If you've been told that your embryos "stopped developing" or "arrested" during an IVF cycle, you're not alone — and it's not your fault.
Embryo arrest — when IVF embryos stop growing before reaching the blastocyst stage — is one of the most common and emotionally challenging parts of the IVF and surrogacy journey. Whether your embryos stopped growing on Day 3, failed to reach Day 5, or you're simply trying to understand what causes poor embryo development, this guide is for you.
The truth is, embryo arrest happens far more often than most people realize, and science is making real progress in understanding why — and what we can do about it.
In this blog, we'll walk you through the causes of embryo arrest in simple, clear language, share insights from the latest medical research, and outline practical steps you and your fertility team can take to improve your chances going forward.
🔑 Key Takeaways
- Embryo arrest is extremely common. Depending on age and egg quality, it's normal for only 30–50% of fertilized eggs to reach the blastocyst stage — even in healthy patients. Up to two-thirds of IVF embryos may stop developing before transfer.
- It's usually not one single cause. Embryo arrest results from a mix of factors including chromosomal errors, egg and sperm quality, energy supply within the embryo, and laboratory conditions.
- Maternal age matters — but it's not the whole story. While chromosomal abnormalities are a leading cause of arrest, recent research shows that even chromosomally normal embryos can stop growing, pointing to other metabolic or cellular pathways.
- Sperm quality plays a bigger role than many people think. Sperm DNA damage is increasingly recognized as a contributor to poor embryo development.
- There are real, evidence-based strategies to improve outcomes — from lifestyle changes and advanced lab techniques to donor gametes and genetic counseling.
- Having embryos arrest does NOT mean you can't have a baby. Many intended parents go on to have healthy pregnancies after experiencing arrest in earlier cycles.
What Is Embryo Arrest, Exactly?
Let's start with the basics.
After an egg is fertilized in the IVF lab, it begins dividing — from one cell to two, then four, then eight, and so on. By around Day 5, a healthy embryo should form what's called a blastocyst — a tiny ball of about 100 to 200 cells that's ready to be transferred to the uterus.
Embryo arrest simply means that an embryo stops dividing before it reaches this stage. Many intended parents first hear about it when their IVF clinic reports that their embryos stopped growing on Day 3, or failed to develop to Day 5. This Day 3 to Day 5 window is the most critical period for embryo growth — and unfortunately, it's where most arrests occur. Once an embryo stops, it won't start again, and it can't be used for transfer.
Here's the part that surprises most people: this is incredibly common. Depending on age and egg quality, it's normal for only 30% to 50% of fertilized eggs to reach the blastocyst stage. A study published in PLOS Biology confirmed that up to two-thirds of IVF embryos may experience developmental arrest. A separate Johns Hopkins University study, published in Genome Medicine (2023), found that nearly half of the embryos they tested stopped developing due to genetic errors that occurred during early cell division.
Can arrested embryos recover and start growing again? Unfortunately, once an embryo truly arrests, it does not resume development. That's why understanding the causes of poor embryo development — and what you can do to reduce the risk — is so important.
Why Do Embryos Stop Growing? The 6 Main Causes of Embryo Arrest in IVF
The short answer: it's complicated. Embryo arrest is rarely caused by just one thing. Instead, it's usually a combination of biological and environmental factors working together. Here's what the latest science tells us:
1. Chromosomal Errors During Cell Division
Every time an embryo's cells divide, all 46 chromosomes need to be copied perfectly. If the copying machinery makes a mistake — resulting in too many or too few chromosomes (a condition called aneuploidy) — the embryo often stops growing as a natural safety mechanism. Chromosomal abnormalities remain one of the leading causes of embryo arrest, and this risk increases with maternal age.
What's particularly interesting is that a 2023 Johns Hopkins study found that most of these errors don't come from the egg or sperm themselves. Instead, they happen after fertilization, during the embryo's own cell divisions. This is actually encouraging news — because it means these errors might be reducible by improving how embryos are cultured in the lab.
