The sympto-thermal methods

The symptothermal methods include all those that identify the woman's fertile period through the basal body temperature and the periovulatory signs. Research conducted following the discovery over a century ago of the hyperthermic plateau in the later part of the menstrual cycle has confirmed that under normal conditions, and when the daily temperature is taken under comparable conditions, infertility may be assumed when the high temperature plateau is confirmed. A reliable temperature curve requires certain conditions: it should be taken upon awakening with a basal thermometer over a sufficient time to obtain an accurate measure, at almost the same time every day, and the graph paper should be appropriately scaled for recording. Various guidelines of interpretation have been developed throughout the world. Serena considers infertility assured from the 3rd consecutive day of elevated temperature as long as other fertility symptoms have disappeared. Among symptoms of ovulation that are perceptible to the woman are cyclic changes in the quantity and consistency of the cervical mucus, which has the advantage of predating and thus forecasting ovulation and of being less sensitive than the basal temperature to nongenital infections, sleepless nights, or other stresses. Use of mucus changes alone as an indicator of fertility carries the risk that such changes may not be noticed or may be due to an estrogen surge not related to ovulation. Other symptoms that are useful for some women in confirming temperature or mucus changes include 4 different alterations in the cervix, abdominal pain or mittelschmerz, intramenstrual bleeding, feeling of heaviness in the breasts, and variations in mood and libido. Many groups that teach the temperature curve and clyclical symptoms also provide instructions or mathematical rules for determining the number of infertile days at the beginning of the cycle. Some programs state that 6-7 days are usually infertile provided that the menses were preceded by a hyperthermic plateau. Many groups recommend the calculation of Ogino or a variant. The symptothermal method of fertility control combines the basal temperature curve with the other signs of fertility to serve as a basis for modification of sexual behavior to enhance or suppress fertility. Different programs stress different elements or combinations. The efficacy of the symptothermal methods depends on precise recordkeeping and observation and on competent instruction and counseling, as well as the willingness of the couple to modify their sexual behavior. Statistical measures of the method's efficacy are complex and unsatisfactory as they attempt to apply rigid rules to actions and decisions that are in fact filled with nuance.