What is Thailand Embryo Glue Technology? The Real Role of Hyaluronic Acid Medium in IVF Transfer
In the reproductive clinic, I encounter patients almost every week who come with information on their phones and ask: "Doctor, is that embryo glue technology in Thailand really effective? My friend used it and succeeded, should I use it too?" As someone who deals with embryos, endometrium, and transfers every day, my answer is usually not "use it" or "don't use it," but "let me first see if your situation is suitable." Embryo glue is not magic; it is an adjunctive method with clear indications. Below, I will explain this clearly from the perspective of clinical decision-making.
1. What exactly is Thailand embryo glue technology?
Thailand embryo glue technology essentially involves using a specialized culture medium called "EmbryoGlue" (brand name) to treat embryos during the embryo transfer stage of in vitro fertilization (IVF). The core component of this culture medium is high-concentration hyaluronic acid (hyaluronic acid, typically at a concentration of 0.5 mg/ml), along with recombinant albumin, amino acids, vitamins, and other nutrients. Hyaluronic acid is a naturally occurring polysaccharide in the human body, abundant in uterine fluid, amniotic fluid, and joint synovial fluid. Before transfer, the embryo is placed in this culture medium for a short incubation of 20–30 minutes. Hyaluronic acid molecules attach to the embryo's surface, helping it bind to CD44 receptors on the endometrium, thereby enhancing adhesion ability—simply put, making it easier for the embryo to "stick" to the lining.
This technology is not unique to Thailand; many reproductive centers worldwide use it. However, some Thai clinics promote it as a signature procedure, leading many patients to mistakenly believe it is a "miraculous technology invented in Thailand." In reality, it is a well-established adjunctive method, but not a groundbreaking breakthrough.
2. Under what circumstances would a doctor consider using embryo glue?
As a clinical decision-maker, I do not routinely use embryo glue for first-time transfers or patients with excellent embryo quality. My decision is primarily based on the patient's previous transfer history, embryo quality, and endometrial receptivity. The following are situations where I would consider its use:
| Consideration Factor | Specific Scenario | Decision Tendency |
|---|---|---|
| Previous transfer attempts | 2 or more failed transfers with good quality embryos | Tend to use |
| Endometrial thickness | Endometrial thickness < 7 mm (measured on ovulation day or transfer day) | Tend to use |
| Embryo quality grade | Grade B or C embryos, fragmentation rate 15%–30% | May consider using |
| History of implantation disorders | Known poor endometrial receptivity or abnormal CD44 expression | Tend to use |
| First transfer with good embryo quality | AA or AB grade blastocyst, normal endometrium | Usually not used |
| Embryo chromosomal abnormality | PGT indicates aneuploidy or mosaicism | Not recommended |
It is important to note that the above decision tendencies are based on current clinical evidence and my personal experience, and are not absolute standards. Each patient's situation is unique, and the final decision requires comprehensive judgment.
3. The most easily overlooked details: timing, conditions, and operation
In clinical practice, I find that patients and even some practitioners often overlook key details that directly affect the effectiveness of embryo glue:
- Incubation time cannot be arbitrary: Embryos need to be cultured in embryo glue for 20–30 minutes. Too short a time results in insufficient hyaluronic acid binding, while too long may cause embryo stress. The laboratory timer must be accurate and not based on "feeling."
- Storage and rewarming: Embryo glue must be stored at 2–8°C in the dark. Before use, it needs to be rewarmed to 37°C in an incubator and the pH balanced. Using it directly from the refrigerator can harm the embryo.
- Incubator conditions: The binding efficiency of hyaluronic acid to the embryo is affected by the pH and osmolarity of the culture medium. The CO2 concentration, temperature, and humidity of the incubator must be stable; significant deviations can affect the outcome.
- Transfer procedure itself: Even with embryo glue, the choice of transfer catheter, the path into the uterine cavity, and the speed and position of embryo expulsion remain crucial. Improper operation can negate the advantages of embryo glue.
These details explain why the same technology can yield significantly different clinical results across different centers. The skill level of the laboratory and the experience of the embryologist are core variables.
4. Common pitfalls: misunderstandings about embryo glue
In my clinic, I often encounter patients with deep-seated misunderstandings. If these are not corrected, they can lead to wrong decisions or unnecessary financial losses:
- Misunderstanding 1: Embryo glue can compensate for poor embryo quality. The truth is, if the embryo itself has a very low grade (Grade D, fragmentation > 50%, slow development), or has chromosomal aneuploidy, embryo glue cannot improve these fundamental issues. It only helps with "adhesion" and cannot repair intrinsic defects in the embryo.
- Misunderstanding 2: Using embryo glue means you don't need to worry about the endometrium. The truth is, embryo glue only aids adhesion. If the endometrium is too thin, has poor blood flow, or has polyps or adhesions, the embryo will still struggle to implant. Endometrial preparation is fundamental; using embryo glue does not mean you can relax the requirements for the lining.
- Misunderstanding 3: Everyone should use embryo glue, and using it guarantees success. The truth is, for first-time transfers with good embryo quality and a normal endometrium, the benefit of using embryo glue is very limited. Blind use only adds unnecessary cost and may create false expectations for the patient.
