Table 3.

Adjusted ORs for primary placental pathologic, according to demographic and medical factors.^a

Variable	P value for test of association between risk factor and placental pathologic condition	OR
		AFIS (95% CI)	Chronic villitis (95% CI)	Maternal vascular pathologic condition (95% CI)	Fetal vascular pathologic condition (95% CI)
Age (y)	.1079
< 35		Reference	Reference	Reference	Reference
≥35		0.55 (0.26, 1.18)	0.87 (0.58, 1.33)	1.64 (1.11, 2.41)	1.16 (0.74, 1.83)
PIR (%)	.0864
>200		Reference	Reference	Reference	Reference
100-200		1.03 (0.51, 2.10)	0.75 (0.44, 1.29)	0.79 (0.46, 1.36)	0.60 (0.32, 1.12)
<100		1.93 (1.05, 3.56)	0.55 (0.32, 0.94)	1.03 (0.63, 1.69)	0.74 (0.40, 1.36)
Smoking during pregnancy	.1343
No		Reference	Reference	Reference	Reference
Yes		1.64 (0.85, 3.14)	0.75 (0.41, 1.37)	1.32 (0.78, 2.24)	1.76 (1.00, 3.11)
Previous birth	.0025
None		Reference	Reference	Reference	Reference
≥1		0.44 (0.26, 0.74)	1.34 (0.94, 1.92)	0.67 (0.47, 0.96)	1.01 (0.68, 1.51)
Previous preterm birth	.0218
No		Reference	Reference	Reference	Reference
Yes		0.50 (0.19, 1.30)	1.60 (1.10, 2.55)	1.17 (0.70, 1.94)	0.52 (0.26, 1.04)
Previous elective termination	.0032
No		Reference	Reference	Reference	Reference
Yes		3.28 (1.89, 5.70)	0.67 (0.43, 1.04)	1.13 (0.74, 1.72)	1.20 (0.76, 1.89)
PIH	.0659
No		Reference	Reference	Reference	Reference
Yes		0.93 (0.55, 1.58)	1.12 (0.77, 1.62)	1.44 (1.01, 2.07)	1.61 (1.10, 2.37)
Preeclampsia	.1077
No		Reference	Reference	Reference	Reference
Yes		0.21 (0.02, 1.84)	1.22 (0.57, 2.58)	0.99 (0.47, 2.08)	0.55 (0.21, 1.42)

^aAdjusted for PIH, age, maternal smoking during pregnancy, PIR percent, and previous elective termination.