# Monophasic basal body temperature in ovulatory menstrual cycles Johansson, E.D.B., Larsson-Cohn, U. and Gemzell, C. (1972) ‘Monophasic basal body temperature in ovulatory menstrual cycles’, American Journal of Obstetrics & Gynecology, 113(7), pp. 933–937. Available at: [LINK](https://doi.org/10.1016/0002-9378(72)90659-X). >[!Abstract] > The plasma concentration of progesterone, the urinary excretion of estrogens, and the basal body temperature were followed in 17 normally menstruating women during 33 menstrual cycles. A monophasic basal body temperature was found in 4 cycles (12 per cent) in spite of the fact that the other parameters investigated suggested that ovulation had occurred. It is thus concluded that the registration of a monophasic basal body temperature during a menstrual cycle does not give sufficient information for the conclusion that the cycle is anovulatory. ## Limitations of study - The study only looked at a small number of women - Carried out in 1972 (other ways to verify if ovulation took place) ## Notes - Some women do not see an increase in BBT despite ovulation occurring - may be due to other factors such as thyroid issues - If yours does not increase, worth getting checked out to see what's going on - monophasic bbt does not mean that you have not ovulated %% [Open in Zotero](zotero://select/items/@johansson1972) ### [[monophasic bbt does not mean that you have not ovulated]] > The plasma concentration of progesterone, the urinary excretion of estrogens, and the basal body temperature were followed in 17 normally menstruating women during 33 menstrual cycles. A monophasic basal body temperature was found in 4 cycles (12 per cent) in spite of the fact that the other parameters investigated suggested that ovulation had occurred. It is thus concluded that the registration of a monophasic basal body temperature during a menstrual cycle does not give sufficient information for the conclusion that the cycle is anovulatory. ^vllod - Some women do not see an increase in BBT despite ovulation occurring - may be due to other factors such as thyroid issues - If yours does not increase, worth getting checked out to see what's going on