Table 1.

Birth prevalence of gastroschisis per 10 000 newborn infants (with 95% confidence intervals) in two age groups in Spain between 1980 and 2004

Maternal age	1980-5	1986-99	2000-4
<20*	1.57 (0.43 to 4.02)	2.24 (1.16 to 3.91)	2.99 (0.97 to 6.98)
≥20†	0.48 (0.28 to 0.76)	0.30 (0.20 to 0.42)	0.27 (0.15 to 0.46)

^*Total population surveyed=95 814.

^†Total population surveyed=1 949 593.