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Duplex ultrasound of the common femoral vein in pregnancy and puerperium.

The common femoral veins of 34 apparently normal women were examined by ultrasound during or just after pregnancy. The cross sectional areas of these veins were measured at rest in the supine position and during a Valsalva manoeuvre. The veins were also assessed by pulsed Doppler ultrasound. We believe that Doppler examination is superior to calibre response assessment during the Valsalva manoeuvre in excluding an isolated iliac occlusion in women in late pregnancy and in early puerperium.