Defining the high-risk nature of triplet pregnancies.

Triplet pregnancies are by nature rare. Assisted reproductive technologies have multiplied their rate of occurrence in the last two decades. Whether spontaneous or induced, triplet pregnancies present obstetric and neonatal-and then often lifelong-medical problems severalfold more often than singletons, or even twins. The major cause of problems for triplet gestations stems from preterm delivery and low birth weight.