TABLE 1.

Demographic Characteristics (%) of Hispanic Subjects Born between 1997 and 2006 in Eight Counties in the San Joaquin Valley of California

	Controls (n = 466)	NTDs (n = 139)	Spina bifida (n = 94)	Anencephaly (n = 45)
Maternal education (years)
<12	48	45	43	51
12	28	35	37	29
>12	24	20	20	20
Maternal nativity
Foreign-born	53	58	56	62
U.S.-born	47	42	44	38
Multi-vitamin usea
Yes	57	62	59	69
No	41	37	40	29
Missing	2	1	1	2
Smokingb
None	84	77	74	82
Active only	4	6	5	7
Passive only	8	17	19	11
Active and passive	3	1	1	0
Maternal age (years)
<20	19	14	14	16
20–24	33	30	34	20
25–29	24	32	31	36
30–34	17	16	16	16
≥35	7	8	5	13
Infant sex
Male	54	47	48	44
Female	46	47	49	44
Missing	0	6	3	11
Plurality
Singletons	100	98	98	98
Multiples	<1	2	2	2
Parity
0	33	27	31	20
1	31	34	30	42
2+	36	39	39	38
Year of expected delivery date
1997–2000	36	32	32	31
2001–2003	31	40	41	36
2004–2006	33	29	27	33

^aAny folate-containing multi-vitamin use during 1 month before through 2 months after conception.

^bAny smoking during 1 month before through 2 months after conception.