Contraceptives, Oral: Compounds, usually hormonal, taken orally in order to block ovulation and prevent the occurrence of pregnancy. The hormones are generally estrogen or progesterone or both.Contraceptives, Oral, Combined: Fixed drug combinations administered orally for contraceptive purposes.Contraceptive Agents: Chemical substances that prevent or reduce the probability of CONCEPTION.Contraceptives, Oral, Hormonal: Oral contraceptives which owe their effectiveness to hormonal preparations.Contraceptive Agents, Female: Chemical substances or agents with contraceptive activity in females. Use for female contraceptive agents in general or for which there is no specific heading.Contraceptives, Oral, Synthetic: Oral contraceptives which owe their effectiveness to synthetic preparations.Contraceptive Devices: Devices that diminish the likelihood of or prevent conception. (From Dorland, 28th ed)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.Contraceptive Devices, Female: Contraceptive devices used by females.Contraception Behavior: Behavior patterns of those practicing CONTRACEPTION.Contraceptive Agents, Male: Chemical substances or agents with contraceptive activity in males. Use for male contraceptive agents in general or for which there is no specific heading.Intrauterine Devices: Contraceptive devices placed high in the uterine fundus.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.Ethinyl Estradiol: A semisynthetic alkylated ESTRADIOL with a 17-alpha-ethinyl substitution. It has high estrogenic potency when administered orally, and is often used as the estrogenic component in ORAL CONTRACEPTIVES.Desogestrel: A synthetic progestational hormone used often as the progestogenic component of combined oral contraceptive agents.Norgestrel: A synthetic progestational agent with actions similar to those of PROGESTERONE. This racemic or (+-)-form has about half the potency of the levo form (LEVONORGESTREL). Norgestrel is used as a contraceptive, ovulation inhibitor, and for the control of menstrual disorders and endometriosis.Levonorgestrel: A synthetic progestational hormone with actions similar to those of PROGESTERONE and about twice as potent as its racemic or (+-)-isomer (NORGESTREL). It is used for contraception, control of menstrual disorders, and treatment of endometriosis.Contraceptives, Postcoital: Contraceptive substances to be used after COITUS. These agents include high doses of estrogenic drugs; progesterone-receptor blockers; ANTIMETABOLITES; ALKALOIDS, and PROSTAGLANDINS.Mestranol: The 3-methyl ether of ETHINYL ESTRADIOL. It must be demethylated to be biologically active. It is used as the estrogen component of many combination ORAL CONTRACEPTIVES.Norethindrone: A synthetic progestational hormone with actions similar to those of PROGESTERONE but functioning as a more potent inhibitor of ovulation. It has weak estrogenic and androgenic properties. The hormone has been used in treating amenorrhea, functional uterine bleeding, endometriosis, and for contraception.Vaccines, Contraceptive: Vaccines or candidate vaccines used to prevent conception.Pregnancy, Unplanned: Unintended accidental pregnancy, including pregnancy resulting from failed contraceptive measures.Sterilization, Reproductive: Procedures to block or remove all or part of the genital tract for the purpose of rendering individuals sterile, incapable of reproduction. Surgical sterilization procedures are the most commonly used. There are also sterilization procedures involving chemical or physical means.Pregnancy, Unwanted: Pregnancy, usually accidental, that is not desired by the parent or parents.Medroxyprogesterone Acetate: A synthetic progestin that is derived from 17-hydroxyprogesterone. It is a long-acting contraceptive that is effective both orally or by intramuscular injection and has also been used to treat breast and endometrial neoplasms.Spermatocidal Agents: Chemical substances that are destructive to spermatozoa used as topically administered vaginal contraceptives.Contraception, Postcoital: Means of postcoital intervention to avoid pregnancy, such as the administration of POSTCOITAL CONTRACEPTIVES to prevent FERTILIZATION of an egg or implantation of a fertilized egg (OVUM IMPLANTATION).Norethynodrel: A synthetic progestational hormone with actions and uses similar to those of PROGESTERONE. It has been used in the treatment of functional uterine bleeding and endometriosis. As a contraceptive, it has usually been administered in combination with MESTRANOL.Menstruation: The periodic shedding of the ENDOMETRIUM and associated menstrual bleeding in the MENSTRUAL CYCLE of humans and primates. Menstruation is due to the decline in circulating PROGESTERONE, and occurs at the late LUTEAL PHASE when LUTEOLYSIS of the CORPUS LUTEUM takes place.Intrauterine Devices, Copper: Intrauterine contraceptive devices that depend on the release of metallic copper.