Even minor oxygen deprivation at birth can harm later cognitive function


January 22, 2003
Blog Entry, Brain & Behavior, Health

Birth is a time of peril for the human brain, especially in pre-term infants. For vulnerable “preemies,” biochemical signs of reduced blood oxygen levels (hypoxia) soon after birth are associated with lower IQs and language skills. In 2001, premature babies were 12 percent of U.S. births – the highest level in 20 years, due in part to more multiple pregnancies, induced labor, and older mothers. The January issue of Neuropsychology, published by the American Psychological Association (APA) reports on links among pre-term birth, risk for birth hypoxia and cognitive problems, and reveals how the risk threshold for brain damage in preterm babies could be lower than thought. From the American Psychological Association:EVEN MINOR RISK OF OXYGEN DEPRIVATION AT OR IMMEDIATELY AFTER BIRTH MAY PLACE PREMATURE BABIES AT GREATER RISK FOR COGNITIVE AND LANGUAGE PROBLEMS, PROPORTIONATE TO THE DEGREE OF “HYPOXIA”

WASHINGTON – Birth is a time of peril for the human brain, especially in pre-term infants. For vulnerable “preemies,” biochemical signs of reduced blood oxygen levels (hypoxia) soon after birth are associated with lower IQs and language skills. In 2001, premature babies were 12 percent of U.S. births – the highest level in 20 years, due in part to more multiple pregnancies, induced labor, and older mothers. The January issue of Neuropsychology, published by the American Psychological Association (APA) reports on links among pre-term birth, risk for birth hypoxia and cognitive problems, and reveals how the risk threshold for brain damage in preterm babies could be lower than thought.

Psychologists compared the intellectual and language development of five- and six- year olds, all of whom had been born prematurely. Half the group were, during or immediately following birth, at slight to moderate risk for hypoxia. The other half had no such risk, although they resembled the risk group on other early risk factors and on socio-demographic characteristics. Despite the relatively small difference between the groups in the degree of risk, the authors report that the two groups “diverged significantly” in their development.

The relationship between mild to moderate birth hypoxia and later cognitive abilities contradicts established wisdom that regards severe oxygen deprivation as the threshold for brain damage in an “all or nothing” manner. The findings add to other recent evidence of a continuum of brain injury due to asphyxia around birth.

The researchers, at Wayne State University, The University of Memphis, and Baptist Memorial Hospital in Memphis, studied 52 children. All had been born at or before 36 weeks (normal term is about 40 weeks). Twenty six of the children were at slight to moderate risk of perinatal hypoxia, as measured by higher blood acidity within two hours of birth (lower than normal arterial blood pH). The other 26 children in the comparison group were at lower perinatal risk.

Co-authors Tracy Hopkins-Golightly, Ph.D., Sarah Raz, Ph.D., and Craig J. Sander, M.D. tested all 52 children at an average age of six on intelligence and language (receptive and expressive) skills.

There was a significant relationship between blood pH soon after birth and later cognitive and language skills. For example, the pre-term group, with mild to moderate acidosis, scored about 10 to 11 points lower on verbal and visuospatial tests than the low-risk pre-term group – a large discrepancy. Such data, say the authors, reveal that even a minor risk for hypoxia around birth may have a “discernible influence on the course of cognitive development.”

Says Raz, now at Wayne State University in Detroit, “most neonatologists would probably not expect to find a statistically significant relationship between degree of acidosis measured soon after birth and performance on cognitive tests in preschool and early school-age children, when acidosis is only mild to moderate, at worst”.

Although it is well-known that premature babies tend to have more cognitive problems than full-term infants, scientists want to tease out the specific complications — from a host of many – that cause the most trouble. A good way to do that is to compare two groups of preterm infants, who share the risks of pregnancy, delivery and the vulnerable postnatal period, but who differ in terms of one single, special risk factor (such as birth hypoxia).

Structural or functional imaging, such as MRI, may shed light on which brain areas are the most vulnerable to damage by hypoxia in the preterm infant. For now the authors speculate that, in babies born prematurely, even minor risk may be associated with damage to the periventricular white matter, deep inside the brain.

By linking birth complications to specific cognitive problems occurring later, scientists hope to understand the brain’s vulnerability to insult during early human development. Furthermore, knowledge of how early risk factors affect cognitive abilities may help doctors to evaluate the effectiveness of medical interventions that support preterm infants during and after birth.

