Neural tube defects in the Republic of Ireland in 2009-11

Neural tube defects (NTDs) are associated with deficient maternal folic acid peri-conceptionally. In Ireland, there is no mandatory folic acid food fortification, partly due to declining NTD rates in recent years. The aim of this study was to ascertain the incident rate of NTD during the period 2009-11 and describe epidemiologically NTD in Ireland. Cases were ascertained through multiple sources, including three regional congenital anomaly registers, all maternity hospitals nationally and paediatric hospitals providing care for children with spina bifida in the Republic of Ireland during the period 2009-11. From 225 998 total births, 236 NTDs were identified, giving an incidence of 1.04/1 000 births, increasing from 0.92/1 000 in 2009 to 1.17/1 000 in 2011. Of all cases, 45% (n = 106) had anencephaly, 49% (n = 115) had spina bifida and 6% (n = 15) had an encephalocoele; 78% (n = 184) were liveborn or stillborn and 22% (n = 52) were terminations abroad. Peri-conceptional folic acid supplement intake was 13.7% among the 52.5% (n = 124) of cases whose folic acid supplement intake was known. The incidence of NTDs in the Republic of Ireland appears to be increasing. Renewed public health interventions, including mandatory folic acid food fortification, must be considered to reduce the incidence of NTD.