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Ethynodiol Diacetate: A synthetic progestational hormone used alone or in combination with estrogens as an oral contraceptive.Contraception, Immunologic: Contraceptive methods based on immunological processes and techniques, such as the use of CONTRACEPTIVE VACCINES.Abortion, Induced: Intentional removal of a fetus from the uterus by any of a number of techniques. (POPLINE, 1978)Norpregnenes: Pregnenes with one double bond or more than three double bonds which have undergone ring contractions or are lacking carbon-18 or carbon-19..Progestins: Compounds that interact with PROGESTERONE RECEPTORS in target tissues to bring about the effects similar to those of PROGESTERONE. Primary actions of progestins, including natural and synthetic steroids, are on the UTERUS and the MAMMARY GLAND in preparation for and in maintenance of PREGNANCY.Ethinyl Estradiol-Norgestrel Combination: ETHINYL ESTRADIOL and NORGESTREL given in fixed proportions. It has proved to be an effective contraceptive (CONTRACEPTIVES, ORAL, COMBINED).Synthetic Biology: A field of biological research combining engineering in the formulation, design, and building (synthesis) of novel biological structures, functions, and systems.Contraceptives, Oral, Sequential: Drugs administered orally and sequentially for contraceptive purposes.Contraceptives, Postcoital, Hormonal: Postcoital contraceptives which owe their effectiveness to hormonal preparations.Sterilization, Tubal: Procedures that render the female sterile by interrupting the flow in the FALLOPIAN TUBE. These procedures generally are surgical, and may also use chemicals or physical means.Genes, Synthetic: Biologically functional sequences of DNA chemically synthesized in vitro.Progesterone Congeners: Steroidal compounds related to PROGESTERONE, the major mammalian progestational hormone. Progesterone congeners include important progesterone precursors in the biosynthetic pathways, metabolites, derivatives, and synthetic steroids with progestational activities.Androstenes: Unsaturated derivatives of the steroid androstane containing at least one double bond at any site in any of the rings.Menstrual Cycle: The period from onset of one menstrual bleeding (MENSTRUATION) to the next in an ovulating woman or female primate. The menstrual cycle is regulated by endocrine interactions of the HYPOTHALAMUS; the PITUITARY GLAND; the ovaries; and the genital tract. The menstrual cycle is divided by OVULATION into two phases. Based on the endocrine status of the OVARY, there is a FOLLICULAR PHASE and a LUTEAL PHASE. Based on the response in the ENDOMETRIUM, the menstrual cycle is divided into a proliferative and a secretory phase.Parity: The number of offspring a female has borne. It is contrasted with GRAVIDITY, which refers to the number of pregnancies, regardless of outcome.Intrauterine Devices, Medicated: Intrauterine devices that release contraceptive agents.Health Knowledge, Attitudes, Practice: Knowledge, attitudes, and associated behaviors which pertain to health-related topics such as PATHOLOGIC PROCESSES or diseases, their prevention, and treatment. This term refers to non-health workers and health workers (HEALTH PERSONNEL).Contraceptive Devices, Male: Contraceptive devices used by males.Megestrol: 17-Hydroxy-6-methylpregna-3,6-diene-3,20-dione. A progestational hormone used most commonly as the acetate ester. As the acetate, it is more potent than progesterone both as a progestagen and as an ovulation inhibitor. It has also been used in the palliative treatment of breast cancer.Pregnancy in Adolescence: Pregnancy in human adolescent females under the age of 19.Contraceptives, Postcoital, Synthetic: Postcoital contraceptives which owe their effectiveness to synthetic preparations.Menstruation Disturbances: Variations of menstruation which may be indicative of disease.Drug Implants: Small containers or pellets of a solid drug implanted in the body to achieve sustained release of the drug.Sex Education: Education which increases the knowledge of the functional, structural, and behavioral aspects of human reproduction.Medroxyprogesterone: (6 alpha)-17-Hydroxy-6-methylpregn-4-ene-3,20-dione. A synthetic progestational hormone used in veterinary practice as an estrus regulator.Estradiol Congeners: Steroidal compounds related to ESTRADIOL, the major mammalian female sex hormone. Estradiol congeners include important estradiol precursors in the biosynthetic pathways, metabolites, derivatives, and synthetic steroids with estrogenic activities.Spermatogenesis-Blocking Agents: Chemical substances which