Amniotic fluid

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Amniotic fluid surrounds the fetus during intrauterine development.
This fluid cushions the fetus against trauma, has antibacterial properties to lessen infections, and functions as a reservoir that may provide a short-term source of fluid and nutrients to the fetus.

Amniotic fluid are required for the fetal musculoskeletal system to develop normally, for gastrointestinal system development, and for the fetal lungs to develop.

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Amniotic fluid

  1. 1. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID By: Amir Nader Emami Razavi
  2. 2. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Fertilization: Four Major Steps • Sperm contacts the egg • Sperm or its nucleus enters the egg • Egg becomes activated and developmental changes begin • Sperm and egg nuclei fuse June 26, 2012 Slide No. 2 Total slide: 88
  3. 3. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Fertilization June 26, 2012 Slide No. 3 Total slide: 88
  4. 4. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID The Nuclei Fuse Together June 26, 2012 Slide No. 4 Total slide: 88
  5. 5. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID What happens now? Development of the zygote, the study of which is known as embryology or developmental biology. The zygote undergoes a series of mitotic cell divisions called cleavage. The stages of development are: Fertilized ovum (zygote)  2-cell stage  4-cell stage  8-cell stage  Morula  Blastula  Early Gastrula  Late Gastrula June 26, 2012 Slide No. 5 Total slide: 88
  6. 6. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Cleavage (divide via mitosis) forms the 2 cell stage June 26, 2012 Slide No. 6 Total slide: 88
  7. 7. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID They split again to form the 4 cell stage June 26, 2012 Slide No. 7 Total slide: 88
  8. 8. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID And again to form the 8 cell stage… June 26, 2012 Slide No. 8 Total slide: 88
  9. 9. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID And eventually form a Morula June 26, 2012 Slide No. 9 Total slide: 88
  10. 10. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Next it becomes a blastula June 26, 2012 Slide No. 10 Total slide: 88
  11. 11. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID And next, a gastrula June 26, 2012 Slide No. 11 Total slide: 88
  12. 12. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID The Regents Diagram… • Sperm and ovum • Zygote (fertilized ovum) • 2-cell stage • 4-cell stage • Morula • Blastula • Gastrula June 26, 2012 Slide No. 12 Total slide: 88
  13. 13. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Differentiation (Organogenesis) Organogenesis is the formation of the organs (Organo = organs, genesis = creation) Arises from the layering of cells that occurs during gastrula stage The layers are germ layers; they have specific fates in the developing embryo: June 26, 2012 Slide No. 13 Total slide: 88
  14. 14. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Differentiation (Organogenesis) Endoderm The innermost layer Goes on to form the gut Mesoderm In the middle Goes on to form the muscles, circulatory system, blood and many different organs Ectoderm The outermost Goes on to form the skin and nervous system June 26, 2012 Slide No. 14 Total slide: 88
  15. 15. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Late Gastrula Endoderm Ectoderm Mesoderm June 26, 2012 Slide No. 15 Total slide: 88
  16. 16. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Differentiation of Primary Germ Layers (from the gastrula) Ectoderm Mesoderm Endoderm Nervous system Skeleton Digestive tract Epidermis of Muscles Respiratory skin system Circulatory Liver, pancreas system Gonads Bladder June 26, 2012 Slide No. 16 Total slide: 88
  17. 17. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Implantation The embryo implants in the wall of the uterus on about the 7th day of development June 26, 2012 Slide No. 17 Total slide: 88
  18. 18. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID 12-day Human Embryo June 26, 2012 Slide No. 18 Total slide: 88
  19. 19. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Where does this all take place? June 26, 2012 Slide No. 19 Total slide: 88
  20. 20. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Development of the Placenta June 26, 2012 Slide No. 20 Total slide: 88
  21. 21. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 21 Total slide: 88
  22. 22. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID The chorion and amnion enclose the embryo The chorion surrounds the entire embryo The amnion encloses the embryo and forms an open volume between the embryo & the amnion called the amniotic cavity The amniotic cavity fills with amniotic fluid, which envelops the embryo and cushions it June 26, 2012 Slide No. 22 Total slide: 88
