Reliability of ovulation tests in infertile women

To assess the reliability of the most widely used clinical methods for predicting or confirming ovulation.

We monitored spontaneous cycles in 101 infertile women using basal body temperature (BBT), transvaginal ultrasound, a urinary stick system for LH surge, and three serum progesterone measurements in the midluteal phase. Transvaginal ultrasound monitoring was standard for ovulation detection and sensitivity. We calculated specificity and accuracy of each method compared with that standard.

Follicular development and ultrasound evidence of ovulation were confirmed in 97 of 101 cycles (96%). Urinary LH surge preceded follicular rupture assessed by ultrasonography in all cycles and showed concordance with ultrasound-evidenced ovulation in 98 of 101 cases. The timing of BBT nadir had wide variability, and BBT and ultrasonography agreed in a similar percentage of cases (74%). Midluteal serum progesterone assessments showed ovulatory values in 93 subjects, and ovulation was concordant with ultrasonography in 90 subjects.

Urinary LH was accurate in predicting ovulation with ultrasonography as the standard for detection, but time varied widely. The nadir of BBT predicted ovulation poorly. The BBT chart was less accurate for confirming ovulation, whereas a single serum progesterone assessment in midluteal phase seemed as effective as repeated serum progesterone measures.