Table 1.
Prevalence of neural tube defects, pre, during and post folic acid fortification
| Years (period) | Neural tube defects prevalence (per 10,000 live births; CI 95 %) |
Prevalence ratio (pre-fortification referent) |
Decrease relative to pre-fortification prevalence (%) |
Year published, type of fortified staples and amounts published in the official Costa Rican newsletter |
|---|---|---|---|---|
| 1987–1991; 1996–1998 (pre- fortification)* |
9.8 (9.1–10.5) |
NA | NA | 1997 (October): wheat flour (1.5 mg/kg)† |
| 1999–2002 (fortification implementation) |
6.3a (5.4–7.2) |
0.65 | 35 % | 1999: corn flour (1.3 mg/kg) 2001: dairy products (40 μg/250 ml) 2002: wheat flour (1.8 mg/kg) 2002: rice (1.8 mg/kg) |
| 2003–2012 (post- fortification) |
4.8a, b (4.3–5.3) |
0.49 | 51 % | – |
Source: Registry Center for Congenital Anomalies (Centro de Registro de Enfermedades Congénitas—CREC)
NA not applicable
*
1992–1995 data were excluded from the analysis because there were only 8 hospitals participating in CREC
†
Although published in October 1997, the first infants under this mandate were not likely born until early 1999
a
Values were significantly (p < 0.05) different from baseline (pre-fortification period; 1987–1991; 1996–1998)
b
Values were significantly (p < 0.05) different from baseline (pre-fortification period; 1987–1991; 1996–1998) and during fortification (1999–2002)