Prevalence rates of spina bifida in Alberta, Canada: 2001-2015. Can we achieve more prevention?

Background: Despite a substantial prevention of neural tube defects with mandatory folic acid (FA) fortification, a significant number of cases still exist in Alberta, Canada, particularly spina bifida (SB). The purpose of this study was to review cases with SB to provide a possible explanation as to why SB is still prevalent in Alberta.

Methods: Cases with SB born between 2001 and 2015, ascertained by the Alberta Congenital Anomalies Surveillance System, were reviewed. Cases were classified as lipomeningomyelocele, syndrome/recognized condition, chromosome, associated multiple congenital anomalies, and isolated. The notice of birth forms were reviewed to determine FA supplement use before and/or during pregnancy. Socioeconomic status (SES) was also examined.

Results: The majority of cases were isolated (58%). The total prevalence of SB for 2001-2015 was 0.37/1,000 births, with isolated SB being 0.21/1,000 births. Urinary and congenital heart defects were the most frequently identified associated anomalies. FA supplementation could not be determined for 69% of our cases because of a lack of completeness of the notice of birth forms. There was no significant difference regarding SES between mothers of cases and all mothers in Alberta.

Conclusions: It is important to examine cases with isolated SB to determine why mandatory FA fortification has not completely prevented SB and to identify which cases are not folate-responsive. A more concerted effort of public health education and promotion with the identification of women with suboptimal folate status and a better understanding of the role of other micronutrients is necessary.