What are the reasons behind failed blastocyst culture?

Let’s explore the reasons for failed blastocyst culture from both internal and external factors. Blastocyst culture refers to continuing the in vitro cultivation of day 3 embryos to develop into blastocysts on days 5–6.

Blastocyst culture is essentially a process of embryo selection. Embryos with poor quality and developmental potential tend to halt development early and self-eliminate, while higher-quality embryos continue developing into blastocysts. The development potential of the embryo is largely related to the quality of the sperm and egg, as well as the embryo's quality formed after fertilization.

If the sperm or egg quality is poor, it will directly affect the embryo’s quality. Such embryos are more likely to stop growing before reaching the blastocyst stage. For instance, sperm morphology, motility, source, and DNA damage can significantly reduce the blastocyst formation rate.

Additionally, the choice of which cleavage-stage embryos to culture is also an important factor affecting blastocyst formation. Most fertility centers typically prioritize freezing or transferring the 1–2 highest-rated embryos, while the remaining embryos are cultured into blastocysts. This strategy can slightly influence the blastocyst formation rate. Furthermore, if the cleavage-stage embryos from a particular patient are of poor quality, blastocyst culture may be chosen to further select embryos with developmental potential. This shows that the strategy for transferring cleavage-stage embryos also plays a role in blastocyst formation.

External Causes of Blastocyst Failure

In addition to the embryo's inherent quality, blastocyst culture demands a high level of expertise in the laboratory environment and from the embryologist!

Whether it’s blastocyst culture or embryo culture, the goal is essentially to simulate the environment of the mother’s body. However, even the most advanced laboratories in the world cannot fully replicate the maternal environment. Since sperm, eggs, and embryos are extremely fragile, the process of blastocyst culture requires perfection in both the environmental conditions and the technical skills.

For instance, in cleavage-stage embryos, pyruvate is the key energy source for early development, while glucose becomes the more important energy source during the blastocyst stage. Different developmental stages of embryos require different nutrients, and a stable yet adaptable culture environment is essential for successful blastocyst culture. This means that the embryologist must have precise control over the amount and timing of culture medium changes, as well as real-time monitoring of embryo development, allowing for prompt responses to any abnormal situations to ensure the culture process proceeds smoothly.

Therefore, although blastocysts are more compatible with the uterine environment, blastocyst culture is not universally applicable. For patients with a low number of embryos or embryos of poor quality, the chances of complete failure in blastocyst culture are high. As a result, RSMC’s professional doctors evaluate the patient's specific situation, weigh the pros and cons, and make the most reasonable decision regarding embryo transfer, freezing, or continuous culture.

In conclusion, apart from the internal factors (sperm and egg quality), choosing a top-quality laboratory and advanced techniques is the key to successful blastocyst culture and the development of superior embryos!

Most standard laboratories can culture embryos up to five days, but RSMC’s laboratory is already equipped with the technology to culture embryos for up to 7.5 days, making it one of the few laboratories in the world capable of culturing embryos to this level. The advancement in technology means that RSMC’s embryologists must frequently and precisely control all conditions affecting embryo development, sometimes returning to the lab at 2 or 3 a.m. to observe the blastocyst's condition and adjust the environment. Many external factors can harm developing embryos. To address this, RSMC’s laboratory has specially designed HVAC systems and high-performance air filters that circulate the air in the lab 20 times per hour, significantly reducing the risk of embryo contamination.

In addition to using genetic screening technologies to ensure embryos are free from hereditary diseases, such as Preimplantation Genetic Diagnosis (PGD) which screens for over 200 genetic disorders, and Preimplantation Genetic Screening (PGS/PGT-A) to screen for chromosomal abnormalities, we also use a time-lapse imaging system for real-time embryo monitoring. Combined with AI-driven big data analysis, we can identify the best-quality embryos, significantly improving IVF success rates.

From our in-house egg bank to the surrogate talent pool and laboratory operations, RSMC aims to provide you with a comprehensive service, ensuring every detail that may affect success rates in the IVF process is handled to perfection. If you're interested in IVF treatments or need more information about the process and costs, feel free to contact us for a free consultation via video call with Dr. Harari, the director of RSMC, who has over 30 years of clinical experience. Dr. Harari will offer you professional fertility advice. Please contact us on Line / WeChat: rsmctw, WhatsApp: +1 858-342-6046.

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