Table 3.

Crude and adjusted ORs (95% CI) for perinatal mortality by maternal age

	1982			1993			2004				Pooled cohorts
	Deaths/Births (PMR)*	Crude OR (95%CI)	Adjusted OR (95%CI) ¹	Deaths/Births (PMR)*	Crude OR (95%CI)	Adjusted OR (95%CI) ¹	Deaths/Births (PMR)*	Crude OR (95%CI)	Adjusted OR (95%CI) ¹	P valuec	Deaths/Births (PMR)*	Crude OR (95%CI)2	Adjusted OR (95%CI) 3
Maternal age, y										0.859
< 16	2/65 (30.8)	1.2 (0.4; 8.7)	1.9 (0.4; 8.7)	2/108 (18.5)	1.0 (0.2; 4.2)	0.8 (0.2; 3.4)	5/113 (44.2)	2.6 (1.0; 6.6)	1.7 (0.5; 5.0)		9/286 (31.5)	1.9 (1.0; 3.8)	1.4 (0.7; 2.9)
16-19	23/852 (27.0)	1.0 (0.6; 1.6)	1.1 (0.6; 2.2)	14/810 (17.3)	0.9 (0.5; 1.7)	0.8 (0.4; 1.5)	10/685 (14.6)	0.8 (0.4; 1.7)	0.7 (0.3; 1.5)		47/2,347 (20.0)	1.0 (0.7; 1.4)	0.8 (0.6; 1.2)
20-29	90/3,424 (26.3)	1.0	1.0	51/2,779 (18.4)	1.0	1.0	37/2,079 (17.8)	1.0	1.0		178/8,282 (21.5)	1.0	1.0
P-value		0.972 a	0.707 a		0.979 a	0.752a		0.163 a	0.265 a			0.241 a	0.373 a
		0.838 b	0.475 b		0.885 b	0.474 b		0.376 b	0.887 b			0.313 b	0.934 b
Maternal age, y										0.725
< 20	25/917 (27.3)	1.0 (0.7; 1.6)	1.2 (0.6; 2.3)	16/918 (17.4)	0.9 (0.9; 1.7)	0.8 (0.4; 1.5)	15/798 (18.8)	1.1 (0.6; 1.9)	0.8 (0.4; 1.7)		56/2,633 (21.3)	1.1 (0.8; 1.5)	0.9 (0.6; 1.3)
20-29	90/3,424 (23.4)	1.0	1.0	51/2,779 (18.4)	1.0	1.0	37/2,079 (17.8)	1.0	1.0		178/8,282 (21.5)	1.0	1.0
P-value		0.870 a	0.599 a		0.855 a	0.451 a		0.858 a	0.545 a			0.625 a	0.540 a

Pelotas, Brazil, 1982, 1993, and 2004

^* PMR (perinatal mortality rate) = number of perinatal deaths per 1,000 births (stillbirths and live births).

^a Likelihood ratio test.

^b Likelihood ratio test for trend.

^c Likelihood ratio test for interaction.

¹ Adjusted for family income, maternal schooling, maternal skin color, marital status, and parity.

² Adjusted for cohort year.

³ Adjusted for variables in model ¹ plus model ².