A large 2025 study in the journal Aging, analyzing nearly 26,000 embryos, added another important layer: while arrest rates climb with maternal age (from about 33% in women under 35 to 44% in those over 42), aneuploidy alone doesn't explain all of this increase. Even chromosomally normal embryos can arrest, suggesting that other metabolic or cellular pathways — like mitochondrial energy production — are also at play. This is actually good news, because it means there may be more ways to intervene than previously thought.
If this has happened to you — please know that it's a normal part of human reproduction, not a reflection of anything you did or didn't do.
2. The Embryo Can't "Switch On" Its Own DNA
For the first two to three days after fertilization, the embryo runs on stored instructions from the egg — like a car running on reserve fuel. Around Day 3 — typically at the transition from the 4-cell to the 8-cell stage — something critical must happen: the embryo needs to activate its own genome and start reading its own DNA. Scientists call this embryonic genome activation (EGA).
Research published in PLOS Biology showed that a significant group of arrested embryos simply fail to make this switch. Without its own genetic program running, the embryo has no roadmap for continued development.
In some cases, this failure is linked to inherited mutations in what are called maternal-effect genes — genes like PADI6 and TLE6 that are active in the egg before fertilization. If you've experienced embryo arrest across multiple IVF cycles, this could be a factor worth exploring with a genetics specialist.
3. The Embryo Runs Out of Energy
Think of mitochondria as tiny batteries inside every cell. Each egg contains about 100,000 of them, and they're responsible for powering the rapid cell division that an embryo needs in its first days of life.
If these batteries are weak — due to aging, oxidative damage, or genetic factors — the embryo simply doesn't have enough energy to keep growing. Studies in animal models have shown that older eggs have weaker mitochondrial function, which directly leads to lower blastocyst rates. When researchers transferred healthy mitochondria into these eggs, development improved.
This is one of the reasons why egg quality matters so much — and why younger egg donors tend to produce embryos with higher developmental potential.
4. Sperm DNA Damage
Here's something that doesn't get talked about enough: the sperm's role in embryo arrest.
Sperm DNA fragmentation (SDF) — essentially tiny breaks in the sperm's genetic material — is increasingly recognized as a significant factor in poor embryo development. A 2025 study analyzing 870 ICSI cycles found that for every 1% increase in sperm DNA fragmentation, the chance of producing a top-quality blastocyst on Day 5 dropped by about 2.5%.
What causes sperm DNA damage? Common culprits include oxidative stress, advanced paternal age, smoking, excessive alcohol, obesity, heat exposure, and environmental toxins. The silver lining? Many of these are lifestyle factors that can be improved.
The sperm also contributes the centrosome — the structure that organizes chromosome separation during cell division. If the centrosome is defective, the embryo's cell divisions can go wrong from the very start.
5. Oxidative Stress
Both eggs and sperm are exposed to reactive oxygen species (ROS) throughout their lives. In small amounts, ROS are normal and even helpful. But when levels get too high — from aging, smoking, poor diet, or environmental exposures — they create what's called oxidative stress, which damages DNA, proteins, and those critical mitochondria we just talked about.
Oxidative stress also weakens the egg's ability to repair sperm DNA damage after fertilization — a process that recent research in Reproductive BioMedicine Online (2025) highlighted as essential for healthy embryo development.
6. IVF Laboratory Conditions
The IVF lab is essentially trying to recreate the environment inside the human body — and even small differences can matter. Key factors include:
- Oxygen levels: The reproductive tract has only 2–8% oxygen, but the air around us is 21%. Research shows that culturing embryos at about 5% oxygen produces better results. Top labs use low-oxygen incubators for this reason.
- Air quality: Volatile organic compounds (VOCs) from cleaning products, perfumes, plastics, and building materials can harm embryos. The best labs use advanced air filtration and ban fragrances in the embryology suite.
- Temperature control: Even tiny fluctuations in incubator temperature can disrupt development.
- Culture media: The nutrient solution embryos grow in must be carefully formulated and contamination-free.
Lab quality varies significantly between clinics. This is one of the most important — and most overlooked — factors that intended parents can actually influence by choosing a high-quality fertility center.
