Cryptorchidism: A developmental defect in which a TESTIS or both TESTES failed to descend from high in the ABDOMEN to the bottom of the SCROTUM. Testicular descent is essential to normal SPERMATOGENESIS which requires temperature lower than the BODY TEMPERATURE. Cryptorchidism can be subclassified by the location of the maldescended testis.Hypospadias: A birth defect due to malformation of the URETHRA in which the urethral opening is below its normal location. In the male, the malformed urethra generally opens on the ventral surface of the PENIS or on the PERINEUM. In the female, the malformed urethral opening is in the VAGINA.Orchiopexy: A surgical procedure in which an undescended testicle is sutured inside the SCROTUM in male infants or children to correct CRYPTORCHIDISM. Orchiopexy is also performed to treat TESTICULAR TORSION in adults and adolescents.Testis: The male gonad containing two functional parts: the SEMINIFEROUS TUBULES for the production and transport of male germ cells (SPERMATOGENESIS) and the interstitial compartment containing LEYDIG CELLS that produce ANDROGENS.Testicular Hydrocele: Accumulation of serous fluid between the layers of membrane (tunica vaginalis) covering the TESTIS in the SCROTUM.Genitalia, Male: The male reproductive organs. They are divided into the external organs (PENIS; SCROTUM;and URETHRA) and the internal organs (TESTIS; EPIDIDYMIS; VAS DEFERENS; SEMINAL VESICLES; EJACULATORY DUCTS; PROSTATE; and BULBOURETHRAL GLANDS).Urogenital Surgical Procedures: Surgery performed on the urinary tract or its organs and on the male or female genitalia.Heptachlor Epoxide: An oxidation product of HEPTACHLOR formed by many plants and animals, including humans, after exposure to HEPTACHLOR. It has been shown to remain in soil treated with HEPTACHLOR for over fifteen years and is toxic to animals and humans. (From ATSDR Public Heath Statement, April 1989)Testicular Diseases: Pathological processes of the TESTIS.Leydig Cells: Steroid-producing cells in the interstitial tissue of the TESTIS. They are under the regulation of PITUITARY HORMONES; LUTEINIZING HORMONE; or interstitial cell-stimulating hormone. TESTOSTERONE is the major androgen (ANDROGENS) produced.Chlordan: A highly poisonous organochlorine insecticide. The EPA has cancelled registrations of pesticides containing this compound with the exception of its use through subsurface ground insertion for termite control and the dipping of roots or tops of non-food plants. (From Merck Index, 11th ed)Seminiferous Tubules: The convoluted tubules in the TESTIS where sperm are produced (SPERMATOGENESIS) and conveyed to the RETE TESTIS. Spermatogenic tubules are composed of developing germ cells and the supporting SERTOLI CELLS.Infertility, Male: The inability of the male to effect FERTILIZATION of an OVUM after a specified period of unprotected intercourse. Male sterility is permanent infertility.Urogenital Abnormalities: Congenital structural abnormalities of the UROGENITAL SYSTEM in either the male or the female.Organotin Compounds: Organic compounds which contain tin in the molecule. Used widely in industry and agriculture.Testicular Neoplasms: Tumors or cancer of the TESTIS. Germ cell tumors (GERMINOMA) of the testis constitute 95% of all testicular neoplasms.Sperm Count: A count of SPERM in the ejaculum, expressed as number per milliliter.Scrotum: A cutaneous pouch of skin containing the testicles and spermatic cords.Spermatogenesis: The process of germ cell development in the male from the primordial germ cells, through SPERMATOGONIA; SPERMATOCYTES; SPERMATIDS; to the mature haploid SPERMATOZOA.DenmarkTestosterone: A potent androgenic steroid and major product secreted by the LEYDIG CELLS of the TESTIS. Its production is stimulated by LUTEINIZING HORMONE from the PITUITARY GLAND. In turn, testosterone exerts feedback control of the pituitary LH and FSH secretion. Depending on the tissues, testosterone can be further converted to DIHYDROTESTOSTERONE or ESTRADIOL.Endocrine Disruptors: Exogenous agents, synthetic and naturally occurring, which are capable of disrupting the functions of the ENDOCRINE SYSTEM including the maintenance of HOMEOSTASIS and the regulation of developmental processes. Endocrine disruptors are compounds that can mimic HORMONES, or enhance or block the binding of hormones to their receptors, or otherwise lead to activating or inhibiting the endocrine signaling pathways and hormone metabolism.Sertoli Cells: Supporting cells projecting inward from the basement membrane of SEMINIFEROUS TUBULES. They surround and nourish the developing male germ cells and secrete ANDROGEN-BINDING PROTEIN and hormones such as ANTI-MULLERIAN HORMONE. The tight junctions of Sertoli cells with the SPERMATOGONIA and SPERMATOCYTES provide a BLOOD-TESTIS BARRIER.Infant, Newborn: An infant during the first month after birth.Gonadal Dysgenesis: A number of syndromes with defective gonadal developments such as streak GONADS and dysgenetic testes or ovaries. The spectrum of gonadal and sexual abnormalities is reflected in their varied sex chromosome (SEX CHROMOSOMES) constitution as shown by the karyotypes of 45,X monosomy (TURNER SYNDROME); 46,XX (GONADAL DYSGENESIS, 46XX); 46,XY (GONADAL DYSGENESIS, 46,XY); and sex chromosome MOSAICISM; (GONADAL DYSGENESIS, MIXED). Their phenotypes range from female, through ambiguous, to male. This concept includes gonadal agenesis.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.Trialkyltin Compounds: Organometallic compounds which contain tin and three alkyl groups.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.