Inpatient Obstetric Nurse (NCC) Practice Exam 2025 - Free NCC Practice Questions and Study Guide

The primary response when neonates begin air breathing is an increase in oxygen levels in circulation. When a newborn takes its first breath, it initiates significant changes in the pulmonary and systemic circulations. Air breathing facilitates the expansion of the lungs and allows for the exchange of gases. As the lungs fill with air, oxygen enters the bloodstream, leading to an increase in the partial pressure of oxygen in the circulating blood. This process is crucial for the newborn's adaptation to extrauterine life, as it shifts the body’s dependency from placental oxygenation to pulmonary oxygenation.

Additionally, the increase in oxygen levels in circulation stimulates the closure of the fetal shunts (such as the ductus arteriosus), redirects blood flow to the lungs for gas exchange, and helps to stabilize the newborn’s cardiovascular function. This transition is vital for ensuring adequate oxygen supply to meet the metabolic needs of the neonate, which is essential for survival and development.