Longitudinal semen parameter assessments and live birth: variability and implications for treatment strategies.

OBJECTIVE: To examine whether semen parameters are associated with live birth among couples seeking infertility treatment after accounting for semen parameter variability. DESIGN: Folic Acid and Zinc Supplementation Trial (FAZST) prospective cohort. SETTING: Four US reproductive endocrinology and infertility care study centers, 2013-2017. PATIENT(S): Couples (n = 2,369) seeking fertility consultations at 4 US infertility care study centers. INTERVENTION(S): Semen volume, pH, sperm viability, morphology, progressive and total motility, concentration, count, and total and progressive motile count assessed at baseline and at 2, 4, and 6 months after enrollment. MAIN OUTCOME MEASURE(S): Log-binomial models stratified by fertility treatment received (in vitro fertilization [IVF], intrauterine insemination [IUI], ovulation induction [OI], or no treatment) estimated risk differences (RDs) between semen parameter quartiles and live birth and accounted for multiple semen assessments per person. We accounted for abstinence time, the biological interdependence of semen parameters, and potential selection bias because of loss to follow-up. RESULT(S): Among couples using OI only or no treatment, 39% had a live birth, and relative to the highest quartile, the lowest quartiles of morphology (RD, -19 [95% CI, -23 to -15] per 100 couples), motility (RD, -13 [95% CI, -17 to -9]), concentration (RD, -22 [95% CI, -26 to -19]), and total motile count (RD, -18 [95% CI, -22 to -14]) were associated with fewer live births. For IUI, 26% had a live birth, and the lowest quartiles of volume (RD, -6 [95% CI, -11 to -0.4]), concentration (RD, -6 [95% CI, -11 to -0.1]), count (RD, -10 [95% CI, -15 to -4]), and total motile count (RD, -7 [95% CI, -13 to -1]) were associated with fewer live births. For IVF, 61% had a live birth, and only morphology (Q1 RD, -7 [95% CI, -14 to 0.2]; Q2 RD, -10 [95% CI, -17 to -2.2]) was associated with live birth. CONCLUSION(S): Semen parameters are critical in couples undergoing OI/IUI. Only low morphology was important for live birth after IVF. Although data supporting the use of semen parameters are fragmented across differing populations, current findings are generalizable across the range of male fertility and couple fertility treatments, providing evidence about which semen parameters are most relevant in which settings. CLINICAL TRIAL REGISTRATION NUMBER: NCT#01857310.

Preconception caffeine metabolites, caffeinated beverage intake, and fecundability.

BACKGROUND: 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. OBJECTIVES: Our objective was to examine associations between preconception serum caffeine metabolites, caffeinated beverage intake, and fecundability. METHODS: 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. RESULTS: 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 FOR: 0.87; 95% CI: 0.71, 1.08], paraxanthine (T3 compared with T1 FOR: 0.92; 95% CI: 0.75, 1.14), nor theobromine (T3 compared with T1 FOR: 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 servings/d adjusted FOR: 0.99; 95% CI: 0.74, 1.34), nor was caffeinated coffee (>2 compared with 0 servings/d adjusted FOR: 0.93; 95% CI: 0.45, 1.92) or caffeinated soda (>2 servings/d adjusted FOR: 0.92; 95% CI: 0.71, 1.20). CONCLUSIONS: 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.

Effect of Folic Acid and Zinc Supplementation in Men on Semen Quality and Live Birth Among Couples Undergoing Infertility Treatment: A Randomized Clinical Trial.

