A. Introduction.- B. Origin of Human Amniotic Fluid.- C. Origin and Regulation of Steroids in Human Amniotic Fluid.- D. Methods of Isolation and Identification of Steroids in Human Amniotic Fluid.- I. C30, C29, and C28 Steroids.- II. C27 Steroids.- 1. Cholesterol.- 2. Cholestanol.- 3. ?7-Cholestenol and ?8-Cholestenol.- 4. 7-Dehydrocholesterol and Desmosterol.- III. ?5-C21 Steroids.- 1. Pregnenolone.- 2. 16?-Hydroxypregnenolone.- 3. 17?-Hydroxypregnenolone.- 4. Pregn-5-ene-3?, 20?-diol.- 5. Pregn-5-ene-3?, 17?, 20?-triol.- 6. 21-Hydroxypregnenolone.- 7. Pregn-5-ene-3?, 20?, 21-triol.- IV. ?4-C21 Steroids.- 1. Progesterone.- 2. 16?-Hydroxyprogesterone.- 3. 17?-Hydroxyprogesterone.- 4. Cortisol.- 5. 6?-Hydroxycortisol.- 6. 6?, 20?-Dihydroxycortisol.- 7. 11-Deoxycortisol.- 8. 21-Deoxycortisol.- 9. Cortisone.- 10. 6?, 20?-Dihydroxycortisone.- 11. Corticosterone.- 12. 11-Dehydrocorticosterone.- 13. 11-Deoxycorticosterone.- 14. Aldosterone.- V. Pregnane Steroids.- 1. Pregnanolone.- 2. Pregnanediol.- 3. 5?-Pregnane-3?, 20?-diol and 5?-Pregnane-3?, 20?-diol.- 4. 5?-Pregnane-20-one-3?, 21-diol.- 5. 5?-Pregnane-20-one-3?, 16?-diol and 5?-Pregnane-20-one-3?, 16?-diol.- 6. 5?-Pregnane-20-one-3?, 6?-diol.- 7. Pregnanetriol.- 8. 5?-Pregnane-3?, 20?, 21-triol.- 9. 5?-Pregnane-3?, 16?, 20?-triol.- 10. Tetrahydrocortisol, Tetrahydrocortisone, and Tetrahydro-11-dehydrocorticosterone.- 11. Tetrahydro-11-deoxycortisol.- 12. 6?-OH-Tetrahydrocortisol, 6?-OH-Tetrahydrocortisone, 6?-OH-Allotetrahydroxycortisol, 6?-OH-Allotetrahydroxycortisone, 6?-OH-20?-Cortolone, and 6?-OH-20?-Cortolone.- VI. ?5-C19 Steroids.- 1. Dehydroepiandrosterone.- 2. Androst-5-ene-3?, 17?-diol.- 4. 16?-Hydroxydehydroepiandrosterone.- 5. 16?-Hydroxydehydroepiandrosterone.- 6. 16, 18-Dihydroxydehydroepiandrosterone.- 7. 16-Ketoandrostenediol.- 8. Androstenetriol.- 9. Androst-5-ene-3?, 16?, 17?-triol.- VII. ?4-C19 Steroids.- 1. ?4-Androstenedione.- 2. Testosterone.- VIII. Androstane Steroids.- 1. Dihydrotestosterone.- 2. 5?-Androstan-17-one-3?, 18-diol.- IX. C18 Steroids.- 1. Estrone.- 2. 16?-Hydroxyestrone.- 3. 16?-Hydroxyestrone.- 4. 15?-Hydroxyestrone.- 5. 2-Methoxyestrone.- 6. Estradiol-17?.- 7. 16-Ketoestradiol.- 8. 11-Dehydroestradiol-17?.- 9. Estriol.- 10. 16-Epiestriol.- 11. 17-Epiestriol.- 12. Estetrol.- E. Quantitation of Steroids in Human Amniotic Fluid.- I. C30, C29, and C28 Steroids.- II. C27 Steroids.- 1. Cholesterol.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 2. Other C27 Steroids.- III. ?5-C21 Steroids.- 1. Pregnenolone.- 2. 16?-Hydroxypregnenolone.- 3. 17?-Hydroxpregnenolone.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 4. Other ?5-C21 Steroids.- IV. ?4-C21 Steroids.- 1. Progesterone.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 2. 16?-Hydroxyprogesterone.- 3. 17?-Hydroxyprogesterone.- 4. Cortisol.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 5. 6?-Hydroxycortisol and 6?, 20?