Comparison of two local anaesthetics in transvaginal ultrasound-guided oocyte retrieval.

Transvaginal ultrasound-guided oocyte retrieval is an accepted procedure in most in-vitro fertilization programmes. In order to simplify the anaesthetic procedure into a minimally invasive one, we perform the oocyte retrieval under a modified para-cervical block combined with a standard pre-medication. In order to maximize the patient's comfort we evaluated two different local anaesthetics and their side-effects. Patients were allocated at random to receive a modified para-cervical block with mepivacaine 1% (n = 46) or with prilocaine 1% (n = 54). The patients were asked to fill in a visual analogue scale (VAS) including assessment of anxiety, pain and comfort concerning the procedure. The two local anaesthetics were both effective in reducing pain during transvaginal oocyte retrieval. The mean VAS scores were acceptable and were efficient as indicators of patient's comfort during the procedure. Mepivacaine was selected for routine use since prilocaine induced methaemoglobinaemia.