Importance: Dietary supplements marketed for male fertility commonly contain folic acid and zinc based on limited prior evidence for improving semen quality. However, no large-scale trial has examined the efficacy of this therapy for improving semen quality or live birth. Objective: To determine the effect of daily folic acid and zinc supplementation on semen quality and live birth. Design, Setting, and Participants: The Folic Acid and Zinc Supplementation Trial was a multicenter randomized clinical trial. Couples (n = 2370; men aged ≥18 years and women aged 18-45 years) planning infertility treatment were enrolled at 4 US reproductive endocrinology and infertility care study centers between June 2013 and December 2017. The last 6-month study visit for semen collection occurred during August 2018, with chart abstraction of live birth and pregnancy information completed during April 2019. Interventions: Men were block randomized by study center and planned infertility treatment (in vitro fertilization, other treatment at a study site, and other treatment at an outside clinic) to receive either 5 mg of folic acid and 30 mg of elemental zinc (n = 1185) or placebo (n = 1185) daily for 6 months. Main Outcomes and Measures: The co-primary outcomes were live birth (resulting from pregnancies occurring within 9 months of randomization) and semen quality parameters (sperm concentration, motility, morphology, volume, DNA fragmentation, and total motile sperm count) at 6 months after randomization. Results: Among 2370 men who were randomized (mean age, 33 years), 1773 (75%) attended the final 6-month study visit. Live birth outcomes were available for all couples, and 1629 men (69%) had semen available for analysis at 6 months after randomization. Live birth was not significantly different between treatment groups (404 [34%] in the folic acid and zinc group and 416 [35%] in the placebo group; risk difference, -0.9% [95% CI, -4.7% to 2.8%]). Most of the semen quality parameters (sperm concentration, motility, morphology, volume, and total motile sperm count) were not significantly different between treatment groups at 6 months after randomization. A statistically significant increase in DNA fragmentation was observed with folic acid and zinc supplementation (mean of 29.7% for percentage of DNA fragmentation in the folic acid and zinc group and 27.2% in the placebo group; mean difference, 2.4% [95% CI, 0.5% to 4.4%]). Gastrointestinal symptoms were more common with folic acid and zinc supplementation compared with placebo (abdominal discomfort or pain: 66 [6%] vs 40 [3%], respectively; nausea: 50 [4%] vs 24 [2%]; and vomiting: 32 [3%] vs 17 [1%]). Conclusions and Relevance: Among a general population of couples seeking infertility treatment, the use of folic acid and zinc supplementation by male partners, compared with placebo, did not significantly improve semen quality or couples' live birth rates. These findings do not support the use of folic acid and zinc supplementation by male partners in the treatment of infertility. Trial Registration: ClinicalTrials.gov Identifier: NCT01857310.

A Randomized Trial to Evaluate the Effects of Folic Acid and Zinc Supplementation on Male Fertility and Livebirth: Design and Baseline Characteristics.

The Folic Acid and Zinc Supplementation Trial (FAZST) was a multicenter, double-blind, block-randomized, placebo-controlled trial to determine whether folic acid and zinc supplementation in men improves semen quality and increases livebirth rate among couples seeking infertility treatment (2013-2017). Eligible men were aged 18 years or older with female partners aged 18-45 years, seeking infertility treatment. Men were randomized (1:1) to 5 mg folic acid and 30 mg elemental zinc daily or matching placebo for 6 months. Randomization was stratified by site and intended infertility treatment (in vitro fertilization (IVF), non-IVF/study site, and non-IVF/outside clinic). Follow-up of men continued for 6 months, and female partners were passively followed for a minimum of 9 months. Women who conceived were followed throughout pregnancy. Overall, 2,370 men were randomized during 2013-2017 (1,185 folic acid and zinc, 1,185 placebo); they had a mean age of 33 years and body mass index (weight (kg)/height (m)2) of 29.8. Most participants were white (82%), well educated (83% with some college), and employed (72%). Participant characteristics were balanced across intervention arms. Study visits were completed by 89%, 77%, and 75% of men at months 2, 4, and 6, respectively. Here we describe the study design, recruitment, data collection, lessons learned, and baseline participant characteristics.

Serum caffeine and paraxanthine concentrations and menstrual cycle function: correlations with beverage intakes and associations with race, reproductive hormones, and anovulation in the BioCycle Study.

