LONDON: A new smartphone app, which can accurately tell women when they are fertile, may prove to be an effective alternative to give the female body a break from contraceptive pills, researchers have claimed.
Input your daily temperature into the app, and by comparing the readings with those in its data set, it lets you know when you can have unprotected sex (shown as a green day in its calendar) and when to use contraception (shown as red).
"I wanted to give my body a break from the pill, but I could not find any good forms of natural birth control, so I wrote an algorithm for myself," said Elina Berglund, co-founder and CTO at Natural Cycles.
Based on advanced statistical methods from Berglund's time at CERN, the European Organisation for Nuclear Research, the algorithm uses body temperature to determine fertility.
After ovulation, increased levels of progesterone make women's bodies up to 0.45 degree Celsius warmer.
Natural Cycles has conducted two clinical trials, the second of which analysed the data of more than 4,000 women aged 20-35, 'Wired' reported.
Over the course of one year, there were 143 unplanned pregnancies, ten of which occurred on green days, giving the app a 99.5% efficacy rating - the same as the pill.
It is currently the only app of its kind to be regulated as an approved medical device, putting it in the same category as condoms and IUDs - albeit in a different class.
"We are a natural alternative to the pill - with no side effects," said Berglund.
"Natural Cycles is not recommended to those who are very young or very keen to avoid a pregnancy, since there are other more effective methods," said lead author Kristina Gemzell Danielsson, from Karolinska Institutet in Sweden.
"The efficacy is far below that of intrauterine contraception or implants, but similar to that of the pill when used in real life," said Danielsson.