Urinary Luteinizing Hormone Tests: Which Concentration Threshold Best Predicts Ovulation?

Abstract

ObjectiveTo study the best possible luteinizing hormone (LH) threshold to predict ovulation within the 24, 48, and 72 h.DesignObservational study.SettingMulticenter collaborative study.PatientsA total of 107 women.InterventionsWomen collected daily first morning urine for hormonal assessment and underwent serial ovarian ultrasound. This is a secondary analysis of 283 cycles.Main outcome measuresThe sensitivity, specificity, positive and negative predictive values, and positive and negative likelihood ratios were estimated for varying ranges of LH thresholds. Receiver operating characteristic curves and cost–benefit ratios were used to estimate the best thresholds to predict ovulation.ResultsThe best scenario to predict ovulation at random was within 24 h after the first single positive test. The false-positive rate was found to increase as (1) the cycle progressed or (2) two or three consecutive tests were used, or (3) ovulation was predicted within 48 or 72 h. Testing earlier in the cycle increases the predictive value of the test. The ideal thresholds to predict ovulation ranged between 25 and 30 mIU/ml with a PPV (50–60%), NPV (98%), LR+ (20–30), and LR− (0.5). At least, one day with LH ≥25 mIU/ml followed by three negatives (LH <25) occurred before ovulation in 31% of all cycles. When used throughout the cycle and evaluated together, peak-fertility type mucus with a positive LH test ≥25 mIU/ml provides a higher specificity than either mucus or LH testing alone (97–99 vs. 77–95 vs. 91%, respectively).ConclusionWe identified that beginning LH testing earlier in the cycle (day 7) with a threshold of 25–30 mIU/ml may present the best predictive value for ovulation within 24 h. However, prediction by LH testing alone may be affected negatively by several confounding factors so LH testing alone should not be used to define the end of the fertile window. Complementary markers should be further investigated to predict ovulation and identify the fertile window. The use of the peak cervical mucus along with an LH test may provide a higher specificity and predictive value than either of them alone. We recommend that manufacturers disclose their tests’ threshold to the public.

Expressing the quantity of urinary analytes: a discussion of some issues arising from the monitoring of the menstrual cycle

“…After all, in 1957 Wray [158: 529] observed that "[t]he practice of reporting pregnanediol outputs in mg per unit volume is contra-indicated by its great inaccuracy" and very similar comments were made a century earlier by Thudichum [159]. Despite this, the use of u A in the measurement of urinary metabolites of reproductive hormones continues [2,6,7,[30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. Moreover, there is still confusion in the literature about u A , J A and their link to J V .…”

“…The inevitable question is whether such a difference in u A has any physiological significance. In spite of these uncertainties, reports of the use of concentration measurements to monitor reproductive hormones in urine are increasingly common and in some it is claimed that specific threshold values are associated with particular events in the cycle [2,6,7,[30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. In none of these cases were the data of a single cycle used by a woman to monitor her own fertility.…”

Can apps and calendar methods predict ovulation with accuracy?

“…Intact LH surges prior to ovulation and is excreted quickly, whereas assays measuring beta LH also detect LH breakdown products that are excreted more slowly. Therefore, beta LH assays can often provide profiles with more than one surge and have peak levels occurring at a considerable time after ovulation [14][15][16][17][18] . As peak levels can occur post ovulation, even with an intact LH assay, it is more appropriate to measure the LH surge: there are a wide variety of methods for determining the surge 19 , with the most accurate method providing 1-day prediction of ovulation with maximal error of ±1 day 14,15 .…”

Towards the Clinical Evaluation of the Luteal Phase in Fertile Women: A Preliminary Study of Normative Urinary Hormone Profiles

“…In clinical settings, with a prospective approach, the use of home kits that detect threshold urinary LH rise to target the luteal phase has become main stream. However, a recent paper points out the inaccuracy of using these threshold LH tests by themselves to detect ovulation ( 19 ), even though, they could be utilized along with PG rise threshold in-home tests or with the peak mucus sign.…”