An isolated fetal cor triatriatum dexter during a targeted anatomic survey at 22 weeks' gestation.

Objective: Cor triatriatum dexter is a rare cardiac malformation characterized by division of the right atrium into two compartments by a usually fenestrated membrane, whose degree of partitioning or septation is responsible for different clinical manifestations.

Methods: We report the first case of an isolated fetal cor triatriatum dexter that was diagnosed during ultrasound screening at 22 weeks of gestation.

Results: The sonographic examination of the fetal cardiac morphology revealed the presence of a membrane stretched between the medial and lateral walls of right atrium in the apical four-chamber view. Fetal morphology and biometric features were normal and appropriate for gestational age.

Conclusion: This is the first report of an isolated fetal cor triatriatum dexter that was diagnosed during ultrasound screening at 22 weeks of gestation.