBES.Abortion, Habitual: Three or more consecutive spontaneous abortions.Ultrasonography, Prenatal: The visualization of tissues during pregnancy through recording of the echoes of ultrasonic waves directed into the body. The procedure may be applied with reference to the mother or the fetus and with reference to organs or the detection of maternal or fetal disease.Pregnancy Proteins: Proteins produced by organs of the mother or the PLACENTA during PREGNANCY. These proteins may be pregnancy-specific (present only during pregnancy) or pregnancy-associated (present during pregnancy or under other conditions such as hormone therapy or certain malignancies.)Birth Weight: The mass or quantity of heaviness of an individual at BIRTH. It is expressed by units of pounds or kilograms.Risk Factors: An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.Pregnancy Rate: The ratio of the number of conceptions (CONCEPTION) including LIVE BIRTH; STILLBIRTH; and fetal losses, to the mean number of females of reproductive age in a population during a set time period.Maternal Age: The age of the mother in PREGNANCY.Parity: The number of offspring a female has borne. It is contrasted with GRAVIDITY, which refers to the number of pregnancies, regardless of outcome.Antibodies, Antiphospholipid: Autoantibodies directed against phospholipids. These antibodies are characteristically found in patients with systemic lupus erythematosus (LUPUS ERYTHEMATOSUS, SYSTEMIC;), ANTIPHOSPHOLIPID SYNDROME; related autoimmune diseases, some non-autoimmune diseases, and also in healthy individuals.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Placental Insufficiency: Failure of the PLACENTA to deliver an adequate supply of nutrients and OXYGEN to the FETUS.Pregnancy Trimesters: The three approximately equal periods of a normal human PREGNANCY. Each trimester is about three months or 13 to 14 weeks in duration depending on the designation of the first day of gestation.Placentation: The development of the PLACENTA, a highly vascularized mammalian fetal-maternal organ and major site of transport of oxygen, nutrients, and fetal waste products between mother and FETUS. The process begins at FERTILIZATION, through the development of CYTOTROPHOBLASTS and SYNCYTIOTROPHOBLASTS, the formation of CHORIONIC VILLI, to the progressive increase in BLOOD VESSELS to support the growing fetus.Multiple Birth Offspring: The offspring in multiple pregnancies (PREGNANCY, MULTIPLE): TWINS; TRIPLETS; QUADRUPLETS; QUINTUPLETS; etc.Pregnancy Tests: Tests to determine whether or not an individual is pregnant.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.Maternal-Fetal Exchange: Exchange of substances between the maternal blood and the fetal blood at the PLACENTA via PLACENTAL CIRCULATION. The placental barrier excludes microbial or viral transmission.Pregnancy in Diabetics: The state of PREGNANCY in women with DIABETES MELLITUS. This does not include either symptomatic diabetes or GLUCOSE INTOLERANCE induced by pregnancy (DIABETES, GESTATIONAL) which resolves at the end of pregnancy.Prospective Studies: Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.Pregnancy, Tubal: The most common (>96%) type of ectopic pregnancy in which the extrauterine EMBRYO IMPLANTATION occurs in the FALLOPIAN TUBE, usually in the ampullary region where FERTILIZATION takes place.Antiphospholipid Syndrome: The presence of antibodies directed against phospholipids (ANTIBODIES, ANTIPHOSPHOLIPID). The condition is associated with a variety of diseases, notably systemic lupus erythematosus and other connective tissue diseases, thrombopenia, and arterial or venous thromboses. In pregnancy it can cause abortion. Of the phospholipids, the cardiolipins show markedly elevated levels of anticardiolipin antibodies (ANTIBODIES, ANTICARDIOLIPIN). Present also are high levels of lupus anticoagulant (LUPUS COAGULATION INHIBITOR).Maternal Welfare: Organized efforts by communities or organizations to improve the health and well-being of the mother.Reproductive Techniques, Assisted: Clinical and laboratory techniques used to enhance fertility in humans and animals.Fetal Development: Morphological and physiological development of FETUSES.Infant, Low Birth Weight: An infant having a birth weight of 2500 gm. (5.5 lb.) or less but INFANT, VERY LOW BIRTH WEIGHT is available for infants having a birth weight of 1500 grams (3.3 