Updated on May 18, 2022

Is "quality" more important than quantity when it comes to eggs?
4 things you can start doing now to help with your fertility journey

egg
High-quality eggs
Daily care

Reading time: 4 minutes 30 seconds

When it comes to eggs, quality is more important than quantity!? 4 things you can do now to prepare for conception.

Three common powers of "high-quality eggs"
Daily care for developing healthy eggs

Dr. Masahide Shiotani, Chairman of the Board, Ei Women's Clinic

Supervision

Chairperson of the Board, Ei Women's Clinic: Professor Masahide Shiotani

After graduating from Shimane Medical University in 1985, she joined the Department of Obstetrics and Gynecology at Kyoto University. At Kyoto University, she belonged to the in vitro fertilization team and pursued research while working on the clinical aspects of infertility, earning a PhD in Medicine (Kyoto University) in 1994. Her research theme was the analysis of the implantation process of fertilized eggs. From 1994 to February 2000, she worked at Kobe Central Municipal Hospital. During this time, she contributed to the birth of the first baby conceived through intracytoplasmic sperm injection (ICSI) in Hyogo Prefecture. In March 2000, she opened the Ei Women's Clinic, a specialized infertility clinic.

Three common powers of "high-quality eggs"

Illustration of a woman who is troubled.

Last time, I was surprised to learn that the number of eggs decreases every day regardless of ovulation, and that the rate of decrease varies from person to person.

Professor Masahide Shiotani

Yes, that's true. I think it's something that's surprisingly not well known.
As I mentioned, what's important for a body that's likely to get pregnant isn't the number of eggs, but actually the "quality of the eggs."

Are your eggs decreasing every day!? The surprisingly little-known functions of the ovaries.

Illustration of a woman who is troubled.

Why is egg quality so important?
I thought the number of eggs was related to how easily one could get pregnant.

Professor Masahide Shiotani

For example, if a 20-year-old woman has the same number of eggs as a 40-year-old woman, one might assume that her ovarian age is 40, but this is actually incorrect.
While the number of eggs may be small, the quality of each remaining egg is completely different from that of a 40-year-old.

Illustration of a woman

What constitutes a "high-quality egg"?

Professor Masahide Shiotani

A high-quality egg is one that possesses the following three qualities:

1. It has the power to awaken from its slumber and grow.

For example, an egg released at age 30 remains immature for 30 years (due to the action of AMH). Then, when it's time, it suddenly begins to grow.
It is said that the growth period is approximately 40 hours. Only eggs that have the power to awaken from a long slumber and grow rapidly in such a short time as 40 hours can reach ovulation. It is said that about 1 in 10 eggs lack this power.

2. It has the power to receive sperm and fertilize.

Even if sperm reach the egg, some eggs may not be able to be fertilized. This happens about 1 in 10 eggs. Including the eggs with low sperm strength (as explained earlier), approximately 2 out of 10 eggs are unlikely to be fertilized. (This explains why the fertilization rate in in vitro fertilization is about 70%.)

3. (Cells) have the power to divide.

After fertilization, the fertilized egg repeatedly divides as it implants in the uterus. In the five days leading up to implantation, it must divide approximately 100 times. It requires the power to continue dividing at a rapid pace.

Illustration of a woman who is troubled.

So, eggs need a lot of power, huh?
Where does that power come from?

Professor Masahide Shiotani

Mitochondria are organelles that are the source of energy production.
When mitochondria produce energy, reactive oxygen species are inevitably released. As we age, if the amount of reactive oxygen species exceeds the amount of energy produced, the amount of energy decreases, which can affect the power of egg cells.
These reactive oxygen species accumulate in the body due to lifestyle habits, so daily care is also important to ensure that eggs can perform at their best.

Daily care for developing healthy eggs

Illustration of a woman

Please tell me about daily care I can do to maintain egg quality.

Professor Masahide Shiotani

There are four important points for developing healthy eggs.

1. Avoid smoking and excessive drinking.

Smoking is such a bad habit for eggs that you can tell if someone smokes just by looking at their eggs. In fact, you often see that the fertilized eggs of smokers divide very slowly, and the division is uneven.

2. 7-8 hours of sleep is ideal.

While some people in certain professions may have unavoidable circumstances, maintaining a regular lifestyle is essential for creating a body that is more conducive to pregnancy.

3. Don't bottle up stress.

Stress can cause poor blood circulation and the generation of reactive oxygen species. It's important to manage stress effectively.

4. Eat a balanced diet that includes seasonal foods.

Instead of relying on convenience store food or frozen meals, try to eat a balanced diet of seasonal ingredients.
Furthermore, in recent years, many people have been found to have low levels of folic acid and vitamin D. It's important to actively utilize supplements to make up for any nutrient deficiencies.

Illustration of a woman who is troubled.