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Published on: January 11, 2016
Cerebral palsy in twins: a national study
P O D Pharoah1, T S Price, R Plomin
1Department of Public Health, University of Liverpool, Liverpool L69 3GB, UK. p.o.d.pharoah@liv.ac.uk
Insights
Like-sex twins face a higher risk of cerebral palsy (CP), especially if a co-twin dies. However, when both twins survive, the risk of CP is lower compared to cases where a co-twin death occurred.
Area of Science:
- Perinatology
- Neurology
- Epidemiology
Background:
- Cerebral palsy (CP) is more prevalent in twins than singletons.
- The risk of CP in a surviving twin significantly increases if the co-twin experiences fetal or infant death.
- Like-sex twin pairs are identified as having a particularly high risk for CP.
Purpose of the Study:
- To compare birthweight-specific cerebral palsy prevalence in like-sex versus unlike-sex twins when both survive infancy.
- To present a comprehensive view of CP prevalence based on co-twin survival status.
- To analyze CP risk factors in twin gestations.
Main Methods:
- Data collected from twins born in England and Wales (1994-1995).
- Parental questionnaires identified children with cerebral palsy, hemiplegia, diplegia, or quadriplegia.
- Birthweight-specific CP prevalence rates were calculated for like-sex and unlike-sex twins across various birthweight categories.
Main Results:
- Like-sex twins showed a higher risk of cerebral palsy than unlike-sex twins when both survived, though this difference was not statistically significant.
- The birthweight-specific prevalence of cerebral palsy was significantly lower when both twins survived infancy compared to situations where a co-twin had died.
- Analysis stratified by birthweight revealed specific risk patterns.
Conclusions:
- Like-sex twins face an elevated risk of cerebral palsy, particularly when a co-twin death occurs.
- While zygosity was not determined, monozygosity and monochorionicity are hypothesized as key factors for increased CP risk in like-sex twins.
- Early identification and management of risk factors in twin pregnancies are crucial for reducing CP incidence.
Background:
Cerebral palsy is more common in twins than singletons. Among twins, if one twin suffers a fetal death or dies in infancy, the prevalence of cerebral palsy in the surviving co-twin is considerably increased, and those from like-sex pairs are particularly at high risk.
Aim:
To compare birthweight specific cerebral palsy prevalence in like-sex and unlike-sex twins where both twins survive infancy and to provide a comparative and composite picture of cerebral palsy prevalence according to whether a co-twin died or where both twins survived.
Methods:
Parents of twins born in England and Wales in 1994 and 1995 completed a booklet with open ended questions asking whether their twins had any medical, physical, visual, genetic, or chromosomal problems. Any mention of cerebral palsy, hemiplegia, diplegia, or quadriplegia allowed the child to be included as a case of cerebral palsy. Birthweight specific prevalence rates of cerebral palsy were determined for like and unlike-sex twins in birthweight groups < 1000 g, 1000-1499 g, 1500-1999 g, 2000-2499 g, and > or = 2500 g.
Results:
When both twins survived infancy, like-sex were at greater risk of cerebral palsy than unlike-sex twins, but the difference was not statistically significant. If both twins survived infancy, the birthweight specific prevalence of cerebral palsy was significantly less than if the co-twin had died.
Conclusions:
Among the generality of twins, like-sex compared with unlike-sex twins are at greater risk of cerebral palsy particularly if one twin suffers a fetal or infant death. Although it is not possible to subdivide the twins according to zygosity, it is postulated that monozygosity and, specifically, monochorionicity may be the crucial feature that leads to the higher prevalence of cerebral impairment among like-sex twins.
