A 7-month-old infant is examined during a well-child visit. The examiner notes that the Moro reflex is still easily elicitable. Persistence of the Moro reflex beyond what age is considered abnormal and should raise suspicion for a motor disorder such as cerebral palsy?
- A 2 months
- B 4 months
- C 6 months ✓
- D 9 months
Correct answer: C. 6 months
Explanation
The Moro reflex is normally present at birth and disappears by 3 to 4 months, but it may be elicited up to 6 months in normal infants. Persistence beyond 6 months is pathological and suggests an upper motor neuron lesion such as cerebral palsy. Asymmetry of the Moro reflex is also abnormal and points to a unilateral lesion such as brachial plexus injury or hemiplegia.
Reference: Nelson Textbook of Pediatrics, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.