inhibit the process of spermatozoa formation at either the first stage, in which spermatogonia develop into spermatocytes and then into spermatids, or the second stage, in which spermatids transform into spermatozoa.Ovulation Inhibition: Blocking the process leading to OVULATION. Various factors are known to inhibit ovulation, such as neuroendocrine, psychological, and pharmacological agents.Norpregnadienes: Pregnadienes which have undergone ring contractions or are lacking carbon-18 or carbon-19.Fertility: The capacity to conceive or to induce conception. It may refer to either the male or female.Condoms: A sheath that is worn over the penis during sexual behavior in order to prevent pregnancy or spread of sexually transmitted disease.Sexual Behavior: Sexual activities of humans.Transdermal Patch: A medicated adhesive patch placed on the skin to deliver a specific dose of medication into the bloodstream.Ethisterone: 17 alpha-Hydroxypregn-4-en-20-yn-3-one. A synthetic steroid hormone with progestational effects.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Uterine Hemorrhage: Bleeding from blood vessels in the UTERUS, sometimes manifested as vaginal bleeding.Metrorrhagia: Abnormal uterine bleeding that is not related to MENSTRUATION, usually in females without regular MENSTRUAL CYCLE. The irregular and unpredictable bleeding usually comes from a dysfunctional ENDOMETRIUM.Estrogens: Compounds that interact with ESTROGEN RECEPTORS in target tissues to bring about the effects similar to those of ESTRADIOL. Estrogens stimulate the female reproductive organs, and the development of secondary female SEX CHARACTERISTICS. Estrogenic chemicals include natural, synthetic, steroidal, or non-steroidal compounds.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.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.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Nonoxynol: Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Nonoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide, formulated primarily as a component of vaginal foams and creams.Coitus: The sexual union of a male and a female, a term used for human only.Abortion Applicants: Individuals requesting induced abortions.XanthurenatesPeptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.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.Abortion, Legal: Termination of pregnancy under conditions allowed under local laws. (POPLINE Thesaurus, 1991)Reproductive Health Services: Health care services related to human REPRODUCTION and diseases of the reproductive system. Services are provided to both sexes and usually by physicians in the medical or the surgical specialties such as REPRODUCTIVE MEDICINE; ANDROLOGY; GYNECOLOGY; OBSTETRICS; and PERINATOLOGY.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.Marriage: The social institution involving legal and/or religious sanction whereby individuals are joined together.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.Women's Health: The concept covering the physical and mental conditions of women.Reproductive History: An important aggregate factor in epidemiological studies of women's health. The concept usually includes the number and timing of pregnancies and their outcomes, the incidence of breast feeding, and may include age of menarche and menopause, regularity of menstruation, fertility, gynecological or obstetric problems, or contraceptive usage.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.Sexually Transmitted Diseases: Diseases due to or propagated by sexual contact.Coitus Interruptus: A contraceptive method whereby coitus is purposely interrupted in order to prevent EJACULATION of SEMEN into the VAGINA.Amenorrhea: Absence of menstruation.Chlormadinone Acetate: An orally active synthetic progestational hormone used often in combinations as an oral contraceptive.Birth Rate: The number of births in a given population per year or other unit of time.Men: Human males as cultural, psychological, sociological, political, and economic entities.Postpartum Period: In females, the period that is shortly after giving birth (PARTURITION).Counseling: The giving of advice and assistance to individuals with educational or personal problems.Socioeconomic Factors: Social and economic factors that characterize the individual or group within the social structure.United StatesDelayed-Action Preparations: Dosage forms of a drug that act over a period of time by controlled-release processes or technology.Family Planning Policy: A course or method of action selected, usually by a government, to guide and determine present and future decisions on population control by limiting the number of children or controlling fertility, notably through family planning and contraception within the nuclear family.