The decision to use contraception and the choice of one
method over another depend primarily on two practical matters:
Evaluating these two issues is complicated. No one
contraceptive method is always best or safest.
When evaluating effectiveness and safety, remember that
information from various sources may be biased. The
popular media, for instance, are eager to report the
latest news about the real or suspected hazards of a
contraceptive method . Yet the story is usually condensed
to a few paragraphs in the newspaper or is crammed into less
than sixty seconds of TV or radio broad cast time. Scientific
accuracy or caution is often lost in a process of oversimplification,
misinterpretation, and unwarranted conclusions. In addition,
much of the research on the effectiveness and safety
of birth control methods is paid for by the drug companies that
manufacture them. These companies have an obvious interest in presenting
their merchandise in a way that will boost sales.
All scientific
studies are not equivalent in their applicability to you.
In general, studies about people close to your age, cultural
background, and socioeconomic status are more meaningful than
studies about other groups. For example, if you are a twenty two
year old single Bangladeshi woman, you cannot put faith in the
findings of a study about thirty five year old married women in
American.
Understanding some other aspects of evaluating effectiveness
can also be helpful.
First, it is important to distinguish
between two factors: theoretical versus actual effectiveness.
The theoretical effectiveness of particular method is how
it should work if used correctly and consistently, without human
error or negligence. The actual effectiveness is what
occurs in real life, when inconsistent use or improper technique
( user failure ) combines with failures of the method
alone. For example, if couple
runs out of condoms on a week long camping trip yet continues to
have intercourse, the woman's subsequent pregnancy is not
counted as a method failure. But if she used a contraceptive
foam exactly according to instructions, her pregnancy qualifies
as a method failure.
Second, for most types of contraception, the longer a person
uses a particular method, the more effective it becomes.
The reason is that people improve their technique and
become more accustomed to using the method regularly.
Third, effectiveness' rates for almost every no surgical
contraceptive method vary depending on whether a couple uses the
method to prevent pregnancy or to delay (space ) pregnancy.
Failure rates are generally 50 to 100 percent higher for delay
compared to prevention, since there seems s to be less consistency
in method use.
There are other difficulties in assessing the safety of
contraceptive methods .
First there are often wide differences
in the frequency of side effects reported by different
investigator. Their results reflect differences in
research design, choice of control group, different
characteristics in the populations studied ) such as
age , health, socioeconomic status ), and the methods investigator
use to identify a problem (self-administered questionnaire,
personal interview, laboratory testing ).
Second, there are some
relative aspects to the safety question. How important is
avoiding pregnancy? Are the side effects of a
contraceptive method more or less serious than the risks
of pregnancy and childbirth? How do the risks of a contraceptive
method compare to other health risks ( such as the risk of getting
cancer of having high blood pressure ) or to risks of everyday
life?
These question will be addressed in more detail as we
review the safely and side effects of each method of
contraception.
Sexual
Physiology
