Why Embryos Don’t Stick (and What You Can Do About It)

One of the most common questions IVF specialists hear is: “If everything looked good, why didn’t my embryo stick in the uterus?” This question often arises after an embryo transfer that seemed promising but didn’t result in pregnancy. Understanding why embryos fail to implant and what can be done to improve the chances of success is crucial for individuals and couples undergoing IVF.

This report will explore why embryos don’t stick, what causes these failures, and what steps can be taken to improve embryo implantation rates during IVF.

The Two Main Steps in IVF

In vitro fertilization (IVF) consists of two major stages:

1. Creating an embryo in the IVF laboratory
2. Transferring the embryo into the woman’s uterus

The process of creating embryos takes place outside the body, where embryologists can observe and test the embryos to find the ones that are most likely to implant. However, even with advanced technology, many embryos created through IVF fail to result in a pregnancy. This can be frustrating, especially when everything seems to be going well.

Why Don’t Embryos Stick?

Abnormal Embryos

The majority of embryos produced during IVF are not capable of becoming a baby. These are often referred to as “bad embryos.” Even though advanced methods exist to help identify these abnormal embryos, they are not foolproof. Embryologists typically rely on visual observation under a microscope to assess embryo health. Good embryos tend to divide in a certain way, while abnormal embryos may exhibit the following signs:

1. Embryos that Don’t Divide After fertilization, the embryo is supposed to divide into two cells, then four, and so on. If an embryo doesn’t divide or stops dividing, it’s known as an “arrested” embryo, and it should not be transferred into the uterus because it has no chance of producing a pregnancy.
2. Embryos that Divide Too Slowly The best embryos reach the eight-cell stage by the third day after retrieval and the blastocyst stage (over 100 cells) by the fifth or sixth day. Embryos that divide more slowly than this have a reduced chance of implantation.
3. Fragmented Embryos A healthy embryo divides evenly into equally sized cells. However, some embryos develop small fragments during cell division, which reduces their chance of successful implantation. The more fragments observed, the less likely the embryo will stick.
4. Degenerating Embryos Sometimes, even though an embryo is still developing, signs of degeneration appear, such as darkening cells. These embryos are likely to stop developing soon after.

What Causes Embryo Development Problems?

There are three main factors that can cause these problems:

1. Sperm Quality
2. Egg Quality
3. Laboratory Conditions

Each factor plays a significant role in determining whether an embryo will develop normally or face abnormalities that reduce its chances of successful implantation.

Embryo Abnormalities that Can’t Be Seen Under a Microscope

Not all embryo issues are visible under a microscope. Some embryos may look perfect and divide normally but still be abnormal due to chromosomal issues. Chromosomal abnormalities are one of the leading causes of failed implantation in IVF.

Chromosomal Issues

Embryos with an abnormal number of chromosomes, known as aneuploidy, have a much lower chance of resulting in a pregnancy. Humans should have 46 chromosomes—23 from the mother and 23 from the father. However, many embryos created during IVF do not have the correct number of chromosomes, often due to issues with the egg, especially in older women.

As women age, more of their eggs become of lower quality, resulting in higher rates of embryos with chromosomal abnormalities. These embryos often fail to implant, and if they do, they are more likely to result in miscarriage.

What Can Be Done to Improve Embryo Implantation?

There are a few strategies to increase the chances that an embryo will implant and lead to a successful pregnancy.

Can You Improve Egg Quality?

Unfortunately, no. There is no evidence that lifestyle changes, dietary supplements, or even acupuncture can improve egg quality. Once a woman is born, she already has all the eggs she will ever have, and these eggs decline in quality over time, especially after the age of 35. While it may be tempting to explore various treatments to boost egg quality, there is no proven method to do so.

Can You Improve Sperm Quality?

Yes, possibly. Unlike eggs, sperm are produced continuously throughout a man’s life. This means that improving sperm quality is possible through lifestyle changes, such as avoiding smoking, maintaining a healthy weight, and managing stress. There are also techniques that IVF labs can use to select the best sperm for fertilization.

Choosing the Best IVF Laboratory

The quality of the IVF laboratory is crucial in maximizing the chances of a successful implantation. Leading IVF labs focus on small details that can make a big difference, such as:

• Maintaining optimal air quality
• Providing each patient with their own incubator
• Ensuring that culture conditions are ideal for embryo growth

These measures help create the best possible environment for embryos to develop, increasing the likelihood of success during transfer.

In a Conclusion

While not all embryos are capable of producing a successful pregnancy, understanding the factors that contribute to embryo failure can help individuals make informed decisions during the IVF process. Improving sperm quality, selecting the best embryos, and choosing a top-notch IVF laboratory are all ways to boost the chances of success. However, it’s important to acknowledge that some aspects, such as egg quality, cannot be changed.

By staying informed and working with experienced fertility specialists, couples undergoing IVF can optimize their chances of embryo implantation and pregnancy success.