Intake of Sugar-sweetened Beverages and Fecundability in a North American Preconception Cohort

Associations of periconception dietary glycemic index and load with fertility in women and men: a study among couples in the general population

BACKGROUND

The dietary glycemic index (GI) and load (GL) reflect carbohydrate quality and quantity, potentially impacting fertility through modulation of insulin sensitivity and generation of oxidative stress. While fertility is influenced by both women and men, reproductive research often emphasizes maternal factors. We first examined periconception dietary intake in both women and male partners, and subsequent associations of dietary GI and GL with fecundability and subfertility.

METHODS

Among 830 women and 651 male partners, participating in a population-based prospective cohort study from preconception onwards, we assessed periconception dietary intake and calculated GI and GL, using a food frequency questionnaire (FFQ) at median 12.4 weeks gestation (95% range 10.9, 18.4). Information on time to pregnancy was obtained through questionnaires, with subfertility defined as a time to pregnancy ≥ 12 months or use of assisted reproductive technology.

RESULTS

In the periconception period, mean energy intake in women was 1870 kcal (SD: 500; 46% carbohydrates, 16% protein, 33% fat; dietary GI 56.2 (SD: 3.5) and GL 141.4 (SD: 67.4)). Mean energy intake in men was 2350 kcal (SD: 591; 43% carbohydrates, 16% protein, 33% fat; dietary GI 56.8 (SD: 3.2) and GL 156.7 (SD: 75.4)). Median time to pregnancy was 4.8 months (IQR: 1.2, 16.4), with 30.6% of 830 women experiencing subfertility. Dietary GI and GL were not associated with fertility outcomes in women. In men, higher dietary GI and GL across the full range were associated with decreased fecundability, after adjusting for socio-demographic and lifestyle factors, as well as dietary GI or GL of female partners [FR: 0.91, 95% CI 0.83, 0.99; FR: 0.90, 95% CI 0.81, 0.99, per SDS increase in dietary GI and GL, respectively]. When assessing the combined influence of dietary GI clinical categories in women and men, both partners adhering to a low GI diet tended to be associated with increased fecundability, but not with subfertility risk.

CONCLUSIONS

Suboptimal periconception carbohydrate intake may be negatively associated with male fertility, but not with fertility outcomes in women. Further studies are needed to assess whether a lower GI and GL diet is a feasible lifestyle intervention to improve couples fertility.

Dietary Glycemic Index and Load and Semen Quality: A Cross-Sectional and Prospective Analysis within the FERTINUTS Trial

PURPOSE

Infertility is a global health issue and nutrition plays a significant role in fertility outcomes. We aimed to investigate the cross-sectional and prospective associations of glycemic index (GI) and glycemic load (GL) with semen quality parameters in a cohort of healthy young men.

MATERIALS AND METHODS

The study included 106 men aged 18-35 years from the FERTINUTS trial. Dietary intake was estimated through 3-day dietary records and several semen parameters were assessed. Multivariable linear regression analysis with the Least Absolute Shrinkage and Selection Operator (LASSO) approach was employed.

RESULTS

The cross-sectional analysis revealed positive associations between GI and GL and total sperm count, sperm concentration, and total motility. In the prospective analysis, baseline GI was associated with increases in pH, vitality, immotile sperm or abnormal midpiece and decreases in total sperm count and motility. Conversely, GL was positively associated with changes in vitality and total sperm count.

CONCLUSIONS

While these findings suggest that GI may have adverse effects on several sperm quality parameters, the results were not consistently observed in the cross-sectional analysis. However, GL was consistently associated with better sperm quality in both analyses. The impact of carbohydrate quality and quantity on fertility remains uncertain and larger prospective studies are needed.

Effect of perinatal consumption of low-calorie sweetener on maternal health: A systematic review and meta-analysis

BACKGROUND AND AIMS

Evidence regarding perinatal low-calorie (or artificial) sweetener (LCS) consumption and its effect on maternal health outcomes is limited and inconclusive. The primary outcomes of our systematic review and meta-analysis were the effect of preconception and pregnancy LCS exposure on reproductive and pregnancy outcomes. Secondary outcomes included long-term maternal health.

METHODS

A systematic search of electronic databases, including PubMed, Embase, CINAHL, the Cochrane Library, Scopus, Web of Science, PsycINFO, ProQuest Health and Medical, ClinicalTrials.gov and Google Scholar, was conducted up to 20 November 2023. Primary studies, including clinical trials, cohort studies, case-control studies, which reported any LCS consumption during perinatal period and pregnancy and maternal health outcomes were eligible. A random effects model with restricted maximum likelihood estimation was used for the meta-analysis. We appraised the quality of the included studies using the National Institute of Health study quality appraisal tool and the overall quality of evidence using the Grading of Recommendations Assessment, Development, and Evaluation tool.

