The nurse is performing a newborn physical assessment and is about to elicit the Moro reflex. Which of the following responses should the nurse expect to see?
Select one:
A.
The cheek of the newborn is touched, and the newborn turns toward the side that was touched.
B.
The newborn is suddenly lowered or startled, and they extend their arms, legs and neck, then rapidly bring their arms together.
C.
The newborn is supine and their head is turned to one side, then the arm on that same side extends.
D.
The lateral aspect of the sole of the newborn’s foot is stroked, and the toes extend and fan outward.
The correct answer and Explanation is :
The correct answer is B.
The Moro reflex, also known as the startle reflex, is an important neonatal reflex that is assessed during a newborn physical examination. When eliciting the Moro reflex, the nurse will suddenly lower or startle the newborn. The expected response is that the newborn will extend their arms, legs, and neck, and then rapidly bring their arms back together. This reflex is a sign of a healthy nervous system and is usually present at birth, diminishing around 4 to 6 months of age as the infant’s nervous system matures.
Here’s a breakdown of the Moro reflex and why the other options do not fit:
- Option A: This describes the rooting reflex, not the Moro reflex. The rooting reflex is when the newborn turns their head toward a touch on their cheek, which helps them find the breast or bottle for feeding.
- Option C: This describes the asymmetrical tonic neck reflex (ATNR), also known as the “fencing” reflex. When the newborn’s head is turned to one side, the arm on that same side extends while the opposite arm and leg flex. This reflex helps develop hand-eye coordination.
- Option D: This describes the Babinski reflex, where stroking the lateral aspect of the newborn’s sole causes the toes to fan outward. This reflex is a sign of healthy neurological development but is not related to the Moro reflex.
The Moro reflex is crucial in assessing the integrity of the newborn’s central nervous system. An absence or asymmetry in the reflex can indicate neurological problems that may require further evaluation. The reflex is part of a group of primitive reflexes that are vital for survival in the early stages of life and gradually integrate as the baby develops more voluntary control over their movements.