Table 2a.

Prevalence, crude and adjusted odds ratio (OR_crude/OR_adj) of maternal occupational exposure and congenital heart defects (CHD) in the offspring. [CI=confidence interval; d-TGA=dextro-transposition of the great arteries; LVOTO/RVOTO=left/right ventricular outflow tract obstruction; HLHS=hypoplastic left heart syndrome; P(v)S=pulmonary (valve) stenosis; CoA=coarctation of aorta; VSD=ventricular septal defect; ASD=atrial septal defect; AVSD=atrioventricular septal defect; APVR=anomalous pulmonary venous return; NC=not calculated due to sparse data]. BOLD indicates significant values (P<0.05).

CHD classification	Total	Any occupational exposure						Organic dust exposure
		N	%	ORcrude	95% CI	ORadj a	95% CI	N	%	ORcrude	95% CI	ORadj a	95% CI
Controls	5602	1992	35.6	Ref		Ref		1617	28.9	Ref		Ref
Total CHD	1174	442	37.6	1.09	0.96–1.25	1.04	0.90–1.20	356	30.3	1.07	0.94–1.23	1.10	0.95–1.28
Conotruncal	174	69	39.7	1.19	0.88–1.62	1.13	0.81–1.57	57	32.8	1.20	0.87–1.66	1.30	0.93–1.82
d-TGA	74	28	37.8	1.10	0.69–1.77	1.00	0.60–1.68	23	31.1	1.11	0.68–1.82	1.18	0.70–1.99
Tetralogy of Fallot	60	28	46.7	1.59	0.95–2.64	1.50	0.88–2.57	23	38.3	1.53	0.91–2.59	1.68	0.98–2.89
Truncus arteriosus	10	5	50.0	1.81	0.52–6.27	1.46	0.41–5.24	<5		NC		NC
LVOTO	173	62	35.8	1.01	0.74–1.39	0.94	0.67–1.31	53	30.6	1.09	0.78–1.51	1.14	0.80–1.60
HLHS	50	19	38.0	1.11	0.63–1.97	0.86	0.47–1.57	15	30.0	1.06	0.58–1.94	0.87	0.46–1.67
Aortic stenosis	31	5	16.1	0.35	0.13–0.91	0.32	0.11–0.94	<5		NC		NC
Coarctation of aorta	42	18	42.9	1.36	0.74–2.51	1.33	0.70–2.54	17	40.5	1.68	0.90–3.11	1.90	1.01–3.59
Bicuspid aortic valve	42	16	38.1	1.12	0.60–2.08	1.14	0.59–2.18	14	33.3	1.23	0.65–2.35	1.37	0.70–2.65
RVOTO	139	58	41.7	1.30	0.92–1.83	1.24	0.87–1.77	49	35.3	1.34	0.94–1.91	1.35	0.94–1.95
P(v)S	104	44	42.3	1.33	0.90–1.97	1.26	0.84–1.90	37	35.6	1.36	0.91–2.04	1.36	0.89–2.07
Pulmonary atresia	13	6	46.2	1.55	0.52–4.63	1.37	0.45–4.20	6	46.2	2.11	0.71–6.30	2.13	0.70–6.43
Septal	544	194	35.7	1.01	0.84–1.21	0.96	0.79–1.17	150	27.6	0.94	0.77–1.14	0.97	0.79–1.19
Perimembranous VSD	117	51	43.6	1.40	0.97–2.03	1.34	0.91–1.99	40	34.2	1.28	0.87–1.88	1.40	0.94–2.10
Muscular VSD	248	79	31.9	0.85	0.65–1.11	0.87	0.65–1.16	63	25.4	0.84	0.63–1.12	0.90	0.67–1.22
Other VSD	78	27	34.6	0.96	0.60–1.53	0.98	0.60–1.61	18	23.1	0.74	0.44–1.26	0.82	0.47–1.41
ASD	98	36	36.7	1.05	0.70–1.59	0.93	0.60–1.43	28	28.6	0.99	0.63–1.53	0.95	0.60–1.51
AVSD	28	7	25.0	0.60	0.26–1.42	0.67	0.27–1.63	6	21.4	0.67	0.27–1.66	0.81	0.32–2.06
APVR	17	9	52.9	2.04	0.79–5.29	1.88	0.69–5.10	8	47.1	2.19	0.84–5.69	1.99	0.73–5.41
Total APVR	11	5	45.5	1.51	0.46–4.96	1.48	0.44–4.97	5	45.5	2.05	0.63–6.74	2.03	0.61–6.76
Complex	45	19	42.2	1.32	0.73–2.40	1.30	0.68–2.47	16	35.6	1.36	0.74–2.51	1.39	0.72–2.70
Single ventricle	14	8	57.1	2.42	0.84–6.97	2.54	0.80–8.11	6	42.9	1.85	0.64–5.34	2.13	0.69–6.54
Associations
CoA + VSD	15	7	46.7	1.59	0.57–4.38	1.69	0.59–4.83	5	33.3	1.23	0.42–3.61	1.36	0.56–4.08
P(v)S + VSD	19	11	57.9	2.49	1.00–6.21	3.06	1.20–7.81	9	47.4	2.22	0.90–5.47	2.68	1.07–6.73

^aAdjusted for child sex, maternal age at delivery (as continuous variable), education level, maternal BMI (as continuous variable), smoking and alcohol use during pregnancy, folic acid supplementation, and fertility problems.