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The eggs that launched a thousand
headlines
Montreal mom Melanie Boivin
didn't make the decision to freeze her eggs for
her daughter lightly. Ms Boivin's seven-year old
daughter suffers from Turner's syndrome, a condition
that will make her infertile by the time she reaches
adulthood, and Ms Boivin wanted her to have the
option to have babies later on. So after much
thought, the 35-year old lawyer went to the McGill
Reproductive Centre (MRC) for help. Little did
she know she'd set off an ethical controversy.
If she decides to use her mother's
eggs, Flavie Boivin could give birth to her own
sibling. Ms Josephine Quintavalle, of UK lobby
group Comment on Reproductive Ethics, sees major
problems ahead for the future offspring. "In psychiatry
we are hearing more and more of children suffering
from identity problems, more specifically a condition
called 'genealogical bewilderment'," Ms Quintavalle
said in a BBC interview. "Could it possibly get
more bewildering than this?"
There have been cases of sister-to-sister
egg donations, but this mother-to-daughter one
was a medical first. Dr Seang Lin Tan, the MRC's
director, asked the advice of an independent ethics
committee before going ahead with the procedure.
"The committee agreed to it because the mother
giving to a daughter is out of love," Dr Tan told
the BBC.
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Switching off a woman's ovaries
during chemo protects her fertility later on, according
to a study presented July 3 at the European Society
of Human Reproduction and Embryology in Lyon.
Australian researchers used a gonadotropin-releasing
hormone (GnRH) analogue to switch off the brain signal
for ovulation while the pre-menopausal women were taking
high doses of the chemo drug cyclophosphamide. A whopping
94% of the women returned to normal menstrual cycles
within a year.
Early menopause is a common side
effect of the chemo med when used in women as young
as 30. Alkylating agents like cyclophosphamide reduce
the number of eggs in a woman's ovaries. The decreased
ovarian reserve means that the longer women stay on
the drug, the higher the risk of infertility. "The risk
increases with age and dosage," says fertility expert
and lead author Dr Kate Stern, Royal Women's Hospital,
Melbourne. "The women in our study received high doses
of cyclophosphamide."
OVULATION
SUPPRESSED
Dr Stern and her team studied 18 women between the ages
of 18 and 35, who were due to undergo chemo. The patients
were given three injections of cetrorelix, a GnRH antagonist,
at four day intervals to coincide with their chemo treatments.
The ovaries were switched off during treatment and switched
back on when the chemo stopped.
The way the analogue works is not
completely clear, Dr Stern says. But suppressing ovulation
protects the remaining eggs from the chemo drug, making
it easier for women to conceive naturally after treatments.
"Other studies have tried to analyze
whether similar treatments work, but the medications
used have been long-acting and therefore cause shutdown
for the whole time the patient is in chemo," says Dr
Stern. "This means that patients get unpleasant side
effects related to having low estrogen levels, such
as hot flushes, that can also lead to loss of bone mass."
Dr Stern's brief GnRH-antagonist
treatment produced few side effects. "It's a short acting
analogue," Dr Stern explains. "Only 6% of the women
reported persistent side effects and none of them were
dangerous or serious."
Next step for the doc and her team
is a large randomized trial on 400 female cancer patients.
FERTILE
GROUND
Women about to undergo chemo currently have few options
to protect their fertility. They can have their ovarian
tissue removed and frozen, then re-implanted at a later
date. This technique is still experimental and requires
surgery as well as holding off on the chemo — a
big risk for many cancer patients.
Another alternative for women is
to have their eggs frozen for future use. Until recently,
this method required ovarian stimulation so the eggs
could mature in the ovaries before being collected.
Unfortunately, the hormonal stimulation increased estrogen
levels which makes some tumours, like estrogen-receptor
positive breast cancer, grow. Another new development
— by McGill researchers and unveiled at the same
conference — gives women the option to freeze eggs
before they mature. But Dr Stern's method has the distinct
advantage of avoiding surgery.
BABE
IN ARMS
Dr Stern expects many patients will not see these methods
as either/or options, but rather choose to do both.
She's thrilled with the new research being done in the
field. "The medical community needs to acknowledge the
importance of future fertility for young people having
cancer treatments," she says.
Over 10,000 young adults, ages
20 to 44, are diagnosed with cancer every year, according
to a 2006 Health Canada survey. More than half are women
and fertility tops their list of concerns. Yet a concurrent
report in the American Journal of Clinical Oncology
shows that fertility preservation methods are rarely
used.
"Not all patients having cancer
treatment have the opportunity to talk with a fertility
specialist before beginning treatment," says Dr Stern.
"And yet there are already several options for protecting
the ovaries and even preserving eggs, embryos or ovarian
tissue. In addition to raising awareness among the medical
profession, more support is needed for research in this
important area," she adds.
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