Which of the following immunoglobulins cross the placenta?

a) Projectile vomiting: A hallmark symptom of pyloric stenosis due to the narrowing of the pyloric sphincter, leading to forceful and projectile vomiting.

b) Watery diarrhea: Not typically associated with pyloric stenosis.

c) Increased urine output: Unrelated to pyloric stenosis, urinary output might vary based on other factors.

d) Bloody stools: Typically not a primary symptom of pyloric stenosis, which primarily affects the passage of food from the stomach.

• Coarctation of the aorta
  Explanation: This condition involves a narrowing of the aorta, typically occurring just after the left subclavian artery. It causes higher blood pressure in the arms and lower blood pressure in the legs due to the obstruction of blood flow.

• Patent ductus arteriosus
  Explanation: This is a condition where the ductus arteriosus, a blood vessel in the fetal heart, does not close after birth. It usually causes increased blood flow to the lungs rather than a discrepancy between upper and lower body blood pressures.

• Tetralogy of Fallot
  Explanation: This congenital heart defect consists of four heart abnormalities. While it affects blood flow and oxygen levels, it does not typically cause a significant difference in blood pressure between the arms and legs.

• Transposition of the great arteries
  Explanation: This condition involves the aorta and pulmonary artery being switched. It leads to severe oxygenation issues but does not usually result in a notable difference in blood pressure readings between the arms and legs.