Leiva, R. A., Bouchard, T. P., Abdullah, S. H., & Ecochard, R. (2017). Urinary Luteinizing Hormone Tests: Which Concentration Threshold Best Predicts Ovulation? Frontiers in public health. https://doi.org/10.3389/fpubh.2017.00320
Leiva RA, Bouchard TP, Abdullah SH, Ecochard R. Urinary Luteinizing Hormone Tests: Which Concentration Threshold Best Predicts Ovulation? Frontiers in public health. 2017. doi:10.3389/fpubh.2017.00320
Leiva, Rene Antonio, et al. "Urinary Luteinizing Hormone Tests: Which Concentration Threshold Best Predicts Ovulation?" Frontiers in public health, 2017.
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Of nine scenarios, a first positive LH test best predicted ovulation
Of nine scenarios, a first positive LH test predicted ovulation best within 24 hours. In this observational study of 107 women, daily urine tests and serial ultrasound covered 283 cycles. On cycle day 11, thresholds near the middle of the commercial range had a positive predictive value of 50 to 60% for ovulation within 24 hours.
Study at a glance, Observational study of 107 women: A first positive LH test best predicted ovulation within 24 hours. Source: Leiva RA et al., 2017, PMID 29234665.
Key Findings
Ovulation within 24 hours after the first single positive test was predicted best. False positives rose later in the cycle, with repeated tests, and with 48 or 72 hour windows.
On cycle day 11, thresholds near the middle of the commercial range had a positive predictive value of 50 to 60% and a negative predictive value of 98%.
In 88 of 283 cycles (31%), one positive day followed by three negative days came before ovulation, so the LH criteria marked a false end of the fertile window.
Peak-fertility mucus plus a positive LH test had a specificity of 97 to 99%, against 77 to 95% for mucus alone and 91% for LH alone.
Interpretation
This cohort study followed women at eight natural family planning clinics in Europe. They joined the study in 1996 and 1997. Ultrasound confirmed ovulation in every cycle studied. The authors note that luteinized unruptured follicles could affect LH test accuracy. The findings support larger studies of LH-based ovulation prediction.
RRM Context
Fertility awareness methods read several body signs together. The mucus-plus-LH result fits that approach. The authors describe urine LH tests as a possible add-on to these methods. The authors name a urine pregnanediol test as a backup marker.
Our editorial summary of this paper, not the article's abstract.
Abstract
Objective
To study the best possible luteinizing hormone (LH) threshold to predict ovulation within the 24, 48, and 72 h.
Design
Observational study.
Setting
Multicenter collaborative study.
Patients
A total of 107 women.
Interventions
Women collected daily first morning urine for hormonal assessment and underwent serial ovarian ultrasound. This is a secondary analysis of 283 cycles.
Main Outcome Measures
The 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.
Results
The 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).
Conclusion
We 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.
