Why is the charting of manual BBT measurement so variable?
The very act of waking and moving to take the temperature means that the body has warmed up above the basal temperature affecting the accuracy of the results; in fact the body generally changes temperature more on waking than at any point during sleep. Data collected by one of the DuoFertility users who compared DuoFertility and their basal thermometer during an initial trial clearly showed that the act of waking up and taking a temperature measurement was causing the temperature to increase and thus masking the true value of the BBT. The likelihood of user errors using BBT charting has been used by some urine test manufacturers to down play the BBT method in favour of their own products. However, DuoFertility collects 20,000 temperature measurements every 24 hours, which allow it to pick the best representation of body basal temperature every night. By being worn continuously, the user doesn’t have to remember to wake early to take a temperature measurement, reducing the stress involv