RESULTS

A total of 19 eligible studies with 203,706 participants were included. LCS consumption during pregnancy was associated with 11% increased risk of preterm birth (RR = 1.11, 95% CI: 1.07-1.16, I2 = 0.01%) and 42% increased risk of gestational diabetes (RR = 1.42, 95% CI: 0.98-2.04, I2 = 67.60%) compared with no consumption, however, the effect size for gestational diabetes was not precise as the 95% CI indicated that the effect estimate could range from 2% lower risk to 204% (or 2.04 times) higher risk. We found no association between LCS consumption during pregnancy and gestational weight gain (standardized mean difference (SMD) = 0.04; 95% CI: -0.17 - 0.24, I2 = 41.31%) or gestational age at birth (SMD = 0.00; 95% CI: -0.13 - 0.14, I2 = 80.13%). The effect of LCS consumption on reproductive treatment outcomes were inconsistent.

CONCLUSIONS

Based on the evidence available, LCS consumption in pregnancy was associated with increased risk of preterm birth and gestational diabetes. Robust research, such as well-designed randomized trials and large prospective cohort studies, is required to confirm the causal effect of LCS consumption during perinatal period on adverse maternal health outcomes.

Healthy eating index and risk of diminished ovarian reserve: a case-control study

Diminished ovarian reserve (DOR) is associated with reduced fertility and poor reproductive outcomes. The association between dietary patterns and DOR was not well studied. The purpose of this study was to evaluate the relationship between adhering to the healthy eating index (HEI-2015) and the risk of DOR. In this case-control study, 370 Iranian women (120 with DOR and 250 age- and BMI-matched controls) were examined. A reliable semi-quantitative food frequency questionnaire was used to collect diet-related data. We analyzed the HEI-2015 and their dietary intake data to determine major dietary patterns. The multivariable logistic regression was used in order to analyze the association between HEI-2015 and risk of DOR. We found no significant association between HEI-2015 score and risk of DOR in the unadjusted model (OR 0.78; 95%CI 0.59, 1.03). After controlling for physical activity and energy intake, we observed that women in the highest quartile of the HEI-2015 score had 31% decreased odds of DOR (OR 0.69; 95%CI 0.46, 0.93). This association remained significant even after adjusting for all potential confounders. Overall, increased adherence to HEI may lead to a significant reduction in the odds ratio of DOR. Clinical trials and prospective studies are needed to confirm this association.

Common Beverage Consumption and Benign Gynecological Conditions

The purpose of this article is to review the effects of four commonly consumed beverage types-sugar-sweetened beverages (SSBs), caffeinated beverages, green tea, and alcohol-on five common benign gynecological conditions: uterine fibroids, endometriosis, polycystic ovary syndrome (PCOS), anovulatory infertility, and primary dysmenorrhea (PD). Here we outline a plethora of research, highlighting studies that demonstrate possible associations between beverage intake and increased risk of certain gynecological conditions-such as SSBs and dysmenorrhea-as well as studies that demonstrate a possible protective effect of beverage against risk of gynecological condition-such as green tea and uterine fibroids. This review aims to help inform the diet choices of those with the aforementioned conditions and give those with uteruses autonomy over their lifestyle decisions.

Assessing the influence of preconception diet on male fertility: a systematic scoping review

BACKGROUND

The last decade has seen increased research on the relationship between diet and male fertility, but there are no clearly defined nutritional recommendations for men in the preconception period to support clinical fertility outcomes.

OBJECTIVE AND RATIONALE

The purpose of this scoping review is to examine the extent and range of research undertaken to evaluate the effect(s) of diet in the preconception period on male clinical fertility and reproductive outcomes.

SEARCH METHODS

Four electronic databases (MEDLINE and EMBASE via Ovid, CAB Direct, and CINAHL via EBSCO) were searched from inception to July 2023 for randomized controlled trials (RCTs) and observational studies (prospective/retrospective, case-control, and cross-sectional). Intervention studies in male participants or couples aiming to achieve dietary or nutritional change, or non-intervention studies examining dietary or nutritional components (whole diets, dietary patterns, food groups or individual foods) in the preconception period were included. Controls were defined as any comparison group for RCTs, and any/no comparison for observational studies. Primary outcomes of interest included the effect(s) of male preconception diet on clinical outcomes such as conception (natural or via ART), pregnancy rates and live birth rates. Secondary outcomes included time to conception and sperm parameters.

