Rules for adjusting BBT

[MiniMe30]

Hey all,

I usually take my BBT at 7 a.m. but I also use an online adjuster to amend it if it gets taken at a different time i.e. I happen to wake up earlier or at weekends when I sleep in a little later. That's fairly easy to do and seems to give accurate results.

My question is - how do you adjust your BBT when other factors are involved? For example, you've had a bad night sleep (thus not getting the solid 3-4 hours in before you take it) or you have a drink or 2 the night before?

Last night, I woke up at 3 a.m and then had broken sleep right through until my alarm at 7 a.m. - my temp was higher than what I thought it would be, which was expected because of my disturbed sleep. I therefore had to discard that temp, so was wondering if there was a good way of adjusting it?

 

[ArmyWifey11]

I was wondering about this also and I found this on Fertility Friend yesterday

"When I wake up at a different time, should I adjust my temperature?

We are often asked whether temperatures should be "adjusted" when not taken exactly at the same time. Some simple formulas are sometimes applied to adjust for differences in waking time. We are often asked whether this is accurate or not and if it is worth correcting the chart.

We recommend against adjusting temperatures as in general the resulting temperature, though it may be more pleasing, is not more accurate. The reasoning behind our recommendation is based on the fact that the Basal Body Temperature variation with time is dependent on your own unique metabolism. While most women see a difference, some women do not see much dependence of the BBT with time and can live with a variation in time without masking their pattern. For many others even a 10-20 minute difference will have strong effects on their charts. Similarly, some women see an increase of their BBT with time while others may actually see a decrease. From the diversity of the charts that we have seen, it is quite clear that no simple generic formulas will be able to compensate for time differences.

Our advice is to use an alarm clock if necessary to try to keep the time as constant as possible. If you have an occasional waking time difference, just record the time but leave the data as measured and make a note if there are unusual circumstances. In most cases our software should be able to see your ovulation pattern despite a few inaccurate data points.

If you have inaccurate data points that are causing you to have an invalid or confusing interpretation, please ask for support to help evaluate your chart."

 

[Impet Limpet]

I don't know, I don't think there is a way to adjust. if it's on the odd occaison you should be fine. I tend to keep the odd temps that are affected by poor sleeping, I record the one closest to 7am (I now only drink at start of AF to cure that problem). I don't adjust for time at all as sometimes I take my temp at 5am and it is exactly the same as when I take it at 7am, sometimes it's .5 a degree different, there is no regualr way to adjust mine it would appear (it's even been the same at 5am and 9am!) So I just stick to the 7am temp (or 30mins either way).
I have figured I get a pretty reasonable reading even if I haven't had a solid 3 hours sleep beforehand.

Good luck with your temping

 

[PositiveUs]

I wake up at 4, 5 or 6 am depending. So as long as I have had 3hrs of solid sleep, that's when I take my temp and I do not adjust either.

Hope that helps!!