Embryos are kept in a solution called an embryo transfer medium before being transferred to the uterus. Over the years, much research has been performed to determine whether there are ways to increase the chance of embryo implantation. One area of research has focused on the addition of adherence compounds to the embryo transfer medium in an attempt to increase the chance of the embryo adhering to the uterus, with a greater chance of pregnancy and the birth of a healthy newborn as a result.
EmbryoGlue® is a special transfer medium that contains a high concentration of hyaluronan which is a natural substance found in all tissues of the body including the uterus. The concentration of this molecule in the uterus increases during the implantation window and then gradually returns to a normal level. The high concentration of hyaluronan in EmbryoGlue® tries to mimic the condition in the uterus at around the time of embryo implantation, and it also makes EmbryoGlue® more viscous thus minimizes the drifting of the embryo inside the uterus and the chance of expulsion of the embryo out of the body.
A meta-analysis of the 16 studies involving nearly 4000 women found that the addition of a high concentration of hyaluronan to the embryo transfer medium improves the chance of pregnancy and increases the live birth rate by up to 8%. However, the evidence obtained from this meta-analysis is of moderate quality only because amongst all the 16 studies that contributed to this finding, only one was of high quality, whilst the others were of moderate quality. Therefore, more high quality studies are needed before it can be regarded as a generalized recommendation.
Although the evidence does seem to favor the use of EmbryoGlue®, the meta-analysis also showed that the chance of a multiple pregnancy is higher with the use of EmbryoGlue®. The increase in multiple pregnancy may be the result of improved implantation and pregnancy outcomes due to the addition of hyaluronan.
As its role is to aid embryo implantation, EmbryoGlue® is of greatest benefit to patients who have the following conditions:
Women 35 years of age or older;
Couples with repeated implantation failure after multiple embryo transfers;
Couples with poor quality embryos.