lb.) or less.Fetal Membranes, Premature Rupture: Spontaneous tearing of the membranes surrounding the FETUS any time before the onset of OBSTETRIC LABOR. Preterm PROM is membrane rupture before 37 weeks of GESTATION.Fertilization in Vitro: An assisted reproductive technique that includes the direct handling and manipulation of oocytes and sperm to achieve fertilization in vitro.Pregnancy in Adolescence: Pregnancy in human adolescent females under the age of 19.Cohort Studies: Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.Decidua: The hormone-responsive glandular layer of ENDOMETRIUM that sloughs off at each menstrual flow (decidua menstrualis) or at the termination of pregnancy. During pregnancy, the thickest part of the decidua forms the maternal portion of the PLACENTA, thus named decidua placentalis. The thin portion of the decidua covering the rest of the embryo is the decidua capsularis.Odds Ratio: The ratio of two odds. The exposure-odds ratio for case control data is the ratio of the odds in favor of exposure among cases to the odds in favor of exposure among noncases. The disease-odds ratio for a cohort or cross section is the ratio of the odds in favor of disease among the exposed to the odds in favor of disease among the unexposed. The prevalence-odds ratio refers to an odds ratio derived cross-sectionally from studies of prevalent cases.Thrombophilia: A disorder of HEMOSTASIS in which there is a tendency for the occurrence of THROMBOSIS.Logistic Models: Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.Treatment Outcome: Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.Pregnancy, Unplanned: Unintended accidental pregnancy, including pregnancy resulting from failed contraceptive measures.Risk Assessment: The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)Pregnancy, Unwanted: Pregnancy, usually accidental, that is not desired by the parent or parents.Intraoperative Complications: Complications that affect patients during surgery. They may or may not be associated with the disease for which the surgery is done, or within the same surgical procedure.Homocysteine: A thiol-containing amino acid formed by a demethylation of METHIONINE.NorwayIncidence: The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.Pregnancy Complications, Parasitic: The co-occurrence of pregnancy and parasitic diseases. The parasitic infection may precede or follow FERTILIZATION.Infant, Premature: A human infant born before 37 weeks of GESTATION.Pregnancy, Prolonged: A term used to describe pregnancies that exceed the upper limit of a normal gestational period. In humans, a prolonged pregnancy is defined as one that extends beyond 42 weeks (294 days) after the first day of the last menstrual period (MENSTRUATION), or birth with gestational age of 41 weeks or more.Abortion, Induced: Intentional removal of a fetus from the uterus by any of a number of techniques. (POPLINE, 1978)United StatesTime Factors: Elements of limited time intervals, contributing to particular results or situations.Case-Control Studies: Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.Questionnaires: Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.Confidence Intervals: A range of values for a variable of interest, e.g., a rate, constructed so that this range has a specified probability of including the true value of the variable.Prevalence: The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.Pregnancy, Abdominal: A type of ectopic pregnancy in which the EMBRYO, MAMMALIAN implants in the ABDOMINAL CAVITY instead of in the ENDOMETRIUM of the UTERUS.Follow-Up Studies: Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.Pregnancy Maintenance: Physiological mechanisms that sustain the state of PREGNANCY.Embryo Implantation: Endometrial implantation of EMBRYO, MAMMALIAN at the BLASTOCYST stage.Embryo Transfer: The transfer of mammalian embryos from an in vivo or in vitro environment to a suitable host to improve pregnancy or gestational outcome in human or animal. In human fertility treatment programs, preimplantation embryos ranging from the 4-cell stage to the blastocyst stage are transferred to the uterine cavity between 3-5 days after FERTILIZATION IN VITRO.Diabetes Complications: Conditions or pathological processes associated with the disease of diabetes mellitus. Due to the impaired control of BLOOD GLUCOSE level in diabetic patients, pathological processes develop in numerous tissues and organs including the EYE, the KIDNEY, the BLOOD VESSELS, and the NERVE TISSUE.Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.Prenatal Exposure Delayed Effects: The consequences of exposing the FETUS in utero to certain factors, such as NUTRITION PHYSIOLOGICAL PHENOMENA; PHYSIOLOGICAL STRESS; DRUGS; RADIATION; and other physical or chemical factors. These consequences are observed later in the offspring after BIRTH.Pregnancy Reduction, Multifetal: Selective abortion of one or more embryos or fetuses in a multiple gestation pregnancy. The usual goal is to improve the outcome for the remaining embryos or fetuses.Infertility, Female: Diminished or absent ability of a female to achieve conception.Progesterone: The major progestational steroid that is secreted primarily by the CORPUS LUTEUM and the PLACENTA. Progesterone acts on the UTERUS, the MAMMARY GLANDS and the BRAIN. It is required in EMBRYO IMPLANTATION; PREGNANCY maintenance, and the development of mammary tissue for MILK production. Progesterone, converted from PREGNENOLONE, also serves as an intermediate in the biosynthesis of GONADAL STEROID HORMONES and adrenal CORTICOSTEROIDS.Abnormalities, Drug-Induced: Congenital abnormalities caused by medicinal substances or drugs of abuse given to or taken by the mother, or to which she is inadvertently exposed during the manufacture of such substances. The concept excludes abnormalities resulting from exposure to non-medicinal chemicals in the environment.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).Reoperation: A repeat operation for the same condition in the same patient due to disease progression or recurrence, or as followup to failed previous surgery.Puerperal Disorders: Disorders or diseases associated with PUERPERIUM, the six-to-eight-week period immediately after PARTURITION in humans.Fetus: The unborn young of a viviparous mammal, in the postembryonic period, after the major structures have been outlined. In humans, the unborn young from the end of the eighth week after CONCEPTION until BIRTH, as distinguished from the earlier EMBRYO, MAMMALIAN.Laparoscopy: A procedure in which a laparoscope (LAPAROSCOPES) is inserted through a small incision near the navel to examine the abdominal and pelvic organs in the PERITONEAL CAVITY. If appropriate, biopsy or surgery can be performed during laparoscopy.Twins: Two individuals derived from two FETUSES that were fertilized at or about the same time, developed in the UTERUS simultaneously, and born to the same mother. Twins are either monozygotic (TWINS, MONOZYGOTIC) or dizygotic (TWINS, DIZYGOTIC).Lactation: The processes of milk secretion by the maternal MAMMARY GLANDS after PARTURITION. The proliferation of the mammary glandular tissue, milk synthesis, and milk expulsion or let down are regulated by the interactions of several hormones including ESTRADIOL; PROGESTERONE; PROLACTIN; and OXYTOCIN.Prenatal Diagnosis: Determination of the nature of a pathological condition or disease in the postimplantation EMBRYO; FETUS; or pregnant female before birth.Abortion, Therapeutic: Abortion induced to save the life or health of a pregnant woman. (From Dorland, 28th ed)Chorionic Gonadotropin: A gonadotropic glycoprotein hormone produced primarily by the PLACENTA. Similar to the pituitary LUTEINIZING HORMONE in structure and function, chorionic gonadotropin is involved in maintaining the CORPUS LUTEUM during pregnancy. CG consists of two noncovalently linked subunits, alpha and beta. Within a species, the alpha subunit is virtually identical to the alpha subunits of the three pituitary glycoprotein hormones (TSH, LH, and FSH), but the beta subunit is unique and confers its biological specificity (CHORIONIC GONADOTROPIN, BETA SUBUNIT, HUMAN).Fetal Diseases: Pathophysiological conditions of the FETUS in the UTERUS. Some fetal diseases may be treated with FETAL THERAPIES.Maternal Exposure: Exposure of the female parent, human or animal, to potentially harmful chemical, physical, or biological agents in the environment or to environmental factors that may include ionizing radiation, pathogenic organisms, or toxic chemicals that may affect offspring. It includes pre-conception maternal exposure.Abortifacient Agents, Nonsteroidal: Non-steroidal chemical compounds with abortifacient activity.Length of Stay: The period of confinement of a patient to a