A prospective randomized study comparing aspiration only with aspiration and flushing for transvaginal ultrasound-directed oocyte recovery. Is follicular flushing necessary for oocyte retrieval? A randomized trial. Electro-acupuncture as a peroperative analgesic method and its effects on implantation rate and neuropeptide Y concentrations in follicular fluid. Is analgesia required for transvaginal single-follicle aspiration in in vitro fertilization? A double-blind study.
To compare aspiration only with aspiration and flushing of ovarian follicles during transvaginal ultrasound (US)-directed oocyte recovery.
                Prospective randomized study.
                One hundred patients who were undergoing an in vitro fertilization (IVF) treatment cycle.
                All patients underwent pituitary desensitization before the administration of gonadotropins. Monitoring of ovarian stimulation and the criteria for the administration of human chorionic gonadotropin were similar in both groups. In patients in whom aspiration alone was used, each follicle was aspirated until it was empty. The US probe was then rotated until every drop of follicular fluid had been aspirated before the next follicle was aspirated and the procedure repeated. For patients who had aspiration and flushing, each follicle was aspirated and then flushed up to a maximum of six times before moving to the next follicle. In both groups, all follicles greater than 10 mm were aspirated.
                The indication for IVF and mean age of the patients were comparable in the two groups. There were no significant differences between the aspiration and the aspiration and flushing groups in terms of the number of oocytes retrieved (11 versus 9), the oocyte recovery rates (77.5% versus 77.0%), the fertilization rates (55.6% versus 60.0%), the number of embryos transferred (2 versus 2), or the number of clinical pregnancies (12 versus 13). The time taken for oocyte recovery was significantly shorter (15 versus 30 minutes, P less than 0.00001), and the dose of pethidine required significantly less (50 mg versus 100 mg, P less than 0.00001) in the aspiration only group.
                Aspiration alone produces comparable oocyte recovery rates as aspiration and flushing while significantly reducing the length of the procedure and the dose of analgesia required. Aspiration alone suffices for virtually all cases during transvaginal US-directed oocyte recovery. A prospective randomized trial was performed to evaluate the necessity of follicular flushing during transvaginal, ultrasonically guided oocyte recovery under mild sedation. Patients with tubal damage as the sole cause of their infertility were randomized into one of two groups. Group one had their follicles aspirated only. Follicles of patients in Group 2 were aspirated and flushed with a total of 10 ml of flushing medium. There was no significant difference in the number of oocytes retrieved, fertilization rate or pregnancy rate in each group. There was, however, a significant shortening of operating time in the aspiration only group. In a previous study on the effect of electro-acupuncture (EA) in combination with a paracervical block (PCB) as an analgesic method during oocyte aspiration in IVF treatment, EA appeared to increase the pregnancy rate. This study was designed to test the hypothesis that EA as an analgesic during oocyte aspiration would result in: (i) a better IVF pregnancy rate than with alfentanil; (ii) peroperative analgesia that was as good as that produced by alfentanil; (iii) less postoperative abdominal pain, nausea and stress; and (iv) a reduction in the use of additional analgesics. Neuropeptide Y (NPY) concentrations in follicular fluid (FF) were analysed when possible.
                In this prospective, randomized, multicentre clinical trial, 286 women undergoing oocyte aspiration were randomly allocated to the EA group (EA plus a PCB) or to the alfentanil group (alfentanil plus a PCB). No significant differences were found between the EA and alfentanil groups in any of the IVF variables. NPY concentrations in FF were significantly higher in the EA group compared with the alfentanil group. No correlation between pregnancy rate and NPY concentrations was found in either analgesic group. Both EA plus a PCB and alfentanil plus a PCB induced adequate peroperative analgesia during oocyte aspiration evaluated using the visual analogue scale. After 2 h, the EA group reported significantly less abdominal pain, other pain, nausea and stress than the alfentanil group. In addition, the EA group received significantly lower amounts of additional alfentanil than the alfentanil group.
                EA does not improve pregnancy rate in the present clinical situation. The observation that NPY concentrations in FF were higher in the EA group may be important for human ovarian steroidogenesis. The analgesic effects produced by EA are as good as those produced by conventional analgesics, and the use of opiate analgesics with EA is lower than when conventional analgesics alone are used. 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.
There is no evidence that follicular aspiration and flushing is associated with improved clinical or ongoing pregnancy rates, nor an increase in oocyte yield. The operative time is significantly longer and more opiate analgesia is required for pain relief during oocyte retrieval. There is a lack of evidence regarding the effect of follicular aspiration and flushing on live birth rates in the identified data.