Persistence of which reflex beyond 6 months may indicate a neurological abnormality?

RRB Nsg. Superintendent-2026 (Shift -1st)

Child Health Nursing (Pediatrics)

Easy

Appeared in: RRB Nsg. Superintendent-2026 (Shift -1st)

Explanation

The Moro reflex is an infantile startle response, normally present from birth.
In a healthy, developing infant, this reflex integrates and disappears by 3 to 6 months of age.
Persistence of the Moro reflex after 6 months is considered abnormal and is a classic sign of a generalized disturbance of the central nervous system, such as cerebral palsy.

Option A: The parachute reflex is a protective postural reaction that only begins to appear around 6 to 9 months of age and then persists throughout life. Its presence at 6 months is not abnormal.
Option B: The Babinski reflex (extensor plantar response) is normal in infants and persists much longer than 6 months. It typically disappears between 12 and 24 months of age.
Option C: The corneal reflex (blink reflex) is a permanent, protective reflex that is present from birth and persists throughout life. Its absence, not its persistence, would be a sign of a neurological problem.

Visual 1: Table - A comparative chart showing the typical onset and disappearance ages for key primitive and postural reflexes (Moro, Babinski, Parachute, Rooting, Sucking). This helps visualize the timeline mentioned in the question.
Visual 2: Diagram - A simple illustration showing the two phases of the Moro reflex: arm extension/abduction followed by flexion/adduction. This clarifies what the reflex looks like.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Normal and abnormal timelines for the disappearance of primitive neonatal reflexes as background academic context rather than a clinical decision trigger.
Assessing primitive reflexes is a fundamental part of the neonatal and infant neurological examination, allowing nurses and doctors to screen for CNS dysfunction.
A nurse observing a persistent Moro reflex during a 6-month well-child visit must document the finding and ensure prompt referral to a pediatrician or pediatric neurologist for further evaluation.
What if? If the Moro reflex was asymmetrical (present on one side but not the other) in a newborn, the primary suspicion would shift from a central nervous system issue to a peripheral injury, such as a clavicle fracture or brachial plexus injury on the non-responsive side.

How to Approach the Question

First, identify the core of the question: which reflex is abnormal if it's still present after 6 months.
This is a factual recall question about developmental milestones in pediatrics.
Mentally review the timelines for the reflexes listed in the options.
Eliminate reflexes that are supposed to persist for life (Corneal) or appear around that time (Parachute).
Compare the remaining reflexes (Babinski and Moro). Recall that the Babinski reflex lasts for 1-2 years, while the Moro reflex disappears much earlier.
Select the reflex whose disappearance timeline is around 3-6 months, making its persistence beyond that point abnormal.

Concept Tested & Keywords

Concept Tested: Normal and abnormal timelines for the disappearance of primitive neonatal reflexes.
Stem keywords: persistence, reflex, beyond 6 months, neurological abnormality
Lead-in keywords: which
Clinical cues: The 6-month timeline is the critical clue for differentiating between normal and abnormal reflex patterns.

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