Symmetrical thalamic lesions (STL) is a rare condition that affects term newborns who have suffered an antenatal hypoxic insult and present at birth with specific clinical features: feeding and swallowing difficulties, facial hypomimia, apnea, and frequently hypertonia. Recently STL have also been described in preterm infants.

We describe the first case series of STL in preterm triplets with a variable spectrum of clinical outcomes, following a clearly identified perinatal anoxic insult. Spontaneous male triplets, two monochorionic-diamniotic (T1 and T2) and one dichorionic-diamniotic (T3), were born at 31 1/7 gestational weeks by emergency Caesarean section due to maternal anaphylactic shock and presented with severe neonatal asphyxia.

The clinical presentation, neuroimaging studies, and autoptic findings of the two monochorionic twins are compatible with STL with a more severe neurological presentation of T1. The dichorionic triplet was completely unaffected. Genetic and metabolic studies excluded alternative etiologies.