Moro reflex
 [mo´ro] flexion of an infant's thighs and knees, fanning and then clenching of fingers, with arms first thrown outward and then brought together as though embracing something; produced by a sudden stimulus, such as striking the table on either side of the child, and seen normally in the newborn. Called also 
embrace reflex.

The Moro reflex occurs when the infant is startled.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.
star·tle re·flex
a primitive reflex response observed in the normal newborn but typically suppressed by 3-4 months of age. Any sudden stimulus (for example, a loud noise, a blow to the supporting surface, or being dropped 5-10 cm through space) causes flexion of the hip and knee joints with fanning of the fingers followed by fist clenching and extension of the upper limbs followed by flexion. Synonym(s): 
Moro reflex, 
parachute reflex, 
startle reactionSee also: 
cochleopalpebral reflex. 
Farlex Partner Medical Dictionary © Farlex 2012
Mo·ro re·flex
 (mō'rō rē'fleks) Response of infants at birth and for the first 3 months of life to acoustic stimuli characterized by extension and abduction of arms, hands, and fingers. 
Medical Dictionary for the Health Professions and Nursing © Farlex 2012
Moro, 
Ernst, German physician, 1874-1951. Moro reflex - the reflex response of an infant when allowed to drop a short distance through the air or startled by a sudden noise or jolt. Synonym(s): startle reflex
Medical Eponyms © Farlex 2012