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.Norprogesterones: Progesterones which have undergone ring contraction or which are lacking carbon 18 or 19.Vasectomy: Surgical removal of the ductus deferens, or a portion of it. It is done in association with prostatectomy, or to induce infertility. (Dorland, 28th ed)Natural Family Planning Methods: A class of natural contraceptive methods in which SEXUAL ABSTINENCE is practiced a few days before and after the estimated day of ovulation, during the fertile phase. Methods for determining the fertile period or OVULATION DETECTION are based on various physiological indicators, such as circulating hormones, changes in cervical mucus (CERVIX MUCUS), and the basal body temperature.Thromboembolism: Obstruction of a blood vessel (embolism) by a blood clot (THROMBUS) in the blood stream.Reproductive Medicine: A medical-surgical specialty concerned with the morphology, physiology, biochemistry, and pathology of reproduction in man and other animals, and on the biological, medical, and veterinary problems of fertility and lactation. It includes ovulation induction, diagnosis of infertility and recurrent pregnancy loss, and assisted reproductive technologies such as embryo transfer, in vitro fertilization, and intrafallopian transfer of zygotes. (From Infertility and Reproductive Medicine Clinics of North America, Foreword 1990; Journal of Reproduction and Fertility, Notice to Contributors, Jan 1979)Single Person: The unmarried man or woman.Sexual Partners: Married or single individuals who share sexual relations.Dysmenorrhea: Painful menstruation.Religion and SexPeptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Reproductive Health: The physical condition of human reproductive systems.Drug Interactions: The action of a drug that may affect the activity, metabolism, or toxicity of another drug.Women's Health Services: Organized services to provide health care to women. It excludes maternal care services for which MATERNAL HEALTH SERVICES is available.Menopause: The last menstrual period. Permanent cessation of menses (MENSTRUATION) is usually defined after 6 to 12 months of AMENORRHEA in a woman over 45 years of age. In the United States, menopause generally occurs in women between 48 and 55 years of age.Rural Population: The inhabitants of rural areas or of small towns classified as rural.Menarche: The first MENSTRUAL CYCLE marked by the initiation of MENSTRUATION.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.Choice Behavior: The act of making a selection among two or more alternatives, usually after a period of deliberation.Venous Thrombosis: The formation or presence of a blood clot (THROMBUS) within a vein.Acne Vulgaris: A chronic disorder of the pilosebaceous apparatus associated with an increase in sebum secretion. It is characterized by open comedones (blackheads), closed comedones (whiteheads), and pustular nodules. The cause is unknown, but heredity and age are predisposing factors.Health Services Accessibility: The degree to which individuals are inhibited or facilitated in their ability to gain entry to and to receive care and services from the health care system. Factors influencing this ability include geographic, architectural, transportational, and financial considerations, among others.Uganda: A republic in eastern Africa, south of SUDAN and west of KENYA. Its capital is Kampala.Pyridoxine: The 4-methanol form of VITAMIN B 6 which is converted to PYRIDOXAL PHOSPHATE which is a coenzyme for synthesis of amino acids, neurotransmitters (serotonin, norepinephrine), sphingolipids, aminolevulinic acid. Although pyridoxine and Vitamin B 6 are still frequently used as synonyms, especially by medical researchers, this practice is erroneous and sometimes misleading (EE Snell; Ann NY Acad Sci, vol 585 pg 1, 1990).Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.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.Risk: The probability that an event will occur. It encompasses a variety of measures of the probability of a generally unfavorable outcome.Premenopause: The period before MENOPAUSE. In premenopausal women, the climacteric transition from full sexual maturity to cessation of ovarian cycle takes place between the age of late thirty and early fifty.Menorrhagia: Excessive uterine bleeding during MENSTRUATION.Oligopeptides: Peptides composed of between two and twelve amino acids.Spermatozoa: Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.Ethiopia: An independent state in eastern Africa. Ethiopia is located in the Horn of Africa and is bordered on the north and northeast by Eritrea, on the east by Djibouti and Somalia, on the south by Kenya, and on the west and southwest by Sudan. Its capital is Addis Ababa.Menstrual Hygiene Products: Personal care items used during MENSTRUATION.