Table 2

Crude rates of SIDS and non-SIDS deaths according to maternal age, birth order and marital status, by period of birth. Postperinatal deaths, Norway 1967-93

		Period of birth
		1967-71	1972-76	1977-81	1982-85	1986-89	1990-93
SIDS
Maternal age (years)
⩽19	1.47	1.85	2.94	4.22	5.54	2.74
20-24	1.39	1.41	2.06	2.90	3.31	1.43
25-29	1.00	1.13	1.40	1.60	1.89	0.85
30-34	0.72	0.96	1.23	1.80	1.61	0.50
⩾35	0.69	0.53	1.08	1.39	1.23	0.58
Birth order
1	0.74	1.04	1.32	1.61	1.63	0.61
2	1.47	1.40	2.06	2.45	2.77	1.02
3	1.41	1.50	1.82	2.94	2.91	1.31
4+	1.14	1.18	1.77	2.26	3.83	1.81
Marital status
Married	1.06	1.20	1.57	2.02	2.13	0.80
Unmarried	2.22	1.73	2.48	2.70	2.78	1.17
Cohabiting	—	—	—	—	2.14	0.83
Single	—	—	—	—	3.90	2.32
Non-SIDS
Maternal age (years)
⩽19	4.00	3.64	3.37	2.79	2.68	2.74
20-24	3.28	2.82	2.53	2.61	2.57	2.04
25-29	3.05	2.65	2.18	2.03	2.14	1.79
30-34	3.48	2.94	2.11	1.90	2.46	2.18
⩾35	4.75	4.32	2.76	1.78	3.01	2.23
Birth order
1	3.21	2.82	2.58	2.19	2.37	2.00
2	3.22	2.63	2.16	2.36	2.27	1.83
3	3.56	3.38	2.46	1.88	2.51	2.17
4+	4.53	4.21	2.82	2.34	3.74	2.99
Marital status
Married	3.37	2.86	2.25	2.08	2.45	2.05
Unmarried	4.69	3.80	3.41	2.65	2.39	2.00
Cohabiting	—	—	—	—	2.32	1.93
Single	—	—	—	—	2.41	2.27