The number of eggs a woman has changes throughout her lifetime, starting from when she is in the womb. Read on to find out just how and why this change occurs.

How many eggs does a woman have?

If you're carrying a baby girl in your uterus, she will start making eggs right there in your womb. She has to make all her eggs while still developing in the womb because she cannot produce anymore once she is born. On the other hand, boys continue to produce sperms as they grow into men.

So, how many eggs does a woman have?

While in the womb, the female fetus will have about 6 million to 7 million eggs. However, by the term you push her out at birth, she will be left with only a million eggs. By the time she has her first period at puberty, this number will have plummeted and about 300,000 eggs remain.

Going by numbers only, this still seems to be a large amount to last a lifetime. However, majority of these will not even be release to have a chance at fertilization and becoming a baby. The ovaries will only release about 300 to 400 eggs during your lifetime.

How does a woman's reproductive system work?

Your system is a complex cycle that goes through various phases. The main goal of this is to put forward a viable egg so that it can get fertilized and bring forth another life.

During this process, plenty of eggs are lost each month whenever one is presented for ovulation. Each month, you might lose around 1000 eggs, with only one chosen to continue to try its chance at furthering life.

As state earlier, all this happens in phases which make up your menstrual cycle.

What are the phases of the menstrual cycle?

The cycle contains three phases:

1. follicular phase

2. ovulatory phase

3. luteal phase

In the follicular phase, the pituitary gland in the brain releases follicle stimulating hormone (FSH) and luteinizing hormone (LH). These stimulate the growth of around 20 eggs in their ovarian follicles. The increasing presence of FSH causes the ovaries to release estrogen which in turn prevents further release of FSH to prevent overstimulation of the follicles.

Further along in this phase, one follicle dominates the rest and becomes primed for ovulation while the rest wither away.

After two weeks since the beginning of the previous phase, you enter the ovulatory phase. In this phase, the estrogen and LH work together to release the egg from the follicle- ovulation. This egg then goes into the fallopian tube, awaiting a sperm to fertilize it.

When ovulation is done, your cycle moves into the luteal phase. During this time, the empty follicle transforms into the corpus luteum. It releases more estrogen and another hormone, progesterone. The latter prepares your uterus for pregnancy, thickening the walls in anticipation of a fertilized egg.

However, when the egg is not fertilized, it passes through without implanting. The uterus sheds the thickened walls which you see as your period. The cycle then repeats.

How can you the number of eggs you are left with?

If you are trying to get pregnant, you can always check for the number of eggs you are left with. This is known as your ovarian reserve.

There are a number of ways to check your ovarian reserve, including antral follicle count (AFC), ovarian volume, and anti-mullerian hormone (AMH).

AMH is a hormone that the follicles secrete. Higher amounts indicate that you have a larger amount of follicles still present. The AFC test is an ultrasound scan that involves counting the number of antral follicles in the first 2 to 4 days of the cycle. A combination of these tests gives you a better idea of the number of eggs you're left with.