Autosomal trisomy syndromes: a detailed study of 27 cases of Edwards' syndrome and 27 cases of Patau's syndrome.

Maternal Age.In Edwards' syndrome and Patau's syndrome maternal age is raised, and birth order is inevitably correlated with maternal age, but there are not sufficient data to separate the effects of these two factors.Maternal and paternal ages are inevitably corre- lated.Survival.Very few infants with these two con- ditions survive the first six months of life.Survival, is related to the severity of the congenital malforma- tions and, to some extent, to the availability of paediatric care.Season of Birth.This series indicates an ex- 228