  23. 23. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amnion & Amniotic Fluid Composition of Amniotic Fluid 99% H2O Undisolved material Organic & inorganic salts Pregnancy advancement changes its composition Meconium & urine June 26, 2012 Slide No. 23 Total slide: 88
  24. 24. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic Fluid Before 20 weeks gestation – AF is an ultrafiltrate of maternal serum Maternal & AF osmolality, sodium, urea, and creatinine are roughly equal. At term Volume = 900cc Reflective of fetal renal function. Progressively hypotonic. Contains fetal debris: squamous cells, mucin, lanugo. June 26, 2012 Slide No. 24 Total slide: 88
  25. 25. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic Fluid Amniotic fluid surrounds the fetus during intrauterine development. This fluid cushions the fetus against trauma, has antibacterial properties to lessen infections, and functions as a reservoir that may provide a short-term source of fluid and nutrients to the fetus. June 26, 2012 Slide No. 25 Total slide: 88
  26. 26. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic Fluid Amniotic fluid are required for the fetal musculoskeletal system to develop normally, for gastrointestinal system development, and for the fetal lungs to develop. It is not surprising to find that oligohydramnios and polyhydramnios are associated with increased rates of perinatal morbidity and mortality. June 26, 2012 Slide No. 26 Total slide: 88
  27. 27. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 27 Total slide: 88
  28. 28. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Sources of amniotic fluid The two primary sources of amniotic fluid are fetal urine and lung liquid, with an additional small contribution due to secretions from the fetal oral-nasal cavities. Fetal urine is a major source of amniotic fluid in the second half of pregnancy. June 26, 2012 Slide No. 28 Total slide: 88
  29. 29. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Sources of amniotic fluid Urine production Approximately 110/ml/kg every 24 hours at 25 weeks to approximately 190 ml/kg every 24 hours at 39 weeks At term, the current best estimate of fetal urine flow rate may average 700-900 ml/day. June 26, 2012 Slide No. 29 Total slide: 88
  30. 30. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Sources of amniotic fluid The fetal lungs are the second major source of amniotic fluid during the second half of gestation. Studies in near-term fetal sheep have shown that there is an outflow from the lungs of 200-400 ml/day June 26, 2012 Slide No. 30 Total slide: 88
  31. 31. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Sources of amniotic fluid The inward transfer of solute across the amnion with water following passively is the most likely source of amniotic fluid very early in gestation Part of AFV may be derived from water transport across the highly permeable skin of the fetus during the first half of gestation, at least until keratinization of the skin occurs around 22-25 weeks. June 26, 2012 Slide No. 31 Total slide: 88
  32. 32. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Routes of amniotic fluid removal The two primary routes of amniotic fluid removal are fetal swallowing and absorption into fetal blood perfusing the fetal surface of the placenta. Fetal swallowing plays an important role in determining AFV during the last half of gestation. June 26, 2012 Slide No. 32 Total slide: 88
  33. 33. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Routes of amniotic fluid removal The fetus begins swallowing at the same gestational age when urine first enters the amniotic space, that is around 8-11 weeks. It is estimated that the volume of amniotic fluid swallowed in late gestation averages 210-760 ml/day June 26, 2012 Slide No. 33 Total slide: 88
  34. 34. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Intermembranous & transmembranous pathways As a further pathway, rapid movements of both water and solute occur between amniotic fluid and fetal blood within the placenta and membranes; this is referred to as the intramembranous pathway. Movement of water and solute between amniotic fluid and maternal blood within the wall of the uterus is an exchange through the transmembranous pathway June 26, 2012 Slide No. 34 Total slide: 88
  35. 35. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic fluid volume June 26, 2012 Slide No. 35 Total slide: 88
  36. 36. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic fluid volume June 26, 2012 Slide No. 36 Total slide: 88
  37. 37. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic fluid volume The rate of change in AFV is a strong function of gestational age. There is a progressive AFV increase from 30 ml at 10 weeks’ gestation to 190 ml at 16 weeks and to a mean of 780 ml at 32-35 weeks, after which a decrease occurs The decrease in post-term pregnancies has been found to be as high as 150 ml/week from 38 to 43 weeks June 26, 2012 Slide No. 37 Total slide: 88
  38. 38. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Individual amniotic fluid volumes from a collection of 705 measurements in patients with a normal pregnancy outcome June 26, 2012 Slide No. 38 Total slide: 88
