Slone Epidemiology Center at Boston University, Boston, Massachusetts and 2Lombardi Comprehensive Cancer Center at Georgetown University Medical Center, Washington, District of ColumbiaROR
To assess the effect of randomization to FertilityFriend.com, a mobile computing fertility-tracking app, on fecundability.
Design
Parallel non-blinded randomized controlled trial nested within the Pregnancy Study Online (PRESTO), a North American preconception cohort. PATIENT(S): Female participants aged 21 to 45 years attempting conception for ≤6 menstrual cycles at enrolment (2013-2019).
Intervention
Randomization (1:1) of 5532 participants to receive a premium Fertility Friend (FF) subscription. MAIN OUTCOME MEASURE(S): Fecundability (per-cycle probability of conception). Participants completed bimonthly follow-up questionnaires until pregnancy or a censoring event, whichever came first. We first performed an intent-to-treat analysis of the effect of FF randomization on fecundability. In secondary analyses, we used a per-protocol approach that accounted for adherence in each trial arm. In both analyses, we used proportional probabilities regression models to estimate fecundability ratios (FR) and 95% confidence intervals (CI) comparing those randomized vs. not randomized and applied inverse probability weights to account for loss-to-follow-up (intent-to-treat and per-protocol analyses) and adherence (per-protocol analyses only).
Results
Using life-table methods, 64% of the 2775 participants randomized to FF and 63% of the 2767 participants not randomized to FF conceived during 12 cycles; these respective percentages were each 70% among those with 0-1 cycles of attempt time at enrolment. Of those randomized to FF, 72% were defined as adherent (68% of observed menstrual cycles). In intent-to-treat analyses, there was no appreciable association overall (FR = 0.97; 95% CI, 0.90-1.04) or within strata of pregnancy attempt time at enrolment, age, education, or other characteristics. In per-protocol analyses, we observed little association overall (FR = 1.06; 95% CI, 0.99-1.14), but weak-to-moderate positive associations among participants who had longer attempt times at enrolment (FR = 1.15; 95% CI, 0.98-1.35 for 3-4 cycles; FR = 1.14; 95% CI, 0.87-1.48 for 5-6 cycles), were aged <25 years (FR = 1.29; 95% CI, 1.01-1.66), had ≤12 years of education (FR = 1.32; 95% CI, 0.92-1.89), or were non-users of hormonal contraception within 3 months before enrolment (FR = 1.10; 95% CI, 1.02-1.19).
Conclusion
No appreciable associations were observed in intent-to-treat analyses. In secondary per-protocol analyses that accounted for adherence, randomization to FF was associated with slightly greater fecundability among selected subgroups of participants; however, these results are susceptible to unmeasured confounding.
fertility tracking app, FertilityFriend software, fecundability fertility app, web-based fertility tracking, mobile computing ovulation detection, randomized trial fertility app, time to pregnancy fertility software, ovulation prediction app, fertility awareness technology, digital fertility tracking
PMID 36774978 36774978 DOI 10.1016/j.fertnstert.2023.02.005 10.1016/j.fertnstert.2023.02.005
Cite this article
Wise, L. A., Wang, T. R., Stanford, J. B., Wesselink, A. K., Ncube, C. N., Rothman, K. J., & Murray, E. J. (2023). A randomized trial of web-based fertility-tracking software and fecundability. Fertility and sterility, 119(6), 1045-1056. https://doi.org/10.1016/j.fertnstert.2023.02.005
Wise LA, Wang TR, Stanford JB, Wesselink AK, Ncube CN, Rothman KJ, et al. A randomized trial of web-based fertility-tracking software and fecundability. Fertil Steril. 2023;119(6):1045-1056. doi:10.1016/j.fertnstert.2023.02.005
Wise, L. A., et al. "A randomized trial of web-based fertility-tracking software and fecundability." Fertility and sterility, vol. 119, no. 6, 2023, pp. 1045-1056.
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.
Caffeine is the most frequently used psychoactive substance in the United States and >90% of reproductive-age women report some amount of intake daily. Despite biological plausibility, previous studies on caffeine and fecundability report conflicting results. Importantly, prior studies measured caffeine exposure exclusively by self-report, which is subject to measurement error and does not account for factors that influence caffeine metabolism. Our objective was to examine associations between preconception serum caffeine metabolites, caffeinated beverage intake, and fecundability. Participants included 1228 women aged 18-40 y with a history of 1-2 pregnancy losses in the EAGeR (Effects of Aspirin in Gestation and Reproduction) trial. We prospectively evaluated associations of preconception caffeine metabolites (i.e., caffeine, paraxanthine, and theobromine) measured from 1191 serum samples untimed to a specific time of day, self-reported usual caffeinated beverage intakes at baseline, and time-varying cycle-average caffeinated beverage intake, with fecundability. Using Cox proportional hazards models, we estimated fecundability odds ratios (FORs) and 95% CIs according to each metabolite. Follow-up was complete for 89% (n = 1088) of participants. At baseline, 85%, 73%, and 91% of women had detectable serum caffeine, paraxanthine, and theobromine, respectively. A total of 797 women became pregnant during ≤6 cycles of preconception follow-up. After adjusting for potential confounders, neither serum caffeine [tertile (T)3 compared with T1 0.87; 95% CI: 0.71, 1.08], paraxanthine (T3 compared with T1 0.92; 95% CI: 0.75, 1.14), nor theobromine (T3 compared with T1 1.15; 95% CI: 0.95, 1.40) were associated with fecundability. Baseline intake of total caffeinated beverages was not associated with fecundability (>3 compared with 0 0.99; 95% CI: 0.74, 1.34), nor was caffeinated coffee (>2 compared with 0 0.93; 95% CI: 0.45, 1.92) or caffeinated soda (>2 0.92; 95% CI: 0.71, 1.20). Our findings are reassuring that caffeine exposure from usual low to moderate caffeinated beverage intake likely does not influence fecundability.This trial was registered at clinicaltrials.gov as NCT00467363.
Time to pregnancy (TTP) is a biomarker of fecundability and has been associated with behavioral and environmental characteristics; however, these associations have not been examined in a large population-based sample of application (app) users. This observational study followed 5,376 women with an age range of 18 to 45 years who used an app to identify their fertile window. We included women who started trying to conceive between September 30, 2017 and August 31, 2018. TTP was calculated as the number of menstrual cycles from when the user switched to "Plan" mode up to and including the cycle in which they logged a positive pregnancy test. We examined associations with several characteristics, including age, gravidity, body mass index, cycle length and cycle length variation, frequency of sexual intercourse, and temperature measuring frequency. Discrete time fecundability models were used to estimate fecundability odds ratios. For the complete cohort the 6-cycle and 12-cycle cumulative pregnancy probabilities were found to be 61% (95% confidence interval [CI]: 59-62) and 74% (95% CI: 73-76), respectively. The median TTP was four cycles. The highest fecundability was associated with an age of less than 35 years, with cycle length variation <5 days and logging sexual intercourse on at least 20% of days added (the proportion of days in which intercourse was logged) (11.5% [n = 613] of entire sample). This group achieved a 6and 12-cycle cumulative pregnancy probability of 88% (95% CI: 85-91) and 95% (95% CI: 94-97), respectively, and a TTP of 2 cycles. Natural Cycles was an effective method of identifying the fertile window and a noninvasive educational option for women planning a pregnancy. Women under age 35 with regular cycles showed a high pregnancy rate.