How Many Eggs is a Woman Born With?

Many people are pretty in tune with their bodies. So, for instance, you won’t have any difficulty pointing to that tight spot on your shoulder that knots when you’re tensed.

Yet you might be anxious about more about what’s going on within your body. For example, maybe you want to know the “real gist” behind your eggs.

Do babies with ovaries have eggs at the time of birth?

The short answer is YES!

All babies with ovaries are born with all the egg cells they will ever have. This is because they don’t make any new egg cells during their lifetime.

This has been accepted as a fact.

A 2004 study by Joshua Johnson et al. claimed that new egg stem cells were formed in mice. However, this theory has since been refuted by the scientific community. Nevertheless, a small group of researchers is still pursuing this work.

By mi_viri | Adobe Stock

How many eggs are babies with ovaries born with?

A fetus with ovaries has over 6 million eggs. These eggs are called oocytes. The number of oocytes in a human with ovaries is steadily reduced, leaving the baby with 1–2 million eggs.

Why does the menstrual cycle not start from birth?

Excellent question! The truth is that the eggs are there, so why does the menstrual cycle not start?

The menstrual cycle is on hold until a person reaches puberty. Puberty starts when the hypothalamus in your brain begins to produce a hormone called gonadotropin-releasing hormone (GnRH).

The GnRH stimulates the pituitary gland to produce follicle-stimulating hormone (FSH). FSH triggers the egg development process and causes an astronomic rise in estrogen levels.

During puberty, menstruation begins about two years after the breast bud. The breast bud means the appearance of the tissue that develops into a breast. Menstruation begins at an average age of 12 but can also start as early as eight. Most people experience their first menstruation by the age of 15 years.

How many eggs are left by puberty?

A human with ovaries has between 300,000 and 400,000 eggs when they reach puberty. This decrease is attributed to more than 10,000 eggs dying monthly before puberty.

How many eggs are lost monthly after puberty?

Once the follicles mature, they become more sensitive to the hormones of your monthly cycle.

Each month, the body naturally selects a group of eggs to ovulate. This group of eggs is known as “contenders.” But only one egg will become the dominant follicle.

The follicle contains the egg that has been ovulated that month, and that one egg represents your chance at conceiving that month. (There may be exceptions, for instance, in the case of fraternal twins).

The other eggs in the “contenders” group that haven’t been selected will die off — a process known as atresia. This process happens every month. First, you ovulate a single egg, and the rest die off. The cycle continues until the individual reaches’ menopause, where no eggs are left.

It is important to note that the number of eggs that die every month decreases after puberty. After the start of the menstrual cycle, a person loses no less than 1,000 immature eggs monthly.

Medical researchers are not sure what prompts this, but factors beyond our control mainly influence it. For example, it is not affected by the following:

Pregnancies
Your hormones
Birth control pills
Nutritional supplements

The data is not yet precise on whether food choices or health status affect the quantity or quality of oocytes.

There are a few exceptions. According to a 2018 study, smoking speeds up egg loss. Some chemotherapies and radiation accelerate egg loss too.

Why does egg quality decrease as you get older?

We’ve discussed the number of eggs a person has. But we’ve not said anything about the quality of these eggs.

Age is an essential factor that determines the quality of an egg. As you get older, the quality and quantity of your eggs decrease. This is because, before your monthly ovulation, your eggs start to divide. In older eggs, errors may occur during this division process, thus increasing the chance that they will contain abnormal chromosomes.

As the egg quality decreases, the genetic material becomes damaged and irreparable. So, when sperm and the egg combine to form an embryo, there is a higher chance of genetic defects or chromosomal abnormalities.

This explains the high risk of having a baby with Down syndrome in old age. A chromosomal abnormality is also a common cause of miscarriages.

Takeaway

If getting pregnant is a goal and has been difficult, the information we’ve discussed on the average number and life cycle of your eggs may help you discuss your concerns with a healthcare professional.

If you have questions or concerns about your ovarian reserve or egg quality, speak with a board-certified OB-GYN or fertility doctor who can help assess your risk factors and discuss your options.

Suppose you’re concerned about your eggs’ life cycle time limits. In that case, you may want to consider freezing your eggs, also known as oocyte vitrification or elective fertility preservation (EFP).

Although many people consider freezing their eggs because of the time limits mentioned, others may consider it before starting chemotherapy treatments that could affect their fertility.

Considering EFP? According to one source, your chances of having a child with your frozen eggs are better if you freeze before age 35.

It’s also important to remember that the more eggs you freeze, the better your chances of having a baby if you choose to do so or need to use those eggs. Also, if you’re younger, freezing a higher number of higher-quality eggs is more likely.

However, reproductive technologies, such as in vitro fertilization (IVF), allow people to start or grow their families much later.

Though IVF with your own eggs is unlikely to be viable if you have difficulty with fertility and are older than your early 40s, according to research from 2015, donor eggs from a younger person can allow people in their 40s and 50s to conceive.

Talk with a doctor early and often about fertility plans and how fertility can change over time. Know that you have options.

Disclaimer: Dr. Berner does not diagnose, treat, or prevent any medical diseases or conditions; instead, he analyzes and corrects the structure of his patients with Foundational Correction to improve their overall quality of life. He works with their physicians, who regulate their medications. This blog post is not designed to provide medical advice, professional diagnosis, opinion, treatment, or services to you or any other individual. The information provided in this post or through linkages to other sites is not a substitute for medical or professional care. You should not use the information in place of a visit, consultation, or the advice of your physician or another healthcare provider. Foundation Chiropractic and Dr. Brett Berner are not liable or responsible for any advice, the course of treatment, diagnosis, or any other information, services, or product you obtain through this article or others.