  39. 39. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Regulatory mechanisms act at three levels: Placental control of water and solute transfer. Regulation of inflows and outflows from the fetus: fetal urine flow and composition are modulated by vasopressin, aldosterone, and angiotensin II in much the same way as they in adults. Maternal effect on fetal fluid balance: during pregnancy, there is a strong relationship between maternal plasma volume and AFV, June 26, 2012 Slide No. 39 Total slide: 88
  40. 40. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic fluid testing The amniotic fluid can be sampled to test for developmental abnormalities June 26, 2012 Slide No. 40 Total slide: 88
  41. 41. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Alpha fetoprotein Measurement of AFP in maternal serum and amniotic fluid is used extensively throughout the United states and the United kingdom for prenatal detection of some serious fetal anomalies. June 26, 2012 Slide No. 41 Total slide: 88
  42. 42. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AFP Biochemistry AFP is produced initially by the fetal yolk sac in small quantities and then in larger quantities by fetal liver as the yolk sac degenerates.trace amounts are also produced in the fetal gut and kidneys. June 26, 2012 Slide No. 42 Total slide: 88
  43. 43. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AFP Biochemistry Concentrations of AFP in fetal serum Erly in embryonic life:1/10 the concentration of albumin in fetal serum 16 weeks gestation:3,000,000 ng/ml At term:declines steadily to 5000 to 120,000 ng/ml June 26, 2012 Slide No. 43 Total slide: 88
  44. 44. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AFP Biochemistry The rise and fall in concentration of AFP in the amniotic fluid roughly parallels that in the fetal serum but lower in concentration 20,000 ng/ml at 16 weeks gestation June 26, 2012 Slide No. 44 Total slide: 88
  45. 45. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Clinical significance of AFP Maternal serum and amniotic fluid AFP are useful tests for detecting some serious fetal anomalies Maternal serum AFP is elevated in 85% to 95% of cases of fetal open neural tube defect and is low in about 30% of cases of fetal Down’s syndrome. June 26, 2012 Slide No. 45 Total slide: 88
  46. 46. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Acetyl cholinesterase A useful adjunct in the diagnosis of neural tube defects is the measurment of acetylcholinesterase (AChE,EC 3.1.1.7) in amniotic fluid The usual technique for identification of AChE is polyacrylamide gel electrophoresis. June 26, 2012 Slide No. 46 Total slide: 88
  47. 47. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Acetyl cholinesterase test sensitivity A study of more than 5000 patients reported that determination of AChE by electrophoresis had specificity of 99.76% and following sensitivities: June 26, 2012 Slide No. 47 Total slide: 88
  48. 48. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Anencephaly,97% June 26, 2012 Slide No. 48 Total slide: 88
  49. 49. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Open spina bifida,99% June 26, 2012 Slide No. 49 Total slide: 88
  50. 50. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Abdominal wall defects,94% June 26, 2012 Slide No. 50 Total slide: 88
  51. 51. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic fluid testing Testing amniotis fluid for AFP and AChE can predict open neural tube defects more accurately than maternal serum screening. Patient with unexplained high maternal serum AFP levels and normal ultrasonography findings should be offered amniotic fluid testing. Any petient who has had a child with a neural tube defect has 3% to5% risk for recurrence and also should be offered amniotic fluid AFP testing Any elevation of AFP in amniotic fluid should lead to AChE analysis June 26, 2012 Slide No. 51 Total slide: 88
  52. 52. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic fluid testing Testing should be performed at or before 16 weeks’gestation. Determination of fetal kariotype is also reasonable. June 26, 2012 Slide No. 52 Total slide: 88
  53. 53. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF and Respiratory distress syndrome (RDS) June 26, 2012 Slide No. 53 Total slide: 88
  54. 54. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF and Respiratory distress syndrome (RDS) Respiratory distress syndrome (RDS) was estimated to affect approximately 3,000 newborns yearly in the United States, and this disease was associated with a significant mortality rate approaching approximately 30%. In the 1950s, it was discovered that the resistance of pulmonary alveoli to collapse during expiration was mainly caused by the presence of a surface tension-lowering material lining the alveolus (surfactant). As the lungs develop, significant quantities of surfactant are washed out of the fetal lung and accumulate in the amniotic fluid. June 26, 2012 Slide No. 54 Total slide: 88
