In vitro fertilization (IVF) is a popular fertility treatment today that involves fertilizing a woman’s egg with a man’s sperm in a laboratory dish.

Although IVF has enabled thousands of couples to conceive a child who otherwise would not have been able to, the success rate of this procedure is still low. Only about one-third of IVF embryos result in a live birth, which means that two-thirds never develop fully. This raises an important question: What stops two-thirds of IVF embryos from developing?.

Chromosomal abnormalities

One of the most common reasons why many IVF embryos fail to develop is due to chromosomal abnormalities. Chromosomes are the structures in a cell that hold genetic information.

Embryos with chromosomal abnormalities usually have too few or too many chromosomes, which makes it difficult for them to divide and develop normally. This can lead to miscarriage or abnormal growth and development of the embryo. In fact, studies have shown that nearly 70% of failed IVF cycles are due to chromosomal abnormalities in the embryo.

Poor quality embryos

Another reason why some IVF embryos fail to develop is because they are of a poor quality. Embryos that are of poor quality have abnormal cell division, are not symmetrical, and have uneven cell sizes.

They may also have fragmentation or other abnormalities. These abnormalities make it difficult for the embryo to implant in the uterus or to continue growing normally.

Poor quality embryos can result from various factors such as the woman’s age, exposure to environmental toxins, or a genetic predisposition.

Implantation failure

Implantation is a crucial step for the development of any embryo. For IVF embryos, successful implantation is critical for their development to continue.

Factors that can lead to implantation failure include issues with the embryo itself, problems with the uterine lining or implantation environment, or immune system issues. For example, embryos that are too large or too small may not be able to implant properly. Similarly, women with thin or damaged uterine linings or those with hormonal imbalances may also struggle with implantation issues.

Some women may also have immune system issues that cause their body to reject the embryo, leading to implantation failure.

Age is a major factor when it comes to IVF success rates. As women age, their eggs begin to decline in quality and quantity. This means that older women may produce fewer viable embryos or embryos with chromosomal abnormalities.

Women over the age of 35 are more likely to experience implantation failure, miscarriage, or birth defects in the baby. Age-related factors may also affect the quality of the uterus, making it more difficult for the embryo to implant and develop normally.

Problems with the sperm

It’s not just the egg that matters when it comes to achieving a successful IVF pregnancy; the quality of the sperm also plays a role.

Sperm quality can be affected by various factors such as age, lifestyle habits, genetic defects, or medical conditions. Sperm that are of poor quality may not be able to fertilize the egg or support embryo development properly.

In some cases, the sperm may have structural defects or may have a low sperm count, leading to failed fertilization or problems with embryo development.

Infection or inflammation

Infection or inflammation of the reproductive system can also impact the success of IVF treatment.

Infections such as chlamydia, gonorrhea, or bacterial vaginosis can cause inflammation of the uterus or fallopian tubes, which can make it difficult for the embryo to implant properly. In some cases, these infections can also affect the sperm quality or cause damage to developing embryos.

Even mild inflammation can lead to the production of reactive oxygen species, which can damage the egg or embryo and prevent it from developing normally.

Toxic exposures

Exposure to toxins and environmental pollutants can also impact the success of IVF. Toxins such as lead, cadmium, or mercury can cause damage to the egg or sperm, leading to chromosomal abnormalities or poor embryo quality.

Exposure to pesticides and other chemicals can also lead to problems with implantation or fetal growth. Women who are exposed to toxins may have a harder time getting pregnant, and those who do become pregnant may be at a higher risk of miscarriage or birth defects in the baby.

Genetic factors

Finally, genetic factors can also play a role in determining the success of IVF treatment. Some women may be carriers of genetic mutations that affect their fertility or the quality of their eggs.

Similarly, men may carry genetic mutations that impact the quality of their sperm or their ability to fertilize an egg. In some cases, these genetic factors may make it difficult for embryos to develop normally or lead to chromosomal abnormalities that prevent the embryo from developing into a healthy baby.

Conclusion

IVF is a complex and often challenging process, and there are many factors that can impact the success of this treatment.

While some of these factors can be addressed through lifestyle modifications or medical intervention, others may be beyond our control. By understanding the various factors that impact the success of IVF treatment, couples can work with their healthcare providers to optimize their chances of success and achieve their dream of having a healthy baby.