CONTRACEPTION, EMERGENCY
CONTROLLED DRUG
C
Some spermicides should not be used
with rubber barrier devices.
Mechanical and chemical means used
together correctly can be highly effec-
tive in preventing conception.
contraception, emergency
Measures
to avoid
pregnancy
following unprotec-
ted
sexual intercourse
.
There are 2 main
methods: hormonal and physical. In the
first,
oral contraceptives
(the “morning
after” pill) are taken in a high dose as
soon as possible, but not longer than
72 hours, after unprotected intercourse,
with a second dose taken
12
hours later.
They may be given as a high-dose
pro-
gesterone
-only pill or as a high-dose
combined (
oestrogen
and progesterone)
pill. In the physical method, an
IUD
is
inserted by a doctor within 5 days of
unprotected intercourse.
contraception, hormonal methods
of
The use by women of synthetic pro-
gestogen drugs, which are often combined
with synthetic
oestrogens
,
to prevent
pregnancy. These drugs suppress
ovula-
tion
and make cervical mucus thick and
impenetrable to sperm. They also cause
thinning of the
endometrium
(lining of the
uterus), which reduces the chance of a
fertilized egg implanting successfully. The
best-known form of hormonal contracep-
tion is the contraceptive pill (see
oral
contraceptives
). The hormones can also
be given as
contraceptive implants
under
the skin, by injection (see
contracep-
tives, injectable
), or be released by
IUDs
.
contraception, natural methods of
Methods of avoiding conception based
on attempts to pinpoint a woman's fer-
tile period around the time of
ovulation
,
so that sexual
intercourse
can be avoided
at this time. The
calendar method
is based
on the assumption that ovulation occurs
around 14 days before menstruation. Be-
cause of its high failure rate, it has been
largely superseded by other methods.
The
temperature method
is based on the
normal rise of a woman's body tempera-
ture in the second half of the menstrual
cycle, after ovulation has occurred. The
woman takes her temperature daily
using an ovulation thermometer. Sex is
considered to be only safe after there
has been a sustained temperature rise
for at least 3 days.
The
cervical mucus method
attempts to
pinpoint the fertile period by observing
and charting the amount and appearance
of cervical mucus during the menstrual
cycle. Recognized changes in the mucus
occur before and often at ovulation. The
symptothermal method
combines the
temperature and cervical mucus methods.
contraception, withdrawal method
of
See
coitus interruptus.
contraceptive
Any agent that reduces
the likelihood of
conception
. (See also
contraception
.)
contraceptive
implant
A hormonal
method of
contraception
in which long-
acting contraceptive drugs are inserted
under the skin. An implant consists of a
small rod that steadily releases a
pro-
gestogen drug
into the bloodstream.
contraceptives, injectable
A hormonal
method of
contraception
in which long-
acting
progestogen drugs
are given by
injection every 2-3 months. Injectable
contraceptives are very effective but may
cause menstrual disturbances, weight
gain, headaches, and nausea, especially
during the first few months of use.
contractions, uterine
Spasms of rhyth-
mic, squeezing muscular activity affecting
the walls of the
uterus
during
childbirth
.
Regular contractions indicate the start
of
labour
and increase in strength and
frequency throughout the first stage.
(See also
Braxton Hicks' contractions.
)
contracture
A deformity caused by
shrinkage of tissue in the skin, muscles,
or tendons that may restrict movement
of joints. Skin contractures commonly
occur as a result of scarring following
extensive burns. Other types are caused
by inflammation and shrinkage of
con-
nective tissues
.
Examples are
Dupuytren's
contracture
and
Volkmann's contracture
.
contraindication
Factors in a patient's
condition that would make it unwise to
pursue a certain line of treatment.
contrast medium
A substance opaque
to
X-rays
, introduced into hollow or
fluid-filled body parts to show them up
on X-ray film. Barium is one of the most
commonly used contrast media (see
barium X-ray examinations
).
controlled drug
One of a number of
drugs subject to restricted use because
of their potential for abuse. They include
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