Sonographic Antenatal Diagnosis of Acardia Acephalus

Abstract

DOI: http://dx.doi.org/10.5915/15-3-12411

The sonographic criteria for prenatal diagnosis of Acardia Acephalus are presented. These criteria are readily identifiable and should lead to the diagnosis of Acardia Aoephalus in every case.

Two cases of Acardia Acephalus are presented. One case was diagnosed prenatally by compound and real-time sonography. The criteria for prenatal diagnosis is discussed as well as a review of the current literature of acardia. The presence of twins, which continue to grow despite the lack of fetal heart motion in one of the twins, is a readily identifiable pathognomonic sonographic finding for this syndrome.

Acardia Acephalus is a rare condition which occurs only in monozygotic twins or triplet pregnancies. Its incidence has been reported as approximately one in 35,000 deliveries or less than 1 % of all identical twin pregnancies. The abnormal twin lacks all cephalic structures and lacks many of the normal thoracic and upper extremity structures. The etiology is unknown, but other investigators have reported chromosomal abnormalities as a possible cause.' In order for the acardiatic twin to survive, a twin-to-twin transfusion syndrome must be present.

Numerous studies have had retrospective diagnoses of the acardia syndrome, however, we report a case of prenatal diagnosis by ultrasound scanning. Also included in this report is a previous case of acardia with retrospective sonographic findings at our institution five years ago. These findings are characteristic and should be recognized sonographically.