It’s an embryo transfer media that contains among other things, high levels of a special component called hyaluronan, also known as hyaluronic acid. Embryo glue is designed specifically for embryo transfer to ease the embryo’s adhesion to the mucous membrane of the uterus. The special component in the glue helps the media wrap itself around the embryo and enhance its adhesion capabilities with the mucous membrane of Uterus due to the "sticky factor" of Hyaluronan.
What is Hyaluronan?
Hyaluronan occurs naturally in your womb, fallopian tubes and ovaries. Studies have shown that it makes secretions from these organs stickier, aiding fertilisation and implantation. Studies show that Hylarunan’s secretions increases exponentially during the receptive stage and immediately declines the next day. This indicates the importance of hyaluronan in initial stages of implanatation.
What does Embryoglue do?
Embryo glue mimics the composition of uterine secretions. Although the similarity in composition between the viscous embryoglue solution and the uterine secretions partly explains the improved implantation rates, it is the high levels of Hyaluronan in the embryoglue that makes the components of the embryoglue mixable with the uterine secretions. It also plays a major role in helping the embryo adhere to the endometrium, there by aiding implantation.
The process of implantation has three stages:
Stage1 - Contact Stage:
The high viscosity of the glue makes the content of the transfer medium mixable with the uterine fluid thereby enabling the embryo to stay within the uterine lumen. By enabling the embryo to stay in the uterine lumen it helps minimize the unwanted movement of embryos. The viscous embryo glue solution readily diffuses with the viscous uterine secretions and brings the embryo into close contact with the endometrium.
Stage 2 - Adhesion Stage:
The embryo expresses cell surface glycoprotein called CD44. The CD44 is a receptor for Hyaluronan. CD44 receptor are also found in the cell wall of endometrium cells exclusively during the receptive phase. The Hyaluronan have pods on its surface that act as receptacles for these CD44 receptors to dock on. Therefore The Hyaluronan molecules effectively serve the purpose of linking the CD44 receptors on the embryo and CD 44 receptors of the endometrium, thereby tightening the contact between the two. Hyaluronan is naturally present in the Uterine Secretions as well as provided externally by the embryoglue. In this stage the glue helps the embryos to adhere, by working on certain specialized enzymes secreted by the uterus which increase the adhesion rate.
Stage 3 - Implantation:
Embryoglue helps in implantation, it helps in cohesion between the cells of the embryo and endometrial lining of the endometrium. Once the embryo is able to settle into a suitable position the invasive part of implantation can begin.
When is it used?
On your embryo transfer day, your embryos are dipped into the ‘glue’. Then they’re placed in your uterus. The adhesive effect of the medium may help your embryos stick to your endometrium.
What about statistics?
When EmbryoGlue was used for embryo transfer the clinical pregnancy rate was significantly increased from 41% to 50% compared to when a conventional culture medium with low or no hyaluronan was used. The meta-analysis of the 13 publications included in the Cochrane review article included more than 3200 patients. Importantly, the analysis did not show any increase in miscarriages or other adverse events. The conclusion by the Cochrane authors was that “a clear positive effect (of having high concentrations of hyaluronan in the transfer medium) was identified”. Clinical Pregnancy rates over age 34 having a day 5 embryo transfer
Standard Transfer Medium
Clinical Pregnancy Rate in Patients with Multiple Failed Attempts
According to the results of a study done by Dr. Basak Balabanov, which were presented in 2011 at the ESHRE (European Society of Human Reproduction and Embryology), the number of births using EmbryoGlue® increased by 11.2%.