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.
For EndNote, Zotero or Mendeley:
Open access
No open license is recorded for this paper. Reuse terms are set by the publisher.
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.
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
The work is a secondary analysis of an observational study. The outcomes were measures of test accuracy, and pregnancy was not measured. The analyzed cycles all had ultrasound-confirmed ovulation. Women joined in 1996 and 1997 at eight natural family planning clinics in Europe. The authors left out cycles without ovulation and possible luteinized unruptured follicles. The group was also fairly uniform in body mass index and background, which limits how far the results extend. In roughly one-half to one-third of cycles, a first positive test did not predict ovulation within 24 hours.
RRM Context
Fertility awareness methods read several body signs together, and the mucus-plus-LH result fits that approach. The authors describe urine LH tests as a possible adjunct to Fertility Awareness Methods. Of 298 cycles left after exclusions, 15 showed no confirmation of ovulation, possibly luteinized unruptured follicles. The authors list these follicles among the confounders of LH testing. The authors name a urinary pregnanediol test as a confirmatory 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.
