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fertility hormones

Charting your fertility
on the hormone fertility chart

Observing your cervical mucus

Monitoring cervical mucus

Charting your fertility
on the cervical mucus chart

The mucus cycle

Arousal Fluid
and Seminal Fluid Instructions

Monitoring basal body

Monitoring Basal Body Temperature

If a woman monitors her waking temperature on a daily basis she will be able to observe an elevation or shift in temperature around the middle of her menstrual cycle. The temperature shift is a good biological indicator that ovulation has taken place and thus a good biological marker for the end of the fertile phase of the menstrual cycle. Right after and during menstruation a woman’s waking (basal) body temperature is in a low phase and remains low until ovulation. After ovulation the body temperature elevates (about 0.8 – 1.0 degree) and remains elevated until the next menstruation.

To monitor basal body temperature (BBT) the woman needs to use a good (accurate) digital thermometer. The woman should take her (oral) temperature as the first activity when waking and before getting out of bed. Water or food should not be ingested right before taking an oral temperature. The temperature should then be recorded (circled) on the chart/graph provided. The temperature charts are graded in .1 tenth of a degree Fahrenheit (or Centigrade). If the temperature was taken more than an hour off the usual time or if unusual circumstances occurred (e.g., sickness, lack of sleep, stress, etc) that should also be recorded on the chart.

There are two simple ways of determining the actual shift (rise) in body temperature that correlates with the time of ovulation and the end of the fertile phase; -- one is called the Rule of 3 over 6 and the other alternate is the cover-line method.

The Rule of 3 over 6:

Identify the first day your temperature rises at least 0.2 a degree Fahrenheit (Centigrade) higher than it had been the previous 6 days.
Highlight or circle the last 6 temperatures before the rise.
Locate the highest of those 6 highlighted temperatures.
Draw a coverline 0.1 a degree above the highest of the 6 highlighted temperatures preceding the rise. Your infertility begins on the end of the day after the 3rd consecutive temperature reading is above the coverline.

This example chart (below) shows a BBT chart illustrating the "Rule of 3 over 6". The coverline was drawn one-tenth of a degree above the highest of the preceding 6 days. You might also notice that during the first 2-3 days of the cycle the temperatures are higher than the coverline. This is due to residual progesterone from the previous cycle and can be ignored.

cover line

The Cover-line Method is determined
in the following manner:

After recording the waking body temperatures for 10 consecutive days (beginning with the first day of menstruation), locate the highest of these 10 recordings and draw a line that is 0.1 degree Fahrenheit (Centigrade) above this temperature.
Continue to take and record your temperature. Your BBT will eventually rise above this coverline.
Your infertile phase begins on the night of the 3rd consecutive temperature recorded above the coverline. Please note you must have 3 consecutive readings above the coverline - if one of the temperatures falls below then you should begin again to observe 3 consecutive

Errors in Temperature Recordings:

There are a number of reasons for erratic temperature recordings. Oral temperatures should be taken for a minimum of 5 minutes, failing to do so might give a lower temperature. Every hour that a person sleeps longer than the normal wake time the body temperature increases about a tenth of a degree. Some experts recommend subtracting a tenth of a degree for every hour that is added on to normal waking time. Alteration of route, for example from oral to vaginal, or changing the thermometer or type of thermometer will most likely result in erratic temperatures. If you are using a battery driven electronic digital thermometer and the battery runs down the temperature recordings could be off. Failing to shake down a glass mercury thermometer will result in faulty reading. Care must be taken in shaking down a glass thermometer.

Other factors and behaviors that might affect
the basal body temperature and the recordings are:

Alcohol consumption
Late night
Disturbed night of sleep
Holiday stress
Time zone shifts
Shift work
Gynecological problems
Thyroid disease