BACKGROUND: Clinicians often recommend limiting caffeine intake while attempting to conceive; however, few studies have evaluated the associations between caffeine exposure and menstrual cycle function, and we are aware of no previous studies assessing biological dose via well-timed serum measurements. OBJECTIVES: We assessed the relation between caffeine and its metabolites and reproductive hormones in a healthy premenopausal cohort and evaluated potential effect modification by race. DESIGN: Participants (n = 259) were followed for ≤2 menstrual cycles and provided fasting blood specimens ≤8 times/cycle. Linear mixed models were used to estimate associations between serum caffeine biomarkers and geometric mean reproductive hormones, whereas Poisson regression was used to assess risk of sporadic anovulation. RESULTS: The highest compared with the lowest serum caffeine tertile was associated with lower total testosterone [27.9 ng/dL (95% CI: 26.7, 29.0 ng/dL) compared with 29.1 ng/dL (95% CI: 27.9, 30.3 ng/dL), respectively] and free testosterone [0.178 ng/mL (95% CI: 0.171, 0.185 ng/dL) compared with 0.186 ng/mL (95% CI: 0.179, 0.194 ng/dL), respectively] after adjustment for age, race, percentage of body fat, daily vigorous exercise, perceived stress, depression, dietary factors, and alcohol intake. The highest tertiles compared with the lowest tertiles of caffeine and paraxanthine were also associated with reduced risk of anovulation [adjusted RRs (aRRs): 0.39 (95% CI: 0.18, 0.87) and 0.40 (95% CI: 0.18, 0.87), respectively]. Additional adjustment for self-reported coffee intake did not alter the reproductive hormone findings and only slightly attenuated the results for serum caffeine and paraxanthine and anovulation. Although reductions in the concentrations of total testosterone and free testosterone and decreased risk of anovulation were greatest in Asian women, there was no indication of effect modification by race. CONCLUSION: Caffeine intake, irrespective of the beverage source, may be associated with reduced testosterone and improved menstrual cycle function in healthy premenopausal women.

Higher urinary lignan concentrations in women but not men are positively associated with shorter time to pregnancy.

Phytoestrogens have been associated with subtle hormonal changes, although effects on fecundity are unknown. Our objective was to evaluate the association between male and female urinary phytoestrogen (isoflavone and lignan) concentrations and time to pregnancy (TTP) in a population-based cohort of 501 couples desiring pregnancy and discontinuing contraception. Couples were followed for 12 mo or until pregnancy. Fecundability ORs (FORs) and 95% CIs were estimated after adjusting for age, body mass index, race, site, creatinine, supplement use, and physical activity in relation to female, male, and joint couple concentrations. Models included the phytoestrogen of interest and the sum of the remaining individual phytoestrogens. FORs <1 denote a longer TTP and FORs >1 a shorter TTP. Urinary lignan concentrations were higher, on average, among female partners of couples who became pregnant during the study compared with women who did not become pregnant (median enterodiol: 118 vs. 80 nmol/L; P < 0.10; median enterolactone: 990 vs. 412 nmol/L; P < 0.05) and were associated with significantly shorter TTP in models based on both individual and couples' concentrations (couples' models: enterodiol FOR, 1.13; 95% CI: 1.02, 1.26; enterolactone FOR, 1.11; 95% CI: 1.01, 1.21). Male lignan concentrations were not associated with TTP, nor were isoflavone concentrations. Sensitivity analyses showed that associations observed are unlikely to be explained by potential unmeasured confounding by lifestyle or other nutrients. Our results suggest that female urinary lignan concentrations at levels characteristic of the U.S. population are associated with a shorter TTP among couples who are attempting to conceive, highlighting the importance of dietary influences on fecundity.

Validation of different instruments for caffeine measurement among premenopausal women in the BioCycle study.

Effects of caffeine on women's health are inconclusive, in part because of inadequate exposure assessment. In this study we determined 1) validity of a food frequency questionnaire compared with multiple 24-hour dietary recalls (24HDRs) for measuring monthly caffeine and caffeinated beverage intakes; and 2) validity of the 24HDR compared with the prior day's diary record for measuring daily caffeinated coffee intake. BioCycle Study (2005-2007) participants, women (n = 259) aged 18-44 years from western New York State, were followed for 2 menstrual cycles. Participants completed a food frequency questionnaire at the end of each cycle, four 24HDRs per cycle, and daily diaries. Caffeine intakes reported for the food frequency questionnaires were greater than those reported for the 24HDRs (mean = 114.1 vs. 92.6mg/day, P = 0.01) but showed high correlation (r = 0.73, P < 0.001) and moderate agreement (К = 0.51, 95% confidence interval: 0.43, 0.57). Women reported less caffeinated coffee intake in their 24HDRs compared with their corresponding diary days (mean = 0.51 vs. 0.80 cups/day, P < 0.001) (1 cup = 237 mL). Although caffeine and coffee exposures were highly correlated, absolute intakes differed significantly between measurement tools. These results highlight the importance of considering potential misclassification of caffeine exposure.

