contraception
Contraceptives - The Condom
Choosing the right method of contraception depends on a couples’
religious and personal beliefs. There are many different methods of
contraception available, e.g. the condom
A condom is a rubber sheath rolled
down over the penis before intercourse.
During intercourse, the condom prevents
sperm entering the vagina.
Contraceptives - The Condom
After intercourse, the penis has to be withdrawn carefully, and the
condom (together with the semen), disposed of in a sensible
manner.
Care has to be taken to ensure that the condom
is not torn or split, as this may cause the sperm
to escape into the vagina, possibly
resulting in pregnancy.
Contraceptives - The Diaphragm (Cap)
The diaphragm is a rubber cap which is placed inside the vagina, and
moved up over the cervix.
The first time a diaphragm is used it
should be fitted by a nurse.
The diaphragm must be inserted some
time before sexual intercourse, and
remain in the vagina for 6 to 8 hours after
a man’s last ejaculation.
A diaphragm should be used together
with a spermicide, which kills sperm.
Spermicides can be in a gel or cream form.
Spermicides can also be used with a condom.
Contraceptives - The IUD (Coil)
The Intrauterine device (IUD or coil) sits in the woman’s womb
and prevents her from getting pregnant in three main ways...
 prevents sperm from getting through to
the womb and into the fallopian tubes
 alters the secretions (mucus) in the cervix,
so creating a further barrier to the sperm
 irritates the womb lining - it is unable to
‘accept’ an embryo.
Using Sex Hormones as Contraceptives
Oral contraceptives, usually known as ‘the pill’ prevent sperm
from fertilising ova, i.e. they prevent conception.
They may contain oestrogen and/or progesterone
which prevent conception in several ways:
 Oestrogen prevents ovulation by inhibiting
the production of
follicle-stimulating hormone (FSH) by the
pituitary gland. No ova will develop.
 Oestrogen causes a sticky substance to block the uterus
entrance at the cervix, preventing sperm from entering.
 Progesterone makes the uterus lining so thick that an embryo
(if conception occurred) cannot implant.
Using Sex Hormones as Contraceptives
Oestrogen is so effective at inhibiting
the production of FSH and thereby
the production of ova that a section
through the ovary of a female taking
the combined pill reveals only
immature follicles.
Notice that in this sectional view of
an ovary, mature follicles and the
corpus luteum are absent – this is
enough to act as a contraceptive as
ovulation cannot occur.
Ovary
The Pill
There are two main types of contraceptive pill - each is defined by
the hormones they contain...
1.
Progesterone Only Pill
- contains only progesterone
2.
The Combined Pill
contains both oestrogen and progesterone
Both types of pill have to be taken every day.
Progesterone Only Pill
The ‘progesterone only’ pill prevents the release of an egg cell,
and makes it more difficult for an embryo to be implanted in the
womb.
It also alters the cervical mucus so that sperm cannot move easily
through it. Both types of pill can have side effects such as feeling
sick and gaining weight.
Some reports even suggest that long term use of the contraceptive
pill could increase the risk of cervical cancer.
The Combined Pill
The ‘combined pill’ contains two hormones (a progestogen and an
oestrogen) and prevents ovulation (production of an egg cell).
The combined pill also makes it difficult for the embryo, should one
be produced, to be implanted in the womb.
Medical Concerns About the Combined Pill
Evidence suggests that the oestrogen
levels in the combined pill can
interfere with the blood clotting
mechanism and increase the risk of
thrombosis, heart attacks and
strokes.
Therefore, oestrogen levels in
A blood clot forming inside a
capillary – this could lead to
the combined pill are kept as low
major clot (thrombosis)
as possible and a different kind
of pill, the mini-pill, has been developed.
The mini-pill is a progesterone-only pill that appears to act by
interfering with development of the egg cell.
The Morning After Pill
The morning after pill is taken after unprotected
sexual intercourse has taken place.
The pill has to be taken within 72 hours
after intercourse has taken place.
It contains a high dose of progesterone,
and prevents an embryo from being
implanted.
The initial high level of progesterone in the female body stimulates
development of the lining of the womb.
The sudden drop in progesterone in the days after the pill has been
taken, prevents implantation of a potential embryo into the lining
of the womb.