If you polled your female patients
on contraception, it's almost certain that a good number
of them would prefer a non-hormonal method of birth
control. Some can't take oral contraceptives (OCs),
some just don't want to, and still more don't like "messing
with their bodies." Even patients who opted for the
patch for its ease of use may now be tempted to switch
— a study published in Obstetrics and Gynecology
in February found that women who use the patch are twice
as likely to develop blood clots as those on OCs.
Whatever their reasons, more and
more of your patients will be asking you for an alternative.
It's certainly not for everyone, but natural family
planning (NFP) might be what some are looking for. A
large study just published in Human Reproduction
suggests it's as effective as OCs. But before they jump
on the "all-natural" bandwagon, make sure they have
all the facts.
TIMELESS
SOLUTION
Not to be confused with the calendar or rhythm method,
NFP relies on the observation of physical symptoms to
predict a woman's fertile period, during which abstinence
is required. "With the calendar method, the woman basically
guesses when she will ovulate next from past experience,"
explains Dr Suzanne Parenteau, a retired GP and medical
advisor for Serena, a community-based organization that
promotes NFP. "But if she goes on vacation, is stressed
or has an infection, the cycle will change. With modern
NFP, we observe ovulation based on the physical changes
caused by hormones, which take those changes into account.
It's very different," she says.
There are several methods of NFP,
but tell your patients that each relies on physical
cues to predict fertility. The main ones taught in Canada
are the Billings Method, which is based only on changes
in cervical mucous, and the more comprehensive symptothermal
method (STM), which measures this as well as basal body
temperature (BBT), the position of the cervix and other
minor changes.
DOES
IT WORK?
According to the Society of Obstetricians and Gynaecologists
of Canada (SOGC), the efficacy of STM (or the Billings
method, which yields similar results) is nowhere near
comparable to OCs — with a Pearl Index of 15-20
(unplanned pregnancies per 100 women). "If you really
don't want to get pregnant, then I personally don't
think this is the way to go," says Dr Melissa Mirosh,
an ob/gyn in High River, AB, who sits on the SOGC's
Contraception Awareness Program committee. "It's certainly
not something I would recommend to a teenager coming
to me for birth control," she says.
Dr Parenteau says more recent data
places the practical efficacy between 5-10. It's the
theoretical efficacy that approaches that of OCs —
with failure rates between 0-1%.
Both agree that it's the difference
between theoretical and practical use that's key. "People
have to have had good training," says Dr Parenteau.
"But if they follow the rules, it can be very, very
effective."
OVULATION
CHECKLIST
NFP requires a significant commitment on behalf of the
woman — and her partner — to record daily
observations and abstain from sex during the "fertile"
periods, usually the "eight to ten days around ovulation,"
according to Dr Parenteau.
It's much too complex to explain
correctly in a quick office visit, but here's some basic
info you can pass along to patients.
Cervical mucous As ovulation
approaches, the cervix opens and the discharge will
become more abundant, thinner and clearer. It's akin
to raw egg whites.
Cervical self-examination
The opening and position of the cervix are also very
useful indicators of ovulation, says Dr Parenteau. As
it approaches, the cervix is "raised", "open" and "soft".
"You have to reach higher up to feel it," she explains.
BBT Basal body temperature
will rise by a few degrees just after ovulation. But
this is only useful as confirmation that ovulation has
occurred. "Temperature alone has no predictive value,"
says Dr Parenteau.
WORK
FOR PLAY
As Dr Mirosh points out, this may be more self-awareness
than many of your patients are ready for. "Patients
have to be very, very motivated to do it. It takes a
lot of work, and a reasonable amount of abstinence that
both the man and the woman have to be prepared for,"
she says. "It's critical that patients understand that."
Dr Parenteau agrees. "Of course
not all couples will be interested, but some people
are willing to put in the effort. To me, it should always
be presented as a choice," she says. Another advantage,
she says, is that since NFP predicts fertility, it can
just as easily be used to encourage pregnancy as to
prevent it. "More and more of the patients that are
coming to see us are actually trying to conceive," she
says.
If a patient expressed interest
in using NFP as a contraceptive, Dr Mirosh says she
certainly won't discourage them. "What I personally
tell people is 'how important is it to you to not be
pregnant?' If they don't really mind, then why not?"
For more information on the STM,
refer your patients to www.serena.ca.
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