By the time a woman is born, they have 1-2 million eggs remaining, and by the time they hit puberty, they have around 300,000-400,000 eggs. In a woman's reproductive years, they will lose roughly 1000 eggs but ovulate only one egg each month.
How many eggs do women have in their 30s? There is no one right answer to this question, as certain factors – such as smoking or other personal factors – may mean a woman has fewer eggs than others. The average number of oocytes at the age of 30 would be around 72,000 (12% of maximum pre-birth levels).
As eggs, or Oocytes, are microscopic, you cannot really determine how many you have. However, the immature egg cells secrete a hormone call AMH (anti-Mullerian hormone) which can be measured and interpreted in the context of what is the average measure of this hormone for one's age group.
The AMH Test
AMH is one of those hormones. The level of AMH in a woman's blood helps doctors estimate the number of follicles in her ovaries; the more follicles a woman has, the more eggs she can release, and the better her chances of pregnancy.
How many eggs does a woman have at 50? By the age of 50, you may still have around 1,000 eggs in your ovaries but they may not be healthy enough to start a pregnancy. Most women hit menopause between the ages of 45 and 55 years and that's when the reproductive activity completely shuts down.
The number of eggs decreases as women get older. At birth, most girls have about 2 million eggs, at adolescence that number has gone down to about 400, 000, at age 37 there remain about 25,000. By age 51 when women have their menopause they have about 1000 immature eggs but these are not fertile.
The study published by the University of St. Andrews and Edinburgh University in Scotland found that women have lost 90 percent of their eggs by the time they are 30 years old, and only have about 3 percent remaining by the time they are 40.
Doctors have tests to measure egg count.
There are two good ways to measure egg count: an antral follicle count and an AMH (anti-Müllerian hormone) test. During an antral follicle count, a doctor uses ultrasound to count the visible follicles.
Irregular period cycle and difficulty conceiving
If you are facing issues conceiving and have not been able to conceive for a while now, it could be one of the signs of bad egg quality.
An at-home follicle-stimulating hormone (FSH) test aims to tell users the status of their ovarian reserve, or the number of eggs remaining in the ovaries. FSH is secreted by the pituitary gland and stimulates the resting follicles inside the ovaries to develop and mature an egg for ovulation.
For example, a woman at 30 often has around 100,000-150,000 eggs in reserve. By 35, that number is likely around 80,000. Late into the thirties, that number could be 25,000, 10,000, or fewer.
At the age of 37, the average woman has around 25,000 eggs left, and by the time she reaches 51, this will have fallen to 1,000. “Just before menopause, your egg supply reaches below 1,000, and ovulations space out before they stop altogether, eventually,” says Dr. Sekhon.
The mathematical model shows that the average woman has only 12 per cent of her eggs left by the age of 30 and only three per cent by the age of 40. It provides further evidence that women are born with a fixed number of eggs, which declines with increasing age.
When a person is anovulatory, they cannot get pregnant because there is no egg to be fertilized. If a person has irregular ovulation, they will have fewer chances to conceive because they ovulate less frequently. Late ovulation does not produce the best quality eggs, which can also make fertilization less likely.
Supplements containing Myo-inositol, folic acid and melatonin have been shown to help improve egg quality and ovarian function.
The main cause of poor egg quality is age, but it is not the only one; there can be other reasons too, including but not limited to pelvic radiation, ovarian surgery, any reproductive illness, genetic abnormalities, chemotherapy, excess consumption of tobacco, alcohol, and some unknown factors.
In addition to its well-established role in neural tube defect prevention, research suggests folate plays an important role in promoting egg quality, maturation and implantation.
You can leave eggs on the counter about two hours at room temperature or one hour if the temperature is 90 degrees F or hotter before you start to worry, per the Egg Safety Center. After two hours, you'd be safer to throw those eggs out and get a fresh dozen rather than chance it.
Poor Quality Eggs & Poor Quality Embryos
An IVF cycle can be unsuccessful even with good numbers of eggs (and embryos) if egg quality is poor. Egg quality reflects about 95% of the final quality of an embryo. Poor egg quality, therefore, always leads to poor embryo quality.
Women are born with all the oocytes they're ever going to have. Every passing year they lose eggs until they “run out”. When all of their eggs are gone they've reached menopause. During their reproductive years their eggs grow in little “bubbles” on the surface of the ovary called follicles.
Menopause occurs naturally when a woman's ovaries run out of functioning eggs. At the time of birth, most females have about 1 to 3 million eggs, which are gradually lost throughout a woman's life. By the time of girls' first menstrual period, they have an average of about 400,000 eggs.
Because women in their late 30s and 40s have a higher percentage of abnormal eggs, it's much more likely that their one egg each month will be abnormal. That's why natural fertility declines with age, and why we see infertility, miscarriage, and genetic disorders more often with women over 35.