Pain relief during oocyte retrieval--exploring the role of different frequencies of electro-acupuncture.

Electro-acupuncture has previously proven its analgesic effect in oocyte retrieval for IVF. The aim of the present prospective randomized study was to explore the optimal frequency for analgesia when electro-acupuncture was applied a few minutes prior to oocyte retrieval. A total of 152 patients were prospectively randomized to receive either a combination of high (80 Hz) and low frequency (2 Hz), 3 s each, a so-called mixed frequency, or a fixed frequency of 20 Hz during oocyte retrieval. In addition to electro-acupuncture, both groups had a paracervical block and manual acupuncture. No differences in pain before, during or after oocyte retrieval between the two groups were seen. In the fixed frequency group, however, a higher level of anxiety (P < 0.05) before oocyte retrieval was seen, and a higher level of nausea after aspiration of one ovary (P < 0.01) was seen in the mixed frequency group. No differences were seen regarding clinical outcome parameters. Contrary to previous reports on acute and chronic pain, the analgesic effect of the mixed frequency and the fixed frequency was similar when used for short duration electro-acupuncture.