hospital or other health facility.Insemination, Artificial: Artificial introduction of SEMEN or SPERMATOZOA into the VAGINA to facilitate FERTILIZATION.Amniotic Fluid: A clear, yellowish liquid that envelopes the FETUS inside the sac of AMNION. In the first trimester, it is likely a transudate of maternal or fetal plasma. In the second trimester, amniotic fluid derives primarily from fetal lung and kidney. Cells or substances in this fluid can be removed for prenatal diagnostic tests (AMNIOCENTESIS).Endometrium: The mucous membrane lining of the uterine cavity that is hormonally responsive during the MENSTRUAL CYCLE and PREGNANCY. The endometrium undergoes cyclic changes that characterize MENSTRUATION. After successful FERTILIZATION, it serves to sustain the developing embryo.Infertility: Inability to reproduce after a specified period of unprotected intercourse. Reproductive sterility is permanent infertility.Sperm Injections, Intracytoplasmic: An assisted fertilization technique consisting of the microinjection of a single viable sperm into an extracted ovum. It is used principally to overcome low sperm count, low sperm motility, inability of sperm to penetrate the egg, or other conditions related to male infertility (INFERTILITY, MALE).Pregnant Women: Human females who are pregnant, as cultural, psychological, or sociological entities.Gravidity: The number of pregnancies, complete or incomplete, experienced by a female. It is different from PARITY, which is the number of offspring borne. (From Stedman, 26th ed)Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.Tomography, X-Ray Computed: Tomography using x-ray transmission and a computer algorithm to reconstruct the image.Hemorrhage: Bleeding or escape of blood from a vessel.Surgical Wound Infection: Infection occurring at the site of a surgical incision.Abortion, Legal: Termination of pregnancy under conditions allowed under local laws. (POPLINE Thesaurus, 1991)Parturition: The process of giving birth to one or more offspring.Chorionic Gonadotropin, beta Subunit, Human: The beta subunit of human CHORIONIC GONADOTROPIN. Its structure is similar to the beta subunit of LUTEINIZING HORMONE, except for the additional 30 amino acids at the carboxy end with the associated carbohydrate residues. HCG-beta is used as a diagnostic marker for early detection of pregnancy, spontaneous abortion (ABORTION, SPONTANEOUS); ECTOPIC PREGNANCY; HYDATIDIFORM MOLE; CHORIOCARCINOMA; or DOWN SYNDROME.Equipment Failure: Failure of equipment to perform to standard. The failure may be due to defects or improper use.Uterine Hemorrhage: Bleeding from blood vessels in the UTERUS, sometimes manifested as vaginal bleeding.Ovulation Induction: Techniques for the artifical induction of ovulation, the rupture of the follicle and release of the ovum.Live Birth: The event that a FETUS is born alive with heartbeats or RESPIRATION regardless of GESTATIONAL AGE. Such liveborn is called a newborn infant (INFANT, NEWBORN).Device Removal: Removal of an implanted therapeutic or prosthetic device.Maternal Nutritional Physiological Phenomena: Nutrition of a mother which affects the health of the FETUS and INFANT as well as herself.Recurrence: The return of a sign, symptom, or disease after a remission.Drainage: The removal of fluids or discharges from the body, such as from a wound, sore, or cavity.Abortion, Threatened: UTERINE BLEEDING from a GESTATION of less than 20 weeks without any CERVICAL DILATATION. It is characterized by vaginal bleeding, lower back discomfort, or midline pelvic cramping and a risk factor for MISCARRIAGE.Age Factors: Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.Contraception: Prevention of CONCEPTION by blocking fertility temporarily, or permanently (STERILIZATION, REPRODUCTIVE). Common means of reversible contraception include NATURAL FAMILY PLANNING METHODS; CONTRACEPTIVE AGENTS; or CONTRACEPTIVE DEVICES.Myometrium: The smooth muscle coat of the uterus, which forms the main mass of the organ.Pregnancy Tests, Immunologic: Methods of detecting pregnancy by examining the levels of human chorionic gonadotropin (HCG) in plasma or urine.Hydatidiform Mole: Trophoblastic hyperplasia associated with normal gestation, or molar pregnancy. It is characterized by the swelling of the CHORIONIC VILLI and elevated human CHORIONIC GONADOTROPIN. Hydatidiform moles or molar pregnancy may be categorized as