Which birth order is most associated with pyloric stenosis presenting in infancy?

Which birth order is most associated with pyloric stenosis presenting in infancy?

• A. First-born male
• B. Female
• C. Preterm birth
• D. African descent

Answer: (A)

Pyloric stenosis shows a pattern in infancy that is strongest for first-born male infants. This condition tends to present in the first several weeks of life, and epidemiologic data repeatedly show a higher incidence in boys who are the first child in the family, with a familial tendency as well. Among the given options, being the first-born male best matches the most consistent risk pattern, which is why it’s the best answer. The other groups are not as strongly linked: females have a much lower incidence; preterm birth is not a classic associated factor for pyloric stenosis; and while IHPS tends to occur in term infants and is more common in certain populations, African descent is not the typical associated group.

Pyloric stenosis shows a pattern in infancy that is strongest for first-born male infants. This condition tends to present in the first several weeks of life, and epidemiologic data repeatedly show a higher incidence in boys who are the first child in the family, with a familial tendency as well. Among the given options, being the first-born male best matches the most consistent risk pattern, which is why it’s the best answer.

The other groups are not as strongly linked: females have a much lower incidence; preterm birth is not a classic associated factor for pyloric stenosis; and while IHPS tends to occur in term infants and is more common in certain populations, African descent is not the typical associated group.