OUTCOMES

A total of 37 studies were eligible, including one RCT and 36 observational studies (prospective, cross-sectional, and case-control studies; four studies in non-ART populations) published between 2008 and 2023. Eight reported clinical outcomes, 26 reported on secondary outcomes, and three reported on both. The RCT did not assess clinical outcomes but found that tomato juice may benefit sperm motility. In observational studies, some evidence suggested that increasing fish or reducing sugar-sweetened beverages, processed meat or total fat may improve fecundability. Evidence for other clinical outcomes, such as pregnancy rates or live birth rates, showed no relationship with cereals, soy and dairy, and inconsistent relationships with consuming red meat or a 'healthy diet' pattern. For improved sperm parameters, limited evidence supported increasing fish, fats/fatty acids, carbohydrates and dairy, and reducing processed meat, while the evidence for fruits, vegetables, cereals, legumes, eggs, red meat and protein was inconsistent. Healthy diet patterns in general were shown to improve sperm health.

WIDER IMPLICATIONS

Specific dietary recommendations for improving male fertility are precluded by the lack of reporting on clinical pregnancy outcomes, heterogeneity of the available literature and the paucity of RCTs to determine causation or to rule out reverse causation. There may be some benefit from increasing fish, adopting a healthy dietary pattern, and reducing consumption of sugar-sweetened beverages and processed meat, but it is unclear whether these benefits extend beyond sperm parameters to improve clinical fertility. More studies exploring whole diets rather than singular foods or nutritional components in the context of male fertility are encouraged, particularly by means of RCTs where feasible. Further assessment of core fertility outcomes is warranted and requires careful planning in high-quality prospective studies and RCTs. These studies can lay the groundwork for targeted dietary guidelines and enhance the prospects of successful fertility outcomes for men in the preconception period. Systematic search of preconception diet suggests that increasing fish and reducing sugary drinks, processed meats and total fat may improve male fertility, while consuming healthy diets, fish, fats/fatty acids, carbohydrates and dairy and reducing processed meat can improve sperm health.

[First-line management of infertile couple. Guidelines for clinical practice of the French College of Obstetricians and Gynecologists 2022]

OBJECTIVE

To update the 2010 CNGOF clinical practice guidelines for the first-line management of infertile couples.

MATERIALS AND METHODS

Five major themes (first-line assessment of the infertile woman, first-line assessment of the infertile man, prevention of exposure to environmental factors, initial management using ovulation induction regimens, first-line reproductive surgery) were identified, enabling 28 questions to be formulated using the Patients, Intervention, Comparison, Outcome (PICO) format. Each question was addressed by a working group that had carried out a systematic review of the literature since 2010, and followed the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) methodology to assess the quality of the scientific data on which the recommendations were based. These recommendations were then validated during a national review by 40 national experts.

RESULTS

The fertility work-up is recommended to be prescribed according to the woman's age: after one year of infertility before the age of 35 and after 6months after the age of 35. A couple's initial infertility work-up includes a single 3D ultrasound scan with antral follicle count, assessment of tubal permeability by hysterography or HyFOSy, anti-Mullerian hormone assay prior to assisted reproduction, and vaginal swabbing for vaginosis. If the 3D ultrasound is normal, hysterosonography and diagnostic hysteroscopy are not recommended as first-line procedures. Chlamydia trachomatis serology does not have the necessary performance to predict tubal patency. Post-coital testing is no longer recommended. In men, spermogram, spermocytogram and spermoculture are recommended as first-line tests. If the spermogram is normal, it is not recommended to check the spermogram. If the spermogram is abnormal, an examination by an andrologist, an ultrasound scan of the testicles and hormonal test are recommended. Based on the data in the literature, we are unable to recommend a BMI threshold for women that would contraindicate medical management of infertility. A well-balanced Mediterranean-style diet, physical activity and the cessation of smoking and cannabis are recommended for infertile couples. For fertility concern, it is recommended to limit alcohol consumption to less than 5 glasses a week. If the infertility work-up reveals no abnormalities, ovulation induction is not recommended for normo-ovulatory women. If intrauterine insemination is indicated based on an abnormal infertility work-up, gonadotropin stimulation and ovulation monitoring are recommended to avoid multiple pregnancies. If the infertility work-up reveals no abnormality, laparoscopy is probably recommended before the age of 30 to increase natural pregnancy rates. In the case of hydrosalpinx, surgical management is recommended prior to ART, with either salpingotomy or salpingectomy depending on the tubal score. It is recommended to operate on polyps>10mm, myomas 0, 1, 2 and synechiae prior to ART. The data in the literature do not allow us to systematically recommend asymptomatic uterine septa and isthmoceles as first-line surgery.

