INDICATIONS AND USAGE
1. Indications. Progestin-only oral contraceptives are indicated for the prevention of pregnancy.
2. Efficacy. If used perfectly, the first-year failure rate for progestin-only oral contraceptives is 0.5%. However, the typical failure rate is estimated to be closer to 5%, due to late or omitted pills. The following table lists the pregnancy rates for users of all major methods of contraception.
Table 2: Percentage of Women Experiencing an Unintended Pregnancy During the First Year of Typical Use and the First Year of Perfect Use of Contraception and the Percentage Continuing Use at the End of the First Year. United States.
% of Women
Experiencing an
Unintended Pregnancy
within the First
Year of Use
% of Women
Continuing
Use at
One Year
3
Method
(1)
Typical Use
1
(2)
Perfect Use
2
(3)
(4)
Chance
4
85
85
Spermicides
5
26
6
40
Periodic abstinence
25
63
Calendar
9
Ovulation Method
3
Sympto-Thermal
6
2
Post-Ovulation
1
Cap
7
Parous Women
40
26
42
Nulliparous Women
20
9
56
Sponge
Parous Women
40
20
42
Nulliparous Women
20
9
56
Diaphragm
7
20
6
56
Withdrawal
19
4
Condom
8
Female (Reality)
21
5
56
Male
14
3
61
Pill
5
71
Progestin only
0.5
Combined
0.1
IUDs
Progesterone T
2.0
1.5
81
Copper T380A
0.8
0.6
78
LNg 20
0.1
0.1
81
Depo-Provera
0.3
0.3
70
Levonorgestrel Implants
(Norplant
)
0.05
0.05
88
Female Sterilization
0.5
0.5
100
Male Sterilization
0.15
0.10
100
Emergency Contraceptive Pills: Treatment initiated within 72 hours after unprotected intercourse reduces the risk of pregnancy by at least 75%.
9
Lactational Amenorrhea Method: LAM is a highly effective,
temporary method of contraception.
10
Source: Trussell, J, Contraceptive Efficacy. In: Hatcher RA, Trussell J, Stewart F, Cates W, Stewart GK, Kowal D, Guest F, Contraceptive Technology: Seventeenth Revised Edition. New York NY: Irvington Publishers, 1998.
Among
typical couples who initiate use of a method (not necessarily for the first time), the percentage who experience an accidental pregnancy during the first year if they do not stop use for any reason.
Among couples who initiate use of a method (not necessarily for the first time), and who use it
perfectly (both consistently and correctly), the percentage who experience an accidental pregnancy during the first year if they do not stop use for any other reason.
Among couples attempting to avoid pregnancy, the percentage who continue to use a method for one year.
The percentage of women becoming pregnant noted in columns (2) and (3) are based on data from populations where contraception is not used and from women who cease using contraception in order to become pregnant. Among such populations, about 89% become pregnant within one year. This estimate was lowered slightly (to 85%) to represent the percentage that would become pregnant within one year among women now relying on reversible methods of contraception if they abandoned contraception altogether.
Foams, creams, gels, vaginal suppositories, and vaginal film.
Cervical mucus (ovulation) method supplemented by calendar in the pre-ovulatory and basal body temperature in the post-ovulatory phases.
With spermicidal cream or jelly.
Without spermicides.
The treatment schedule is one dose within 72 hours after unprotected intercourse, and a second dose 12 hours after the first dose. The Food and Drug Administration has declared the following brands of oral contraceptives to be safe and effective for emergency contraception: Ovral
(1 dose is 2 white pills), Alesse
(1 dose is 5 pink pills), Nordette
or Levlen
(1 dose is 4 yellow pills).
However, to maintain effective protection against pregnancy, another method of contraception must be used as soon as menstruation resumes, the frequency or duration of breastfeeds is reduced, bottle feeds are introduced, or the baby reaches 6 months of age.