P2.C047: From Infancy to Adulthood: Understanding Long-Term Survival and Mortality Risks in Spina Bifida

Background: Spina bifida (SB) is caused by an incomplete closure of the neural plate and often results in multiple medical issues. Long-term survival and causes of death in individuals with Spina bifida (SB) remain inadequately explored. This study examines mortality rates, causes, and risk factors of death in SB, with the aim to enhance understanding and develop better proactive and preventive care.

Methods: Several Swedish population-based registries were used to identify individuals with spina bifida, and The Causes of Death Register provided information on causes of death. Diagnosis was according to the International Classification of Disease (ICD) from ICD‐10 (from 1997), ICD‐9 (from 1987), and ICD-8 (from 1973). When evaluating risk factors for death, hydrocephalus was considered to have been present from birth regardless of when in life the diagnosis was registered. Chronic kidney disease and scoliosis were considered a risk factor from the time of diagnosis.

Results: 1735 individuals with SB were identified between 1973 and 2021. The prevalence of SB declined from 5.2 to 1.2 per 10,000 births over almost 50 years. Mortality rates during the first year of life notably decreased, with survival rates improving from 75% in the 1970s to 94% in the 2000s. Minimal differences in mortality rates were observed between decades for individuals aged 2 to 18 years and adults. Childhood deaths were linked to congenital abnormalities, hydrocephalus, and infections, with similar causes observed in different ages, but more common in early childhood (figure 1). In adults, previously mentioned causes were observed, but injuries and intoxications with suicidal or unclear intent were also identified, significantly more common than in the general population. Bladder malignancies were more frequent in SB individuals, but we found no increased mortality in individuals who had undergone reconstructive bladder surgery (table 1). Hydrocephalus posed the highest mortality risk for SB individuals, increasing the risk by over six times. Infants classified as small for gestational age or born prematurely faced elevated mortality risks, particularly those classified as SGA, with a 2.5 times higher risk. Congenital heart anomalies and chromosomal anomalies/syndromes were also identified as risk factors in both univariable and multivariable analyses. Additionally, kidney failure was identified as a mortality risk factor in single-variable regression analysis.

Conclusion: Prevalence of SB decreased over time. Survival rates in the first year of life increased whereas there was no difference in survival rate between adults born in the 1970s, 80s, and 90s. Hydrocephalus was the most important risk factor for death, and other congenital anomalies and renal failure were also identified as factors with increased risk. For adults, proactive prevention methods regarding injury/intoxication and bladder cancer are warranted.