CONCLUSION

Based on strong agreement between experts, we have been able to formulate updated recommendations in 28 areas concerning the initial management of infertile couples.

A preconception cohort study of sugar-sweetened beverage consumption and semen quality

BACKGROUND

Dietary factors, including high sugar intake, may have adverse effects on male reproduction. Studies of the association between sugar-sweetened beverage (SSB) intake and semen quality have reported inconsistent results.

OBJECTIVE

We estimated the effects of SSB consumption on semen quality in a North American preconception cohort study.

METHODS

We analyzed baseline data from 690 males (n = 1,247 samples) participating in Pregnancy Study Online (PRESTO) during 2015-2022. Participants aged ≥21 years completed a baseline questionnaire on which they reported information about intake of SSBs, including sodas, energy drinks, sports drinks, and fruit juices. After enrollment, we invited U.S. participants to a semen testing substudy, in which they collected and analyzed two samples using an at-home semen testing kit. We used linear regression models to estimate adjusted percent differences (%D) and 95% confidence intervals (CI) for associations of SSB intake with semen volume, sperm concentration, total sperm count (TSC), motility, and total motile sperm count (TMSC). We used modified Poisson regression models to estimate adjusted risk ratios (RRs) and 95% CIs for the association of SSB intake with World Health Organization semen parameter cut points.

RESULTS

Relative to non-consumers of SSBs, those who consumed ≥7 SSBs/week had lower semen volume (%D = -6, 95% CI: -13, 0), sperm concentration (%D = -22, 95% CI: -38, 0), TSC (%D = -22, 95% CI: -38, -2), motility (%D = -4, 95% CI: -10, 2), and TMSC (%D = -25, 95% CI: -43, -2). High SSB consumers also had greater risks of low sperm concentration (≤16 million/mL; RR = 1.89, 95% CI: 1.11, 3.21), low TSC (≤39 million; RR = 1.75, 95% CI: 0.92, 3.33), low motility (≤42%; RR = 1.23, 95% CI: 0.87, 1.75) and low TMSC (≤21 million; RR = 1.95, 95% CI: 1.12, 3.38). Associations were stronger among participants with body mass index ≥ 25 kg/m2 .

CONCLUSION

Greater SSB consumption was associated with reduced semen quality in a North American preconception cohort.

Preconception sleep duration, non-daytime work schedules, and incidence of spontaneous abortion: a prospective cohort study

STUDY QUESTION

To what extent do self-reported sleep duration and non-daytime work schedules in either partner affect the rate of spontaneous abortion (SAB)?

SUMMARY ANSWER

Incidence of SAB had little association with female sleep duration and a modest positive association with male short sleep duration, female work at night, and discrepant work schedules among partners.

WHAT IS KNOWN ALREADY

Several studies have reported an association between short sleep duration in either partner and reproductive health outcomes, including fecundability. Moreover, certain types of female occupational exposures during pregnancy have been associated with an increased risk of SAB. No studies have evaluated SAB risk in relation to male sleep and work schedules, or joint exposures within a couple.

STUDY DESIGN, SIZE, DURATION

This prospective cohort study included 9357 female participants and 2602 of their male partners residing in North America (June 2013 to April 2023).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants enrolled when they were attempting pregnancy and completed self-administered baseline questionnaires about their average sleep duration and work schedules. Among those who conceived, we ascertained SAB and gestational age at loss via follow-up questionnaires. We used multivariable Cox proportional hazards models with gestational weeks as the time scale to estimate hazard ratios (HRs) and 95% CIs relating SAB with sleep duration and non-daytime work schedules for female and male participants, and the couple. We used inverse probability weighting to account for potential selection bias due to the possibility of differential participation of male partners with respect to the exposures.

