Table 3.

Odds ratios (95% confidence interval) of occurrence of Down syndrome Czech Republic, 1994–98

	Crude	95% CI		Fully adjusted*	95% CI
		Lower	Upper		Lower	Upper
Sex of infants
Boy	1			1
Girl	0.79	0.61	1.01	0.67	0.51	0.89
Education of mother
Primary	0.84	0.51	1.39	1.03	0.57	1.86
Vocational	0.88	0.58	1.34	1.06	0.66	1.70
Secondary	0.76	0.49	1.17	0.85	0.53	1.36
University	1			1
P for trend	0.98			0.44
Maternal age
-19	1			1
20–22	1.31	0.76	2.25	0.89	0.46	1.69
23–25	1.12	0.64	1.93	0.67	0.33	1.33
26–28	1.28	0.72	2.25	0.76	0.37	1.60
29–31	1.44	0.79	2.62	0.61	0.27	1.41
32–34	2.56	1.39	4.69	1.31	0.57	3.03
35–37	2.68	1.32	5.45	1.39	0.55	3.56
38–40	2.96	1.23	7.13	1.00	0.28	3.52
41–43	8.99	3.54	22.82	4.61	1.38	15.40
44+	46.65	17.10	127.25	11.26	2.14	59.36
Paternal age
-19	1			1
20–22	0.63	0.18	2.19	0.68	0.19	2.41
23–25	1.09	0.34	3.51	1.33	0.40	4.50
26–28	1.03	0.32	3.32	1.34	0.39	4.63
29–31	0.94	0.29	3.08	1.23	0.35	4.40
32–34	1.24	0.37	4.12	1.49	0.41	5.46
35–37	1.95	0.58	6.53	1.98	0.52	7.44
38–40	2.21	0.63	7.69	2.02	0.51	7.96
41–43	2.10	0.54	8.14	1.68	0.38	7.42
44+	3.03	0.82	11.20	2.03	0.47	8.77

Note: * -Adjusted for all variables in the Table.