Table 1. Demographic and clinical characteristics of the participants.

	Prenatal intake of folic acid
	Negative (n = 81)	Positive (n = 134)	P value
Age (years)	31.3±4.7	31.9±3.9	0.3588†
Parity, median (IQR)*	1 (0–1)	0 (0–1)	0.0453
BMI	25.1±3.0	24.6±3.2	0.2386
Alcohol history, n (%)			0.1392‡
Drinker	2 (2.4)	0 (0.0)
Non-drinker	83 (97.7)	142 (100.0)
Smoking history, n (%)			–
Smoker	–	–
Non-smoker	85 (100.0)	142 (100.0)
Family monthly income ($US), n (%)			0.0652¶
<2000	20 (23.5)	24 (16.9)
2000–5000	63 (74.1)	104 (73.2)
>5000	2 (2.4)	14 (9.9)
Occupation, n (%)			0.7095¶
Yes	32 (37.7)	57 (40.1)
No	53 (62.4)	85 (59.9)

IQR, interquartile range; BMI, body mass index.

Data are summarized as the mean ± standard deviation or % (n).

*Data are median (IQR). Data were analyzed using the Wilcoxon rank-sum test.

^†P value, Student’s t-test.

^‡P value, Fisher’s exact test.

^¶P value, chi-square test.