All about Ovulation
Major Points in this
Ovulation is the
release of a mature egg (ovum) from the ovarian follicle.
The lifespan of the
egg after ovulation is just 12-24 hours, possibly as little as six
when the ovum is fertilized by the male's sperm during this
Intercourse prior to
ovulation may result in conception because sperm can survive in the
female reproductive tract for a few days before ovulation.
pinpointing the date of ovulation are primary concerns when charting
Ovulation can be
detected by charting your fertility signs because the hormone
progesterone, which is only released after ovulation, causes your
resting temperature to rise and stay elevated throughout the luteal
allows you to see the following: if intercourse was well-timed for
conception; if you can stop having baby-making intercourse; the
length of your luteal phase; when to expect your period or a
positive pregnancy test result.
charting, as you now know, is largely concerned with identifying
ovulation and then using this information to make other predictions
and calculations about your cycle. Once you know when (and if) you
ovulated, you can decide to take a break from baby-making
intercourse, you can tell if intercourse was well timed for
conception and you can get the most reliable due date calculation.
You can also tell when you can either reliably take a pregnancy test
or expect your period.
what exactly is ovulation?
Ovulation is the release of a
mature egg (ovum) from the ovarian follicle. Each menstrual cycle,
several ovarian follicles begin to mature and develop under the
influence of pituitary hormones. Usually only one follicle develops
fully. While the other follicles recede, this dominant follicle
produces an egg which will be released and which can be fertilized.
The growing follicle secretes increasing amounts of the hormone
estrogen. Following peak estrogen production, there is a surge of
luteinizing hormone (LH). The LH surge triggers the release of the
mature egg from its follicle. This is ovulation.
Once ovulated, the egg is picked up by one of the
fallopian tubes and begins to travel towards the uterus in the
fallopian tube. This is where fertilization, if it is to happen,
takes place. The follicle that released the egg becomes known as the
corpus luteum after ovulation and begins to secrete the heat inducing
lifespan of the egg after ovulation is just 12-24 hours, maybe even
less. Fertilization must take place within this time frame. After this
time frame, the egg begins to degenerate and is no longer capable of
being fertilized. This seems like a very short window of time for
conception to take place. However, sperm deposited prior to ovulation
can survive in the female reproductive tract for a few days, so the
few days before ovulation takes place are also considered fertile
and the Cycle Phases
Ovulation is the event that defines the
phases of the menstrual cycle. The phase before ovulation, when the
ovarian follicles are developing, is called the follicular phase. The
phase after ovulation is called the luteal phase. The length of the
follicular phase may vary but the luteal phase length is generally
constant from cycle to cycle for the same woman, lasting 10-16 days.
When cycles are irregular, it is usually because ovulation occurred
earlier or later than usual. Knowing when ovulation occurred allows
you to see if intercourse was well-timed for conception and lets you
determine your luteal phase length. Knowing your luteal phase length
tells you when to expect your period or a positive pregnancy test
does Ovulation take place?
Ovulation takes place, on average,
about two weeks before your period, though it can vary from 10-16
days before the onset of menstruation depending on the length of your
luteal phase. During an "average" 28 day cycle, ovulation
is usually expected to take place between cycle days 13-15. Based on
this guideline, many women are taught to expect ovulation around day
14 of their menstrual cycle. Many women, however, do not have average
cycles and even those who usually do may see irregularities from time
typical menstrual cycle may be anywhere from 21 to 35 days according
to the American Society for Reproductive Medicine. Some women even
notice cycles that are shorter or longer than this. Ovulation, then,
may occur much earlier or later than typical guidelines suggest. For
example, ovulation may occur on cycle day 23 during a cycle that is
35 days long for a woman with a 12 day luteal phase while ovulation
may occur on cycle day 10 for a woman with a 24 day cycle and a 14
day luteal phase length. This variation among women and from cycle to
cycle means that there is really no simple "one-size-fits-all"
mathematical formula to calculate your ovulation date without
observing your fertility signs. However, it is possible to learn how
to identify your own ovulation date and fertile signs by examining
your fertility signals.
Your ovulation date and your time of peak fertility
can be detected by charting your fertility signs. This is because our
bodies produce signals that can alert us that ovulation is
approaching and tell us when ovulation has passed. Fertility signs
that indicate that estrogen levels are high and ovulation is
approaching (and fertility is high) include observing increasingly
stretchy and "egg white" cervical fluid and observing a
high, soft and open cervix. Commercial devices such as ovulation
prediction kits (OPKs) and fertility monitors can also tell us that
ovulation is approaching by measuring the presence of estrogen or
luteinizing hormone (LH) in urine. Charting your basal body
temperature (BBT) allows you to pinpoint the day of ovulation and
tells you when ovulation has passed because progesterone raises the
basal body temperature after ovulation.
Interpreting your Chart.