Is analgesia required for transvaginal single-follicle aspiration in in vitro fertilization? A double-blind study.

High oocyte retrieval rates using transvaginal follicular aspiration for single follicles and improved laboratory techniques have engendered renewed interest in natural-cycle in vitro fertilization (IVF). To assess analgesia requirements during single-follicle aspiration, a double-blind study was set up in 30 patients comparing intraprocedure intravenous fentanyl with normal saline as a placebo. Analysis of pain perception using visual analogue scoring showed a similar pain tolerance in both groups for the procedures of vaginal ultrasound scanning, needle insertion, and follicular aspiration. A correlation between each patient's tolerance of common pain-producing experiences with that for the procedure was not well defined (r = 0.5). We conclude that one of the benefits of natural-cycle IVF using transvaginal single-follicle aspiration is that it can be performed without analgesia.