['The unintentional and unrecognized cannulation of an extradural vein is a potentially serious complication of an epidural anesthetic. The present study was undertaken to assess the incidence of blood vessel puncture related to epidural catheterization in three different body positions, in a cohort of morbidly obese parturients, following the completion of a similar study published in 2001 from which such parturients were excluded.', 'The study was conducted in 450 (three groups of 150) morbidly obese, obstetric patients undergoing continuous epidural analgesia during labour. Epidural catheterization was performed on patients randomized to the sitting, lateral recumbent horizontal, or lateral recumbent head-down position.', 'There was a lower incidence of vessel cannulation when this procedure was performed in the lateral recumbent head-down position [1.3%; body mass index (BMI): 37.0] than in the lateral recumbent horizontal [12.9%; BMI: 38.0] and in the sitting position [12.0%; BMI: 38.0]. The incidence of accidental subarachnoid puncture was 2%, 1.3% and 2% respectively, in these same positions.'] Does the lateral recumbent head-down position decrease the incidence of epidural venous puncture during catheter insertion in obese parturients?