How to Read Luteal Phase Results

Basal body temperature (BBT) can be measured throughout a woman's menstrual cycle in order to gain information about the most fertile time. The cycle is divided into different phases, and the phases can be seen in a BBT chart. The luteal phase is the time period that begins the day after ovulation and ends when the woman begins menstruation, which denotes the end of that cycle. During the luteal phase, the woman's temperature is higher, which serves to incubate the egg if it has been fertilized. Reading a BBT chart can give indications of a woman's fertility at specific times, show some fertility problems related to the luteal phase of the menstrual cycle, and indicate pregnancy.

Instructions

• 1

  Chart your temperature for at least one full cycle. The temperature must be taken with a special BBT thermometer that gives the results with two decimal places. Take your temperature every morning before getting out of bed and within an hour of the same time each day.

• 2

  Chart the temperatures on a BBT chart or graph of your own that shows temperature versus the day. Day one of the chart is the first day of menstruation, and your cycle ends when menstruation begins again. You can also make notes about your cycle, but do not read into the temperatures until the cycle is complete.

• 3

  Look at the chart and be sure it is biphasic, which means that their a two clear phases seen. Typically, the temperatures prior to ovulation will average 0.4 degrees less than those after ovulation, creating two separate sections on the chart.

• 4

  Determine the day of ovulation and the luteal phase days by locating the day where the temperature jumped from the lower temperatures to the higher temperatures. This day is ovulation and all of the days after the day of ovulation are the luteal phase.

• 5

  Determine the length of the luteal phase by counting the number of days on the chart after ovulation. Ovulation can be delayed, causing the number of days prior to ovulation to change each month; the luteal phase, however, should be the same within one or two days.

• 6

  Determine if your luteal phase is normal. Most women have a luteal phase that lasts 12 to 16 days. A shorter luteal phase could mean difficulty getting pregnant, as implantation requires 10 days of higher temperatures to occur. A longer than normal luteal phase could indicate pregnancy.