Table 3

Risks of non-syndromic oral clefts associated with maternal occupational exposures to organic solvents and to non-occupational activities involving use of products containing solvents

	Controls	CL/P			CP
	n	n	OR†	95% CI	n	OR†	95% CI
*Unexposed mothers are women who reported an occupational activity during the first trimester for which the expert assessed no exposure to any the three chemical classes of organic solvents (oxygenated, chlorinated, and petroleum).
†Logistic regression adjusted for centre (Rhône-Alpes, Paris, Auvergne), child’s sex, and mother’s geographic origin (Europe, other).
CL/P, cleft lip with/without cleft palate; CP, cleft palate.
n, number; OR, odds ratio; 95% CI, 95% confidence interval.
p trend = p value of the likelihood ratio test between models with and without the categorical level of exposure included as continuous variable. For each reported p trend, the test of the linearity assumption based on the comparison between the model including the exposure level as categorical and continuous variable, has not been rejected.
Maternal occupational exposure to organic solvents, among women with an occupational activity during the first trimester (187 controls, 116 CL/P, 57 CP)

Unexposed mothers*	114	55	ref		28	ref

Oxygenated solvents	71	58	1.76	1.1 to 2.9	28	1.42	0.7 to 2.7
Aliphatic alcohols	61	49	1.76	1.0 to 3.1	26	1.56	0.8 to 3.0
Very low–low	39	27	1.53	0.8 to 2.8	13	1.20	0.5 to 2.6
Medium–high	22	22	2.14	1.1 to 4.3	13	2.20	1.0 to 5.1
p trend				p = 0.02			p = 0.10
Glycol ethers	41	37	1.88	1.1 to 3.5	18	1.50	0.7 to 3.2
Very low	16	10	1.30	0.5 to 3.1	2	0.40	0.1 to 1.9
Low	22	20	1.88	0.9 to 3.8	12	1.83	0.8 to 4.4
Medium–high	3	7	4.77	1.2 to 19.5	4	4.06	0.8 to 20.3
p trend				p<0.01			p = 0.06
Aliphatic aldehydes, esters, and ketones	56	46	1.74	1.0 to 2.9	28	1.82	1.0 to 3.5
Very low	54	42	1.66	1.0 to 2.8	28
Low–medium–high	2	4	4.41	0.7 to 26.8	0
p trend				p = 0.02
Chlorinated solvents	3	14	9.45	2.5 to 35.3	3	3.78	0.7 to 20.7
Petroleum solvents	10	17	3.64	1.5 to 8.8	3	1.21	0.3 to 4.9
Very low–low	7	10	3.21	1.1 to 9.3	3
Medium–high	3	7	4.60	1.1 to 19.2	0
p trend				p<0.01
Extra professional activities of the mother (during the first trimester of pregnancy), among all women (236 controls, 164 CL/P, 76 CP)
Hair dyes and bleaching products
No reported use	217	145	ref		63	ref
Use	19	17	1.26	0.6 to 2.5	12	2.29	1.0 to 5.1
Painting or varnishing activities
No reported activity	223	151	ref		71	ref
Yes	13	13	1.57	0.7 to 3.5	4	1.00	0.3 to 3.2