P3.220: Caudal Regression Syndrome Undiagnosed by Prenatal Ultrasound

Introduction: Caudal Regression Syndrome (CRS) is a rare congenital anomaly affecting the growth and development of the distal spine and lower extremities, initially diagnosed primarily via prenatal anatomy ultrasound. We present a case in which a neonate was not diagnosed with CRS until after delivery, upon observation of hypoplastic lower extremities and bilateral club feet prompting further workup.

Case Description: A neonate was born via c-section with bilateral club feet and hypoplastic lower extremities. At 34 weeks gestation, prenatal ultrasound reported possible bilateral club feet, but did not indicate sacral agenesis. Upon physical exam, the neonate had resistance to hip extension making the Barlow/Ortolani maneuver difficult, left inverted club foot, right everted club foot, well-perfused hypoplastic lower extremities, good symmetric tone and strength, no gluteal fold, and spinal column appearing short with hypoplastic coccyx and hip dysplasia. Renal ultrasound was unremarkable, spinal cord ultrasound showed absent sacrum and otherwise unremarkable spinal cord. Pelvic x-ray confirmed an absent sacrum with 5 lumbar type vertebrae and intact pelvis. Echocardiogram revealed a small to moderate patent foramen ovale with left to right shunt, with normal biventricular size and function. Further referrals were made to manage conditions surrounding the neonate’s CRS diagnosis, including physical therapy for improving hip range of motion, pediatric urology to manage development of neurogenic bladder, pediatric gastroenterology to manage development of neurogenic bowel, genetics to identify potential underlying mutations, pediatric neurosurgery to evaluate for potential surgical intervention due to neurologic impairment, and pediatric orthopedics for casting of bilateral club feet and sacral reconstruction to improve mobility and quality of life.

Discussion: Prenatal anatomy ultrasounds have greatly assisted in the early diagnosis, preparation, and treatment of neonates born with congenital anatomic anomalies. However, there are limitations to these studies and unavoidable factors that influence visibility of the fetus. This case study emphasizes the importance of a thorough neonatal physical exam despite sufficient prenatal health care.

Conclusion: Neonates born with Caudal Regression Syndrome present with varying severity, the worst of which can be life threatening due to cardiac, digestive, and/or renal complications. It is crucial to diagnose these patients in a timely manner to provide care and improve the quality, and longevity, of life for these neonates.