MAIN RESULTS AND THE ROLE OF CHANCE

Compared to female participants with recommended sleep (7-8.9 h), those reporting short sleep duration (<6 h) did not have a higher rate of SAB (HR 0.88, 95% CI 0.69, 1.13). Short self-reported sleep duration among male participants was modestly associated with a higher rate of SAB (adjusted and weighted HR 1.30, 95% CI 0.96, 1.75). Female night work at night (adjusted HR 1.19, 95% CI 1.02, 1.38) and male non-daytime work (adjusted and weighted HR 1.26, 95% CI 1.00, 1.59) were associated with modestly higher rates of SAB, whereas female rotating shift work was not (adjusted HR 0.91, 0.78, 1.05) compared with daytime workers. Couples in which work schedules were discrepant had an elevated rate of SAB if the male partner worked a non-daytime shift (adjusted and weighted HR 1.46, 95% CI 1.13, 1.88) compared with couples in which both members worked during the day. The corresponding HR if only the female partner worked a non-daytime shift was 1.21 (95% CI 0.92, 1.58).

LIMITATIONS, REASONS FOR CAUTION

Data on sleep duration and work schedules were based on self-report, which is vulnerable to misclassification, particularly since participants were asked to report their average sleep duration during the past month. Work exposures were heterogeneous, as many different types of employment may require night and shift work and may have different associations with SAB.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings are consistent with previous research indicating that some types of female employment schedules may be associated with SAB incidence. This is the first study to indicate a relationship between SAB and male employment schedules, indicating that discrepant work schedules within a couple might be relevant.

STUDY FUNDING/COMPETING INTEREST(S)

This work was funded by the Eunice Kennedy Shriver National Institute of Child Health and Human Development grants R01HD105863 (PIs: L.A.W. and M.L.E.), R01HD086742 (PIs: L.A.W. and E.E.H.), and R21HD072326 (PI: L.A.W.). PRESTO has received in-kind donations from Swiss Precision Diagnostics and Kindara.com for primary data collection. L.A.W. is a consultant for AbbVie, Inc. and the Gates Foundation. M.L.E. is an advisor for and holds stock in Ro, Hannah, Dadi, Underdog, Vseat, & Doveras. The other authors have no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A.

Diet and recreational drug use in relation to male reproductive health

Diet and lifestyle interventions present promising avenues for the improvement of male fertility. Our objective was to review and synthesize the existing observational and experimental studies among humans on the associations of diet and recreational drug use with semen quality and fertility outcomes. The available data on this topic are limited and, at times, conflicting. Nevertheless, on the basis of this review, dietary patterns that are composed of higher intakes of fruits, vegetables, whole grains, nuts, low-fat dairy, and seafood, as well as lower intakes of red and processed meats, sweets, and sugar-sweetened beverages were identified as having the strongest evidence for associations with better sperm quality. However, whether these dietary patterns translate into positive associations with clinical fertility endpoints such as assisted reproductive technology success rates or time-to-pregnancy among couples trying to conceive without medical assistance remains unclear. Male caffeine and alcohol intake, within low-to-moderate ranges of intake, do not appear to be detrimental to semen quality. Yet high-quality research on this topic, focused on clinical fertility endpoints, should continue given the conflicting evidence, particularly in populations undergoing infertility treatment with assisted reproductive technology. Recreational drug use, including marijuana, electronic cigarettes, and other illicit drugs, does not appear to be beneficial for male reproductive health and should be avoided or ceased. In conclusion, men should be encouraged to consume a healthy diet rich in fruits, vegetables, whole grains, nuts, low-fat dairy, and seafood, as well as lacking in red and processed meats, sweets, and sugar-sweetened beverages, and to avoid recreational drug use for improved male reproductive health.

How Food Choices Impact on Male Fertility

PURPOSE OF REVIEW

Increasing evidence on the significance of nutrition in reproduction is emerging from both animal and human studies, suggesting an association between nutrition and male fertility. Here, we have highlighted the impact of the various food groups on reproductive hormones and on spermatogenesis, and the effects of classical and latest dietary patterns such as Mediterranean diet, Western diet, intermittent fasting, ketogenic diet, and vegan/vegetarian diet on male fertility.

RECENT FINDINGS

Nutrients are the precursors of molecules involved in various body's reactions; therefore, their balance is essential to ensure the correct regulation of different systems including the endocrine system. Hormones are strongly influenced by the nutritional status of the individual, and their alteration can lead to dysfunctions or diseases like infertility. In addition, nutrients affect sperm production and spermatogenesis, controlling sexual development, and maintaining secondary sexual characteristics and behaviors. The consumption of fruit, vegetables, fish, processed meats, dairy products, sugars, alcohol, and caffeine importantly impact on male fertility. Among dietary patterns, the Mediterranean diet and the Western diet are most strongly associated with the quality of semen. Nutrients, dietary patterns, and hormonal levels have an impact on male infertility. Therefore, understanding how these factors interact with each other is important for strategies to improve male fertility.

