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Flashcards in Pregnancy and Newborn Testing Deck (19)
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Maternal Biochemical changes

hCG Beta subunit is used to detect pregnancy, levels rise 1 day after conception

  • Same glycoprotein class as FSH, LH, TSH
  • Tested via over the counter kits or quantitative levels in serum/urine

Estrogens have an increase in estriol


Maternal Thyroid Changes

hCG and Estriol maintain maternal thyroid production


Maternal Response to Fetal Developmental Needs

Increased amount of amino acids for protein synthesis

Fetal Liver produces Alpha fetoprotein (AFP)

Lung development requires Lamellar Bodies


Maternal Conditions


Gestational Diabetes

Liver disorders

Ectopic Pregnancy



Hypertension during late pregnancy


Gestational Diabetes

Maternal insulin-deficient state


Liver disorders

Intrahepatic Cholestasis, bile salt accumulation


Ectopic Pregnancy

Fertilization in the fallopian tubes


Tests for placental disorders

hCG measurements

  • Peaks up to 100,000 U/day and drops to 11,000 U/day late in pregnancy
  • Hydatidiform mole measurements of up to 300,000 U/day
  • Low levels in Ectopic pregnancy

Estriol: decline indicates poor fetal prognosis


Premature Birth Complications

Organs are unprepared to live outside uterus

Mainly Lungs, Kidney, and Liver



  • Present in amniotic fluid and maternal serum during gestation
  • Prescence in Amniotic fluid indicates neural tube defects or anencephaly (lacking brain)
  • High values indicate infant sepsis
  • Low values indicate Down Syndrome
  • Triple screening test: AFP, hCG, and unconjugated cortisol
  • Down’s Syndrome Testing: low AFP and estriol, high hCG


Tests for Fetal Lung Maturity

Lecithin and Sphinomyelin: phospholipids that allow the lungs to expand and transfer blood gases

Tested for with Thin layer Chromotography,


IDS (Infant Distress Syndrome), Lamellar Body Test

Causes respiratory acidosis

Lamellar bodies transition to functional lung activity, the structural forms can be counted


Common Newborn Tests

Fetal Fibronectin (fFN): Protein secreted by fetus near end of term and found in cervical fluid. If found in maternal secretions, indicates loss of membrane integrity and potential for premature labor

POCT analyzer now available for this test


ABG Testing on Umbilical Cord Blood

Trauma/anoxia during delivery cause metabolic acidosis from lactic acid production

Capillary sample from heelstick, 10min TAT with results for PO2, PCO2, and pH, HCO3 is calculated with HH equation

Specimen must be delivered on ice, properly labeled, clamps properly placed and working, and with adequate sample for testing.


Electrolyte/Bilirubin measurements

Tests for organ function, renal function (electrolytes)

Liver functionality may be gained slowly and the neonates may be unable to process bilirubin


Required Newborn Testing

Free T4 Testing: for congenital hypothyroidism

Galactosemia: lack of production of liver enzyme needed to digest galactose


Common NICU Tests

  • Blood Typing: determine whether mother is Rh Ab candidate, or to determine if neonate is at risk of developing hemolytic anemia (neonate blood type A/B, mother O)
  • Anemia/Polycythemia
  • Blood Gases for Oxygen and Carbon Dioxide
  • Blood Sugar
  • Electrolyte Levels
  • Xrays


Fetal-Maternal Blood Flow

From Placenta to fetus, then returns to placenta

Blood in Umbilical Vein has higher pH and PO2, and lower PCO2