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Embryo transfer

By: bb, 04 August 2008

Question: In advance I would like to say thanks for all of you who are going to give your best and try to solve this problem.Here it is... We have been using The Frydman ultra soft catheter for E.T.,but recently we started having the problems with embryos being left behind in catheter?What is the best way to load up the catheter?

Replies (4) Write a reply... Hi Guys, All your techniques and Mike's explanation is very valuable. I have worked in the field for many years and recently I found my approx volume of air and volume of embryo loading media for ETs which gives me higher pregnancy rates than my previous loading technique (31% vs 46%). I am looking ways to get this technique patent and manufacture a product with medical companies before publishing my technique. At present I have retrospective ET results performed by me in my clinic with improved P/rates. I am now in the process of finding embryologists in other clinics willing to use this technique to collect random data (global)with confidential agreement. I think ET loading technique can vary among embryologists and clinics. Our clinic doctors (2)push the syringe plunger and Embryologists load the inner catheter when the outer catheter is placed and ready for ET. Feel free to contact me if you need more info on this. I think Et is a technique which needs to be looked at very carefully and make adjustments to suit the clinic/individual to acheive great success. Shantal Rajah - 26 August 2008 Increase the loading medium volume is another way to prevent. We used to use 1 CC syringe and aspirate air, embryos, air and medium for about 20 ul (two lines in the syringe). We had embryo left in the catheter sometime (less than 1% ET). When we changed the loading volume to 40 ul (4 lines in the syringe), we never had such a problem any more, and the pregnancy was not affected. Weihua Wang - 25 August 2008 I have gone through what what Mike has said. I think he is absolutely right. Embryo retension is only about 1% in our centre. Please follow every step meticulously. Good luck I am a clinician! Dee Kini - 12 August 2008 There are a lot a small details that can influence the incidence of retained embryos. If you don't want to try a series of transfers with a different catheter type, you will have to look critically at all aspects of the transfer, and I'm sure that I'll miss a few in this discussion. I don't mean to sound pendantic, but in the past, I've experienced the same thing with different style catheters (in the end, one episode had nothing at all to do with the catheter, yet in a second episode, it all had to do with the catheter - a manufacturing change that changed the shape of the inner lumen at the tip). Not all of the following will apply, but I've tried to ask the basic questions. Look at the catheter under a dissection microscope - have there been been manufacturing changes with the lumen of the catheter or the shape, or other aspects of the tip of the catheter? Does one person always load the catheter? Does one doctor always introduce the catheter at transfer? Does an embryologist push the syringe plunger for the doctor, or does the doctor push the syrine plunger? What is the speed of the syringe plunger push and is it consistent (remember laminar flow principles in the tip of the catheter)? Is the syringe disposable with a rubber tip or is it all plastic with an all plastic tip, or is it glass with a teflon tip plunger, or other? Is the catheter loaded directly from drops under oil, or from a dish of medium? What is the actual volume loaded in the catheter? Is the loaded volume always the same, e.g. do you load by feel or by eye or do you measure volume (it is easy to become complacent when you've done this over and over and over..)? Are the embryos at cleavage stage or blastocyst stage (subtle, but can change how the embryos move)? Is the volume in the catheter continuous or do you use air bubbles? If you use air bubbles, is it one, two, or three? If you don't use air bubbles, is the catheter held horizontally the entire time after loading? Does the doctor use transvaginal ultrasoud for the transfer? Do you score the tranfer as to difficulty, or for cervical mucus, or for blood? Are retained embryos higher for egg donor recipients, frozen embryo replacements, or patient cycles (this can be related to circulating estrogens/cervical mucus)? What medium do you use for loading the embyros, in terms of protein or other supplementation? Is the catheter loaded with a sufficient volume to actually push the embryos out, e.g. do you fill the catheter with a small volume of medium prior to loading the air bubbles if used, or the embryos? I've found most often, that for this clinic and for others, that retained embryos due to actual catheter loading technique occur with changes of loading volume, when the individual loading the catheter is trying to skimp on medium, including the pre-load volume, or the individual is under the belief that the smaller the volume the better. A good way to find out how much medium you use (and to QA different individuals) is to mock load a catheter, express the volume onto a dish, then measure the volume with an adjustable pipetter. The next most common factor has been related to the catheter itself, regarding manufacturing changes that are very subtle. The inner lumen diameter should be consistent across the volume loaded. If there are restrictions then the laminar flow aspect will change, which can dramatically change the movement of the embryos. I've found this problem to be lot related, and I've rejected entire shipmenst of catheters based on this. The other more obvious problem has been speed of the plunger push can become inconsistent, for example the individual believes that much faster is better, or really really slow is better, these are also common changes. Laminar flow. Whomever is doing the syringe push should watch the action of embryos (preferrably discard embryos) under the dissection microscope to see how speed changes the movement. It is hard to control the physiological aspects, e.g. cervical mucus, but I see two very different practice aspects in this clinic, where one doctor does a brief rinse of the cervix, the other does an extensive rinse of the cervix and cervical canal, and there are no differences in embryo retention. I hope this helps. Mike Michael L. Reed - 04 August 2008