Assessing the influence of preconception diet on female fertility: a systematic scoping review of observational studies

BACKGROUND

Preconception diet is a proposed modifiable risk factor for infertility. However, there is no official guidance for women in the preconception period as to which dietary approaches may improve fertility.

OBJECTIVE AND RATIONALE

A comprehensive synthesis of the relevant evidence is key to determine the potentially effective dietary patterns and components as well as evidence gaps, and to provide information for nutritional recommendations for couples planning a pregnancy.

SEARCH METHODS

In this systematic scoping review, four electronic databases (Medline and EMBASE via Ovid processing, CAB Direct, and CINAHL via EBSCO) were searched for observational studies (prospective and retrospective cohort, cross-sectional, and case-control studies) from inception to 27 September 2021. Eligible studies included women of reproductive age during the preconception period, and evaluated exposures related to preconception diet and outcomes related to fertility. Results were synthesized using a descriptive approach.

OUTCOMES

A total of 36 studies were eligible for inclusion (31 prospective, 3 cross-sectional, and 2 case-control studies) and were published between 2007 and 2022. Of the assessed dietary exposures, increased adherence to the Mediterranean diet displayed the strongest and most consistent association with improved clinical pregnancy rates. Reducing trans fatty acids (TFAs), saturated fatty acids, and discretionary food intake (fast food and sugar-sweetened beverages) were associated with improvements in live birth, clinical pregnancy rates, and related ART outcomes. The dietary components of seafood, dairy, and soy demonstrated inconsistent findings across the few included studies.

WIDER IMPLICATIONS

Due to heterogeneity and the limited available literature on most exposures, there is insufficient evidence to support any specific dietary approach for improving fertility. However, following some of the dietary approaches outlined in this review (anti-inflammatory diets, reducing TFA, and discretionary food intake) are consistent with broad healthy eating guidelines, have little to no associated risk, and offer a plausible set of possible benefits. This warrants further exploration in randomized controlled trials.

Association of male fatty acid intake with fecundability among couples planning pregnancy

STUDY QUESTION

To what extent is male fatty acid intake associated with fecundability among couples planning pregnancy?

SUMMARY ANSWER

We observed weak positive associations of male dietary intakes of total and saturated fatty acids with fecundability; no other fatty acid subtypes were appreciably associated with fecundability.

WHAT IS KNOWN ALREADY

Male fatty acid intake has been associated with semen quality in previous studies. However, little is known about the extent to which male fatty acid intake is associated with fecundability among couples attempting spontaneous conception.

STUDY DESIGN, SIZE, DURATION

We conducted an internet-based preconception prospective cohort study of 697 couples who enrolled during 2015-2022. During 12 cycles of observation, 53 couples (7.6%) were lost to follow-up.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants were residents of the USA or Canada, aged 21-45 years, and not using fertility treatment at enrollment. At baseline, male participants completed a food frequency questionnaire from which we estimated intakes of total fat and fatty acid subtypes. We ascertained time to pregnancy using questionnaires completed every 8 weeks by female participants until conception or up to 12 months. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% CIs for the associations of fat intakes with fecundability, adjusting for male and female partner characteristics. We used the multivariate nutrient density method to account for energy intake, allowing for interpretation of results as fat intake replacing carbohydrate intake. We conducted several sensitivity analyses to assess the potential for confounding, selection bias, and reverse causation.

MAIN RESULTS AND THE ROLE OF CHANCE

Among 697 couples, we observed 465 pregnancies during 2970 menstrual cycles of follow-up. The cumulative incidence of pregnancy during 12 cycles of follow-up after accounting for censoring was 76%. Intakes of total and saturated fatty acids were weakly, positively associated with fecundability. Fully adjusted FRs for quartiles of total fat intake were 1.32 (95% CI 1.01-1.71), 1.16 (95% CI 0.88-1.51), and 1.43 (95% CI 1.09-1.88) for the second, third, and fourth vs the first quartile, respectively. Fully adjusted FRs for saturated fatty acid intake were 1.21 (95% CI 0.94-1.55), 1.16 (95% CI 0.89-1.51), and 1.23 (95% CI 0.94-1.62) for the second, third, and fourth vs the first quartile, respectively. Intakes of monounsaturated, polyunsaturated, trans-, omega-3, and omega-6 fatty acids were not strongly associated with fecundability. Results were similar after adjustment for the female partner's intakes of trans- and omega-3 fats.

