Table 1.

Comparison of frequency of genetic polymorphisms, demographic characteristics and vitamin supplement intake between mothers of controls and unilateral cases

	Control (n=97)	Unilateral case (n=103)
	%(n affected/n total informative)	%(n affected/n total informative)
DHFR19bpdel/del*	14.58 (14/96)	39.22 (40/102)
MHTFR677TT	26.04 (25/96)	29.70 (30/101)
Smoked during pregnancy	9.37 (9/96)	3.06 (3/98)
Folic acid supplement use during first trimester	46.39 (45/97)	50.00 (36/72)
	Median (range)	Median (range)
Age at delivery (years)	24.4 (14.4, 39.5)	25.2 (13.17, 38.66)
Years of schooling	9 (0,17)	9 (0,17)
Child’s weight at delivery (kg)	3.3 (1.4, 4.8)	3.3 (2.1, 5.0)

^*p = 0.0002, case control difference detected by Chi-square test.