Updates in Trisomy 18

Aneuploidies represent some of the most common genetic abnormalities within the pediatric population. Among them, trisomies 13, 18, and 21 constitute the most prevalent syndromes. Unlike trisomy 21, trisomies 13 and 18 have historically been regarded as having significant morbidity and mortality leading to being labeled "lethal" conditions. However, within the last few decades there is a growing body of evidence that the long-term outcomes of newborns specifically affected by trisomy 18 are exceeding these preconceived, historical notions. This shift results from increased postnatal intervention due to shared decision-making with families and medical teams. This review summarizes the clinical manifestations of trisomy 18 syndrome but also explores the updated long-term outcomes and subsequent guidance for future medical surveillance in a population of newborns previously expected to die before their first birthday.