Article: “Influence of Slight to Moderate Risk for Birth Hypoxia on Acquisition of Cognitive and Language Function in the Preterm Infant: A Cross-Sectional Comparison With Pre-Term Birth Controls,” Tracy Hopkins-Golightly, Ph.D., University of Memphis; Sarah Raz, Ph.D. University of Memphis and Wayne State University; and Craig J. Sander, M.D., Baptist Memorial Hospital; Neuropsychology, Vol. 17, No. 1.

Full text of the article is available from the APA Public Affairs Office or at http://www.apa.org/releases/oxygen_deprivation.pdf

Sarah Raz can be reached at the Merrill-Palmer Institute, Wayne State University, by email or by phone at (313) 872-1790.




Even minor oxygen deprivation at birth can harm later cognitive function

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6 Responses to Even minor oxygen deprivation at birth can harm later cognitive function

  1. Tammy M. October 28, 2012 at 12:10 pm #

    My daughter was 3 mnths old when she stopped breathing. She was rushed to the hospital and was sedated for a MRI. I was informed that being that young they usually dont do that with the risk of the babies could stop breathing. My daughter stopped breathing during the MRI and CPR had to be done. My daughter has recently been diagnosed with Dyslexia. Could this Dyslexia be caused from the sedation? There is no family history, or any type of brain injuries that could also trigger this. I am very concerned and upset. Any advise would be wonderful. Thank you

  2. Pam March 11, 2012 at 4:04 pm #

    Try DIR Floortime – Stanley Greenspan

  3. michelle January 21, 2012 at 3:29 pm #

    i just happened to stumble upon your post when i was looking up some things about my sons symptoms. i am glad i can help feel free to jot down my email address and write to me direct if you like hun,i am strapped for cash and cannot afford to call you or i would have. My son does take ativan only now, but only AS NEEDED when his anxiety and panic attacks get to much for him. he has had lots of EEGs and MRIs the MRI just showed a line acrossed one side of his brain, the doc he is seeing now just ordered another EEG and it show mental delay, which is already known. HE IS MY ANGEL! still lives with me and most likely always will. :)
    Try not to push your daughter to hard to do things as other children do, when i have triedto push my son to get a job and other daily chores he gets very depressed and and feels inadequate. best thing is just accept them as they are and know you will always have a child :) no matter how old they get. he stilldoes some daily hores buti dont push him too much.
    your welcome hun and good luck
    michelle

  4. michelle December 3, 2011 at 12:16 am #

    i have a son who also has the same problems, feel free to write to me if i can help in anyway! He is now 24 and doing pretty well, he was premature,had oxygen deprivationand , and had seizures until he was a year old , has had learning disabilities all his life, was in special Ed al through school, very fearful, The pshycologists have told me i have done a wonderful job with him, because most children dont turn out as well as he has, His biggest problems now, are Anxiety and panic attacks, fear of getting hurt ( fearful),still clings to me like a child,Lazy eyes,his vision is still a little poor and requires glasses. Unfortunately his friends grow up but he doesnt, they fade away.
    give your daughter lots of support, love and acceptance, is the best advice i can give you without knowing more details. Have her diagnosed by a phsycologist, now dont wait till she is older like i did. but if you can keep her off medicine do so,i would rather deal with the behavior problems than medicate them,they are better off for it.feel free to email me at m.huffman48@hotmail.com

  5. Hi there. I have a daughter that is now 13 years old . She was born at 24 weeks. She is struggeling alot in school as well as socialy. She has had 2 EEG that showed some problems as well as an MRI that also showed problems . There is a discrepancy between November 30, 2010 at 7:11 pm #

    My daughter has some serious problems and I think alot are related to her premature birth. She was born at 24 weeks and suffers from alot. I have alot of tests and drs. Info I would like to see if anyone there may have some advice or help to offer us as we seem to be at an idol in helping her . Please contact me if you can help thanks …………..Melissa Eveleigh …(519)305-5238

  6. Hi there. I have a daughter that is now 13 years old . She was born at 24 weeks. She is struggeling alot in school as well as socialy. She has had 2 EEG that showed some problems as well as an MRI that also showed problems . There is a discrepancy between November 30, 2010 at 7:05 pm #

    My comment is above……

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