- Misunderstanding 4: Embryo glue can replace PGT (preimplantation genetic testing). The truth is, embryo glue addresses the "adhesion" problem, while PGT addresses whether the embryo's chromosomes are normal. They are completely different things. For older patients or those with recurrent miscarriage, the value of PGT far exceeds that of embryo glue.
5. Differences in applicability across age groups
Age is an independent factor affecting IVF success rates and directly influences the decision-making value of embryo glue:
| Age Group | Embryo Chromosomal Abnormality Rate | Potential Value of Embryo Glue | Key Points for Doctor's Assessment |
|---|---|---|---|
| ≤ 35 years | Relatively low (approx. 30%–40%) | May consider use if recurrent failure | Prioritize ruling out endometrial and immune factors |
| 36–40 years | Moderate (approx. 40%–60%) | May help with implantation, but needs to be combined with PGT | Recommend completing chromosomal screening before reassessment |
| ≥ 41 years | High (approx. 60%–80%) | Limited effect; focus should be on embryo selection | PGT-A should take priority over embryo glue |
Simply put, the older the patient, the higher the probability of embryo chromosomal abnormalities, and the less problem embryo glue can solve. Under this premise, if a decision is made to use embryo glue, it should be done after completing embryo genetic screening to ensure that a chromosomally normal embryo is transferred.
6. Actual process: from decision to transfer
Below is a complete transfer process using embryo glue, for patients to understand:
- Morning assessment on transfer day: The embryologist performs a final grading of available embryos, and the clinician confirms endometrial thickness, morphology, blood flow, and hormone levels (E2, P4).
- Selecting the embryo: Choose 1–2 embryos of the best quality from all available embryos. If PGT has been performed, select chromosomally normal embryos.
- Transfer to embryo glue: Move the selected embryo from the standard culture medium (e.g., G-2 series) into the pre-equilibrated embryo glue culture medium.
- Incubate for 20–30 minutes: Culture in an incubator at 37°C, 6% CO2, 5% O2, recording the start and end times.
- Transfer procedure: Under abdominal ultrasound guidance, use a soft catheter to slowly inject the embryo along with the culture medium into the uterine cavity, ideally positioned 1–1.5 cm from the fundus.
- Post-transfer observation: The patient rests in a supine position for 15–30 minutes. If there is no significant discomfort, they can be discharged. Prolonged bed rest is not required; normal daily activities can be resumed.
The entire process is tightly coordinated between the laboratory and the operating room. Any mistake in any step can affect the final outcome. Therefore, when choosing a reproductive center, the strength of the laboratory and the teamwork of the staff are key factors to evaluate.
7. Summary of frequently asked questions
Below are the most common questions I am asked in the clinic, answered uniformly:
- Q: How much does embryo glue increase the success rate?
A: There is no fixed number. Different studies report improvement rates ranging from 5% to 15%, but individual variation is large. For suitable candidates, it may provide a meaningful boost; for unsuitable candidates, it may have no effect at all. - Q: Are there risks associated with using embryo glue?
A: It is currently considered quite safe, as hyaluronic acid is a natural human component. However, any in vitro procedure carries potential risks, such as culture medium contamination, operational errors, or allergic reactions (rare). Choosing an experienced embryologist and a well-regulated laboratory can minimize these risks. - Q: Does embryo glue require an additional fee? How much does it cost?
A: In most reproductive centers, embryo glue is an optional add-on and requires an extra fee. The cost varies by region and center, typically ranging from 3000 to 8000 RMB. In some Thai clinics, it may be included in a package, so it is advisable to clarify the cost details before treatment. - Q: If embryo glue doesn't work this time, can I use it again next time?
A: Yes. However, if implantation still fails after two uses, it is recommended to pause and conduct a comprehensive investigation, including endometrial receptivity testing, immune factors, chronic endometritis, and embryo chromosomes, rather than simply repeating the same protocol. - Q: Is embryo glue the same as assisted hatching (AH)?
A: No. Assisted hatching involves creating a hole or thinning the zona pellucida to help the embryo "hatch" out; embryo glue helps the hatched embryo "stick" to the endometrium. They can be used together, but they are not the same thing.
Risk Reminder
Although embryo glue technology has been used in assisted reproduction for many years and is generally considered safe, the following points still require attention:
- Culture medium contamination is a risk that cannot be completely eliminated in any embryo in vitro procedure. Choosing a reproductive center with a strict quality control system is crucial.
- Although rare, an allergic reaction to hyaluronic acid can occur, potentially causing a local uterine cavity response and affecting implantation. Patients with a history of allergies should inform their doctor in advance.
- Embryo glue cannot replace a comprehensive etiological investigation. If recurrent implantation failure occurs, systematic examinations such as hysteroscopy, endometrial receptivity testing, immune screening, and chromosomal screening should be completed concurrently with or before using embryo glue.
- Do not neglect the quality of the transfer procedure itself just because embryo glue is used. The skill and experience of the transferring doctor are also critical factors determining success or failure.
Every technology has its limits. Rational evaluation, scientific decision-making, and standardized operation are essential for embryo glue to play its proper role, rather than becoming a tool that is either mythologized or dismissed.
