Fact Sheets

In June 1996, the Little Foundation (the British counterpart of our country's UCP Research and Educational Foundation) sponsored a research workshop in London, England. Research findings on a variety of subjects relevant to cerebral palsy were presented and discussed. Among them were "hot issues" on the prevention of cerebral palsy. One of the discussants was Alan Leviton, MD, Director of Neuro-epidemiology at the Children's Hospital in Boston, and a research consultant to our Foundation. Dr. Leviton's overview was so useful we have translated it into non-technical terms to share with you.  
The following research activities were selected by Dr. Leviton from scientific literature published in 1995 and 1996 and presented at the research workshop:  
Infection 
The hypothesis that maternal infection contributes to the occurrence of cerebral palsy is one that is now receiving a great deal of attention. For infants born at term (around 9 months) and whose mothers had infections at admission to the hospital, there was a three fold increased risk of cerebral palsy when compared to mothers who did not have an infection. For infants born either prematurely or who had very low birth weight (3.3 lbs or less) and whose mothers had an infection at admission to the hospital, there was a 2.3 fold increase of risk of cerebral palsy when compared to mothers who did not have an infection. In other studies it has been demonstrated that 21% of the mothers whose infants developed a brain lesion associated with cerebral palsy, had a fever when admitted to the hospital for delivery; only 5% of mothers who did not have a fever delivered babies with similar brain lesions. Thus, evidence of maternal infection at the time of delivery is an important risk factor for the occurrence of cerebral palsy in the infant. The infection may or may not be producing clinical signs of illness in the mother.  
Another set of findings of potential importance: infection of the vagina or uterine cavity before the midpoint of pregnancy is predictive of premature labor and of increased risk of fetal brain damage. Thus, evidence of infection early in pregnancy is an important risk factor for both premature delivery and for fetal brain damage. Finally, how best to diagnose and treat the suspect infections?  
Fetal Distress 
Over one hundred years ago, the hypothesis was presented that problems in labor and delivery contribute to the occurrence of cerebral palsy. One aspect of this is the hypothesis that oxygen lack during and persisting after a uterine contraction not only damages the brain, but also results in persistent slowing of the fetal heart. These appear to be true. What remains unclear is the issue of cause and effect. Does the decrease in fetal heart rate increase the risk of cerebral palsy or are the increased risk of cerebral palsy and of decreased fetal heart rate both due to a common cause? However, if the decrease fetal heart rate is a risk factor for cerebral palsy and if accelerated delivery of the infant would eliminate this risk factor from having an effect, more than 9,000 infants would have to be delivered by cesarean section to prevent one case of cerebral palsy!  
Pregnancy Induced Hypertension 
Infants are usually born before the seventh month of pregnancy for one of three reasons: 1) premature labor (infection?) 2) premature rupture of the membranes; or 3) intervention to protect the mother because of pregnancy-induced hypertension (high blood pressure). Studies indicate that the presence of pregnancy-induced hypertension in the mother decreases the probability of cerebral palsy in infants born prematurely or with very low birth weight. Why? Does the treatment given to protect the mother also protect the infant's brain?  
Magnesium Sulfate 
Please refer to the Research Fact Sheet of February 1995. A retrospective study of records indicates that women who are given a common drug, magnesium sulfate, to suppress premature labor are less at risk of having an infant with cerebral palsy than those who did not get this drug. Does this drug protect the infant's brain during labor and delivery? Our Foundation is presently supporting a research project (clinical trial) to obtain the answer to this question.  
Low Blood Thyroid Level 
Please refer to the Research Fact Sheet of April 1996. The lower the age of the newborn infant, the lower its blood thyroid hormone level during the first week of postnatal life. There are several possible reasons for this and they are being studied. However, we now find that severe levels of thyroid hormone deficiency is associated with a four-fold increase in the risk of cerebral palsy in very low birth weight infants. Would the administration of thyroid hormone to these infants decrease the risk of cerebral palsy? What would be the danger of giving thyroid hormone to these infants? Our Foundation is presently exploring the development of a research project to answer these questions.  
Comment
Although not an exhaustive review of research in cerebral palsy, Dr. Leviton's excellent review has identified a number of the "areas of research excitement". He is planning to publish more details about these in a scientific journal during the next year. We are pleased to learn that our Foundation is already an active partner in these research areas. We will keep you informed as we learn more about the results of these studies.
 
© UCP Research & Educational Foundation, January 1997