Measurement and Statistics · Instrument Development and Validation
Prior JC et al., 1990 · Clin Invest Med
Basal temperature data are known to provide unreliable assessments of luteal phase length when they are evaluated by qualitative, visual-pattern methods. This study of 24 cycles in 24 women compared the serum LH peak day with the luteal phase onset day determined by three quantitative basal temperature a) a new computerized least mean square method developed by the authors; b) the mean temperature method reported by Vollman; and c) a computerized version of the World Health Organization cumulative sum method of Royston. The luteal phase onset day determined by the three quantitative basal temperature methods, (a, b, and c) correlated well with the midcycle LH peak (r = 0.879, 0.891, and 0.791, respectively, all p less than 0.001). The cumulative sum method, however, was only able to analyze 19/24 cycles. The mean delay between the LH peak day and the luteal phase onset day determined by thermal shift was 2.4 +/- 1.5, 2.7 +/- 1.4, and 4.1 +/- 2.0 d (mean +/- SD), respectively. The mean temperature method, but not the other two methods, showed an increasing delay between the LH peak day and the thermal shift day with longer follicular phase lengths. Rectal and oral temperature data from the same cycle give identical luteal onset days when analyzed by the least mean square and mean temperature methods, but discrepant days by the cumulative sum analysis. The least mean square technique is a reliable and precise method for population documentation of luteal phase lengths.
Cycle Biomarkers · Hormonal Markers
Ecochard R et al., 2001 · BJOG
To improve prediction of ovulation in normal cycles. Collection of women's characteristics and their menstrual cycles. Monitoring and analysis of time relationships between several indicators of ovulation: transvaginal ultrasonography, cervical mucus, basal body temperature, urinary luteinising hormone, and ratio of urinary oestrogen to progesterone metabolites. Each of eight natural family planning clinics was to study 12 women for at least three cycles. One hundred and seven normally fertile and cycling women aged 18 to 45. Daily measurements of urinary luteinising hormone, follicle stimulating hormone, oestrone-3-glucuronide and pregnanediol-3alpha-glucuronide. Basal body temperature recording and cervical mucus checking. Transvaginal ultrasound examination of the ovaries. Delays between the expected day of ovulation according to the luteinising hormone peak or to ultrasound evidence and the expected days according to the other indices of ovulation. Ultrasonography was able to show evidence of ovulation in 283 out of 326 cycles. The average time lag between luteinising hormone peak and ultrasound evidence was less than one day (+0.46) but premature and late luteinising hormone-expected date of ovulation were observed in nearly 10% and 23% of cycles, respectively. Basal body temperature rise was observed in 98% of cycles. Cervical mucus peak symptom, rapid drop in the ratio of urinary metabolites, and luteinising hormone initial rise were all close to ultrasonographic evidence in more than 72% of cycles. For accuracy and practical reasons, the cervical mucus peak symptom, the ratio of urinary metabolites and luteinising hormone initial rise might be better indices of ovulation than the luteinising hormone peak.
Methods · Sympto-Thermal Method
Leader A et al., 1985 · Fertil Steril
Ninety-five menstrual cycles were studied in 20 women undergoing donor artificial insemination (AID). In 49 cycles basal body temperature (BBT) changes were charted daily and both daily cervical mucus scoring (modified Insler score) and daily realtime ultrasonography (USS) were performed from day 11 to ovulation. AID was performed only on the day of follicular rupture. A control group, not subjected to USS, were inseminated two to three times per cycle over 46 cycles in the periovulatory period. The Insler score was found to be a reliable indicator of follicular development and rupture. The BBT was found to be less reliable than the Insler score or USS. While USS may be used to confirm follicular development, the Insler score is reliable and less costly.
Methods · Sympto-Thermal Method
Bedford JL et al., 2009 · Eur J Obstet Gynecol Reprod Biol
To assess computerised least-squares analysis of quantitative basal temperature (LS-BT) against urinary pregnanediol glucuronide (PdG) as an indirect measure of ovulation, and to evaluate the stability of LS-QBT to wake-time variation. Cross-sectional study of 40 healthy, normal-weight, regularly menstruating women aged 19-34. Participants recorded basal temperature and collected first void urine daily for one complete menstrual cycle. Evidence of luteal activity (ELA), an indirect ovulation indicator, was assessed using Kassam's PdG algorithm, which identifies a sustained 3-day PdG rise, and the LS-QBT algorithm, by determining whether the temperature curve is significantly biphasic. Cycles were classified as ELA(+) or ELA(-). We explored the need to pre-screen for wake-time variations by repeating the analysis using: (A) all recorded temperatures, (B) wake-time adjusted temperatures, (C) temperatures within 2h of average wake-time, and (D) expert reviewed temperatures. Relative to PdG, classification of cycles as ELA(+) was 35 of 36 for LS-QBT methods A and B, 33 of 34 (method C) and 30 of 31 (method D). Classification of cycles as ELA(-) was 1 of 4 (methods A and B) and 0 of 3 (methods C and D). Positive predictive value was 92% for methods A-C and 91% for method D. Negative predictive value was 50% for methods A and B and 0% for methods C and D. Overall accuracy was 90% for methods A and B, 89% for method C and 88% for method D. The day of a significant temperature increase by LS-QBT and the first day of a sustained PdG rise were correlated (r=0.803, 0.741, 0.651, 0.747 for methods A-D, respectively, all p<0.001). LS-QBT showed excellent detection of ELA(+) cycles (sensitivity, positive predictive value) but poor detection of ELA(-) cycles (specificity, negative predictive value) relative to urinary PdG. Correlations between the methods and overall accuracy were good and similar for all analyses. Findings suggest that LS-QBT is robust to wake-time variability and that expert interpretation is unnecessary. This method shows promise for use as an epidemiological tool to document cyclic progesterone increase. Further validation relative to daily transvaginal ultrasound is required.