Chronological aspects of ultrasonic, hormonal, and other indirect indices of ovulation

Objective To improve prediction of ovulation in normal cycles. Design Collection of women's characteristics and their menstrual cycles. Mo nitoring and analysis of time relationships between several indicators of o vulation: transvaginal ultrasonography, cervical mucus, basal body temperat ure, urinary luteinising hormone, and ratio of urinary oestrogen to progest erone metabolites. Setting Each of eight natural family planning clinics was to study 12 women for at least three cycles. Population One hundred and seven normally fertile and cycling women aged 18 to 45. Methods Daily measurements of urinary luteinising hormone, follicle stimula ting hormone, oestrone-3-glucuronide and pregnanediol-3 alpha -glucuronide. Basal body temperature recording and cervical mucus checking. Transvaginal ultrasound examination of the ovaries. Main outcome measures Delays between the expected day of ovulation accordin g to the luteinising hormone peak or to ultrasound evidence and the expecte d days according to the other indices of ovulation. Results Ultrasonography was able to show evidence of ovulation in 283 out o f 326 cycles. The average time lag between luteinising hormone peak and ult rasound evidence was less than one day (+0.46) but premature and late lutei nising hormone-expected date of ovulation were observed in nearly 10% and 2 3% 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 ultras onographic evidence in more than 72% of cycles. Conclusions For accuracy and practical reasons, the cervical mucus peak sym ptom, the ratio of urinary metabolites and luteinising, hormone initial ris e might be better indices of ovulation than the luteinising hormone peak.