Trisomy 18: review of the clinical, etiologic, prognostic, and ethical aspects.

OBJECTIVE: To review the clinical, etiological, diagnostic, and prognostic characteristics of trisomy 18 (Edwards syndrome). DATA SOURCES: Scientific articles in the MedLine, Lilacs, and SciELO databases were searched using the descriptors 'trisomy 18' and 'Edwards syndrome'. The research was not limited to a specific time period and included all articles in such databases. DATA SYNTHESIS: Edwards syndrome is a disease characterized by a broad clinical picture and a very reserved prognosis. There are descriptions of more than 130 different anomalies, which can involve virtually all organs and systems. Its findings are the result of the presence of three copies of chromosome 18. The main chromosomal constitution observed among these patients is a free trisomy of chromosome 18, which is associated with the phenomenon of nondisjunction, especially in maternal gametogenesis. Most fetuses with Edwards syndrome die during the embryonic and fetal life. The median of survival among live births has usually varied between 2.5 and 14.5 days.
CONCLUSIONS: Knowledge on the clinical picture and on the prognosis of Edwards syndrome patients is of great importance regarding the neonatal care and the decisions about invasive treatments. The speed to have a confirmed diagnosis is important for making decisions about medical procedures. Often, interventions are performed under emergency conditions, without many opportunities for discussion, and they involve difficult medical and ethical issues.