- Information which can be gained from the sympto-thermal chart A fertility chart is a diagnostic aid, giving information concerning normal or abnormal function of the menstrual cycle, which is of use to Doctors or Nurses in General Practice, Family Planning Clinics and in Fertility Clinics For the normal fertile woman: A Bi-phasic Sympto-thermal Chart confirms ovulation which occurs approximately ...www.fertilityuk.org/nfps781.html