L5.2.4.1.1.1: Basal Body Temperature Method (BBT)

• Basal Body Temperature

  ❖ Is the temperature of the body when it is fully at rest. (After at least 3 hours of continuous sleep before temperature taking)

  Basal Body Temperature Method

  ❖ Identifies the fertile and infertile periods of a woman’s cycle by daily taking and recording of the rise in body temperature during and after ovulation.
• Step 1:

  Take body temperature at the same time each morning before you get out of bed or do anything. Upon waking, place the thermometer in the armpit.

  ● You may opt to use a basal thermometer for 10 minutes.

  ● You may also use a digital thermometer for 3-4 minutes.
• Step 2:

  Observe the temperature and keep track of this by charting it each day and take note of the thermal shift.

  ● Watch your temperature rise slightly - 0.2°C to 0.5°C (0.4°F to 1.0°F) - just after ovulation (about midway through the menstrual cycle). This is because ovulation causes an increase in body temperature, due to the increase in progesterone.
• Step 3:

  Chart your basal body temperature each day using a grid chart, as it allows you to easily graph your temperature and see any spikes or drops.

  ● A BBT that has risen above the client’s regular temperature and has stayed high for 3 full days indicates:

  1. Ovulation occurred
  2. Fertile period has passed
• Example: The thermal shift on this chart can be observed on day 15 (36.2 became 36.6). Counting 3 days from day 15, the couple can have unprotected sex on day 18.

  
• When to Avoid Intercourse

  All throughout the first half of the cycle before ovulation occurs.
• When to Resume Intercourse

  Resume unprotected sex 3 days after the thermal shift (On the 4th day) and until your next monthly bleeding begins.
• Factors that Affect BBT

  Such factors can make the BBT method difficult to use:

  ● Sore Throat

  ● Colds and Flu

  ● Fever

  ● Toothache

  ● Vomiting

  ● Diarrhea

  ● Anxiety

  ● Sunburn

  ● Medication

  ● Travel

  ● Sleep disturbance

  ● Alcoholic Beverages
• EFFECTIVENESS OF THE BBT METHOD:

  About 1 per 100 women who consistently and correctly use the BBT method and abstain from fertile days become pregnant in the first year of use.