The word 'basal' denotes base and
as such, Basal Body Temperature refers to the base temperature of your body or
the temperature of your body at rest ie. when you first wake up in the morning
and prior to any other activities. Basal Body Temperature is one of the most important fertility
symptoms and unless there is a medical reason, you should observe BBT together
with
Cervical Mucus (CM), which are the basis for
Fertility Awareness Method (FAM), for clues on your ongoing fertility.
Your
body temperature rises and falls in a consistent pattern. Ovulation
causes your body temperature to remain elevated for about two weeks.
GenderLabs™
looks for
this rise to determine when post-ovulation infertility begins. Your
body temperature is not a consistent 98.6° F / 37° C as most people think.
These figures are the body's normal base high temperature during waking hours.
After going to sleep at night, your body temperature gradually drops, reaching
its lowest point in the early morning. As you get closer to your waking hours,
your metabolism picks up again, raising your body temperature ever so gradually,
and the cycle is repeated. The scale of the drop and rise of body temperature
differs from person to person, but all people experience it to some degree or
another (no pun intended).

When
a woman ovulates, the shell containing the ovum ruptures, releasing the egg and
the hormone progesterone into the body. This hormone has several effects, for
our purposes not the least of which is the raising of the basal body
temperature. This increase in temperature is significant and detectable, as it
typically is about 0.4° Fahrenheit / 0.2° Celsius over the course of several
days. To detect this change, you will need a basal thermometer, available from
most pharmacies. A standard fever thermometer is not accurate enough for our
purposes here, as even a change of 0.1° F / 0.05° C is important. Therefore,
an important first step in the practice of
Fertility Awareness Method
(FAM) is to buy a Basal Thermometer.
GenderLabs™
looks for three temperatures that rise at least 0.2° F / 0.1° C above the high
of the previous six temperatures. A "coverline" is drawn 0.1° F /
0.05° C above the highest of these six temperatures and when three successive
temperatures are above this line, a thermal shift is identified and there's a
good chance that ovulation has already occurred.
The
temperature sign gives us a great albeit late clue that ovulation has occurred.
That’s not to say that it can’t help couples conceive, as if there is a
statistically significant temperature rise compared with previous temperature
observations, there is a good chance that ovulation has JUST taken place and
that intercourse might be 'fruitful'. However,
the primary purpose of the temperature sign is to confirm that ovulation has
already occurred and to help estimate the actual date.
Basal Body Temperature should be taken at a consistent time each
day, preferably upon first rising in the morning before engaging in any
activity, eating, drinking, brushing your teeth, smoking etc. You should enter
the normal time you would expect to rise and take your temperature in the box
provided/
BBT Disturbance