Table 5.

Univariable analysis of factors affecting uterine venous diameter (N = 1014)

Variable		Category /term		Diameter Median [IQR]	Ratio (95% CI)		P value
Age (*)		Linear term		-	1.84 (1.39, 2.44)		< 0.001
		Squared term			0.89 (0.84, 0.95)
		Cubic term			1.01 (1.00, 1.01)
BMI (*)		Linear term		-	1.00 (0.98, 1.02)		0.91
Ethnicity		White		3.2 [2.6, 4.1]	1		< 0.001
		Asian		3.2 [2.7, 3.8]	0.99 (0.93, 1.06)
		Black		3.6 [2.9, 4.5]	1.12 (1.06, 1.18)
		Middle Eastern		3.4 [2.7, 4.4]	1.05 (0.98, 1.13)
		Mixed/other		3.0 [2.6, 4.0]	0.96 (0.89, 1.03)
Parity		0		3.0 [2.4, 3.7]	1		< 0.001
		1		3.3 [2.6, 4.0]	1.09 (1.04, 1.13)
		2		3.4 [2.7, 4.4]	1.15 (1.10, 1.19)
		3		3.6 [2.8, 4.7]	1.20 (1.14, 1.26)
		4 +		3.7 [3.0, 4.7]	1.24 (1.17, 1.32)
Menopausal		Pre		3.2 [2.6, 4.1]	1		< 0.001
Status		Post		3.0 [2.3, 3.8]	0.91 (0.88, 0.94)
Diagnosis		Normal		3.1 [2.4, 3.8]	1		< 0.001
		Abnormal		3.3 [2.6, 4.1]	1.07 (1.03, 1.10)
Pathology		Single		3.2 [2.5, 4.0]	1		0.002
		Multiple		3.3 [2.7, 4.2]	1.06 (1.02, 1.09)
Adenomyosis		No		3.1 [2.5, 3.9]	1		< 0.001
		Yes		3.4 [2.7, 4.3]	1.08 (1.05, 1.12)
Fibroids		No		3.1 [2.5, 3.9]	1		< 0.001
		Yes		3.4 [2.7, 4.2]	1.08 (1.04, 1.11)
Fibroids		No fibroids		3.1 [2.5, 3.9]	1		0.01
(by number)		1–3		3.3 [2.7, 4.3]	1.07 (1.04, 1.11)
		4 +		3.4 [2.7, 4.2]	1.09 (1.03, 1.15)
Fibroids		No fibroids		3.1 [2.5, 3.9]	1		< 0.001
(by mean		≤ 50 mm		3.3 [2.7, 4.1]	1.05 (1.02, 1.09)
diameter)		> 50 mm		3.9 [3.1, 4.7]	1.23 (1.15, 1.31)
Fibroid		Linear term		-	0.99 (0.96, 1.02)		< 0.001
Diameter (+) (*)		Squared term			1.004 (1.001, 1.007)
Ovarian/adnexal cyst		No		3.2 [2.6, 4.0]	1		0.45
		Yes		3.2 [2.6, 4.1]	1.02 (0.98, 1.06)
PCOM		No		3.2 [2.6, 4.0]	1		0.06
Endometriosis		Yes		3.1 [2.5, 3.9]	0.96 (0.91, 1.00)		0.35
		No		3.2 [2.6, 4.0]	1
		Yes		3.3 [2.7, 4.2]	1.03 (0.97, 1.09)

(*) Ratios given for a 10-unit increase in variable

(+) Analysis for subgroup of 488 patients with fibroids only