  55. 55. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF and Respiratory distress syndrome (RDS) all of the available biochemical tests for fetal lung maturity rely on the amniotic fluid content of surfactant adult mature surfactant is approximately 80% phospholipids, about 10% protein, and about 10% neutral lipids (primarily cholesterol). The major species of phospholipid in surfactant is phosphatidylcholine (also referred to as lecithin), which accounts for 80% of the total phospholipid June 26, 2012 Slide No. 55 Total slide: 88
  56. 56. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Surfactant lipid Composition June 26, 2012 Slide No. 56 Total slide: 88
  57. 57. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 57 Total slide: 88
  58. 58. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID L/S ratio test The L/S ratio test remains one of the most commonly used tests, and one of the standardized tests against which all other tests are compared. With a L/S ratio of 1.5-1.9, approximately 50% of infants will develop RDS. Below a ratio of 1.5, the risk of subsequent RDS increases to 73%. One of the major disadvantages of the L/S ratio is the inability to use this test in the setting of contaminated amniotic fluid. Both blood and meconium staining of amniotic fluid have been found to interfere with L/S ratio determinations. June 26, 2012 Slide No. 58 Total slide: 88
  59. 59. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 59 Total slide: 88
  60. 60. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 60 Total slide: 88
  61. 61. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 61 Total slide: 88
  62. 62. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID PG determinations: It is found that the false-positive rate for PG determination was 1.8%. This rate is significantly lower than the false-positive rate they found for the L/S ratio(5%) PG performs much better than the L/S ratio in predicting babies who will develop RDS. Finally, PG determinations accurately predict pulmonary maturity and give a better indication of pulmonary immaturity than does the L/S ratio June 26, 2012 Slide No. 62 Total slide: 88
  63. 63. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 63 Total slide: 88
  64. 64. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Saturated Phosphatidylcholine Saturated Phosphatidylcholine has been found to predict pulmonary maturity Respiratory distress syndrome was correctly predicted 55.5% of the time by L/S ratio and 82% of the time by SPC. Pulmonary immaturity = an SPC <500 μg/dl In addition, the SPC was found to be valid in the presence of blood and meconium, whereas the L/S ratio was not. June 26, 2012 Slide No. 64 Total slide: 88
  65. 65. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Lung Profile The lung profile includes the L/S ratio, disaturated lecithin, PG and PI concentrations. lung profile help to form a clearer picture of fetal lung development The L/S ratio had a false-positive rate of 3%-5%, which was reduced to less than 1% with the combined lung profile test June 26, 2012 Slide No. 65 Total slide: 88
  66. 66. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 66 Total slide: 88
  67. 67. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Microviscosimeter Microviscosimeter testing measures surfactant associated with a phospholipid membrane using fluorescent dye techniques. The microviscosimeter commonly used in the fetal lung maturity analyzer or FELMA machine. June 26, 2012 Slide No. 67 Total slide: 88
  68. 68. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 68 Total slide: 88
  69. 69. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Surfactant/Albumin Ratio A recently introduced TDx FLM assay is an automated fetal lung maturity test based on the principle of fluorescent polarization used previously with the microviscosimeter. A surfactant albumin ratio of 50-70 mg surfactant/g of albumin has been considered mature in most studies The TDx test correlates well with the L/S ratio and has few false-immature results, making it an excellent screening test It only requires approximately 1 ml of amniotic fluid and the test can be performed in less than an hour, June 26, 2012 Slide No. 69 Total slide: 88
  70. 70. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 70 Total slide: 88
  71. 71. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Shake test this test use the principle that when ethanol is added to amniotic fluid, the nonsurfactant foam causing substances in amniotic fluid are removed. any stable foam layer that persists after shaking is due to the presence of surfactant in a critical concentration. when serial dilutions of ethanol are used, the surfactant can be quantified. it is found that the shake test was comparable to the L/S ratio and had a high predictive value for RDS when applied to uncontaminated amniotic fluid. June 26, 2012 Slide No. 71 Total slide: 88
  72. 72. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 72 Total slide: 88
