Some information abt contraception:
How Contraceptives Work
Different contraception methods work in different ways. Mechanical
methods aim to prevent sperm entering the uterus, hormonal methods
prevent ovulation so that no egg is fertilized and "natural"
methods require human skills to perfect.
Contraceptive methods can be divided into the following general
categories:
Hormonal Contraceptives
Combined hormonal contraceptives the Pill, the vaginal ring and
transdermal patch contain both estrogen and progestogen. These
ingredients are similar to the natural hormones women produce in
their ovaries and they ultimately stop the ovaries from releasing
an egg, or ovulating.
The progestogen-only pill, or the mini-pill, contains very low
levels of progestogen not enough to prevent egg release
consistently. The mini-pill, therefore, works by thickening the
cervical mucus and thinning the lining of the womb to prevent
pregnancy. Consequently, it is less effective than other hormonal
methods of contraception.
IUD
The intra-uterine device protects against pregnancy by altering
sperm migration and therefore preventing fertilization. Copper is
usually used as very high concentrations in the cervical mucus can
impair sperm migration. IUDs also generate a foreign body reaction
in the lining of the womb. Large amounts of white blood cells are
produced which help destroy the sperm. The white cells also disrupt
the lining of the womb so that in the event that an egg is
fertilized, it is unable to implant.
Barrier Contraceptives
Barrier contraceptives the diaphragm, cap and condom work by
providing a physical barrier to prevent the sperm meeting an egg.
In some instances, they may be used with a spermicide, a substance
with the ability to kill sperm.
Sterilization
Female tubal sterilization procedures block or cut the fallopian
tubes, thus preventing the sperm from coming into contact with the
egg. Male sterilization involves blocking or cutting each vas
deferens the tubes transporting the sperm from the testes so
that sperm does not enter the ejaculate.
