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

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.

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.

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.

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.