The impact of dietary folate intake on reproductive function in premenopausal women: a prospective cohort study.

BACKGROUND: Folic acid is recommended to reproductive-aged women to prevent birth defects, though little is known about the effects of dietary intake on other reproductive outcomes. Improved pregnancy rates have been documented after folic acid supplement use, suggesting a possible link with ovulation, however research is limited. Our objective was to evaluate the association between dietary folate intake, hormone levels, and sporadic anovulation in healthy, regularly menstruating women. METHODOLOGY/PRINCIPAL FINDINGS: The BioCycle study (2005-2007) prospectively followed 259 healthy women aged 18-44 years from the western New York region for up to 2 menstrual cycles. Total folate and specific sources of folate were assessed up to 4 times per cycle by 24-hour recall. Estradiol, progesterone, luteinizing hormone, and follicle-stimulating hormone were measured in serum up to 8 times per cycle, timed using fertility monitors. Anovulation was defined as a cycle with peak progesterone concentration ≤ 5 ng/mL and no LH peak in the mid/late luteal phase. Higher intake of dietary folate (in dietary equivalents) across tertiles had a marginally significant association with greater luteal progesterone levels (P trend 0.08). Higher intake of synthetic folate was significantly associated with higher luteal progesterone levels (P trend 0.05). Specifically, women in the 3(rd) tertile of synthetic folate intake had, on average, 16.0% (95% CI, 0.5-33.8%) higher luteal progesterone levels compared to women in the 1(st) tertile. Moreover, consumption of synthetic folate was significantly and inversely associated with anovulation such that women in the 3(rd) tertile had a 64% (95% CI, 8-86%) decreased odds of anovulation compared to the women in the 1(st) tertile (P trend 0.03). CONCLUSIONS/SIGNIFICANCE: These findings suggest that a diet high in synthetic folate may be associated with increased progesterone levels and lower risk of sporadic anovulation. Further study of the effect of dietary folate and folic acid supplement use on reproductive health is warranted.

Caffeinated beverage intake and reproductive hormones among premenopausal women in the BioCycle Study.

BACKGROUND: Caffeinated beverages are widely consumed among women of reproductive age, but their association with reproductive hormones, and whether race modifies any such associations, is not well understood. OBJECTIVE: We assessed the relation between caffeine and caffeinated beverage intake and reproductive hormones in healthy premenopausal women and evaluated the potential effect modification by race. DESIGN: Participants (n = 259) were followed for up to 2 menstrual cycles and provided fasting blood specimens for hormonal assessment at up to 8 visits per cycle and four 24-h dietary recalls per cycle. Weighted linear mixed models and nonlinear mixed models with harmonic terms were used to estimate associations between caffeine and hormone concentrations, adjusted for age, adiposity, physical activity, energy and alcohol intakes, and perceived stress. On the basis of a priori assumptions, an interaction between race and caffeine was tested, and stratified results are presented. RESULTS: Caffeine intake ≥200 mg/d was inversely associated with free estradiol concentrations among white women (ß = -0.15; 95% CI: -0.26, -0.05) and positively associated among Asian women (ß = 0.61; 95% CI: 0.31, 0.92). Caffeinated soda intake and green tea intake ≥1 cup/d (1 cup = 240 mL) were positively associated with free estradiol concentrations among all races: ß = 0.14 (95% CI: 0.06, 0.22) and ß = 0.26 (95% CI: 0.07, 0.45), respectively. CONCLUSIONS: Moderate consumption of caffeine was associated with reduced estradiol concentrations among white women, whereas caffeinated soda and green tea intakes were associated with increased estradiol concentrations among all races. Further research is warranted on the association between caffeine and caffeinated beverages and reproductive hormones and whether these relations differ by race.