LIMITATIONS, REASONS FOR CAUTION

Dietary intakes estimated from the food frequency questionnaire may be subject to non-differential misclassification, which is expected to bias results toward the null in the extreme categories when exposures are modeled as quartiles. There may be residual confounding by unmeasured dietary, lifestyle, or environmental factors. Sample size was limited, especially in subgroup analyses.

WIDER IMPLICATIONS OF THE FINDINGS

Our results do not support a strong causal effect of male fatty acid intakes on fecundability among couples attempting to conceive spontaneously. The weak positive associations we observed between male dietary fat intakes and fecundability may reflect a combination of causal associations, measurement error, chance, and residual confounding.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the National Institutes of Health, grant numbers R01HD086742 and R01HD105863. In the last 3 years, PRESTO has received in-kind donations from Swiss Precision Diagnostics (home pregnancy tests) and Kindara.com (fertility app). L.A.W. is a consultant for AbbVie, Inc. M.L.E. is an advisor to Sandstone, Ro, Underdog, Dadi, Hannah, Doveras, and VSeat. The other authors have no competing interests to report.

TRIAL REGISTRATION NUMBER

N/A.

The effect of dietary habits on oocyte/sperm quality

The effects of diet and nutritional habits on reproductive cells can be categorized in a variety of ways. In this review, the literature is divided, based on the dietary consumption effects on oocytes and sperm. Topics on dietary patterns and the intrauterine effect of maternal nutrition are covered. In general fruits, vegetables, whole greens, fish, legumes, and also dietary sources containing unsaturated fats can improve reproductive germ cell quality. In epidemiological studies, the food intake frequency questionnaire is one of the most common methods to assess diet. Due to methodological heterogeneity in dietary assessment and inadequacy in the measurement of dietary intake in the questionnaires used, several unreliable results may be reported. Thus, the quality of evidence needs to be improved, since nutritional diets may not be so simply objective and they are inadequate to explain obvious underlining mechanisms. In addition, various compounds that may be ingested can affect molecular mechanisms, influenced by other external factors (drugs, pesticides, smoking, alcohol) and changes in human nutritional parameters. Artificial Intelligence has recently gained widespread interest and may have a role in accurate analysis of dietary patterns for optimal nutritional benefit. Therefore, future prospective randomized studies and objective measurements, consisting of molecular level analysis of the impact on cells and clear-cut methods are needed for accurate assessment of the effect of dietary habits on reproductive treatment.

Paternal preconception modifiable risk factors for adverse pregnancy and offspring outcomes: a review of contemporary evidence from observational studies

BACKGROUND

The preconception period represents transgenerational opportunities to optimize modifiable risk factors associated with both short and long-term adverse health outcomes for women, men, and children. As such, preconception care is recommended to couples during this time to enable them to optimise their health in preparation for pregnancy. Historically, preconception research predominately focuses on maternal modifiable risks and health behaviours associated with pregnancy and offspring outcomes; limited attention has been given to inform paternal preconception health risks and outcomes. This systematic review aims to advance paternal preconception research by synthesising the current evidence on modifiable paternal preconception health behaviours and risk factors to identify associations with pregnancy and/or offspring outcomes.

METHODS

Medline, Embase, Maternity and Infant care, CINAHL, PsycINFO, Scopus, and ISI Proceedings were searched on the 5^th of January 2023, a date limit was set [2012-2023] in each database. A Google Scholar search was also conducted identifying all other relevant papers. Studies were included if they were observational, reporting associations of modifiable risk factors in the preconception period among males (e.g., identified as reproductive partners of pregnant women and/or fathers of offspring for which outcomes were reported) with adverse pregnancy and offspring outcomes. Study quality was assessed using the Newcastle-Ottawa Scale. Exposure and outcome heterogeneity precluded meta-analysis, and results were summarised in tables.

RESULTS

This review identified 56 cohort and nine case control studies. Studies reported on a range of risk factors and/or health behaviours including paternal body composition (n = 25), alcohol intake (n = 6), cannabis use (n = 5), physical activity (n = 2), smoking (n = 20), stress (n = 3) and nutrition (n = 13). Outcomes included fecundability, IVF/ISCI live birth, offspring weight, body composition/BMI, asthma, lung function, leukemia, preterm birth, and behavioural issues. Despite the limited number of studies and substantial heterogeneity in reporting, results of studies assessed as good quality showed that paternal smoking may increase the risk of birth defects and higher paternal BMI was associated with higher offspring birthweight.

