Barrier Methods of Birth Control
Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: William C. Shiel Jr., MD, FACP, FACR
Introduction to birth control
If a woman is sexually active and she is fertile and physically
able to become pregnant, she needs to ask herself, "Do I want to become pregnant now?"
If her answer is "No," she must use some method of birth control
(contraception).
Terminology used to describe birth control methods
include contraception, pregnancy prevention, fertility control, and family planning. But no matter what
the process is called, sexually active people can choose from a plethora of
methods to reduce the possibility of their becoming pregnant. Nevertheless, no
method of birth control available today offers perfect protection against
sexually transmitted infections (sexually transmitted diseases, or STDs), except
abstinence.
In simple terms, all methods of birth control are based on either preventing
a man's sperm from reaching and entering a woman's egg (fertilization) or
preventing the fertilized egg from implanting in the woman's uterus (her womb)
and starting to grow. New methods of birth control are being developed and
tested all the time. And what is appropriate for a couple at one point may
change with time and circumstances.
Unfortunately, no birth control method, except abstinence, is considered to
be 100% effective.
Barrier methods of contraception
Spermicides
During sexual intercourse, hundreds of millions of sperm are normally
released into a woman's vagina. The large majority of these sperm die. They die
because of the unfriendly environment of the vagina, which is acidic, and
because the mucus in the cervix above the vagina acts as a selective filter for
the sperm. Only about 1% of all the sperm released in an ejaculation
successfully pass through the woman's vagina and cervix to reach the uterus (the womb). However, it only takes one sperm to fertilize the ovum (the egg) and to achieve
conception.
Spermicides are a type of contraceptive agent that act by killing sperm.
Spermicides need to be in place in a woman's vagina before intercourse if
they are to prevent viable sperm from reaching her uterus. Spermicides come in a
wide variety of forms, including jellies, creams, foams, films, and
suppositories. The active ingredient in essentially all spermicides is
Nonoxynol-9. This is a detergent-like chemical that kills sperm.
Once placed inside the vagina, the spermicide melts into a liquid that coats
the vagina in order to set up a chemical barrier between the sperm and the
cervix. Spermicidal foams are more effective than creams or jellies. Not only is
it possible to achieve a better distribution with foam, but foam adheres better
to the vaginal walls and cervix.
Suppositories are solid or semi-solid and need to be inserted in the vagina
15 minutes before intercourse in order to liquefy with vaginal moisture.
Vaginal contraceptive film needs to be in place in the vagina about 5 minutes
prior to sexual intercourse in order to liquefy and become effective.
Spermicides are like all other methods of birth control in that they must be
used properly in order to prevent pregnancy. Each type of spermicide has a
unique method of use. For example, spermicidal creams, gels, and foam need to be
deposited high up in the vagina near the cervix. Spermicidal suppositories must
be unwrapped and inserted in the vagina. Squares
of spermicidal film should be inserted into the vagina with a woman's finger. It is important to follow exact instructions on
the package for each different type of spermicide.
A spermicide should be placed in the vagina prior to the man's penis getting
anywhere near the vagina. It is a common mistake for a couple to wait too long
before using the spermicide.
There are two basic concerns with any given spermicide. 1) How long the
spermicide stays in the desired place; and 2) how long the spermicide is
active in killing sperm. Therefore, the timing of spermicide use must take into account
both of these factors.
In general, spermicides tend to be effective soon after their application.
They can be inserted 15 minutes or more before intercourse. However, if there is
a significant delay before intercourse (for example an hour), more spermicide
must be added.
A fresh application of spermicide must also be used for each act of
intercourse.
Douching should be avoided for at least 8 hours after the last intercourse.
The effectiveness of spermicides in preventing pregnancy varies from 70 to
90%. This depends on the amount of spermicide and how it is used, the timing of
use prior to intercourse, and how well the instructions on the package are
followed.
Spermicides should not be used as protection for the
woman or man against sexually transmitted infections (sexually transmitted
diseases, or STDs). While spermicides may be partially protective against
certain organisms that cause sexually transmitted infections, including
chlamydia and
gonorrhea, they also do not protect against the
human
Immunodeficiency virus (HIV) infection.
The main objection voiced about spermicides is that they
are "messy." A small percent (2% to 4%) of people may have an adverse reaction
to Nonoxynol-9, which is experienced as an irritation or a burning
sensation.
Spermicides, however, have some positive features. They
are relatively inexpensive and they are available over-the- counter (OTC)
without a prescription.
Note that some lubricating jellies also available over-the-counter do not
contain spermicide and are not meant to be used as a form of birth control. It
is important to check the information on the package to be sure that the product
contains spermicide or that the word "contraceptive" appears on the label.
Next: Male condom »
- Natural Methods of Birth Control - Natural methods of birth control are non-mechanical and non-hormonal. They are also considered fertility awareness methods and there are a variety of choices for natural birth control.
- Sexually Transmitted Diseases in Women (STDs) - Learn and become aware of common STDs in women, including descriptions, symptoms, diagnosis, and treatments of each type of infection.
- Hormonal Methods of Birth Control - Read about hormonal birth control methods, such as oral contraceptives, the patch, birth control injection, and vaginal ring. The hormones used in hormonal birth control are estrogen and/or progesterone.
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