Contact Us | Patient Portal | Search:
Printer Friendly VersionEmail A FriendAdd ThisIncrease Text SizeDecrease Text Size

Moro reflex

 

Definition

Moro reflex is type of involuntary response that is present at birth. It normally disappears after 3 or 4 months.

See also: Infant reflexes

Alternative Names

Startle response; Startle reflex; Embrace reflex

Common Causes

This is a normal reflex present in newborn infants. Absence of the Moro reflex in an infant is abnormal. Presence of a Moro reflex in an older infant, child, or adult is also abnormal.

Two-sided absence of the Moro reflex suggests damage to the brain or spinal cord.

One-sided absence of the Moro reflex suggests the possibility of a broken shoulder bone or injury to the group of nerves that run from the lower neck and upper shoulder area. Conditions associated with such nerve injury include Erb's palsy and Erb-Duchenne paralysis. Loss of muscle function on one side of the body may also produce an asymmetrical Moro reflex.

Home Care

It is not necessary to check for a Moro reflex at home. Your doctor will check this reflex during an office visit.

Call your health care provider if

Call your health care provider if you think your baby may have a broken shoulder bone or injury to the nerves that run from the lower neck and upper shoulder area (brachial plexus injury), which can cause the loss of the Moro reflex on one side.

What to expect at your health care provider's office

An abnormal Moro reflex is usually discovered by the health care provider. The health care provider will perform a physical exam and ask questions about the child's medical history. Medical history questions may include:

  • History of the labor and birth
  • Detailed family history
  • Other symptoms

If the reflex is absent or abnormal, further tests may need to be done to examine the child's muscles and nerves. Diagnostic tests, in cases of decreased or absent reflex, may include:

  • Shoulder x-ray
  • Tests for disorders associated with brachial plexus injury
Considerations

The Moro reflex may be demonstrated by placing the infant face up on a soft, padded surface. The head is gently lifted with enough support to just begin to remove the body weight from the pad. (Note: The infant's body should not be lifted off the pad, only the weight removed.)

The head is then released suddenly, allowed to fall backward momentarily, but quickly supported again (not allowed to bang on the padding). The infant may have a "startled" look, and the arms fling out sideways with the palms up and the thumbs flexed. As the reflex ends, the infant draws its arms back to the body, elbows flexed, and then relaxes.

References

Zafeiriou DI. Primitive reflexes and postural reactions in the neurodevelopmental examination. Pediatr Neurol. 2004;31(1):1-8.

Bear LM. Early identification of infants at risk for developmental disabilities. Pediatr Clin North Am. 2004;51(3):685-701.


Review Date: 11/2/2009
Reviewed By: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.
A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2009 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.
MAIMONIDES
MEDICAL CENTER


Home Page
Why Choose Us
Donations
Website Terms of Use
PATIENT
INFORMATION


Visitor & Patient Info
Patient Portal
We Speak Your Language
Patient Privacy
Contact Us
KEY
INFORMATION


Find a Physician
Medical Services
Maimonides In the News
Directions & Parking
FOR HEALTH
PROFESSIONALS


Medical Education
Career Opportunities
Nurses & Physicians
Staff Intranet Access
Maimonides Medical Center    |    4802 Tenth Avenue    |    Brooklyn, NY 11219    |    718.283.6000    |