A new method to detect significant basal body temperature changes during a woman's menstrual cycle

Abstract

Objective To compare the results of a computer programme based on the Trigg's tracking system (TTS) identification of the basal body temperature (BBT) shift day from daily records of BBT values (TTS transition day), with the BBT shift day identified from the same records using the Sensiplan® symptothermal method of natural family planning.Methods A computer programme was written to display the daily BBT readings for 364 menstrual cycles from 51 women aged 24 to 35 years, obtained from the German Natural Family Planning (NFP) database. The TTS transition day so identified from each record was then compared with the BBT shift day estimated from the same record by the Sensiplan® method.Results Total agreement between the methods was obtained for 81% (294/364) of the cycles and 18% (67) cycles differed by ± 1 day. For the 364 pairs of values distributed among 51 women the medians of the differences between the TTS transition day and Sensiplan® initial day of the BBT rise (shift day) were not significantly different (χ2 = 65.28, df = 50, p = 0.07205).Conclusion The advantages of the tracking signal algorithm are that in many cases it was possible to identify the BBT shift day on that very day – rather than only some days later – and to estimate the probability that a transition had occurred from the different values of the tracking signal.Chinese 摘 要 目的 比较基于trigg's追踪系统（ttS）的计算机程序与自然避孕法中的Sensiplan®症状体温法在根据相同的每日基础体温(BBt)测定记录数据的前提下识别基础体温转换日(ttS转换日)所得结果的异同。方法 一种计算机程序被编写用于显示51位年龄位于24至35岁之间妇女的364次月经周期中的每日基础体温测定值（BBt）。资料来源于的德国安全期计划生育数据库（nFP）。程序在每个月经周期中识别出的ttS转换日将与使用相同数据的Sensiplan®法所得出的BBt转换日作比较。结果 81%的周期(294/364)中两种方法所得结果完全相同。18%的周期（67）结果相差±1天。分布于51名妇女的364对数据所得出的ttS转换日与Sensiplan®的BBt升高首日（转换日）的中位数并无显著差异(χ2=65.28, df = 50, p =0.07205)。结论 追踪信号算法的优势在于许多情况下其在月经周期中的BBt转换日当天即可识别而不是在几天之后才识别出转换的发生，并可根据不同的追踪信号数值估计转换已发生的概率。