1. The excess of cases of asymmetric cerebral palsy in twins in this sample is of interest but numbers are too small to permit meaningful statistical comparisons. The population attributable risk per cent quantifies the burden of cerebral palsy due to twinning in NETRHA. RICHS data for 1990 show an increased proportion of twin survivors compared with 1980-86 data. If the risk of cerebral palsy in twins and singletons is the same in 1990 as calculated for 1980-86, the increased proportion of twins would have increased the PAR% from 8.5% to 9.1%
2. Cerebral palsy in twins;Alberman, E.;Guys'Hospital Reports,1964
3. The epidemiology of neonatal death in twins;McCarthy, B.J.; Sachs, B.P.; Layde, P.M.; Burton, A.; Terry, J.S.; Rochat, R.;AmJ Obstet Gynecol,1981
4. Morbidity and mortality factors in twins;Ghai, V.; Vidyasagar, D.;Clin Perinatol,1988
5. Twins, triplets, and cerebral palsy in births in Western Australia in the 1980s;Petterson, B.; Nelson, K.B.; Watson, L.; Stanley, F.;BMJ,1993