1 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 other reason.
2 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.
3 Among couples
attempting to avoid pregnancy, the percentage who continue to
use a method for one year.
4 The percents
becoming pregnant 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 percent who would
become pregnant within one year among women now relying on reversible
methods of contraception if they abandoned contraception altogether.
5 Foams, creams,
gels, vaginal suppositories, and vaginal film.
6 Cervical mucus
(ovulation) method supplemented by calendar in the pre-ovulatory
and basal body temperature in the post-ovulatory phases.
7 With spermicidal
cream or jelly.
8 Without spermicides.
9 The treatment
schedule is one dose within 72 hours after unprotected intercourse,
and a second dose 12 hours after the first dose. Preven is the only dedicated product marketed for emergency contraception in the United States (1 dose is 2 blue pills). 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 or Levlite (1 dose is 5 pink pills),
Nordette or Levlen (1 dose is 4 light-orange pills), Lo/Ovral or Levora
(1 dose is 4 white pills), Trivora (1 dose is 4 pink pills), Triphasil or Tri-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 six months of age.