Prevalence and pathogenesis of congenital anomalies in cerebral palsy

Background: It has been hypothesised that cerebral palsy (CP) and other congenital anomalies are attributable to feto-fetal transfusion problems in a monochorionic multiple gestation. Thus more than one organ could be compromised leading to the coexistence of two or more anomalies in a fetus. Such anomalies in a singleton birth may be attributable to early demise of the co-conceptus as a vanishing twin. Aim: To determine whether the coexistence of congenital anomalies and CP is greater than a chance finding by comparing the prevalence of congenital anomalies in children with CP with that in the general population of children. Methods: A population-based register of children with CP born in 1966-1991 in the counties of Merseyside and Cheshire, UK, comprised the index population. Coexisting congenital anomalies were recorded. For comparison the population prevalence of congenital anomalies was obtained from eight congenital malformation registers in the UK. Results: Children with CP were found to have highly significant increases in risk for microcephaly, isolated hydrocephaly, congenital anomalies of the eye, congenital cardiac anomalies, cleft lip and/or palate and congenital dislocation of the hips and talipes (p<0.001) and atresias of the oesophagus (p<0.001) and intestines (p<0.01). The relative risks ranged from 3.1 (95% Cl 1.9 to 4.8; p<0.001) for congenital malformations of the cardiac septa to 116.09 (95% Cl 84.0 to 162.3; p<0.001) for microcephaly. Conclusions: Congenital anomalies in children with CP are found much more frequently than expected by/chance. A common pathogenic mechanism may account for the coexistence of disparate congenital anomalies. A hypothesis is proposed for such a common pathogenic mechanism.