Randomized controlled trial of transcutaneous electrical nerve stimulation for pain relief during transvaginal oocyte retrieval using conscious sedation: study protocol for a randomized controlled trial

BACKGROUND: Transvaginal oocytes retrieval is an essential step in in-vitro fertilization treatment. There are different pain relief methods, but none has been shown to be superior than the others. Transcutaneous electrical nerve stimulation (TENS) is a non-pharmacological and non-invasive pain relief method. This study aims to compare the pain levels experienced by the women using the conscious sedation and those who had TENS in addition to conscious sedation. METHODS AND ANALYSIS: This is a double-blinded randomized trial that will be carried out in a university-assisted conception unit. Women who will undergo oocyte retrieval under conscious sedation will be recruited. After randomization, women will be allocated to either the active TENS group or placebo TENS group (the TENS machine will not emit active impulse), in addition to the paracervical block and conscious sedation. The primary outcome is pain levels of women during the retrieval assessed by the visual analog scale. Secondary outcomes include satisfaction of women and postoperative side effects. DISCUSSION: TENS is an effective non-pharmacological and non-invasive method for pain relief in a number of clinical conditions. Both women and assisted conception unit can benefit if the addition of non-invasive, simple, and low-cost TENS application is proven to be superior than using conscious sedation and paracervical block alone. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03472430. Registered on 3 May 2018. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13063-019-3227-5) contains supplementary material, which is available to authorized users.