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.Nandrolone: C18 steroid with androgenic and anabolic properties. It is generally prepared from alkyl ethers of ESTRADIOL to resemble TESTOSTERONE but less one carbon at the 19 position.Vagina: The genital canal in the female, extending from the UTERUS to the VULVA. (Stedman, 25th ed)Marital Status: A demographic parameter indicating a person's status with respect to marriage, divorce, widowhood, singleness, etc.Indians, Central American: Individual members of Central American ethnic groups with ancient historic ancestral origins in Asia. Mexican Indians are not included.Adolescent Behavior: Any observable response or action of an adolescent.Administration, Cutaneous: The application of suitable drug dosage forms to the skin for either local or systemic effects.Thrombophlebitis: Inflammation of a vein associated with a blood clot (THROMBUS).Cyproterone Acetate: An agent with anti-androgen and progestational properties. It shows competitive binding with dihydrotestosterone at androgen receptor sites.Ovulation: The discharge of an OVUM from a rupturing follicle in the OVARY.Mifepristone: A progestational and glucocorticoid hormone antagonist. Its inhibition of progesterone induces bleeding during the luteal phase and in early pregnancy by releasing endogenous prostaglandins from the endometrium or decidua. As a glucocorticoid receptor antagonist, the drug has been used to treat hypercortisolism in patients with nonpituitary CUSHING SYNDROME.Ambulatory Care Facilities: Those facilities which administer health services to individuals who do not require hospitalization or institutionalization.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.Kinetics: The rate dynamics in chemical or physical systems.Breast Neoplasms: Tumors or cancer of the human BREAST.Gonadal Steroid Hormones: Steroid hormones produced by the GONADS. They stimulate reproductive organs, germ cell maturation, and the secondary sex characteristics in the males and the females. The major sex steroid hormones include ESTRADIOL; PROGESTERONE; and TESTOSTERONE.MissouriUterine Cervical Neoplasms: Tumors or cancer of the UTERINE CERVIX.Antispermatogenic Agents: Agents, either mechanical or chemical, which destroy spermatozoa in the male genitalia and block spermatogenesis.Women: Human females as cultural, psychological, sociological, political, and economic entities.Nonprescription Drugs: Medicines that can be sold legally without a DRUG PRESCRIPTION.Hormone Replacement Therapy: Therapeutic use of hormones to alleviate the effects of hormone deficiency.Danazol: A synthetic steroid with antigonadotropic and anti-estrogenic activities that acts as an anterior pituitary suppressant by inhibiting the pituitary output of gonadotropins. It possesses some androgenic properties. Danazol has been used in the treatment of endometriosis and some benign breast disorders.Intrauterine Device Expulsion: Spontaneous loss of INTRAUTERINE DEVICES from the UTERUS.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.Patient Acceptance of Health Care: The seeking and acceptance by patients of health service.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.Health Surveys: A systematic collection of factual data pertaining to health and disease in a human population within a given geographic area.Estrogen Replacement Therapy: The use of hormonal agents with estrogen-like activity in postmenopausal or other estrogen-deficient women to alleviate effects of hormone deficiency, such as vasomotor symptoms, DYSPAREUNIA, and progressive development of OSTEOPOROSIS. This may also include the use of progestational agents in combination therapy.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Interviews as Topic: Conversations with an individual or individuals held in order to obtain information about their background and other personal biographical data, their attitudes and opinions, etc. It includes school admission or job interviews.NicaraguaReproductive Behavior: Human behavior or decision related to REPRODUCTION.Vaginal Creams, Foams, and Jellies: Medicated dosage forms for topical application in the vagina. A cream is a semisolid emulsion containing suspended or dissolved medication; a foam is a dispersion of a gas in a medicated liquid resulting in a light, frothy mass; a jelly is a colloidal semisolid mass of a water soluble medicated material, usually translucent.Smoking: Inhaling and exhaling the smoke of burning TOBACCO.Cervix Uteri: The neck portion of the UTERUS between the lower isthmus and the VAGINA forming the cervical canal.Data Collection: Systematic gathering of data for a particular purpose from various sources, including questionnaires, interviews, observation, existing records, and electronic devices. The process is usually preliminary to statistical analysis of the data.