The female urethral orifice is a vertical, slit-like, or irregularly ovoid (egg-shaped) opening, 0.16–0.2 in (4–5 mm) in diameter, located between the clitoris and the vagina. The urinary meatus (opening) is concealed between the labia minora, which are the small folds of tissue that need to be separated to view the opening and insert a catheter. With proper positioning, good lighting, and gloved hands, these anatomical landmarks can be identified. Perineal care or cleansing may be required to ensure a clean procedural environment.

Catheterization of the female patient is traditionally performed without the use of local anesthetic gel to facilitate catheter insertion. But since there are no lubricating glands in the female urethra (as are found in the male urethra), the risk of trauma from a simple catheter insertion is increased. Therefore, an ample supply of an anesthetic or antibacterial lubricant should be used.

Once the catheter is inserted, it is secured as appropriate for the catheter type. A straight catheter is typically secured with adhesive tape. An indwelling catheter is secured by inflating a bulb-like device inside of the bladder.

From http://www.answers.com/topic/catheterization-female