Embryo glue is a hyaluronan-enriched culture medium used at the time of IVF (In-vitro Fertilization) embryo transfer. The embryo is placed in a tiny drop of this medium just before transfer to the uterus. Published evidence, including a Cochrane review, suggests a modest improvement in pregnancy and live birth rates, particularly in selected patient groups.
"Embryo glue" is a marketing term; biologically, it is a transfer medium enriched with hyaluronan (also called hyaluronic acid), a naturally occurring molecule already present in the female reproductive tract. The most widely studied formulation is EmbryoGlue, which contains a higher concentration of hyaluronan than standard culture media plus recombinant human albumin. Despite the name, embryo glue is not an adhesive; it does not stick the embryo to the uterus. Instead, it mimics the natural environment around the embryo at the time of implantation, supporting the embryo's interaction with the endometrium (the lining of the uterus).
Embryo glue has been available in well-equipped fertility laboratories for over two decades, but its use has expanded sharply in India over the last few years, including at Cloudnine Fertility-grade centres in Gurgaon and Delhi NCR. Three reasons explain this shift. First, a 2020 Cochrane systematic review of hyaluronan-enriched embryo transfer media reported a small but real improvement in clinical pregnancy and live birth rates, which gave clinicians more confidence to recommend it. Second, single embryo transfer is becoming standard practice in India to avoid the risks of twin pregnancy, which makes any incremental improvement in implantation per transfer valuable. Third, the cost of an embryo glue add-on is modest relative to a full IVF cycle, so couples with one or two failed cycles often ask whether it could tip the balance.
Embryo glue is best thought of as a biology-mimicking medium rather than a treatment that modifies the embryo. Its proposed mechanism, the published evidence, and its limitations are all worth understanding before deciding whether to add it to your cycle.
In a natural conception, the embryo travels through fluid in the fallopian tube and uterus that is rich in hyaluronan. This molecule supports cell-to-cell adhesion and helps the embryo communicate with the endometrium at the moment of implantation. Standard embryo transfer media contain only small amounts of hyaluronan. The idea behind embryo glue is straightforward: by raising the hyaluronan concentration to physiological levels, the medium more closely matches the natural environment, potentially improving the embryo's ability to attach to the uterine lining.
The procedure for the patient is identical to any other embryo transfer. There are no extra injections, no separate appointment, and no additional discomfort. What happens in the laboratory is straightforward: shortly before transfer, the chosen embryo is moved from its culture droplet into a small drop of embryo glue medium and allowed to equilibrate for typically 10 to 30 minutes. The embryologist then loads the embryo, surrounded by this medium, into the transfer catheter. The fertility specialist places the embryo into the uterus in the usual way. From the patient's experience, nothing changes.
The strongest evidence comes from a Cochrane systematic review of hyaluronan-enriched transfer media, which pooled data from multiple randomised controlled trials. The review concluded that hyaluronan-rich media likely improve clinical pregnancy and live birth rates compared with standard media, with the effect size best described as modest rather than dramatic. Numerically, the absolute improvement in live birth rate is typically a few percentage points, varying by patient group. Embryo glue does not appear to increase the risk of miscarriage, multiple pregnancy, or congenital abnormalities. The European Society of Human Reproduction and Embryology (ESHRE) lists hyaluronan-enriched media among IVF add-ons with at least some supporting evidence, though it stops short of recommending it for every cycle.
Most of the apparent benefit in the published trials is concentrated in patients who have already had implantation failure in previous cycles, those with lower-quality embryos, and women in older age groups, where implantation is the rate-limiting step. In couples with abundant, high-quality blastocysts at a young age, the cumulative live birth rate is already high, and the incremental benefit of embryo glue is harder to demonstrate. A Cloudnine fertility specialist will weigh your age, embryo quality, and previous cycle history when deciding whether to recommend it for you, rather than offering it as a default add-on.
Embryo glue is not appropriate for every IVF cycle. The most common situations in which a Cloudnine fertility specialist will discuss it include:
Embryo glue is a small but real clinical and financial decision. The questions below help anchor that conversation with a Cloudnine fertility specialist:
Embryo glue is not a fix for a poor-quality embryo, an unprepared endometrium, or an underlying medical issue. The most common patient disappointment comes from expecting embryo glue to turn a low chance into a high chance, when the evidence supports only a modest lift. A useful mental model is:
Embryo glue is a discussion, not a tick-box. The situations below are common reasons to ask a Cloudnine Fertility specialist whether it should be part of your transfer plan.
If any of these apply to you, book a fertility consultation with a Cloudnine specialist to discuss whether embryo glue fits your situation.
Outcomes are best understood as a small absolute improvement over an existing baseline, not as a transformation. The numbers below are indicative ranges drawn from published trials and clinical experience; your own results depend on age, embryo grade, uterine factors, and previous cycle history. A Cloudnine specialist will personalise these figures.
Embryo glue does not change embryo quality, does not lower miscarriage risk, and does not raise live birth rates dramatically. What it appears to offer is a small, real shift in the implantation step- sometimes enough to matter, especially when it lands on a baseline that is otherwise borderline.
