Deep vein thrombosis: pregnancy: symptoms in right leg alone made DVT less likely.

Clinical bottom line (level 1b)

  1. About 40% of pregnant or puerperal women with suspected deep vein thrombosis had it.
  2. Pregnant or puerperal women with symptoms of deep vein thrombosis only in their right leg, were less likely to have DVT (LR+0.23) , but it could not be excluded.
de Boer et al: Thrombosis and Haemostasis 1992; 61 (1): 4-7
Expires May 2003

The study

Setting: university hospital, Holland

77 patients (aged mean 38 years, 100% female) pregnant or puerperal women with suspected deep vein thrombosis

Independent blinded reference standard, applied in all patients from a consecutive appropriate spectrum.
Reference standard:
  • impedance plethysmography: if positive, anticoagulated (some had a venogram); if negative, had serial impedance plethysmography on day 2 and 7
Diagnostic test: leg affected clinically

The evidence

pre-test probability of deep vein thrombosis: 42%, (95% CI: 31% to 53%)

diagnostic test DVT no DVT LR+
(95% CI)		 post-test probability LR-
(95% CI)		 post-test probability
left leg 26 27 1.4
(1.0 to 1.8) 		49% 0.47
(0.21 to 1.1) 		25%
right leg 3 18 0.23
(0.075 to 0.73) 		14% 1.5
(1.2 to 2.0) 		52%
both legs 3 0 inf
(0.15 to inf) 		100% 0.91
(0.81 to 1.0) 		39%
total 32 45

  • 20% of patients (95% CI: 7.7% to 39%) had abnormal clotting.

Comments

  1. Many of the patients had no definitive test during pregnancy for venous thromboembolism. Since clinical examination does not accurately predict venous thromboembolism, this makes LR less certain.

Citation

  1. de Boer K, Buller HR, ten Cate JW, et al: Deep vein thrombosis in obstetric patients: diagnosis and risk factors. Thrombosis and Haemostasis 1992; 61 (1): 4-7
Contributor: Chris Ball and Clare Wotton, May 2000
Reviewer: Lucia Balea

Clinical Question.
Patient suspected DVT
Intervention or Exposure leg affected clinically
Comparison impedance plethysmography
Outcome diagnosis