Is a prenatal diagnosis detrimental to the survival of a fetus with trisomy 18?

Abstract

As trisomy 18 is so rare any individual study is unlikely to have a sufficient number of cases to examine whether a prenatal diagnosis is advantageous or detrimental to the survival of these infants. Estimates of survival in prenatally diagnosed live births have been obtained by combining data from individual hospitals, whereas estimates of survival in postnatally diagnosed live births have been obtained from large population studies linking cytogenetic registers to national mortality registers. The estimates of survival are often lower in the prenatally diagnosed series. However, comparing estimates from these two different sources is not valid; both sources are subject to different biases. At present, there is insufficient information available to indicate that receiving a prenatal diagnosis of trisomy 18 is detrimental to the survival of a foetus with trisomy 18. A prenatal diagnosis does enable the parents and clinicians time to reach a consensus on how best to care for the baby.