Neonatal caudal regression syndrome: Devil lies in details

Dear Editor,

A late preterm (36 wk), low birth weight, small for dates, female neonate was born to a multigravida mother in her 30s by lower segment cesarean section due to overt diabetes and gestational hypertension. Mother was diabetic for 8 years with poor glycemic control (HbA1C 7%), i.e., class B according to modified white classification, requiring subcutaneous insulin twice daily but had poor compliance to treatment. She was diagnosed with gestational hypertension during her antenatal period, which was controlled with two oral antihypertensives. An antenatal anomaly scan done at 20 weeks was unremarkable. Placental histopathology showed chorangiosis, a marker of hypoxia. The baby cried immediately after birth and did not require resuscitation.

On clinical examination, the baby had short lower limbs with contractures at the knees and bilateral club foot (Fig. 1). Spine examination revealed prominent vertebrae at the lumbar region (Fig. 2a), bilateral gluteal dimples, and wasting of gluteal muscles (Fig. 2b). External genitalia was normal. Anal canal was patent. Radiographic examination revealed complete absence of sacrum and coccyx (Fig. 3a), both iliac wings are fused (iliac amphiarthosis) (Fig. 3b). These radiographic findings were suggestive of type 4 of caudal regression syndrome according to Renshaw's classification.¹ She was passing stools and urine normally. She had euglycemic records and normal hematocrit on monitoring. She was on room air with no respiratory distress and maintaining saturation above 85% and was hemodynamically stable.

Fig. 1.

Neonate with bilateral short lower limbs with contractures at the knees (extended knees).

Fig. 2.

a: Prominent lumbar vertebrae on spine examination (black arrow). b: Bilateral gluteal dimples with gluteal muscle wasting (black arrow).

Fig. 3.

a. X-ray lateral view of spine showing complete absence of sacrum and coccyx. Both ilia fused to lumbar vertebrae (indicated as white arrow). b. X-ray showing features of type IV caudal regression syndrome (complete absence of sacrum and coccyx and iliac amphiarthrosis) (indicated as white arrow).

As caudal regression syndrome is generally associated with other systemic anomalies, the neonate was investigated accordingly. USG kidney, ureter, and bladder were within normal limit. 2D ECHO done revealed complex cyanotic congenital heart disease, i.e., single ventricle, common atrioventricular valve, D malposed great arteries with restricted PDA, with 6 mm aortopulmonary window, mild atrioventricular valve regurgitation, mild pulmonary valve regurgitation, normal aortic valve, and good ventricular function.

Since the facility for definitive corrective surgery for complex cyanotic heart disease is not available at present in our hospital, parents were updated regarding the same. They were also counseled about over all prognosis and the need for multidisciplinary treatment for caudal regression syndrome as well as complex congenital heart disease after which they opted for palliative care. The neonate was finally discharged on day 4 of life. Parent/ guardian consent was obtained for use of images.

Pregestational diabetes associated with poor periconceptional glycemic control is associated with an increased risk of congenital malformations, correlating with the HbA1c values in the first trimester. Women with HbA1c ≥ 7.5% had a ninefold increased risk of congenital malformations.² Antenatal detection of anomalies requires ultrasound evaluation. Antenatal detection rates depend on multiple factors such as type of malformation, expertise of the sonographer, gestational age, and patient factors such as obesity. A systematic review by Karim et al. first-trimester scan at 11–14 weeks to detect cardiac anomalies had a sensitivity of 67.74%, a specificity of 99.75% in high risk population, and detection rate was improved when outflow tract visualization and/or color flow doppler imaging were added to four-chamber view assessment^3.

Caudal regression syndrome (CRS) is a rare congenital anomaly with an incidence of 0.1–0.25 per 10,000 pregnancies.⁴ The true pathogenesis is unclear, but the etiology is attributed to maternal diabetes, vascular steal theory due to persistent vitelline artery and genetic predisposition. CRS occurs in up to 1% of pregnancies in diabetic women but up to 22% of CRS are associated with maternal diabetes as numerous factors such as hyperglycemia, hypoxia, hyperketonaemia, amino acid abnormalities, and glycosylation of proteins are potential teratogens.⁵ CRS presents with varied physical features and is associated with anomalies of multiple organ systems such as musculoskeletal, genitourinary, gastrointestinal, central nervous and cardiovascular systems.⁶ As the primary pathology is irreversible, the treatment is only supportive and multidisciplinary management. Each associated anomalies is treated based on their own merits. Defects that need special attention are orthopedic problems, urinary and bladder incontinence and preservation of renal function to achieve as much normalcy as possible. For neurogenic bladder, clean intermittent catheterization and/or anticholinergic drug administrations are required to treat urological problems. To improve the quality of life and urinary incontinence and preserve renal function interventions such as vesicoureteral reimplantation, cystostomy is needed. Orthopedic management depends on the type of CRS. Infants with type III and IV defects should be closely observed for progressive kyphosis and spinopelvic instability. Associated hip flexion contractures are managed by physiotherapy and stretching; however, surgical correction is needed in severe cases. Knee contractures may be managed conservatively or by bracing, disarticulation, surgical release or osteotomy/ amputation depending on the severity and functional impairment.⁷ The prognosis depends on the severity of CRS and associated anomalies. The case highlighted the need for strict glycemic control in periconceptional period for preventing such congenital malformation in neonates.

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Patients informed consent was obtained.

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Disclosure of competing interest

The authors have none to declare.