Perinatal outcome and long-term hospitalization of triplets according to birth order.

Purpose: The association between birth order and adverse perinatal outcomes has been well studied in twin pregnancies. However, little is known about the differences in immediate perinatal outcomes as well as long-term hospitalization of the offspring in triplet pregnancies according to their birth order. As such, we aimed to assess the differences in immediate perinatal outcomes and long-term hospitalizations among triplets by their birth order.