What Can You Do About It? Practical Steps Forward
While embryo arrest can't always be prevented, there's a lot you and your fertility team can do to stack the odds in your favor:
✅ Improve Egg and Sperm Health Before Your Cycle
The 2–3 months before an IVF cycle are a critical preparation window. Both egg and sperm quality benefit from:
- A balanced, antioxidant-rich diet (think colorful fruits, vegetables, nuts, and healthy fats)
- Regular moderate exercise
- Quality sleep and stress management
- Avoiding smoking, excessive alcohol, and environmental toxins
For men with known sperm DNA fragmentation, antioxidant supplements (like CoQ10, vitamin C, vitamin E, and selenium) may help reduce DNA damage. Talk to your fertility doctor about testing and treatment options.
✅ Choose an IVF Lab with the Highest Standards
Not all labs are created equal. When selecting a fertility clinic, ask about:
- Low-oxygen (5%) embryo culture environments
- Time-lapse monitoring systems (like EmbryoScope) that observe embryos continuously without opening the incubator
- Air quality control protocols (HEPA and carbon filtration, VOC monitoring)
- The lab's blastocyst formation rate — this is a key performance indicator
The 2025 ESHRE/ALPHA Istanbul Consensus update emphasized that time-lapse technology and standardized observation protocols are now best practices for modern embryology labs.
✅ Consider Advanced Technologies
- ICSI (Intracytoplasmic Sperm Injection): Directly injects a single healthy sperm into the egg, which can help when sperm quality is a concern.
- PGT-A (Preimplantation Genetic Testing for Aneuploidy): Tests embryos that have reached the blastocyst stage for chromosomal normality, helping your team select the embryo most likely to result in a healthy pregnancy. 👉 Learn more about PGT-A testing
- Time-lapse monitoring: Allows embryologists to track developmental patterns and select the best embryos without disturbing the culture environment.
- Assisted oocyte activation: In rare, highly specific cases of recurrent total fertilization failure or severe arrest, calcium ionophore treatment can help kick-start the embryo's development. This is a specialized add-on — not routine — and should only be considered when recommended by your fertility specialist based on your clinical history.
✅ Explore Egg or Sperm Donation
If egg quality is a persistent concern — particularly related to age or recurrent arrest — using donor eggs from a younger, thoroughly screened donor can dramatically improve blastocyst formation rates. At Ivy Surrogacy, we work with a carefully vetted pool of egg donors and help match you with someone who fits your preferences and goals. 👉 Explore our egg donation process
Similarly, if sperm quality remains poor despite lifestyle changes and treatment, donor sperm may be an option worth discussing with your fertility specialist.
✅ Get Genetic Counseling If Arrest Is Recurrent
If you've experienced embryo arrest across multiple IVF cycles, it could point to an inherited genetic factor — such as mutations in maternal-effect genes (like PADI6 or TLE6). A reproductive genetics specialist can help determine whether genetic testing is appropriate and guide your next steps.
❓ Frequently Asked Questions
Q: Can arrested embryos recover and start growing again?
In almost all cases, no. Once an embryo truly arrests, it does not resume development. However, a small 2022 study in PLOS Biology showed that treating certain arrested embryos with a compound called resveratrol could restart cell division in some of them — though very few reached the blastocyst stage. This is an early-stage research finding, not a clinical treatment, but it gives scientists hope that future interventions may be possible.
Q: Why did my IVF embryos stop growing on Day 3 but not earlier?
Day 3 is a critical turning point. Before Day 3, the embryo runs on stored instructions from the egg. Around the 4-cell to 8-cell stage, it must activate its own DNA (a process called embryonic genome activation). If this switch fails — due to genetic issues, energy deficits, or other factors — the embryo stalls. That's why Day 3 arrest is so common.
Q: Is embryo arrest my fault?
Absolutely not. Embryo arrest is a natural biological event that happens in the majority of human embryos — both in IVF and in natural conception. It's not caused by anything you did or didn't do.
Q: How common is embryo arrest?
