Pregnancy and Newborn Testing

Question 1

Maternal Biochemical changes

Answer 1

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

Question 2

Maternal Thyroid Changes

Answer 2

hCG and Estriol maintain maternal thyroid production

Question 3

Maternal Response to Fetal Developmental Needs

Answer 3

Increased amount of amino acids for protein synthesis

Fetal Liver produces Alpha fetoprotein (AFP)

Lung development requires Lamellar Bodies

Question 4

Maternal Conditions

Answer 4

Preclampsia

Gestational Diabetes

Liver disorders

Ectopic Pregnancy

Question 5

Preclampsia

Answer 5

Hypertension during late pregnancy

Question 6

Gestational Diabetes

Answer 6

Maternal insulin-deficient state

Question 7

Liver disorders

Answer 7

Intrahepatic Cholestasis, bile salt accumulation

Question 8

Ectopic Pregnancy

Answer 8

Fertilization in the fallopian tubes

Question 9

Tests for placental disorders

Answer 9

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

Question 10

Premature Birth Complications

Answer 10

Organs are unprepared to live outside uterus

Mainly Lungs, Kidney, and Liver

Question 11

AFP

Answer 11

• 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

Question 12

Tests for Fetal Lung Maturity

Answer 12

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

Tested for with Thin layer Chromotography,

Question 13

IDS (Infant Distress Syndrome), Lamellar Body Test

Answer 13

Causes respiratory acidosis

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

Question 14

Common Newborn Tests

Answer 14

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

Question 15

ABG Testing on Umbilical Cord Blood

Answer 15

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.

Question 16

Electrolyte/Bilirubin measurements

Answer 16

Tests for organ function, renal function (electrolytes)

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

Question 17

Required Newborn Testing

Answer 17

Free T4 Testing: for congenital hypothyroidism

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

Question 18

Common NICU Tests

Answer 18

• 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

Question 19

Fetal-Maternal Blood Flow

Answer 19

From Placenta to fetus, then returns to placenta

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