NATURAL-HISTORY OF TRISOMY-18

It has been suggested that survival in babies with trisomy 18 may be b etter than previously recognised, and that cardiac surgery may be just ified. A population based study spanning seven years in one English he alth region is presented. The fetal prevalence at 18 weeks was 1 in 42 74 and birth prevalence 1 in 8333 live births, Trisomy 18 was detected antenatally in 43% of cases, but almost 90% of those born without a d iagnosis were known to be growth retarded in utero. More than 50% of l iveborn infants were delivered by caesarean section. The median surviv al of those born alive was 3 days with no babies living longer than on e year. Cardiac malformations were not universal but were present in m ore than 87% of those for whom there were data. However, in only three cases were cardiac problems implicated in the death of the infants. C ardiac surgery is not likely to improve the survival of infants with t risomy 18 and at present cannot be justified. The most common mode of death was central apnoea.