complete or partial based on their gross morphology, histopathology, and karyotype.Foreign-Body Migration: Migration of a foreign body from its original location to some other location in the body.Triplets: Three individuals derived from three FETUSES that were fertilized at or about the same time, developed in the UTERUS simultaneously, and born to the same mother.Catheterization: Use or insertion of a tubular device into a duct, blood vessel, hollow organ, or body cavity for injecting or withdrawing fluids for diagnostic or therapeutic purposes. It differs from INTUBATION in that the tube here is used to restore or maintain patency in obstructions.Prenatal Nutritional Physiological Phenomena: Nutrition of FEMALE during PREGNANCY.Abortifacient Agents: Chemical substances that interrupt pregnancy after implantation.Hematoma: A collection of blood outside the BLOOD VESSELS. Hematoma can be localized in an organ, space, or tissue.Surgical Wound Dehiscence: Pathologic process consisting of a partial or complete disruption of the layers of a surgical wound.Chi-Square Distribution: A distribution in which a variable is distributed like the sum of the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.Postoperative Hemorrhage: Hemorrhage following any surgical procedure. It may be immediate or delayed and is not restricted to the surgical wound.HELLP Syndrome: A syndrome of HEMOLYSIS, elevated liver ENZYMES, and low blood platelets count (THROMBOCYTOPENIA). HELLP syndrome is observed in pregnant women with PRE-ECLAMPSIA or ECLAMPSIA who also exhibit LIVER damage and abnormalities in BLOOD COAGULATION.Iatrogenic Disease: Any adverse condition in a patient occurring as the result of treatment by a physician, surgeon, or other health professional, especially infections acquired by a patient during the course of treatment.Mothers: Female parents, human or animal.Anastomosis, Surgical: Surgical union or shunt between ducts, tubes or vessels. It may be end-to-end, end-to-side, side-to-end, or side-to-side.Catheters, Indwelling: Catheters designed to be left within an organ or passage for an extended period of time.Predictive Value of Tests: In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.Biliary Tract Diseases: Diseases in any part of the BILIARY TRACT including the BILE DUCTS and the GALLBLADDER.Fatal Outcome: Death resulting from the presence of a disease in an individual, as shown by a single case report or a limited number of patients. This should be differentiated from DEATH, the physiological cessation of life and from MORTALITY, an epidemiological or statistical concept.Reproductive Techniques: Methods pertaining to the generation of new individuals, including techniques used in selective BREEDING, cloning (CLONING, ORGANISM), and assisted reproduction (REPRODUCTIVE TECHNIQUES, ASSISTED).Risk: The probability that an event will occur. It encompasses a variety of measures of the probability of a generally unfavorable outcome.Oocyte Donation: Transfer of preovulatory oocytes from donor to a suitable host. Oocytes are collected, fertilized in vitro, and transferred to a host that can be human or animal.Stents: Devices that provide support for tubular structures that are being anastomosed or for body cavities during skin grafting.Diabetic Angiopathies: VASCULAR DISEASES that are associated with DIABETES MELLITUS.Anticoagulants: Agents that prevent clotting.Endoscopy: Procedures of applying ENDOSCOPES for disease diagnosis and treatment. Endoscopy involves passing an optical instrument through a small incision in the skin i.e., percutaneous; or through a natural orifice and along natural body pathways such as the digestive tract; and/or through an incision in the wall of a tubular structure or organ, i.e. transluminal, to examine or perform surgery on the interior parts of the body.Thrombosis: Formation and development of a thrombus or blood clot in the blood vessel.Suture Techniques: Techniques for securing together the edges of a wound, with loops of thread or similar materials (SUTURES).Fetal Resorption: The disintegration and assimilation of the dead FETUS in the UTERUS at any stage after the completion of organogenesis which, in humans, is after the 9th week of GESTATION. It does not include embryo resorption (see EMBRYO LOSS).Diabetes Mellitus, Type 1: A subtype of DIABETES MELLITUS that is characterized by INSULIN deficiency. It