Cerebral palsy and multiple births in China

Background A population-based study on prevalence of cerebral palsy in mult iple births has not been carried out in China. The purpose of this paper wa s to determine the prevalence of cerebral palsy in multiple births and to e xplore the influence of multiple pregnancy on cerebral palsy after controll ing for birthweight. Methods A cross-sectional study of cerebral palsy was carried out among 388 192 children aged <7 years in seven cities of Jiangsu province in China. I nformation about birthweight and plurality was obtained from routine health care records. Pediatricians at city level diagnosed all cases. All the doc tors involved had taken part in a training programme held by Beijing Medica l University. Stratified analysis by birthweight and its standard normal de viate was employed to compare the prevalence of cerebral palsy in multiples and singletons. Results The prevalence of cerebral palsy for children aged <7 years in mult iples was 9.7 per 1000 children (95% confidence interval [CI]: 6.5-14.0), w hich was 6.5 times that in singletons (95% CI:4.4-9.3). The overall neonata l mortality rate was 60.9 per 1000 liveborn multiples, being highest (944.4 per 1000) in the 500-999 g birthweight groups. Most liveborn multiples wei ghing <1500 g at birth probably died from diseases related to very low birt hweight prior to this study. The prevalence of cerebral palsy in multiple b irths was likely to be higher than that reported in developed countries for children weighing 1500-2499 g even though our data were from a cross-secti onal study. When stratified by birthweight, the prevalence of cerebral Dais y in multiples weighing <2500 g had tended to be lower than that of singlet ons in the same birthweight group. In contrast, in normal birthweight categ ories multiple births had a higher prevalence of cerebral palsy than single tons. When stratified by birthweight normal deviate, the prevalence of cere bral palsy in multiple births was uniformly higher than that in singletons in all birthweight strata and the prevalence of cerebral palsy among multip les appeared to be augmented as birthweight increased. Conclusion The prevalence of cerebral palsy in multiples, 9.7 per 1000 chil dren, is 6.5 times that in singletons. Survival of low birthweight infants is lower in China than in developed countries and survival quality of Chine se children weighing 1500-2499 g needs to be further improved. In terms of birthweight multiples and singletons may be heterogeneous. It might be diff icult to directly use actual birthweight specific prevalence to compare the prevalence of cerebral palsy in multiples and singletons. Birthweight norm al deviate specific prevalence of cerebral palsy suggests that multiple pre gnancy is an independent risk factor for cerebral palsy in all birthweight groups. Multiples are in adverse circumstances very early in gestation and as the foetus matures the risk of cerebral palsy increases.