Birth Control 101

Most women can become pregnant from the time they are in their early teens until they are in their late 40s. About one half of all pregnancies are unplanned. Birth control helps a woman plan her pregnancies

Methods of Birth Control

There are many methods of birth control.  Each method has good points as well as side effects.  Birth control allows a woman to plan her family - both the number and spacing of children.

The birth control pill, injections, vaginal ring, skin patch, intrauterine device (IUD), diaphragm, Lea's Shield, and cervical cap require a prescription.  Condoms and spermicides do not.

More than one method may be used at the same time.  For instance, a barrier method may be used with any other method.

Birth Control

Barrier Methods

Barrier methods include spermicides, condoms (male and female), the diaphragm, the cervical cap, and Lea's Shield.  Barrier methods are effective when used the correct way every time you have sex.  Even one act of sex without birth control can result in pregnancy.

Hormonal Contraception

With hormonal birth control, a woman takes hormones similar to those her body makes naturally.  These hormones prevent ovulation.  When there is no egg to be fertilized, pregnancy cannot occur.


One of the most popular methods of hormonal birth control is the birth control pill (oral contraceptive).  Most birth control pills are combination pills.  They contain the hormones estrogen and progestin.


One type of injection of hormonal birth control, called depot-medroxyprogesterone acetate (DMPA), provides protection against pregnancy for three months.  This means a woman needs only four injections each year.


The vaginal ring is a flexible, plastic ring that is placed in the upper vagina.  The ring releases both estrogen and progestin continuously to prevent pregnancy.  It is worn for 21 days, removed for 7 days, and then a new ring is inserted.


The contraceptive skin patch is a small (1.75 square inch) adhesive patch that is worn on the skin to prevent pregnancy.  It is a weekly method of hormonal birth control.

Natural Family Planning

Natural family planning used to be called the rhythm method or "safe period."  It also is called periodic abstinence or, more recently, fertility awareness.  It isn't a single method but a variety of methods.

Intrauterine Device

The IUD is a small, plastic device that is inserted and left inside the uterus to prevent pregnancy.  Although there have been several types of IUDs, currently only two are available in the United States: the hormonal IUD and the copper IUD. 


Types of natural family planning include:

  • Basal body temperature method
  • Ovulation/cervical mucus method
  • Symptothermal method
  • Calendar method
  • Lactational amenorrhea


The withdrawal method prevents pregnancy by not allowing sperm to be released in the woman's vagina.  This requires the man to take his penis out of the woman before he ejaculates.  Drawbacks are that sperm can be present in the fluid produced by the penis before ejaculation and some men fail to withdraw completely or in time.

New Option for Sterilization

Women who want a permanent method of birth control now have an option that does not involve surgery.  With this method, a tiny spring like device is inserted through the vagina into each fallopian tube.  This device causes scar tissue to build up in the tubes. This build-up blocks the fallopian tubes and prevents the sperm from reaching the egg.  It takes three months for the scar tissue to grow, so women should use another method of birth control during this period. This device can be inserted in a doctor's office.


Sterilization for women and men works by permanently blocking the pathways of egg and sperm.  This can be done by surgery.

Tubal sterilization is done by laparoscopy and minilaparotomy.  The fallopian tubes are closed by tying, banding, clipping, blocking, or cutting them, or by sealing them with electric current.

Vasectomy involves cutting a man's vas deferens so that sperm cannot mix with semen.  The tubes that carry sperm to the penis are clamped, cut, or sealed so that the ends do not join again.

Choosing a Method

At any given time, a couple may find one method of birth control suits their needs better than others.  Most women and couples use many methods over their lifetime.  All methods have a chance of failure. When a method is used correctly each time, the failure rates are lower.  Choose a method you will be able to use on a regular basis.  If your method fails, you may want to consider emergency contraception.


No matter which method of birth control you choose, be sure that you know how it works, how to use it, and what side effects may occur.  Even with methods that do not need a prescription, you need to learn how to use the method.  This excerpt from ACOG's Patient Education Pamphlet is provided for your information.  It is not medical advice and should not be relied upon as a substitute for visiting your doctor.  If you need medical care, have any questions, or wish to receive the full text of this Patient Education Pamphlet, please contact your obstetrician-gynecologist.  To ensure the information is current and accurate, ACOG titles are reviewed every 18 months.  Copyright © February 2003 The American College of Obstetricians and Gynecologists