Amniotic Fluid and HCG

• What is the appearance of amniotic fluid?

  Clear, colorless, and sometimes yellowish
• When is amniotic fluid usually produced?

  During the first 12 days after conception
• What is the primary purpose of amniotic fluid?

  To surround the growing fetus in the uterus
• What complications can arise from abnormal amniotic fluid levels?

  They can lead to pregnancy complications
• What are the main components of amniotic fluid?

  Fetal urine and fetal cells
• What is the composition of amniotic fluid during the first trimester?

  It is mainly made up of maternal plasma
• How is amniotic fluid described in terms of plasma?

  It is an ultrafiltrate of plasma
• What are the two extraembryonic membranes and their functions?

  • Amnion:
  • Inner membrane covering the embryo
  • Ruptures to release amniotic fluid, signaling delivery
  • Chorion:
  • Outer membrane supporting the fetus and amnion
• What is the role of the extraembryonic membranes?

  They support the embryo's overall development
• What are the primary functions of amniotic fluid?

  • Provides cushion for the fetus
  • Allows fetal movement
  • Stabilizes fetal temperature
  • Controls infection
  • Aids in lung development
  • Exchanges water and chemicals
  • Supports muscle and bone development
  • Provides lubrication
• How much amniotic fluid is derived from maternal circulation during the first trimester?

  Approximately 35 mL
• What contributes to amniotic fluid volume as the fetus grows?

  Fetal urine and lung fluid
• What is the daily volume of amniotic fluid produced later in pregnancy?

  200 to 500 mL per day
• What does high fetal urine indicate regarding amniotic fluid?

  It indicates high fetal swallowing
• What is the significance of phospholipids in amniotic fluid?

  They assess lung maturity
• What is polyhydramnios?

  Increased amniotic fluid volume (>1200 mL)
• What causes polyhydramnios?

  Decreased fetal swallowing and neural tube defects
• What is oligohydramnios?

  Decreased amniotic fluid volume (<300 mL)
• What can oligohydramnios cause?

  Fetal distress syndrome
• What is the water composition of amniotic fluid during the first trimester?

  98 to 99% water with some electrolytes
• What metabolic products may be present in amniotic fluid by the 12th to 14th week?

  Metabolic products from fetal development
• How does the composition of amniotic fluid compare to maternal plasma?

  It is similar but contains sloughed fetal cells
• What substances are produced by the fetus found in amniotic fluid?

  Bilirubin, lipids, enzymes, electrolytes
• How does fetal urine affect the levels of creatinine, urea, and uric acid?

  It increases their levels in amniotic fluid
• How can fetal age be estimated using creatinine levels?

  <36 weeks = 1.5 to 2.0 mg/dL
• What is the purpose of the quadruple screening test?

  To evaluate risks for certain conditions
• When is the quadruple screening test performed?

  During the second trimester (14th to 22nd week)
• What hormones are checked in the quadruple screening test?

  AFP, hCG, UE3, and Inhibin A
• What is amniocentesis?

  An invasive procedure to obtain amniotic fluid
• What are the two types of amniocentesis procedures?

  Transabdominal and vaginal amniocentesis
• Why is ultrasound used during amniocentesis?

  To guide the procedure accurately
• How much amniotic fluid is collected during amniocentesis?

  Maximum of 30 mL
• What should be done with the first 2 to 3 mL of collected amniotic fluid?

  Discard it to avoid contamination
• How should specimens for bilirubin analysis be protected?

  Protect from light using amber tubes
• What are the differences between amniotic fluid and maternal urine?

  • Amniotic Fluid:
  • Less reliable for protein and glucose
  • More reliable for urea and creatinine
  • Serves as cushioning liquid
  • Maternal Urine:
  • More reliable for protein and glucose
  • Responsible for excreting wastes
• What does the fern test detect?

  Ruptured amniotic membranes
• What is the procedure for the fern test?

  Vaginal fluid is dried and visualized
• What does colorless amniotic fluid indicate?

  It is normal
• What does blood-streaked amniotic fluid suggest?

  Traumatic tap or intraamniotic hemorrhage
• What does yellow amniotic fluid indicate?

  Hemolytic disease of the newborn (HDNF)