  73. 73. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Tap Test the tap test examines the ability of surfactant within amniotic fluid to break down bubbles within an ether layer. the test is performed on 1 ml of amniotic fluid mixed with a drop of 6N hydrochloric acid and 1.5 ml of diethylether the tube is tapped 4 times and examined for the presence of bubbles within the ether layer. in mature samples, the bubbles quickly breakdown, whereas in immature amniotic fluid specimens more than 5 bubbles persist in the ether layer. this rapid test was comparable with the phospholipid profile June 26, 2012 Slide No. 73 Total slide: 88
  74. 74. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 74 Total slide: 88
  75. 75. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Visual Inspection The basis is whether or not newspaper could be read through the amniotic fluid sample, that is, was the fluid too turbid to read text through. with clear fluid (readable newsprint) the sensitivity of an immature result is 98%. June 26, 2012 Slide No. 75 Total slide: 88
  76. 76. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Optical Density at 650 nm  with a OD 650 value of 0.15 or greater, the L/S ratio was always greater than 2.0  when the OD 650 was less than 0.15, only 6% of L/S ratios were greater than 2 June 26, 2012 Slide No. 76 Total slide: 88
  77. 77. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Diabetes and pulmonary maturity June 26, 2012 Slide No. 77 Total slide: 88
  78. 78. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID Amniotic fluid and renal maturity June 26, 2012 Slide No. 78 Total slide: 88
  79. 79. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF assesment and Renal maturity The fetal kidneys start to develop during the 4th and 5th weeks of gestation and begin to excrete urine into the amniotic fluid at the 8th to 11th week At the 20th week the fetal kidneys produce most of the amniotic fluid Renal maturity is defined by the increase in glomerular filtration and by the maturity of renal tubular cells that begin to express various tubular transporters over the months of gestation June 26, 2012 Slide No. 79 Total slide: 88
  80. 80. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF assesment and Renal maturity Glomerular filtration in the fetal kidney can be assessed by the concentrations of creatinine and urea in the amniotic fluid Creatinine concentrations of 2 mg/dl represent an age of at least 37 weeks of gestation The function of the renal tubule system, specifically proximal tubules, can also be assessed by the concentrations of ß2- microglobulin and NAG in the third trimester of gestation June 26, 2012 Slide No. 80 Total slide: 88
  81. 81. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF assesment and Renal maturity ß2-Microglobulin produced by the fetus is filtered and reabsorbed by proximal tubules, with an expected reduction in its concentrations at week 36 in normal pregnancies. This reduction can be considered as an index of renal tubular maturation June 26, 2012 Slide No. 81 Total slide: 88
  82. 82. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF assesment and Renal maturity Analysis of creatinine and urea in amniotic fluid permits an evaluation of renal maturation. Creatinine values in the amniotic fluid that best represent fetal maturity are 1.5 to 2.0 mg/dl June 26, 2012 Slide No. 82 Total slide: 88
  83. 83. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 83 Total slide: 88
  84. 84. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF and Bone Healing June 26, 2012 Slide No. 84 Total slide: 88
  85. 85. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF and Bone Healing Hyaluronic acid (HA) is a linear polysaccharide with a high molecular weight. It is found in all extracellular matrices and has the same structure in all species. If HA is administered during surgery, scar formation is prevented. HA is known to reduce scar formation by inhibiting lymphocyte migration, proliferation and chemotaxis, granulocyte phagocytosis , degranulation, and macrophage motility June 26, 2012 Slide No. 85 Total slide: 88
  86. 86. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF and Bone Healing HA influences and enhances tissue regeneration through its ability to retain large amounts of water. HA has been reported to increase osteoblastic bone formation in vitro through increased mesencymal cell differentiation and migration. June 26, 2012 Slide No. 86 Total slide: 88
  87. 87. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID AF and Bone Healing Human amniotic fluid (HAF), obtained by amniocentesis during the second trimester of gestation, contains high molecular weight HA in high concentrations. It has been showed that HASA (HA- stimulating activator) which is present in HAF, stimulates the wound to increase the production of endogenous HA. HAF may increase both endogenous and exogenous HA in the application region. HAF has been reported to enhance new cartilage formation. June 26, 2012 Slide No. 87 Total slide: 88
  88. 88. CLINICAL BIOCHEMISTRY AMNIOTIC FLUID June 26, 2012 Slide No. 88 Total slide: 88

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