puberty, she could have about
250,000 left. With each
menstrual cycle, one of these
ovarian follicles will mature into an egg
to be released into the Fallopian tube
– but thousands more continue to die
off through follicular atresia. (This is why
taking the Pill, which stops ovulation,
does not work to ‘save your eggs’. The
vast majority of ovarian follicles die off
anyway, month by month.)
By the age of 30, the average
woman has about 12% of her original
supply. By 40, only 3% remain. By the
time of menopause, she has almost
none. It’s not only this ever-reducing
‘quantity’ (technically known as our
diminishing ‘ovarian reserve’) that
reduces fertility. As time ticks by
and the ovarian follicles age, there’s
a crucial decline in ‘quality’ too. Up to
75% of the eggs in a woman over 39
are chromosomally abnormal. (People
commonly associate this with birth
defects, which is correct, but more
often, it simply prevents conception
or causes miscarriage.)
“Basically, the eggs pass their sell-by
date,” explains Dr Gillian Lockwood,
medical director of Midland Fertility
Services. “The older the egg, the
greater the chance of a chromosomal
abnormality. It also determines the
levels of oestrogen in your body
which will determine the thickness
of the lining of the womb and the
quality of the cervical mucus – basically
all the factors necessary for
a successful pregnancy.”
BUYING�TIME
However, women have evolved since
the time our biological clock was set.
We now live twice as long as we did
200 years ago. We’re an inch taller
than we were in 1960. Evolution has
also driven us to become more
����WWW�STYLIST�CO�UK
beautiful as scientists have found
beautiful women are more likely to
have more children and we’re more
likely to be pear-shaped as those with
a small waist in comparison to their
hips statistically find it easier to fall
pregnant. Shouldn’t it follow suit that
our biological clock has evolved too?
And if not, surely science must be able
to buy us a little more time?
The hard fact is that our biological
clock is still stuck in the stone age.
However, there are some signs that it
may be beginning to catch on.
Fascinating statistics from the Office
for National Statistics found that
unmarried women over 35 have
emerged to have much higher fertility
levels than their married counterparts.
The stats suggest that the bodies of
those women not yet in a settled
relationship instinctively know that
they need to prolong their period of
fertility. Nature’s way, if you like, of
ensuring reproduction.
Until our biological clock does catch
up to the 21st century, there are also
ways that modern medicine can buy
you a little more time.
Polly Alexander, 35, a marketing
manager says, “I always thought I’d be
married with children by 25.” But, as
always, life got in the way. “People
assume that you’ve made a decision
to delay motherhood but that isn’t the
case.” So in January last year she
called Midland Fertility Services to find
out if she could buy some time. Egg
freezing was their answer.
Despite huge media attention, egg
freezing is still in its infancy. A woman
receives or self-administers two weeks’
of hormone injections to stimulate her
ovaries and ripen multiple eggs. She
returns to the clinic where her eggs are
retrieved through an ultrasoundguided
needle inserted into her vagina
ADD YEARS TO
YOUR FERTILITY
X COMPARATIVE GENOMIC HYBRIDISATION (CGH): up to 75% of
the eggs in women aged over 39 have an abnormality. This process
selects only the normal ones for fertilisation. Experts believe it could
double the chances of women’s IVF success rate.
X EGG FREEZING: eggs are stored in liquid nitrogen until you’re
ready to use them through standard IVF. In theory, this buys you as
much time as you want since they can be transferred back at any age
– though you’d be hard pushed to find a UK clinic that would do it
much beyond age 50. UK success rate: 16.7% per transfer.
X EGG DONATION: the best option for a woman over 40 who has not
frozen her eggs earlier is to use eggs donated by a fertile woman under
35. As with egg freezing, women can and do become pregnant using this
method. UK success rate: around 50%.
X SURROGACY: uses the egg of the surrogate mother and sperm of
the intended father and the resulting embryo is artificially
inseminated into the intended mother. Can be performed in an IVF
clinic or at home. UK success rate: support group COTS
(Childlessness Overcome Through Surrogacy) estimate that 98% of
the arrangements they set up result in live births.
– then frozen in liquid nitrogen. They’re
then thawed, fertilised and transferred
into the client when the time is right.
Midland Fertility Services was one of
the first to offer egg freezing – and, to
date, the five babies born in the UK as a
result have been ‘made’ here. In March
2009, Polly opted to have a go, too, to
use in the future.
A�HAPPY�OUTCOME
Science is also lowering the risks
associated with older motherhood, too.
An older woman unable to become
pregnant because of poor-quality eggs
can now have them screened for
chromosomal abnormalities during
IVF. Last September saw the first
successful birth in the UK as a result. A
41-year-old woman who’d had 13 failed
IVF treatments had her eggs
analysed during an IVF cycle
at the Care Fertility Clinic
in Nottingham. Eight eggs
were tested and only two
were normal. One went on
to produce a baby,
named Oliver.
Another option
which the medical
world is getting
excited about is ‘ovarian
tissue freezing’, quite
“THE FUTURE
HOLDS SOME
EXCITING
POSSIBILITIES.
IN A MATTER
OF YEARS YOU
WILL BE ABLE
TO CONTROL
YOUR CLOCK”
possibly tomorrow’s best bet for
beating the clock. These slivers of
ovary – which are covered in egg
follicles – are removed and frozen
when a woman is young and has a
healthy reserve, then transplanted
back on to her ovary at a later date.
The idea is that the ovary is suddenly
covered in young eggs and a pregnancy
will occur naturally.
There have already been pregnancies
outside the UK using ovarian tissue
freezing. One involved a Missouri-born
woman, Amy Tucker, who had Hodgkin’s
lymphoma in 1998, aged 20, and decided
to have an ovary removed and frozen
before chemotherapy destroyed any
hope of it working.
This took place at the Infertility
Centre of Saint Louis under fertility
pioneer Dr Sherman J Silber. After
intensive chemo and
two relapses which
destroyed her
remaining ovary,
Amy went into
remission and
married her
childhood
sweetheart. In
January 2009, Dr
Silber thawed out
the ovary,
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