Pre-eclampsia exposure linked to cerebral palsy in preterm, low birthweight infants
Preterm and small babies exposed to pre-eclampsia have an increased risk of cerebral palsy, according to a Norwegian study.
Researchers searched through the Cerebral Palsy Registry of Norway and the Medical Birth Registry of Norway for singleton births from 1996 to 2006. They included the records of 849 children with cerebral palsy, aged at least four years and compared data on pre-eclampsia in the mothers of 616,658 other children .
The team compared rates of pre-eclampsia between groups according to whether babies born at term (≥37 weeks), moderate preterm (32–36 weeks) or very preterm (under 31 weeks). Rates of cerebral palsy were adjusted for mother’s age at delivery, infant sex, birth weight and IVF.
The effect of pre-eclampsia varied with the duration of the pregnancy and birth weight. Overall, children exposed to pre-eclampsia had a 2.5 times greater risk of cerebral palsy when compared with unexposed children. However, whereas children born at term and not small for gestational age who were exposed to pre-eclampsia had no increased risk of cerebral palsy, those born at term and small for gestational age who were exposed had a significant 3.2-fold increased risk of cerebral palsy.
Very preterm children exposed to pre-eclampsia had a 50% reduced risk of cerebral palsy compared with those not exposed and a similar, albeit non-significantly reduced risk, even if they were born small for gestational age.
However, in a model adjusting for small for gestational age status, children born at term and exposed to pre-eclampsia did not have an excess risk for cerebral palsy, whereas children born moderately preterm had a nearly fivefold excess risk, and children born very preterm and exposed to pre-eclampsia had a twenty-fold increased risk of cerebral palsy.
What this means for GPs?
According to the authors, this is the first study to report that the association between exposure to pre-eclampsia and cerebral palsy may be mediated by being small at birth.
They concluded: ‘Among term born children exposed to pre-eclampsia only those born small for gestational age had an excess risk of pre-eclampsia. Pre-eclampsia was not associated with specific subtypes of cerebral palsy.’