Very common. Depending on the patient's age, egg quality, and lab conditions, anywhere from 30% to 70% of IVF embryos may stop developing before the blastocyst stage. Even young, healthy egg donors don't see 100% of embryos make it — and that's completely normal.
Q: Does embryo arrest mean there's something wrong with my eggs?
Not necessarily. While egg quality is one factor, recent research shows that many arrests are caused by errors that occur after fertilization — during the embryo's own cell divisions. Sperm quality, mitochondrial function, and lab conditions all play a role too.
Q: Can embryo arrest be prevented?
It can't always be prevented, but the risk can be reduced. Optimizing egg and sperm health before your cycle, choosing a high-quality IVF lab, and using advanced reproductive technologies like ICSI and time-lapse monitoring can all help improve blastocyst formation rates.
Q: Should I consider donor eggs if my embryos keep arresting?
If embryo arrest is recurrent and linked to egg quality or age-related factors, donor eggs can significantly improve outcomes. This is a personal decision that should be made in consultation with your fertility doctor. 👉 Read our guide on fresh vs. frozen donor eggs
Q: Does the IVF lab really make a difference?
Yes — a significant one. Factors like oxygen levels, air quality, culture media, and temperature control all affect whether an embryo continues developing. Choosing a clinic with a state-of-the-art lab and experienced embryologists is one of the most impactful decisions you can make.
Q: What if my FET cycle gets canceled after embryo arrest?
Cycle adjustments and cancellations are a normal part of IVF. Your fertility team may recommend protocol changes, additional testing, or a new approach before your next transfer. The key is to stay in close communication with your doctor and trust the process.
Q: How does embryo quality relate to uterine lining preparation?
Both matter for a successful pregnancy. Even with a high-quality embryo, the uterine lining needs to be properly prepared for implantation. Your fertility team monitors both sides of this equation carefully. 👉 Read our guide on uterine lining and embryo transfer
💙 You Are Not Alone — And There Is a Path Forward
We know how much emotional weight each IVF cycle carries. When embryos arrest, it can feel like a devastating setback — especially when you've invested so much hope, time, and effort.
But here's what we want you to remember:
Embryo arrest is extremely common, even in the healthiest patients. It does not define your journey. Many of the intended parents we work with at Ivy Surrogacy have experienced embryo arrest — and have gone on to welcome healthy, beautiful babies.
At Ivy Surrogacy, we work closely with leading fertility clinics that use the latest lab standards and reproductive technologies. Our experienced team is here to walk with you through every step — answering your questions, connecting you with top specialists, and making sure you never feel alone on this journey.
Your dream of becoming a parent is still within reach. Let us help you get there.
👉 Apply as Intended Parents | Start Your Surrogacy Journey | Ivy Surrogacy 📞 Call us at (626) 545-1617 for a free consultation
References
- Hutchins, A.P., Tong, G., et al. (2022). Metabolic and epigenetic dysfunctions underlie the arrest of in vitro fertilized human embryos in a senescent-like state. PLOS Biology. View Study
- McCoy, R.C., et al. (2023). Genetic analysis of arrested IVF embryos reveals new insights into embryo fate. Genome Medicine, Johns Hopkins University. View Study
- Reig, A., Seli, E., et al. (2025). Embryo arrest correlates with maternal age but not blastocyst aneuploidy rate. Aging, 17(10). View Study
- Machałowski, T., Machałowska, J., Gill, K., et al. (2025). Sperm DNA fragmentation impairs early embryo development: Insights from 870 ICSI cycles. Int. J. Mol. Sci., 26(16). View Study
- Pardiñas, M.L., de Celis, C., Gil, J., et al. (2025). Oocyte-mediated repair of sperm DNA fragmentation. Reproductive BioMedicine Online. View Study
- Coticchio, G., et al. (2025). The Istanbul Consensus update: ESHRE/ALPHA consensus on embryo assessment. Human Reproduction Open. View Study
Disclaimer: This article is for educational purposes only and does not constitute medical advice. Always consult with your fertility specialist for guidance tailored to your specific situation.
