Caudal regression syndrome type 1 with minimally invasive computed tomography and magnetic resonance imaging autopsy: a case report

Caudal regression syndrome is a rare complex congenital anomaly with reduced penetrance and phenotypic variability characterized by osseous defects of the caudal spine, lower limb anomalies, and accompanying genitourinary, gastrointestinal/anorectal, and cardiac system soft tissue defects. We report a rare presentation of type 1 caudal regression syndrome in a pregnant woman with preexisting diabetes, in which early recognition of severe fetal anomalies on routine antenatal ultrasound facilitated confirmation with fetal magnetic resonance imaging to characterize extent of disease and prognosticate fetal outcome.

This case of type 1 caudal regression syndrome in the setting of maternal pregestational diabetes mellitus resulted in stillbirth. The mother was a 29-year-old Caucasian primigravida female with past medical history of poorly controlled type 2 diabetes managed with metformin prior to pregnancy, prompting admission for glucose management and initiation of insulin at 13 weeks. Baseline hemoglobin A1c was high at 8.0%. Fetal ultrasound at 22 weeks was notable for severe sacral agenesis, bilateral renal pelvis dilatation, single umbilical artery, and pulmonary hypoplasia. Fetal magnetic resonance imaging at 29 weeks showed absent lower two-thirds of the spine with corresponding spinal cord abnormality compatible with type 1 caudal regression syndrome. The mother delivered a male stillborn at 39 and 3/7 weeks. Minimally invasive postmortem magnetic resonance imaging and computed tomography autopsy were performed to confirm clinical findings when family declined conventional autopsy. Etiology of sacral agenesis was attributed to poorly controlled maternal diabetes early in gestation.

Maternal preexisting diabetes is a known risk factor for development of congenital malformations. This rare case of type 1 caudal regression syndrome in a mother with preexisting diabetes with elevated hemoglobin A1c highlights the importance of preconception glycemic control in diabetic women and the utility of fetal magnetic resonance imaging for confirmation of ultrasound findings to permit accurate prognostication. Additionally, minimally invasive postmortem magnetic resonance imaging and computed tomography autopsy can facilitate diagnostic confirmation of clinical findings in perinatal death due to complex congenital anomalies while limiting the emotional burden on bereaved family members who decline conventional autopsy.