Neutrophil counts increase with which of the following factors?

• A. Higher altitude
• B. Low birth weight
• C. Vaginal delivery with labor
• D. Increasing gestational age

Answer: (D)

Neutrophil counts in newborns rise as the infant matures in utero. With increasing gestational age, bone marrow granulopoiesis becomes more robust and neutrophil reserves expand, leading to higher baseline neutrophil counts in term compared with preterm infants. This maturational effect provides a clearer, consistent pattern than other factors.

While labor and stress can cause a temporary rise in white blood cells, and other factors like high altitude or low birth weight can influence various hematologic parameters, the strongest and most consistent driver of higher neutrophil counts in this context is advancing gestational age.