This myth needs to be put into context before it will make sense to some. Changes in body temperate can indicate the time of ovulation. After ovulation occurs and the egg has already been released, body temperature will increase. The increase in temperature will typically be by about 0.4 degrees. This method requires temperature to be taken first thing after waking each morning. Body temperature is at its lowest when first waking. This allows for standardisation to facilitate comparison between days.
This myth suggests that, in order to increase the chances of a conception, it is best to wait until body temperature increases before having sex. This advice, is not the ideal. When body temperature increases, ovulation has already taken place. This will result in leaving a very small window of opportunity. After being released, an egg will only remain viable for 12 to 24 hours. Is contrast, sperm can last up to five days whilst waiting in place for the egg to be released. Given this, it is therefore better to have sex before the temperature increase. This will widen the window of opportunity and increase the chances of a conception.
You may then ask, what is the benefit of taking temperatures? It can be informative when done over more than one cycle. The historical timing of ovulation can offer a good indicator for the timing of future ovulations.
*This is the sixth of a list of 13 myths concerning conception which was compiled by Dr Minna Geisler from The Waterstone Clinic in Ireland.