Injection of embryo culture supernatant to the endometrial cavity does not affect outcomes in IVF/ICSI or oocyte donation cycles: a randomized clinical trial Yannis Prapas a,b , Stamatios Petousis a, *, Yannis Panagiotidis a , Giuseppe Gullo a , Lia Kasapi a , Achilleas Papadeothodorou a , Nikos Prapas a,b a Iakentro IVF Center, Agiou Vasileiou 4, 54250 Thessaloniki, Greece b 3rd Department of Obstetrics and Gynaecology, Aristotle University of Thessaloniki, Konstantinoupoleos 49, 54642 Thessaloniki, Greece 1. Introduction The implantation of human embryos in IVF/ICSI cycles represents a black hole in current knowledge, and among other factors the embryo transfer (ET) techniques have been considered important determinants of success rates. Although 30% of IVF failures have been related to poor ET techniques [1], the number of published studies on ET techniques is very low. Ultrasound-guided ET and new catheter materials have been used in order to avoid endometrial lesions caused by catheters [2,3]. Since the reported better pregnancy rates in IVF cases where the endometrium was accidentally flushed prior to ET [4], ET techniques have been given additional attention. Injection of the endometrial cavity with embryo culture supernatant prior to ET was reported to improve implantation and pregnancy rates [5]. However, other similar studies using different flushing medium (culture medium for IVF or day 2 embryo culture supernatant) did not report any improve- ment in pregnancy rates [6,7]. Therefore this study was set up to determine whether in IVF-ICSI and oocyte donation (OD) cycles injection of the endometrial cavity with their embryo culture supernatant at the time of ET performed on either day 3 or day 5, may affect the implantation and pregnancy rates. 2. Materials and methods A prospective, randomized study was performed. IVF-ICSI and OD cycles were randomized into group I (injection of the uterine cavity with embryo culture supernatant) or group II (no injection) by an allocation sequence generated from a computerized random number table. Group I consisted of two subgroups, IA (ET on day 3) and IB (ET on day 5), and group II consisted of IIA (ET on day 3) and IIB (ET on day 5). The study was approved by the Institutional Review Board and informed consent was obtained from all women. Two hundred women participating in the OD program and another 200 in the IVF/ICSI program at the Iakentro IVF centre from June 2009 through November 2010 who underwent ET on either day 3 or day 5 were included in the study. Due to difficult transfer 12 cases from group I and 4 cases from group II were not included in the statistical analysis. All women had a history of at least one previous unsuccessful IVF/ET. The inclusion criteria for the study were age  38 years for the IVF women and 50 years for the oocyte receivers, without known endometriosis, hydrosalpinx or uterine anomalies, including small submucosal myomas or polyps. Four hundred women were allocated into group I or II when they were called to be informed about the day of their embryo transfer. All cases had had a mock transfer in a cycle previous to IVF and if European Journal of Obstetrics & Gynecology and Reproductive Biology 162 (2012) 169–173 A R T I C L E I N F O Article history: Received 17 June 2011 Received in revised form 23 December 2011 Accepted 5 March 2012 Keywords: Direct flushing Implantation rate Pregnancy rate A B S T R A C T Objective: To evaluate whether intrauterine injection of embryo culture supernatant before embryo transfer has any impact on pregnancy and implantation rates. Study design: A total of 400 cycles, of which 200 IVF/ICSI and 200 oocyte donor (OD), were randomly assigned to have their uterine cavity injected (group I) or not (group II). Primary endpoints to be studied were pregnancy and implantation rates. Results: Clinical pregnancy rate per transfer (47.87%, 90/188 versus 48.45%, 94/194) based on transvaginal scan findings at 7 weeks of gestation and implantation rate (25.6% versus 26.5%) were similar in the two groups. The day of embryo transfer, day 3 or day 5, did not affect the final outcome. Conclusion: Injection of embryo culture supernatant into the uterine cavity, 30 min before the embryo transfer on either day 3 or 5, neither improves nor adversely affects the pregnancy rate in IVF/ICSI or oocyte donation cycles. ß 2012 Elsevier Ireland Ltd. All rights reserved. * Corresponding author at: Machedonomachon 3, Oreokastro, 57013 Thessalo- niki, Greece. Tel.: +30 2310325525; fax: +30 2310668881. E-mail address: petustam@mail.gr (S. Petousis). Contents lists available at SciVerse ScienceDirect European Journal of Obstetrics & Gynecology and Reproductive Biology jou r nal h o mep ag e: w ww .elsevier .co m /loc ate/ejo g rb 0301-2115/$ – see front matter ß 2012 Elsevier Ireland Ltd. All rights reserved. doi:10.1016/j.ejogrb.2012.03.003