function is typically directly linked to a woman's age.
A female has the greatest number of eggs that she will
ever have when she is in her mother's womb at midgestation,
or 20 weeks. She has approximately 7 million eggs at
that time, and the number of eggs declines throughout
At birth, the number of eggs is decreased to about 2
million. By the time of her first menstrual cycle, a
woman has only had about 300,000 eggs left. The rate
of loss (or death of her eggs) is a function of her
age. A woman is always loosing eggs, even when she is
pregnant. The only thing that changes is 'how fast'
the eggs die off.
a woman is about 28- 29 years old she starts to loose
eggs a little faster, and by the time she is 35 the
rate of loss of eggs is much increased. By the time
a woman is 40 years old, the rate of dying eggs is extremely
rapid. A woman will ovulate approximately 450 eggs in
her reproductive lifetime, less than 1% of her initial
count. By the age of 35-40 the quality of her eggs are
decreasing, such that by age 40 the chance of conceiving
(with her own eggs) is no more than 10- 15 %. As a woman
gets older her chances of pregnancy and subsequent delivery
is extremely low, with an increased risk of chromosomal
abnormality. Thus, after 35 years of age, a woman has
an increased risk of having a child with Down's syndrome
(and other chromosomal abnormalities).
is no direct way to determine a woman's egg quality.
However, we have indirect ways to access egg quality.
One way is to simply measure hormones, FSH, LH and estradiol
on the third day of the menstrual cycle. If the FSH
is elevated (regardless of the woman's age) she may
have less than 5% chance of getting pregnant with her
can also measure and count the number of egg pockets,
named follicles that she has on the third day of her
menstrual cycle. Eggs are microscopic and cannot be
seen by the naked egg. However, we can see and measure
the egg pockets on transvaginal sonogram. It is generally
accepted that greater than 14 egg pockets (follicles)
are reassuring of fertility. Less than 5-7 follicles
( antral follicle count, or AFC) is significant for
decreased ovarian function or reserve.
test is the Clomid challenge test (CCT). With the CCT
blood is taken on the third day of the menstrual cycle
(checking for the hormones FSH, LH and estradiol). The
woman then takes two Clomid pills (100mg) on cycle days
5 through 9 and she returns on the following day (cycle
day 10) for repeat labs (FSH, and estradiol). This test
is usually recommended for any woman 35 years old or
greater. If either set of labs (day 3 or day 10) is
abnormal, this woman may have less than a 5% chance
of getting pregnant with her own eggs. A woman that
is menopausal typically have an FSH level of 25 or greater.
For example, a woman who is 40 years and has an FSH
of 68, and an AFC of 4, probably has less than 1% chance
of getting pregnant with her own eggs.
(follicular stimulating hormone) is a hormone that stimulates
the eggs to mature and grow within the ovaries, (along
with LH) is produced by the pituitary gland in the brain.
These hormones send messages to the ovary, and in response
the ovary makes estrogens (primarily estradiol). The
estrogen 'message' is sent back to the brain and as
long as the ovary is competent and makes the estradiol
the brain is happy and continues to send 'normal' amounts
of FSH signal back to the ovary.
if the ovary has decreased ovarian reserve (less competent),
the FSH will be elevated. Imagine being in the kitchen
of your home and you're calling out to your husband
who is in the living room (watching TV) and he doesn't
hear you. What are you going to do? Well, you're going
to call him again, and again and perhaps louder each
time (maybe even yelling his name eventually). Well,
this is what happens to the communication between your
brain and ovaries.
If the ovary is not responding (not making enough estradiol)
it fails to communicate with the brain (as your husband
not responding to your calling his name). This will
invariably cause the brain to send more and more messages
(perhaps yelling at the ovary, as you may have done
to your husband). Thus, the lower the ovarian function
the higher the FSH level will be in the blood. So a
high FSH level is not good. This is thus an indirect
indication of poor ovarian reserve or ovarian compromise.
eggs cannot be resurrected, if a woman has a significantly
elevated FSH level, her best option for pregnancy may
be donor eggs. Women over 35 should especially seek
an infertility specialist early (after 6 months of unprotected
intercourse without conception). Of course women 40
years and above should seek an infertility specialist
an Article on Delayed Childbearing Trends by Gordan