Conjoined Twins in a Spontaneous Monochorionic Triplet Pregnancy

To the Editor: Monochorionic triplet pregnancies are very rare, accounting for 3.5–4.0% of all triplet gestations and occurring in 0.001–0.004% of all deliveries.[1] They are associated with higher risks of perinatal morbidity and mortality. Conjoined twins are a unique and rare complication of monochorionic pregnancies and occur when two identical individuals are fused through parts of their anatomy; this rare event occurs with an incidence of one in 100,000–200,000 live births.[2] Although the presence of conjoined twins in a monochorionic triplet is exceptionally rare, it poses great challenges regarding both obstetric counseling and management.