Contraception (pregnancy avoidance) is practiced for many reasons, such as pregnancy planning, limiting the number of children, avoiding medical risks of pregnancy (especially with heart disease, diabetes mellitus, or tuberculosis), and controlling the world population. The use of contraception is increasing in developed countries, but some forms are economically out of reach for those in developing countries. Of the . female population age 15–44 years, it is estimated that 30% are not sexually active, 5% are not using contraception, 5% have surgical sterilization, and 60% are using a contraceptive. Table 26-1 shows an approximate distribution of the different contraceptives. | CONTRACEPTION DEFINITION USAGE effectiveness Contraception pregnancy avoidance is practiced for many reasons such as pregnancy planning limiting the number of children avoiding medical risks of pregnancy especially with heart disease diabetes mellitus or tuberculosis and controlling the world population. The use of contraception is increasing in developed countries but some forms are economically out of reach for those in developing countries. Of the . female population age 15-44 years it is estimated that 30 are not sexually active 5 are not using contraception 5 have surgical sterilization and 60 are using a contraceptive. Table 26-1 shows an approximate distribution of the different contraceptives used in the United States and their relative effectiveness. Contraceptives usually fail when they are unacceptable and therefore not often used or when pregnancy inadvertently occurs. This is difficult to quantify but the latter is termed the failure rate and is expressed as pregnancies per 100 women at 1 year or per 100 woman-years. Pearl s index is another way of expressing the pregnancy rate. Pregnancies X 1200 Pregnancy rate ----------------- Woman-months of use The life table method is an actuarial expression of pregnancy or discontinuation at various intervals and may be a superior method for quantifying contraceptive information. Whatever type of assessment is used it is important to differentiate between method effectiveness and use effectiveness. Method effectiveness is the rate of contraceptive effectiveness when always used correctly whereas 727 Copyright 2001 The McGraw-Hill Companies. Click Here for Terms ofUse. 728 BENSON PERNOLL S HANDBOOK OF OBSTETRICS AND GYNECOLOGY TABLE 26-1 TYPES OF CONTRACEPTIVES USED IN THE UNITED STATES AND FAILURE RATES Using Method0 First Year Failure13 Theoretical Effectiveness3 Sterilization Female 20 Male 15 Norplant 1 System Oral contraceptivec 30 Combination 1-3 Progestin only 5 .
