Randomized, open trial comparing a modified double-lumen needle follicular flushing system with a single-lumen aspiration needle in IVF patients with poor ovarian response.

Study question: Is a modified double-lumen aspiration needle system with follicular flushing able to increase the mean oocyte yield by at least one in poor response IVF patients as compared to single-lumen needle aspiration without flushing? Summary answer: Follicular flushing with the modified flushing system did not increase the number of oocytes, but increased the procedure duration. What is known already: Most studies on follicular flushing were performed with conventional double-lumen needles in patients who were normal responders. Overall, these studies indicated no benefit of follicular flushing. Study design size, duration: Prospective, single-centre, randomized, controlled, open, superiority trial comparing the 17 G Steiner-Tan Needle® flushing system with a standard 17 G single-lumen aspiration needle (Gynetics®); time frame February 2015-March 2016. Participants/materials setting methods: Eighty IVF patients, 18-45 years, BMI >18 kg/m2 to 10 mm in both ovaries at the end of the follicular phase were randomized to either aspirating and flushing each follicle 3× with the Steiner-Tan-Needle® automated flushing system (n = 40) or a conventional single-lumen needle aspiration (n = 40). Primary outcome was the number of cumulus-oocyte-complexes (COCs). Procedure duration, burden (Depression Anxiety and Stress Scale; DASS-21) and post-procedure pain were also assessed. Main results and the role of chance: Flushing was not superior with a mean (SD) number of COCs of 2.4 (2.0) and 3.1 (2.3) in the Steiner-Tan Needle® and in the Gynectics® group, respectively (mean difference -0.7, 95% CI: 0.3 to -1.6; P = 0.27). Likewise no differences were observed in metaphase II  oocytes, two pronuclear oocytes, number of patients having an embryo transfer and DASS 21 scores. The procedure duration was significantly 2-fold increased. Limitations reasons for caution: Testing for differences in the number of patients achieving an embryo transfer or differences in pregnancy rate would require a much larger sample size. Wider implications of the findings: The use of follicular flushing is unlikely to benefit the prognosis of patients with poor ovarian response. Study funding/competing interest(s): The Steiner-Tan Needles® and the flushing system were provided for free by the manufacturer. K.v.H. has received personal fees from Finox and non-financial support from Merck-Serono; M.D. has received personal fees from Finox and non-financial support from Merck-Serono. A.S.-M. has received personal fees and non-financial support from M.D., Ferring, Merck-Serono, Finox, TEVA. G.G. has received personal fees and non-financial support from M.D., Ferring, Merck-Serono, Finox, TEVA, IBSA, Glycotope, as well as personal fees from VitroLife, NMC Healthcare LLC, ReprodWissen LLC and ZIVA LLC. Trial registration number: NCT 02365350 (clinicaltrials.gov). Trial registration date: Sixth of February 2015. Date of first patient's enrolment: Ninth of February 2015.