Journal of Ultrasound in Medicine, Vol 12, Issue 6 323-330, Copyright © 1993 by American Institute of Ultrasound in Medicine
Caudal regression versus sirenomelia: sonographic clues
D. Twickler, N. Budorick, D. Pretorius, M. Grafe and G. Currarino
Department of Radiology, University of Texas Southwestern Medical School, Dallas 75235-7786.
Seven cases with the pathologic/autopsy diagnosis of caudal regression or
sirenomelia in which antenatal sonography had been performed were reviewed.
The three patients with caudal regression had similar findings on antenatal
sonogram, including normal or increased amniotic fluid, mild dilation or
normal urinary systems, nonfused extremities, and sacral agenesis. In the
four patients with sirenomelia, common sonographic findings included marked
oligohydramnios, suspected renal agenesis, and sacral agenesis. A history
of maternal diabetes was elicited in all patients with caudal regression
and in none of the patients with sirenomelia. Findings confirm recent
articles in pediatric pathology suggesting that caudal regression is a
separate entity, distinct from sirenomelia.