Maternal periconceptional environmental exposure and offspring with congenital heart disease: a case–control study in Guangzhou, China

Table 1 Maternal characteristics among infants with and without congenital heart diseases (n = 2220)

Variables	Healthy Controls		All CHDs Cases		P
Variables	n = 1545	%	n = 675	%	P
Maternal age at delivery (year)					0.568
< 35	1308	84.7	565	83.7
≥ 35	237	15.3	110	16.3
Paternal age at delivery (Mean ± SD, year)	31.7 ± 5.1		32.2 ± 5.1		0.053
Child sex					0.078
Male	834	54.0	337	49.9
Female	711	46.0	338	50.1
Family monthly income (per month/RMB)					0.396
< 5000	50	3.2	27	4.0
5000–10,000	467	30.3	216	32.1
10,000–20,000	718	46.6	313	46.6
≥ 20,000	306	19.9	116	17.3
Gravidity (Mean ± SD)	2.09 ± 1.16		2.07 ± 1.18		0.650
Parity (Mean ± SD)	1.57 ± 0.61		1.51 ± 0.65		0.034*
Maternal passive smoking					0.005*
No	1476	95.5	625	92.6
Yes	69	4.5	50	7.4
Maternal use of folic acid					0.005*
No	60	3.9	45	6.7
Yes	1478	96.1	629	93.3
Mode of conception					< 0.001*
Planned pregnancy	1039	67.8	418	62.2
Unplanned Pregnancy	475	31.0	231	34.4
Assisted reproduction	19	1.2	23	3.4
Threatened abortion					0.046*
No	1466	94.9	626	92.7
Yes	79	5.1	49	7.3
Birth weight (Mean ± SD, g)	3165.2 ± 432.5		3126.0 ± 578.0		0.114
Maternal history of internal diseases					0.043*
No	1537	99.5	666	98.7
Yes	8	0.5	9	1.3
Preterm birth					0.006*
No	113	7.3	73	10.8
Yes	1432	92.7	602	89.2
Maternal diabetes					0.941
No	1534	99.3	670	99.3
Yes	11	0.7	5	0.7
Maternal history of CHD					0.004*
No	1545	100	670	99.3
Yes	0	0	5	0.7
Maternal reproductive history of birth defects					< 0.001*
No	1542	99.8	659	97.6
Yes	3	0.2	16	2.4
Taking medicine					< 0.001*
No	1402	90.7	573	84.9
Yes	143	9.3	102	15.1
Maternal hyperthyroidism					0.048*
No	1542	99.8	670	99.3
Yes	3	0.2	5	0.7

ISSN: 1471-2393