There has been a tremendous shift in society over the last 50 years regarding
childbearing. It used to be common for women to begin – and often
complete – their families in their twenties. As more women have
pursued higher education and joined the workforce, however, the average
age when pregnancy is first pursued has risen steadily. Although it is
a wonderful development of the last half-century that women can be full
participants in the workforce and all aspects of social life, the downside
is that for some individuals, this delay in childbearing can have significant
biological repercussions.
Why Is It More Difficult for Older Women to Get Pregnant?
As everyone knows, pregnancy becomes increasingly difficult as women age.
We have always known that there is a decrease in conceptions, which is
accompanied by an increase in miscarriages as well as in children with
genetic issues such as Down's Syndrome as women age. These observations
are a consequence of changes to the eggs over the passage of time. We
can be certain of this because of the proof that treatment using Donor
Eggs provides. Today we know that we can retrieve eggs from a donor in
her twenties, fertilize those eggs with sperm and then transfer the ensuing
embryos into the uterus of women in menopause. That menopausal woman is
able to conceive and carry as if she were in her twenties proving that
the observed declines are not a consequence of an aging uterus or less
potent hormones, rather it is the consequence of changes to the eggs.
Today we can freeze eggs and stop their deterioration. Using IVF technology,
we can retrieve eggs from a woman's ovaries and freeze them. Even
though they may be kept frozen for years, upon thawing they perform as
they would have on the day they were frozen. It's as if we can stop
time! Eggs which have been frozen and then thawed, perform essentially
in the same fashion, with the same outcomes as they would have if they
had not been frozen at all.
About the Egg Freezing Process
The process itself is straightforward and typically takes about one month
to complete.
Synchronization
The first part of the process begins with a menstrual cycle. At that time,
the ovaries are prepared by giving them a “vacation.” Typically
birth control pills are used for a couple of weeks. During this phase,
the existing follicles have a chance to synchronize thereby setting up
a cohort, ie a group of eggs ready to grow together. This also facilitates
scheduling of the process overall.
Stimulation
Once synchronization has been achieved, the stimulation can begin. During
this time, daily subcutaneous injections of hormones are used to stimulate
the growth of multiple follicles. These injections are easy to do at home.
These are the same needles that diabetics use for their daily insulin
injections. Most women find they can do these injections themselves.
Typically the stimulation will take about 10-12 days in total. During the
stimulation, we monitor the growth of the follicles (and indirectly the
eggs) via vaginal ultrasounds and blood tests. These visits become increasingly
frequent and become daily at the end of the process for 3-5 days in a
row. Each visit is fast, just the time needed to draw blood and do an
ultrasound, so most women are in and out of the office within 30 minutes.
Although each visit is not a big deal, the fact that they become so frequent
makes for a very busy week.
Egg Retrieval
The stimulation culminates with the egg retrieval when the eggs are removed
from the ovaries. This process is carried out under IV sedation so the
women are asleep through the process. The aspiration of the follicles
is done under ultrasound guidance and usually takes less than a half hour.
Upon completion of the aspiration, the sedation is stopped and the women
wake up, typically describing menstrual type symptoms. Because IV sedation
has been used, this is the one day in an egg freezing cycle in which women
cannot drive themselves or go to work.
All in all, the process takes about one month, the last week of which is
busy with 3-5 office visits. The previous 3 weeks, we may see the patient
once or twice.
What Happens Next?
Once the eggs are frozen, they will last indefinitely for all practical
purposes. If they are thawed and fertilized 10 years later, they will
function essentially as they would have on the day they were frozen. A
40-year-old woman can, therefore, reproduce with her 30-year-old eggs.
It is a mind-boggling concept that a woman can serve as her own egg donor
to her future self!
Egg freezing is a tool which can revolutionize a woman's reproductive
life. Women no longer need to feel pressured to get pregnant just because
their “clock is ticking.” The uterus does not seem to age
from a practical point of view and as egg donation has shown, menopausal
women can successfully carry the pregnancy. This observation coupled with
egg freezing will allow women to have their pregnancies when they are
ready to do so rather than under pressure from a biological standpoint.
An amazing change in human reproduction!