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.
Murcia-Lora JM et al., 2011·pers.bioét.·
Open Access
El objetivo de este artículo es revisar los principales conceptos en la literatura acerca de la ventana de la fertilidad en pacientes con ciclos menstruales normales. El énfasis principal del artículo se ha dirigido al análisis de la teoría de Brown de la ovulación, revisar conceptos básicos de la ovulación, secreción y metabolismo de la hormona folículo estimulante, y al estudio clínico, ecográfico y bioquímicos del desarrollo folicular de la ventana de la fertilidad. Este artículo también repasa los biomarcadores clínicos y los diferentes metabolitos endocrinos que delimitan en la fase fértil del ciclo. Se revisan diferentes estudios en los cuales las valoraciones en suero y orina de los esteroides sexuales, han corroborado tener una correlación directa para enmarcar el período fértil. Actualmente tienen relevancia estos conocimientos en diferentes grupos de interés, sobre todo en mujeres con un alto nivel de motivación interesadas en el reconocimiento de su fertilidad, las cuales pueden beneficiarse mediante la aplicación de conocimientos técnicos actuales que detectan la ventana fértil. También estos conocimientos suelen cobrar importancia en aquellas personas que pertenecen a programas de regulación de la fertilidad (PRF), con intención de distanciar un embarazo, o de reconocer el periodo fértil del ciclo para conseguir un embarazo espontáneamente, o mediante programas de NaProTecnología. Otros grupos de interés, son aquellos en los cuales no se tiene experiencia en cursos de PRF, pero desean mejorar sus conocimientos en el reconocimiento de la fertilidad por medio de una breve entrevista, o por medio de cursos de orientación familiar.
The purpose of this study was to determine the variability in length of the fertile phase of the menstrual cycle with 140 participants who produced 1,060 cycles with an electronic hormonal fertility monitor. The length of the fertile phase, as defined by the first day with a threshold level of urinary E3G and ending with a second day above a threshold of LH, varied from <1 to >7 days, with the most frequent length being 3 days.
To improve prediction of ovulation in normal cycles. Collection of women's characteristics and their menstrual cycles. Monitoring and analysis of time relationships between several indicators of ovulation: transvaginal ultrasonography, cervical mucus, basal body temperature, urinary luteinising hormone, and ratio of urinary oestrogen to progesterone metabolites. Each of eight natural family planning clinics was to study 12 women for at least three cycles. One hundred and seven normally fertile and cycling women aged 18 to 45. Daily measurements of urinary luteinising hormone, follicle stimulating hormone, oestrone-3-glucuronide and pregnanediol-3alpha-glucuronide. Basal body temperature recording and cervical mucus checking. Transvaginal ultrasound examination of the ovaries. Delays between the expected day of ovulation according to the luteinising hormone peak or to ultrasound evidence and the expected days according to the other indices of ovulation. Ultrasonography was able to show evidence of ovulation in 283 out of 326 cycles. The average time lag between luteinising hormone peak and ultrasound evidence was less than one day (+0.46) but premature and late luteinising hormone-expected date of ovulation were observed in nearly 10% and 23% 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 ultrasonographic evidence in more than 72% of cycles. For accuracy and practical reasons, the cervical mucus peak symptom, the ratio of urinary metabolites and luteinising hormone initial rise might be better indices of ovulation than the luteinising hormone peak.
Bouchard TP et al., 2019·Front Public Health·
Open Access
Progesterone rises \~24-36 h after ovulation. Past studies using ultrasound-confirmed ovulation have shown that three consecutive tests with a threshold of 5μg/mL of urine progesterone (pregnanediol-3-glucuronide, PDG), taken after the luteinizing hormone (LH) surge, confirmed ovulation with 100% specificity. The purpose of this study was to a evaluate a new urine PDG self-test to retrospectively confirm ovulation in women who were monitoring ovulation using a hormonal fertility monitor. Thirteen women of reproductive age were recruited to test urine PDG while using their home hormonal fertility monitor. The monitor measured the rise in estrogen (estrone-3-glucuronide, E3G) and LH to estimate the fertile phase of the menstrual cycle. The women used an online menstrual cycle charting system to track E3G, LH and PDG levels for four menstrual cycles. The participants (Mean age 33.6) produced 34 menstrual cycles of data (Mean length 28.4 days), 17 of which used a PDG test with a threshold of 7μg/mL and 17 with a threshold of 5μg/mL. In the cycles that used the 7μg/mL test strips, 59% had a positive confirmation of ovulation, and with the 5μg/mL test strips, 82% of them had a positive confirmation of ovulation. The 5μg/mL PDG test confirmed ovulation in 82% of cycles and could assist women in the evaluation of the luteal progesterone rise of their menstrual cycle.