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.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: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.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.Leukemia, Biphenotypic, Acute: An acute leukemia exhibiting cell features characteristic of both the myeloid and lymphoid lineages and probably arising from MULTIPOTENT STEM CELLS.Hair Preparations: Hair grooming, cleansing and modifying products meant for topical application to hair, usually human. They include sprays, bleaches, dyes, conditioners, rinses, shampoos, nutrient lotions, etc.Paternal Exposure: Exposure of the male 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.Benzhydryl Compounds: Compounds which contain the methyl radical substituted with two benzene rings. Permitted are any substituents, but ring fusion to any of the benzene rings is not allowed.Air Pollutants: Any substance in the air which could, if present in high enough concentration, harm humans, animals, vegetation or material. Substances include GASES; PARTICULATE MATTER; and volatile ORGANIC CHEMICALS.Infant, Newborn: An infant during the first month after birth.Simazine: A triazine herbicide.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.Environmental Pollutants: Substances or energies, for example heat or light, which when introduced into the air, water, or land threaten life or health of individuals or ECOSYSTEMS.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.Fetal Development: Morphological and physiological development of FETUSES.Phenols: Benzene derivatives that include one or more hydroxyl groups attached to the ring structure.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.Hair Dyes: Dyes used as cosmetics to change hair color either permanently or temporarily.Cleft Lip: Congenital defect in the upper lip where the maxillary prominence fails to merge with the merged medial nasal prominences. It is thought to be caused by faulty migration of the mesoderm in the head region.Diethylstilbestrol: A synthetic nonsteroidal estrogen used in the treatment of menopausal and postmenopausal disorders. It was also used formerly as a growth promoter in animals. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), diethylstilbestrol has been listed as a known carcinogen. (Merck, 11th ed)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.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.Tetrachlorodibenzodioxin: A chemical by-product that results from burning or incinerating chlorinated industrial chemicals and other hydrocarbons. This compound is considered an environmental toxin, and may pose reproductive, as well as, other health risks for animals and humans.Tobacco Smoke Pollution: Contamination of the air by tobacco smoke.Polychlorinated Biphenyls: Industrial products consisting of a mixture of chlorinated biphenyl congeners and isomers. These compounds are highly lipophilic and tend to accumulate in fat stores of animals. Many of these compounds are considered toxic and potential environmental pollutants.Cleft Palate: Congenital fissure of the soft and/or hard palate, due to faulty fusion.Fetal Growth Retardation: The failure of a FETUS to attain its expected FETAL GROWTH at any GESTATIONAL AGE.Environmental Exposure: The exposure 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.Benzene: Toxic, volatile, flammable liquid hydrocarbon byproduct of coal distillation. It is used as an industrial solvent in paints, varnishes, lacquer thinners, gasoline, etc. Benzene causes central nervous system damage acutely and bone marrow damage chronically and is carcinogenic. It was formerly used as parasiticide.Nitrogen Dioxide: Nitrogen oxide (NO2). A highly poisonous gas. Exposure produces inflammation of lungs that may only cause slight pain or pass unnoticed, but resulting edema several days later may cause death. (From Merck, 11th ed) It is a major atmospheric pollutant that is able to absorb UV light that does not reach the earth's surface.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.Air Pollution: The presence of contaminants or pollutant substances in the air (AIR POLLUTANTS) that interfere with human health or welfare, or produce other harmful environmental effects. The substances may include GASES; PARTICULATE MATTER; or volatile ORGANIC CHEMICALS.Estrogens, Non-Steroidal: Non-steroidal compounds with estrogenic activity.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.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.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).Birth Weight: The mass or quantity of heaviness of an individual at BIRTH. It is expressed by units of pounds or kilograms.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.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.Organ Size: The measurement of an organ in volume, mass, or heaviness.Polycyclic Hydrocarbons, Aromatic: A major group of unsaturated cyclic hydrocarbons containing two or more rings. The vast number of compounds of this important group, derived chiefly from petroleum and coal tar, are rather highly reactive and chemically versatile. The name is due to the strong and not unpleasant odor characteristic of most substances of this nature. (From Hawley's Condensed Chemical Dictionary, 12th ed, p96)Pesticides: Chemicals used to destroy pests of any sort. The concept includes fungicides (FUNGICIDES, INDUSTRIAL); INSECTICIDES; RODENTICIDES; etc.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.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).Body Weight: The mass or quantity of heaviness of an individual. It is expressed by units of pounds or kilograms.Animals, Newborn: Refers to animals in the period of time just after birth.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.Water Pollutants, Chemical: Chemical compounds which pollute the water of rivers, streams, lakes, the sea, reservoirs, or other bodies of water.Reproduction: The total process by which organisms produce offspring. (Stedman, 25th ed)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.Pregnancy, Animal: The process of bearing developing young (EMBRYOS or FETUSES) in utero in non-human mammals, beginning from FERTILIZATION to BIRTH.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.Mothers: Female parents, human or animal.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.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.Occupational Exposure: The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.Carcinogens: Substances that increase the risk of NEOPLASMS in humans or animals. Both genotoxic chemicals, which affect DNA directly, and nongenotoxic chemicals, which induce neoplasms by other mechanism, are included.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.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Gene Expression Regulation, Developmental: Any of the processes by which nuclear, cytoplasmic, or intercellular factors influence the differential control of gene action during the developmental stages of an organism.Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Smoking: Inhaling and exhaling the smoke of burning TOBACCO.Time Factors: Elements of limited time intervals, contributing to particular results or situations.