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

Summary 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. Cor triatriatum dexter has been diagnosed incidentally in adults and children by echocardiography, surgery, or autopsy but has not previously been published in fetuses, apart from a report of two early-2nd-trimester fetuses aborted as a result of associated severe nuchal edema. To our knowledge, this is the first report of an isolated fetal cor triatriatum dexter that was diagnosed during ultrasound screening at 22 weeks of gestation.