is manifested by the sudden onset of severe HYPERGLYCEMIA, rapid progression to DIABETIC KETOACIDOSIS, and DEATH unless treated with insulin. The disease may occur at any age, but is most common in childhood or adolescence.Multivariate Analysis: A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.Fetal Macrosomia: A condition of fetal overgrowth leading to a large-for-gestational-age FETUS. It is defined as BIRTH WEIGHT greater than 4,000 grams or above the 90th percentile for population and sex-specific growth curves. It is commonly seen in GESTATIONAL DIABETES; PROLONGED PREGNANCY; and pregnancies complicated by pre-existing diabetes mellitus.Contraception Behavior: Behavior patterns of those practicing CONTRACEPTION.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Chorionic Villi: The threadlike, vascular projections of the chorion. Chorionic villi may be free or embedded within the DECIDUA forming the site for exchange of substances between fetal and maternal blood (PLACENTA).Hyperemesis Gravidarum: Intractable VOMITING that develops in early PREGNANCY and persists. This can lead to DEHYDRATION and WEIGHT LOSS.Acute Disease: Disease having a short and relatively severe course.Embolization, Therapeutic: A method of hemostasis utilizing various agents such as Gelfoam, silastic, metal, glass, or plastic pellets, autologous clot, fat, and muscle as emboli. It has been used in the treatment of spinal cord and INTRACRANIAL ARTERIOVENOUS MALFORMATIONS, renal arteriovenous fistulas, gastrointestinal bleeding, epistaxis, hypersplenism, certain highly vascular tumors, traumatic rupture of blood vessels, and control of operative hemorrhage.Postoperative Care: The period of care beginning when the patient is removed from surgery and aimed at meeting the patient's psychological and physical needs directly after surgery. (From Dictionary of Health Services Management, 2d ed)Estradiol: The 17-beta-isomer of estradiol, an aromatized C18 steroid with hydroxyl group at 3-beta- and 17-beta-position. Estradiol-17-beta is the most potent form of mammalian estrogenic steroids.Maternal Mortality: Maternal deaths resulting from complications of pregnancy and childbirth in a given population.Fetal Weight: The weight of the FETUS in utero. It is usually estimated by various formulas based on measurements made during PRENATAL ULTRASONOGRAPHY.Prognosis: A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.Amniocentesis: Percutaneous transabdominal puncture of the uterus during pregnancy to obtain amniotic fluid. It is commonly used for fetal karyotype determination in order to diagnose abnormal fetal conditions.Corpus Luteum: The yellow body derived from the ruptured OVARIAN FOLLICLE after OVULATION. The process of corpus luteum formation, LUTEINIZATION, is regulated by LUTEINIZING HORMONE.Embryonic and Fetal Development: Morphological and physiological development of EMBRYOS or FETUSES.Surgical Procedures, Minimally Invasive: Procedures that avoid use of open, invasive surgery in favor of closed or local surgery. These generally involve use of laparoscopic devices and remote-control manipulation of instruments with indirect observation of the surgical field through an endoscope or similar device.Cross-Sectional Studies: Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.Laparotomy: Incision into the side of the abdomen between the ribs and pelvis.Liver Transplantation: The transference of a part of or an entire liver from one human or animal to another.Family Planning Services: Health care programs or services designed to assist individuals in the planning of family size. Various methods of CONTRACEPTION can be used to control the number and timing of childbirths.Fetal Blood: Blood of the fetus. Exchange of nutrients and waste between the fetal and maternal blood occurs via the PLACENTA. The cord blood is blood contained in the umbilical vessels (UMBILICAL CORD) at the time of delivery.Fistula: Abnormal communication most commonly seen between two internal organs, or between an internal organ and the surface of the body.Cryopreservation: Preservation of cells, tissues, organs, or embryos by freezing. In histological preparations, cryopreservation or cryofixation is used to maintain the existing form, structure, and chemical composition of all the constituent elements of the specimens.Smoking: Inhaling and exhaling the smoke of burning TOBACCO.