Neonatal Physiology and Birth Transition Flashcards
6 cards from real NRP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Neonatal Physiology and Birth Transition flashcards as text
What is the primary physiological change that must occur in the lungs immediately after birth for successful transition to extrauterine life?
Answer: Replacement of lung fluid with air and establishment of functional residual capacity
At birth, the fluid-filled lungs must be cleared and air must replace the fluid to establish functional residual capacity (FRC), enabling effective gas exchange for the first time.
In the fetus, what is the primary function of the foramen ovale?
Answer: Allowing oxygenated blood from the placenta to bypass the lungs by shunting from right to left atrium
The foramen ovale allows oxygenated blood returning from the placenta via the umbilical vein and inferior vena cava to bypass the pulmonary circulation by shunting from the right atrium to the left atrium.
What happens to pulmonary vascular resistance (PVR) immediately after birth?
Answer: PVR decreases sharply as the lungs inflate and oxygen levels rise
At birth, lung inflation and increased alveolar oxygen tension cause pulmonary vasodilation, dramatically reducing PVR. This increases pulmonary blood flow and enables the lungs to become the primary site of gas exchange.
Which fetal structure connects the ductus arteriosus to allow blood to bypass the pulmonary circulation in utero?
Answer: Ductus arteriosus connecting the pulmonary artery to the aorta
The ductus arteriosus is a fetal blood vessel connecting the main pulmonary artery to the descending aorta, allowing blood to bypass the high-resistance pulmonary circulation and enter the systemic circulation directly.
What is the significance of the first breaths in establishing the birth transition?
Answer: They generate high positive pressures that clear lung fluid and establish FRC
The first breaths require the newborn to generate high negative (subatmospheric) intrathoracic pressures — or equivalently, high distending pressures relative to atmospheric — to overcome surface tension and viscosity of lung fluid and establish functional residual capacity.
What triggers clamping of the umbilical cord to affect neonatal transition, and what is the current NRP recommendation for timing?
Answer: Delayed cord clamping of at least 30–60 seconds is recommended for most vigorous term and preterm infants
NRP 8th edition recommends delayed cord clamping of at least 30–60 seconds for most vigorous term and preterm infants, as it allows placental transfusion that improves blood volume, iron stores, and outcomes especially in preterm infants.