In a national follow-up study of twin births, monozygous compared with dizy
gous twins were at significantly increased for both to die in utero, one to
die in utero and the co-twin to die in infancy, or both to be livebirths b
ut both die in infancy, The prevalence of cerebral palsy among survivors of
a co-twin fetal death was 80.2 and other cerebral impairment was 107.0 per
1000. Many apparently singleton cases of cerebral palsy and impairment may
be due to fetal death of a twin that has: not been recognized or has been
recognized but not registered.