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.Contraception, Barrier: Methods of contraception in which physical, chemical, or biological means are used to prevent the SPERM from reaching the fertilizable OVUM.Ovarian Neoplasms: Tumors or cancer of the OVARY. These neoplasms can be benign or malignant. They are classified according to the tissue of origin, such as the surface EPITHELIUM, the stromal endocrine cells, and the totipotent GERM CELLS.Spermatogenesis: The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.Great BritainFamily Characteristics: Size and composition of the family.Epitopes: Sites on an antigen that interact with specific antibodies.Population Control: Includes mechanisms or programs which control the numbers of individuals in a population of humans or animals.Uterine Perforation: A hole or break through the wall of the UTERUS, usually made by the placement of an instrument or INTRAUTERINE DEVICES.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.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.Pregnanediol: An inactive metabolite of PROGESTERONE by reduction at C5, C3, and C20 position. Pregnanediol has two hydroxyl groups, at 3-alpha and 20-alpha. It is detectable in URINE after OVULATION and is found in great quantities in the pregnancy urine.Administration, Intravaginal: The insertion of drugs into the vagina to treat local infections, neoplasms, or to induce labor. The dosage forms may include medicated pessaries, irrigation fluids, and suppositories.Megaloblasts: Red blood cell precursors, corresponding to ERYTHROBLASTS, that are larger than normal, usually resulting from a FOLIC ACID DEFICIENCY or VITAMIN B 12 DEFICIENCY.GuatemalaPregnancy 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.Nigeria: A republic in western Africa, south of NIGER between BENIN and CAMEROON. Its capital is Abuja.Urban Population: The inhabitants of a city or town, including metropolitan areas and suburban areas.Follicular Phase: The period of the MENSTRUAL CYCLE representing follicular growth, increase in ovarian estrogen (ESTROGENS) production, and epithelial proliferation of the ENDOMETRIUM. Follicular phase begins with the onset of MENSTRUATION and ends with OVULATION.Stereoisomerism: The phenomenon whereby compounds whose molecules have the same number and kind of atoms and the same atomic arrangement, but differ in their spatial relationships. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 5th ed)Intrauterine Device Migration: The shifting in position or location of an INTRAUTERINE DEVICE from its original placement.Vaccines, Synthetic: Small synthetic peptides that mimic surface antigens of pathogens and are immunogenic, or vaccines manufactured with the aid of recombinant DNA techniques. The latter vaccines may also be whole viruses whose nucleic acids have been modified.Vinyl CompoundsStudent Health Services: Health services for college and university students usually provided by the educational institution.Injections, Intramuscular: Forceful administration into a muscle of liquid medication, nutrient, or other fluid through a hollow needle piercing the muscle and any tissue covering it.Sexual Abstinence: Refraining from SEXUAL INTERCOURSE.Educational Status: Educational attainment or level of education of individuals.Factor V: Heat- and storage-labile plasma glycoprotein which accelerates the conversion of prothrombin to thrombin in blood coagulation. Factor V accomplishes this by forming a complex with factor Xa, phospholipid, and calcium (prothrombinase complex). Deficiency of factor V leads to Owren's disease.Rwanda: A republic in eastern Africa, south of UGANDA, east of DEMOCRATIC REPUBLIC OF THE CONGO, west of TANZANIA. Its capital is Kigali. It was formerly part of the Belgian trust territory of Ruanda-Urund.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.Attitude: An enduring, learned predisposition to behave in a consistent way toward a given class of objects, or a persistent mental and/or neural state of readiness to react to a certain class of objects, not as they are but as they are conceived to be.Vaginal Smears: Collection of pooled secretions of the posterior vaginal fornix for cytologic examination.Hormones: Chemical substances having a specific regulatory effect on the activity of a certain organ or organs. The term was originally applied to substances secreted by various ENDOCRINE GLANDS and transported in the bloodstream to the target organs. It is sometimes extended to include those substances that are not produced by the endocrine glands but that have similar effects.