Table 1 Subject characteristics of the CHD cases and controls.

Characteristics	Cases		Controls		χ²	p value
Characteristics	No	%	No	%	χ²	p value
Maternal age (years)					114.03	< 0.001
< 25	167	22.30	46	5.23
25–29	346	46.19	424	48.18
30–34	170	22.70	304	34.55
≥ 35	66	8.81	106	12.05
Maternal education level					222.12	< 0.001
≤ 9 school years	142	18.96	27	3.07
10–12 school years	153	20.43	51	5.80
13–16 school years	392	52.34	649	73.75
≥ 17 school years	62	8.28	153	17.39
Residence					214.96	< 0.001
Urban	428	57.14	783	88.98
Rural	321	42.86	97	11.02
Congenital anomalies family history					13.66	< 0.001
No	645	86.11	808	91.82
Yes	104	13.89	72	8.18
Maternal folate intake^a					52.83	< 0.001
Yes	309	41.26	522	59.32
No	440	58.74	358	40.68
Maternal HNS exposureb					38.99	< 0.001
No	445	59.41	651	73.98
Yes	304	40.59	229	26.02
Paternal smoking^c					24.90	< 0.001
No	429	57.28	609	69.20
Yes	320	42.72	271	30.80

^aTaking folic acid over 90 days or more during the 3 months before conception to the first trimester.
bMaternal HNS (maternal hazardous and noxious substances) exposure during the 3 months before conception to the first trimester.
^cPaternal smoking during 0–3 months before conception.

Quick links

Search