Table 4.

Associations between chronic histologic lesions and placental abruption cases and controls, and between histologically confirmed and unconfirmed abruption cases

	Clinically diagnosed abruption cases				Adjusted odds ratio (95% CI)
Chronic histologic lesions	All clinical cases	Pathology confirmed*	Pathology unconfirmed**	Controls	All clinical cases vs controls†	Pathology confirmed vs unconfirmed†
	(n=162)	(n=49)	(n=113)	(n=173)
Chronic deciduitis	97.5	98.0	97.4	96.5	1.4 (0.4, 4.9)	1.5 (0.2, 15.2)
Decidual necrosis	2.5	4.1	1.8	4.1	0.6 (0.2, 2.2)	2.1 (0.3, 15.6)
Decidual vasculopathy‡	19.8	30.6	15.0	13.3	1.6 (0.9, 3.0)	2.5 (1.1, 5.9)
Placental infarctions	29.0	49.0	20.4	13.3	3.1 (1.7, 5.6)	3.9 (1.9, 8.4)
Advanced maturation	9.3	6.1	10.6	5.8	1.9 (0.8, 4.6)	0.5 (0.1, 1.8)
Dysmaturation	73.5	80.0	70.8	80.4	0.6 (0.4, 1.0)	1.9 (0.8, 4.3)
Hemosiderin deposition	1.2	0.0	1.8	1.2	1.1 (0.2, 8.0)	—
Intervillous thrombus††	5.6	8.1	4.4	19.1	0.3 (0.1, 0.6)	1.83 (0.5, 7.2)
Villitis	0.0	0.0	0.0	0.6	—	—
At least 1 lesion	98.7	100	98.2	100	—	—

^*Clinically diagnosed abruption cases also confirmed on placental pathology

^**Clinically diagnosed abruption cases not confirmed as placental abruption on placental pathology

^†Odds ratios are adjusted for maternal age

^‡Decidual vasculopathy includes muscular thickening and atherosis

^††Intervillous thrombus includes lesions associated with feto-maternal hemorrhage, and large placentas of diabetes or erythroblastosis