-Dihydroxycortisol.- 6. Cortisone.- 7. 6?, 20?-Dihydroxycortisone.- 8. Other ?4-C21 Steroids.- V. Pregnane Steroids.- 1. Pregnanelone.- 2. Pregnanediol.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 3. Pregnanetriol.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 4. Other Pregnane Steroids.- VI. 17-Hydroxycorticosteroids.- a) Normal Pregnancies.- b) Complicated Pregnancies.- VII. 11-Hydroxycorticosteroids.- VIII. ?5-C19 Steroids.- 1. Dehydroepiandrosterone.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 2. Androst-5-ene-3?, 17?-diol and Androst-5-ene-3?, 17?-diol.- 3. 16?-Hydroxydehydroepiandrosterone.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 4. 16-Ketoandrostenediol.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 5. 16, 18-Dihydroxydehydroepiandrosterone.- 6. Androstenetriol.- a) Normal Pregnancies.- b) Complicated Pregnancies.- IX. ?4-C19 Steroids.- 1. Androstenedione.- 2. Testosterone.- a) Normal Pregnancies.- b) Complicated Pregnancies.- X. Androstane Steroids.- 1. Dihydrotestosterone.- XI. 17-Ketosteroids.- a) Normal Pregnancies.- b) Complicated Pregnancies.- XII. C18 Steroids.- 1. Estrone.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 2. Estradiol-17?.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 3. Estriol.- a) Normal Pregnancies.- b) Complicated Pregnancies.- 4. Estetrol.- a) Normal Pregnancies.- b) Complicated Pregnancies.- F. Steroid Conjugates in Human Amniotic Fluid.- I. C30, C29, und C28 Steroids.- II. C27 Steroids.- III. ?5-C21 Steroids.- IV. ?4-C21 Steroids.- V. 17-Hydroxycorticosteroids.- VI. Pregnane Steroids.- VII. ?5-C19 Steroids.- VIII. ?4-C19 Steroids.- IX. 17-Ketosteroids.- X. Estrogens.- G. Steroid Profiles in Human Amniotic Fluid and Distribution of Steroids in Several Compartments.- H. Transfer and Metabolism of Steroids in Human Amniotic Membranes.- I. Fate of Steroids Injected into the Amniotic Cavity.- J. Binding of Steroids in Human Amniotic Fluid.- K. Proteohormones in Human Amniotic Fluid.- I. Luteinizing Hormone (LH).- II. Follicle-Stimulating Hormone (FSH).- III. Human Chorionic Gonadotropin (HCG).- IV. Human Placental Lactogen (HPL).- V. Prolactin (Prl).- VI. Adrenocorticotropic Hormone (ACTH).- VII. Human Growth Hormone (HGH).- VIII. Somatomedin and Somatomedin C.- IX. Thyroid-Stimulating Hormone (TSH).- X. Thyroid Hormones.- 1. Thyroxine (T4).- 2. 3,3',5-Triiodothyronine (T3).- 3. Reverse 3,3',5'-Triiodothyronine (rT3).- 4. 3,3'-Diiodothyronine (T2).- 5. 3',5'-Diiodothyronine and 3,5-Diiodothyronine.- 6. 3'-Monoiodothyronine (3'-T1).- XI. Parathyroid Hormone (PTH).- XII. Oxytocin.- XIII. Glucagon.- XIV. Insulin.- XV. Hypothalamic-Releasing Hormones.- 1. Thyrotropin-Releasing Hormone (TRH).- 2. Luteinizing Hormone-Releasing Hormone (LH-RH).- XVI. Neurophysin.- XVII. ?-Endorphin and "Humoral Endorphin".- XVIII. ?-Melanocyte-Stimulating Hormone (?-MSH).- XIX. Conclusions.- Acknowledgments.- References.