To assess the sensitivity and specificity of the self-identified fertile window.
Design
Observational study.
Setting
Not applicable.
PATIENT(S): A total of 107 women.
INTERVENTION(S): Women recorded cervical mucus observation and basal body temperature daily while undergoing daily ovarian ultrasound.
MAIN OUTCOME MEASURE(S): The biological fertile window, defined as the 6 days up to and including the day of ovulation; and the 2-day ovulation window, defined as the day before and the day of ovulation.
RESULT(S): The self-identification of the biological fertile window by the observation of any type of cervical mucus provides 100% sensitivity but poor specificity, yielding a clinical fertile window of 11 days. However, the identification of the biological fertile window by peak mucus (defined as clear, slippery, or stretchy mucus related to estrogen) yielded 96% sensitivity and improved specificity. The appearance of the peak mucus preceded the biological fertile window in less than 10% of the cycles. Likewise, this type of mucus identified the ovulation window with 88% sensitivity.
CONCLUSION(S): These results suggest that, when perceived accurately, more accurate clinical self-detection of the fertile window can be obtained by identification of peak mucus. This may improve efforts to focus intercourse in the fertile phase for couples with fertility concerns.
PMID 25724738 25724738 DOI 10.1016/j.fertnstert.2015.01.031 10.1016/j.fertnstert.2015.01.031 Ecochard et al. 2015, Ecochard 2015
Cite this article
Ecochard, R., Duterque, O., Leiva, R., Bouchard, T., & Vigil, P. (2015). Self-identification of the clinical fertile window and the ovulation period. Fertility and sterility, 103(5), 1319-25.e3. https://doi.org/10.1016/j.fertnstert.2015.01.031
Ecochard R, Duterque O, Leiva R, Bouchard T, Vigil P. Self-identification of the clinical fertile window and the ovulation period. Fertil Steril. 2015;103(5):1319-25.e3. doi:10.1016/j.fertnstert.2015.01.031
Ecochard, R., et al. "Self-identification of the clinical fertile window and the ovulation period." Fertility and sterility, vol. 103, no. 5, 2015, pp. 1319-25.e3.
Keywords
Body Temperature Regulation, Cervix Mucus/metabolism, Europe, Female, Fertile Period, Fertility, Humans, Ovary/diagnostic Imaging/physiology, Ovulation, Ovulation Detection/methods, Predictive Value of Tests, Self Care, Time Factors, Ultrasonography, Fertile Window, Cervical Mucus, Fertility Awareness Methods, Menstrual Cycle, Ovulation
Women wishing to conceive are largely unaware of fertility symptoms at the time of ovulation. This study investigated the effectiveness of fertility-awareness in achieving pregnancy, particularly fertile mucus pattern, in the context of infertility. The 384 eligible participants were taken from consecutive women desiring pregnancy who attended 17 Australian Billings Ovulation Method(®) clinics from 1999-2003. This cohort included couples with infertility ≥12 months (51%) and female age >35 years (28%). Under fertility-awareness instruction, pregnancy was achieved by 240 couples (62.5%) after maximum follow-up of two years. Mucus symptom observations effectively stratified 'low pregnancy-potential' (35.2%) and 'high pregnancy-potential' groups. Pregnancy rates were ∼30% higher in the latter group (44.4% versus 72.3%) in addition to consistent effects observed on pregnancy achievements within subgroups defined by prognostic factors such as duration of infertility (p = 0.001) and increasing female age (p = 0.04). Fertile symptoms were also associated with significantly shorter time to conception (4.2 versus 6.4 months) in a survival analysis (p = 0.003). Billings Ovulation Method(®) observations strongly predicted successful conception. This has the capacity to provide a rapid, reliable and cost-effective approach to stratifying fertility potential, including directing timely and targeted investigations/management, and is accessible for women who may be remote from primary or specialist care.
To quantify the frequency of use of selected fertility awareness indicators and to assess their influence on fecundability. Web-based prospective cohort study. Not applicable. PATIENT(S): Female pregnancy planners, aged 21-45 years, attempting conception for ≤6 cycles at study entry. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): We ascertained time to pregnancy, in menstrual cycles, with bimonthly questionnaires. We estimated adjusted fecundability ratios (FRs) and confidence intervals (CIs) using proportional probabilities models, controlling for age, income, education, smoking, intercourse frequency, and other lifestyle and reproductive factors. RESULT(S): A total of 5,688 women were analyzed, with a mean age of 29.9 years and mean time trying of 2.1 cycles at baseline; 30% had ever been pregnant. At baseline, 75% were using one or more fertility indicators (counting days or charting menstrual cycles [71%], measuring basal body temperature [BBT, 21%], monitoring cervical fluid [39%], using urine LH tests [32%], or feeling for changes in position of the cervix [12%]). Women using any fertility indicator at baseline had higher subsequent fecundability (adjusted FR 1.25, 95% CI 1.16-1.35) than those not using any fertility indicators. For each individual indicator, adjusted FRs ranged from 1.28-1.36, where 1.00 would indicate no relation with fecundability. The adjusted FR for women using a combination of charting days, cervical fluid, and urine LH was 1.48 (95% CI 1.31-1.67) relative to women using no fertility indicators. CONCLUSION(S): In a North American preconception cohort study, use of fertility indicators indicating the fertile window was common, and was associated with greater fecundability.
