When the egg meets the sperm and a fusion occurs,
it means fertilization has happened. It means you
have conceived and you are on your way to becoming
a mum to a unique, complex being some 9 months later.
Fertilization
Facts
• It takes only one out of the millions of
sperms released during ejaculation to fertilize
the single matured egg
• When trying to conceive have intercourse
every 48 hours during the fertile period
• Fertilization takes place about an hour
after intercourse
• Millions of eggs die; millions of eggs leave
the female body because of gravity. Only 2000 odd
sperm succeed in the journey to the vagina
• The egg can survive for 12-24 hours in the
fallopian tube
• The sperm can survive for 2-3 days inside
the female body
• Ovulation is an essential precursor to conception.
Regardless of the length of cycles ovulation occurs
14 days before a period is due
• The best position to achieve conception
is the missionary position
• Lying on your back with a cushion tucked
under your buttocks for about 20 minutes after intercourse
increases the number of sperm in your body
Journey
of the EGG
Once a mature egg has been released by the ovary
or ovulation has taken place, the egg will move
into the fallopian tube. At this time, your body
makes the necessary preparations for a possible
pregnancy. The uterus lining called the endometrium
thickens all set for the fertilized egg to embed
itself. Fertilization takes place in the fallopian
tube. Contractions of the tube along with the tiny
hairs called cilia help to move the egg towards
the uterus. The egg survives for only 24 hours in
the fallopian tube. If fertilization does not take
place, the egg will be reabsorbed into the system,
the endometrium will come away and bleeding will
commence as another menstrual cycle begins.
Journey of the SPERM
The sperm swims very quickly from the vagina into
the cervix after ejaculation. It will swim towards
the waiting egg into the fallopian tube. Special
chemicals emitted from the egg attract the sperm
towards it. Of the many sperms racing toward the
egg, only one sperm will succeed in penetrating
the egg. New chemicals are released by the egg to
seal it and hence prevent other sperm from breaking
through. The sperm that managed to fuse with the
egg sheds its tail and body. Chromosomes from the
sperm join with those of the egg.
Fertilization
The egg is usually fertilized in the fallopian tubes.
Once the fusion occurs, hormones prevent the endometrium
from breaking down. (No periods for 9 months or so).
The blastocyst burrows into the thick lining. Finger-like
projections sprout to develop into the placenta from
the outer layer of cells. The pregnancy is now established
with the placenta forming a crucial link between the
mother and the embryo. The moment the egg becomes
fertilized, the sex of your baby is established. Each
parent contributes one sex determining chromosome,
an X or a Y. It is the man's contribution which will
determine the baby's gender
After Fertilization
With the fusion of the sperm and egg complete, a new
cell forms called the zygote. The sperm and the egg
are only cells which contain 23 chromosomes each;
all human cells have 46 chromosomes. The new cell
now containing 46 chromosomes will travel down the
fallopian tube slowly. During its travel it will divide
into identical cells of 2 then 4 and 8 and so on.
By day four, it will be a solid mass of cells and
is called a morula. By the time the morula reaches
the uterus it will be a hollow ball of 100 odd cells
now called a blastocyst. The blastocyst takes about
6 days to reach the uterus and implant. Once it is
embedded in the endometrium it will continue to grow
and develop into an embryo. The implantation process
can cause slight bleeding in some which can be mistaken
for a very light period.
X or Y - The Sex Chromosomes
The sperm and egg cells each contain 23 chromosomes.
Of the 46 chromosomes, the sex of a baby is determined
by just 2, the X and the Y. The egg has the single
X chromosome while the sperm have either the X or
the Y chromosome. The sperm with the X chromosome
when united with the egg will go on to produce a baby
girl. The sperm carrying the Y chromosome will go
on to make a boy baby after it fertilizes the egg.
In a gist 2 X or XX make a girl. One X and one Y or
XY will result in a boy child.
When you have more than one .. at one Go
About 1 in every 80 pregnancies results in twins.
The rise is due to fertility treatments being administered
and the age of the mother. Women becoming pregnant
after 35 are more likely to have twins. About two
thirds are fraternal or non-identical and the rest
are identical twins. Triplets are also becoming common
with fertility treatments although its incidence is
not as high, only 1 in 6000 pregnancies. These multiple
births of identical and fraternal babies occur in
the same way as twins do.
When the Egg Fails to Implant
In some instances the fertilized egg fails to implant
in the womb. This is caused by some abnormality in
the egg which doesn't allow it to survive. When this
happens the woman isn't usually aware that the fertilization
has occurred. What usually follows is a slight delay
in periods which is possibly heavier than the usual
periods.