Chorionic GonadotropinChorionic Gonadotropin, beta Subunit, HumanGonadotropinsLuteinizing HormoneGonadotropins, EquineReceptors, LHFollicle Stimulating HormoneReceptors, GonadotropinGlycoprotein Hormones, alpha SubunitChoriocarcinomaGonadotropins, PituitaryGonadotropin-Releasing HormoneHormonesPregnancyProgesteroneOvulationOvaryTestosteroneLeydig CellsTrophoblastic NeoplasmsEstradiolPregnancy TestsCorpus LuteumPituitary GlandGranulosa CellsOvarian FollicleThyroid HormonesHydatidiform MoleReceptors, FSHGonadal Steroid HormonesTestisOvulation InductionPregnancy-Associated Plasma Protein-APregnancy Trimester, FirstPregnancy, EctopicEstriolUterine NeoplasmsReproductive Control AgentsLuteinizing Hormone, beta SubunitPlacentaHormones, EctopicFollicle Stimulating Hormone, beta Subunitalpha-FetoproteinsPlacental LactogenSuperovulationProlactinHypogonadismGestational Trophoblastic DiseaseTrophoblastsParathyroid HormoneFertility Agents, FemaleRadioimmunoassayInhibinsEstrusMenotropinsHorsesAdrenocorticotropic HormoneSexual MaturationHypophysectomyThyrotropinSteroidsInsemination, ArtificialPituitary Hormone-Releasing HormonesPituitary Hormones, AnteriorLuteinizationHormone AntagonistsTesticular NeoplasmsRNA, MessengerNuchal Translucency MeasurementDown SyndromePituitary HormonesTheca CellsFertilization in VitroHuman Growth HormoneLeydig Cell TumorReceptors, Thyroid HormoneLeuprolidePregnancy Tests, ImmunologicFluoroimmunoassayReceptors, LHRHPituitary Gland, AnteriorCyclic AMPImmunoassayAndrostenedioneAbortifacient Agents, NonsteroidalFollicular PhaseMolecular Sequence DataOvariectomyCattlePeptide FragmentsPrenatal DiagnosisPerissodactylaEstrogensPregnancy Trimester, SecondCastrationCells, CulturedLuteal PhaseOocytes3-Hydroxysteroid DehydrogenasesImmunoradiometric Assay