To assess the use of cervical mucus monitoring (CMM) in women trying to conceive and determine whether monitoring is associated with increased cycle-specific probability of conception (fecundability). Time-to-pregnancy cohort study. Population-based cohort. PATIENT(S): Three hundred thirty-one women trying to conceive, ages 30 to 44 years, without known infertility. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): CMM prevalence and fecundability. RESULT(S): During the first cycle of the study, CMM was performed consistently (checked on >66% of pertinent cycle days) by 20 women (6%), inconsistently (34% to 66% of days) by 60 women (18%), infrequently (≤33% of days) by 73 women (22%), and not performed by 178 women (54%). Cycles in which CMM was consistently performed were statistically significantly more likely to result in conception after adjusting for age, race, previous pregnancy, body mass index, intercourse frequency, and urinary luteinizing hormone (LH) monitoring. Fecundability also increased with increasing consistency of CMM. CONCLUSION(S): Among women trying to conceive, CMM is uncommon, but our study suggests that CMM-a free, self-directed method to determine the fertile window-is associated with increased fecundability independent of intercourse frequency or use of urinary LH monitoring.
Accurate timing of ovulation is especially necessary (1) in artificial insemination in order to avoid wastage of donor semen; (2) in cases where the husband is relatively infertile and it is necessary to conserve his semen. While many physicians rely upon the basal body temperature curve for timing ovulation, the interpretation of such curves is varied. Some physicians believe ovulation occurs prior to the lowest point in the temperature cycle, while others believe that ovulation occurs either at the low point or following the thermal shift. We have been disappointed in our ability to interpret the basal body temperature curve for accurate timing of ovulation, and have placed greater reliance upon concurrent phenomena, such as changes in the quantity and viscosity of cervical mucus and the cyclic changes observed in the vaginal smear. Although the relationship between the occurrence of a profuse, thin cervical mucus discharge and the optimal time of fertility in the human has been recognized for the past century, in our opinion this relationship requires further evaluation.
In his excellent review, "Cervical mucus: Cyclic variations and their clinical significance," Shettles quotes Robin who, in 1848, noted the viscous nature of human cervical secretions; and Smith who, in 1865, concluded that conception is most likely when the mucus contents of the cervix are in the most fluid condition. J. Marion Sims, who invented a vaginal speculum and first described the postcoital examination in 1868, observed that the test is positive for motile spermatozoa when the cervical mucus becomes clear and translucent, and about the consistency of the white of egg. Although these observations on human cervical mucus have been well documented, they have been almost disregarded by gynecologists. The significance of the cyclical outpouring of cervical mucus has been rediscovered in the past few years and has aroused great interest in students of sterility.
The optimal time of fertility in domestic animals is the period of heat or estrus. In 1925, Woodman and Hammond showed that during estrus, bovine cervical mucus is fluid and capable of being drawn out into threads, whereas in diestrus the mucus is thick. Seguy and Vimeux, and Seguy and Simonnet called attention to the optimal conditions of longevity of human spermatozoa in the fluid, glairy mucus of the cervix at midcycle. They postulated that these changes in cervical mucus were associated with ovulation and could be compared to the period of estrus in subprimate mammals. They correlated these changes with visual evidence of ovulation at laparotomy. Subject: ively, many women observe an increased sticky, mucoid discharge which is typical at midcycle and which is present over a period of days. On occasion this discharge is blood-tinged and may be compared to the distinct bloody mucoid discharge present in the domestic animal "in heat."
This mucus can be seen exuding from the cervix at midcycle and it may be aspirated from the endocervix and actually weighed, as reported by Viergiver and Pommerenke. Clift demonstrated certain rheologic properties of cervical mucus, especially flow elasticity and Spinnbarkeit. Flow elasticity, or elastic recoil of mucus, is measured by an instrument described by Blair. The use of the Blair capillary viscometer is a cumbersome method which we discontinued. We have had no experience with the new modification of the viscometer described by Clift, Glover, and Blair. Spinnbarkeit is easily tested, and we have found it to be a very practical objective method for determining viscosity of cervical mucus. In performing this test (Fig. 1), a vaginal speculum is inserted, exposing the cervix. A glass cannula is inserted into the endocervix and by means of gentle suction, a quantity of endocervical mucus is obtained. This mucus is blown onto a glass slide and a cover slip is placed on it. The mucus adheres to both the slide and the cover slip, and by withdrawing the cover slip, a thread of mucus is formed which can be measured in centimeters (Fig. 2). Usually, the cover slip is withdrawn several times, and the average length of the thread is ascertained. It is our purpose to show the relationship of Spinnbarkeit to other cyclic phenomena occurring during the menstrual cycle, such as basal body temperatures, vaginal smears, quantity of cervical mucus, and longevity of spermatozoa (Fig. 3).