are women fertile? Knowing when a woman can
get pregnant is essential in a heterosexual
relationship. If you are wanting to
conceive a baby, it helps to know when the
best time for intercourse is. If you do
not want a pregnancy, you must use contraception
to avoid it, or abstain from specific types
of sex during a specific time of the month.
You will find
it much easier to understand the following
passage after reading up on
sex hormones and the reproductive cycle.
The female reproductive cycle lasts on
average between 24 to 35 days. It consists
of 4 distinct phases:
the menstrual phase, the pre-ovulatory
phase, ovulation itself, and the
post-ovulatory phase. The only fertile
period during a woman's cycle is just
before, during, and just after ovulation.
pre-ovulation phase follicles grow within
the ovaries of a woman. They release the sex
hormone estrogen. This hormone builds a
positive feedback loop with another hormone,
called luteinizing hormone or LH, which is
released from the pituitary gland in the
brain. Each hormone stimulates more of the
other hormone to be released during the
pre-ovulation phase until the concentration
of LH reaches a threshold. At this point the
high amount of LH will trigger ovulation.
the process whereby the most dominant
follicle out of a group ruptures and
releases one single egg. This egg, or the
medical term is oocyte, is caught by the
Fallopian tubes, which envelope the ovaries.
The egg then continues to travel down the
tube to the uterus, a journey which will
normally take about 7 days.
Fertilization of the egg is the process
whereby the egg and a sperm cell fuse.
This triggers further development of the egg
cell, which results in a tiny bubble of
cells called a blastocyst, which implants
itself in the inner lining of the uterus.
Here the tiny cluster of cells can grow into
an embryo, which is protected and nourished
by the uterine lining.
At the moment
of fertilization a pregnancy is possible.
However, many fertilized egg cells do not
implant themselves properly or are lost
somewhere during the process.
only way to avoid a pregnancy for sure is to
not introduce sperm into the vagina during a
specific time of the month. The released egg
cell survives inside the Fallopian tube
without fertilization for 24 hours after
ovulation. If fertilization has not occurred
by then the egg cell dies and no pregnancy
is possible during that month. Sperm cells
can survive for about 48 hours inside the
vagina. This results in a window of 3 days
during which most pregnancies occur: 2 days
prior to ovulation and 1 day after
ovulation. To give this time period some
extra leeway to account for natural
variation, a woman is fertile during 4 to 5
days surrounding ovulation.
Unfortunately, it is not as easy as it
sounds. The natural cycle in a woman can
show strong variations. Normally,
ovulation occurs about 14 days after the end
of the last period. However, the pre-ovulatory
phase is the most variable on in the cycle.
Stress, nutrition or living around other
women can influence a woman's cycle. Most
women are not able to feel when they are
ovulating and there are no obvious outside
signs that this process is happening.
Therefore, the actual time period during
which the use of contraception to avoid
pregnancy is necessary is much longer then
4-5 days, depending on how safe you want to
word on introducing sperm into the vagina.
The most obvious way to do so is through
ejaculation during intromission, when the
penis is inside the vagina. However,
sperm, which is deposited on the outside the
vagina on the vulva can make it's way inside
and result in a pregnancy. If you are
masturbating together care must be taken to
avoid contact of sperm with the outside of
the vagina, not just the inside. The same
holds true for anal intercourse. If the man
ejaculates it is possible that sperm
trickles down the perineum of the woman to
the outside of the vagina.
sperm is ejected from the penis not only
during ejaculation. Many men secret little
droplets of fluid when they get aroused from
the tip of the penis. These drops not only
aid lubrication, but will also already
contain some sperm.
you are using a condom for birth control you
must apply the condom before the penis first
enters the vagina. It is possible to get
pregnant if you only apply the condom after
some thrusting has already occurred.
for the facts cited in this page:
Francoeur, R. (1995) The
Complete Dictionary of Sexology. New
expanded edition. Continuum New York
of anatomy and physiology (2000) Ninth
edition by Gerard J. Tortora and Sandra
Reynolds Grabowski. Publishers: John Wiley
Written by Anna, 16.08.07
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