5) Anatomical and Physiological Characteristics of Full-term and Premature newborns; Hemolytic Disease of Newborn

Question 1

What is the Physiology of a Full-Term Newborn?

Answer 1

Consists of

1) Foramen Ovale = This connects the left + right atrium

2) Ductus Arteriosus

• Connects the Pulmonary Artery –> Aorta
• Eventually forms REMNANT LIGAMENTUM ARTERIOSUM, after closure

3) Ductus Venosum

• Connects the Umbilical Vein –> Inferior Vena Cava
• allowing 02 blood from placenta to bypass liver
• forms REMNANT LIGAMENTUM VENOSUM

Question 2

Explain the Fetal Circulation System

Answer 2

1) There’s GREATER Pressure in RIGHT Atrium, supposed to the Left

2) Blood comes from the placenta + body, which enters the Right Atrium; where only a small amount is from Lungs (Fetal Lungs are not functional yet)

3) Blood from RA –> BYPASSES the Lungs; flows DIRECTLY into –> LA via the foramen ovale

Question 3

Explain the Changes in Circulation, once a baby is born

Answer 3

Baby is BIRTHED + breathes air for 1st Time

• Decreased Pulmonary Resistance
• Increased Pulmonary Blood Flow
• Pressure Changes SWAP ; RA < LA; thereby closing of foramen ovale

CLOSURE OF:

• Ductus Arteriosus = At Hrs - Days
• Ductus Venosus = Within Week

Pressure Changes in LUNGS / CLOSES of Fetal Route + Redirects –> Pumped to LUNGS

Question 4

What are Pre-Term Newborns?

Answer 4

• Also known as Premature Newborns
• Babies born BEFORE 37th Gestational Week

Question 5

What are the Signs of Prematurity?

Answer 5

• Small Size + LARGE Head
• LESS Body Fat
• Lanugo = Soft hair that covers the fetus during development
• Transparent-looking Skin = Shows Veins
• LACK of Reflexes = Sucking + Swallowing
• Decreased Muscle Tone
• Respiratory Distress

Question 6

What is Hemolytic Disease of Newborn?

Answer 6

• Autoimmune Condition that develops in Peripartum Fetus
• Where IgG molecules are produced by Mother - from the PREVIOUS Pregnancy
• Due to Rh INCOMPATIBILITY - exposure of Rh- MOTHER –> to Rh+ RED CELL

Question 7

What are the Clinical Features of Hemolytic Disease of Newborn

Answer 7

• Jaundice AT Birth ; or Within 24h of Birth
• Hepatosplenomegaly
• Anemia
• Fetal Hydrops - due to hypoxia, anemia, and Congestive Heart Failure

Question 8

How is HD of Newborn, Diagnosed?

Answer 8

• +ve Neonatal DIRECT COOMBS Test
• Hemolysis on Blood Film

Question 9

How is HD of Newborn, Managed?

Answer 9

• Rh Immunoglobulin = For Prevention
• Phototherapy
• anti-D Antibodies
• Exchange Transfusion