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.Intrauterine Devices, Medicated: Intrauterine devices that release contraceptive agents.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, Postcoital, Synthetic: Postcoital contraceptives which owe their effectiveness to synthetic preparations.Contraceptives, Oral, Synthetic: Oral contraceptives which owe their effectiveness to synthetic preparations.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.Contraceptives, Oral, Combined: Fixed drug combinations administered orally for contraceptive purposes.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.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).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.Ovulation Inhibition: Blocking the process leading to OVULATION. Various factors are known to inhibit ovulation, such as neuroendocrine, psychological, and pharmacological agents.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..Uterine Hemorrhage: Bleeding from blood vessels in the UTERUS, sometimes manifested as vaginal bleeding.Norpregnadienes: Pregnadienes which have undergone ring contractions or are lacking carbon-18 or carbon-19.Menorrhagia: Excessive uterine bleeding during MENSTRUATION.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.Androstenes: Unsaturated derivatives of the steroid androstane containing at least one double bond at any site in any of the rings.Contraceptives, Postcoital: Contraceptive substances to be used after COITUS. These agents include high doses of estrogenic drugs; progesterone-receptor blockers; ANTIMETABOLITES; ALKALOIDS, and PROSTAGLANDINS.Contraceptives, Postcoital, Hormonal: Postcoital contraceptives which owe their effectiveness to hormonal preparations.Contraceptives, Oral, Hormonal: Oral contraceptives which owe their effectiveness to hormonal preparations.Drug Implants: Small containers or pellets of a solid drug implanted in the body to achieve sustained release of the drug.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.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.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.Contraceptive Devices, Female: Contraceptive devices used by females.Endometrial Ablation Techniques: Procedures used for the targeted destruction of the mucous membrane lining of the uterine cavity.Thyroxine-Binding Globulin: A thyroid hormone transport protein found in serum. It binds about 75% of circulating THYROXINE and 70% of circulating TRIIODOTHYRONINE.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.Contraceptive Agents: Chemical substances that prevent or reduce the probability of CONCEPTION.Transdermal Patch: A medicated adhesive patch placed on the skin to deliver a specific dose of medication into the bloodstream.Intrauterine Devices: Contraceptive devices placed high in the uterine fundus.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.Ethinyl Estradiol-Norgestrel Combination: ETHINYL ESTRADIOL and NORGESTREL given in fixed proportions. It has proved to be an effective contraceptive (CONTRACEPTIVES, ORAL, COMBINED).Intrauterine Device Expulsion: Spontaneous loss of INTRAUTERINE DEVICES from the UTERUS.Chlormadinone Acetate: An orally active synthetic progestational hormone used often in combinations as an oral contraceptive.Lynestrenol: A synthetic progestational hormone used often in mixtures with estrogens as an oral contraceptive.Intrauterine Devices, Copper: Intrauterine contraceptive devices that depend on the release of metallic copper.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.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.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.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.Menstruation Disturbances: Variations of menstruation which may be indicative of disease.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.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.Sex Hormone-Binding Globulin: A glycoprotein migrating as a beta-globulin. Its molecular weight, 52,000 or 95,000-115,000, indicates that it exists as a dimer. The protein binds testosterone, dihydrotestosterone, and estradiol in the plasma. Sex hormone-binding protein has the same amino acid sequence as ANDROGEN-BINDING PROTEIN. They differ by their sites of synthesis and post-translational oligosaccharide modifications.Venous Thromboembolism: Obstruction of a vein or VEINS (embolism) by a blood clot (THROMBUS) in the blood stream.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)KansasSocial Welfare: Organized institutions which provide services to ameliorate conditions of need or social pathology in the community.Hallucinations: Subjectively experienced sensations in the absence of an appropriate stimulus, but which are regarded by the individual as real. They may be of organic origin or associated with MENTAL DISORDERS.Dreams: A series of thoughts, images, or emotions occurring during sleep which are dissociated from the usual stream of consciousness of the waking state.