CONCLUSION

The current evidence demonstrates a role of paternal preconception health in influencing outcomes related to pregnancy success and offspring health. The evidence is however limited and heterogenous, and further high-quality research is needed to inform clinical preconception care guidelines to support men and couples to prepare for a health pregnancy and child.

The Influence of Metabolic Factors and Diet on Fertility

Infertility is a disease globally affecting 20-30% of the reproductive age female population. However, in up to 50% on recorded cases, problems with infertility are ascribed to men; therefore, it is important to popularize healthy eating also in this group. During the last decade, it has been observed that society's lifestyle changed drastically: reduced energy expenditure in physical activity per day, increased consumption of hypercaloric and high-glycemic-index foods with high content of trans fats, and reduced consumption of dietary fiber, which negatively affects fertility. Increasing evidence points to a link between diet and fertility. It is becoming clear that well-planned nutrition can also contribute to the effectiveness of ART. The low-GI plant-based diet appears to have a positive effect, especially when it is based on Mediterranean dietary patterns: rich in antioxidants, vegetable protein, fiber, MUFA fatty acids, omega-3, vitamins, and minerals. Importantly, this diet has been shown to protect against chronic diseases associated with oxidative stress, which also translates into pregnancy success. As lifestyle and nutrition seem to be important factors affecting fertility, it is worth expanding knowledge in this regard among couples trying to conceive a child.

Development of a nutrition screening tool to identify need for dietetic intervention in female infertility

BACKGROUND

One in seven couples are impacted by infertility in the UK, and female infertility is often associated with several health conditions impacted by nutrition. Despite many studies aimed at identifying the critical role of nutrition in infertility, there is currently no screening tool that identifies nutritional risk factors for infertility.

AIM

To propose a self-administered screening tool to identify women who would benefit from nutritional intervention to promote fertility.

METHODS

A narrative review was carried out to identify and summarise modifiable nutritional risk factors that can influence female fertility, including comorbidities that can influence nutrition intake, absorption, and metabolism.

KEY FINDINGS

A nutrition screening tool outlining modifiable nutrition risk factors potentially improving female fertility has been proposed, comprising of BMI, medical history and quality of diet and lifestyle which would aid in designing evidence based dietetic services for female infertility.

Artificially Sweetened Beverages Beyond the Metabolic Risks: A Systematic Review of the Literature

We carried out a review of the available literature on the effects that artificially sweetened beverages (ASBs) such as diet soda (DS) have on health, particularly those not related to incident diabetes mellitus, obesity, and metabolic syndrome. A search of scientific articles was carried out using 11 different databases: PubMed, Cochrane, LILACS, MEDLINE Ovid, JAMA Network, IBECS, Cumed, Scopus, SciELO, MEDLINE-EBSCO, and Taylor & Francis Online. Articles published in the last 10 years were considered, considering cross-sectional studies, retrospective or prospective cohort studies, case-control studies, and randomized controlled clinical trials. Only articles in Spanish or English were considered using the MeSH (Medical Subject Heading) and DeCS (Descriptores en Ciencias de la Salud) terms, including "Diet soda," "Health," "Artificial sweetener," "Gaseosa sin azúcar," "Refresco sin azúcar," and "Salud." Additionally, Boolean operators "AND" and "Y" were used. A total of 1,323 articles were obtained in the initial search, of which 21 main ones were selected for review, which included the topic of DS consumption and explored the health consequences that it poses on different organs. The question of whether ASBs such as DS are a preferred substitute is becoming more and more important in terms of public policy due to mounting evidence of the potential negative health effects of their excessive consumption. This systematic review, the first of its kind to our knowledge, sheds light on how excessive DS consumption can affect multiple organ systems, and associations have been made to mental health burden, delays in child neurodevelopment, cardiac remodeling, worsening retinopathy in diabetics, incidental end-stage renal disease, non-Hodgkin's lymphoma and multiple myeloma in men, rheumatoid arthritis in women, hip fractures, dental erosion, increases in breath alcohol concentration when used in alcoholic beverages, and accelerated cell aging. Further studies should delve further to understand the pathophysiologic mechanisms of these associations.

Obese outbred mice only partially benefit from diet normalization or calorie restriction as preconception care interventions to improve metabolic health and oocyte quality

STUDY QUESTION

Can diet normalization or a calorie-restricted diet for 2 or 4 weeks be used as a preconception care intervention (PCCI) in Western-type diet-induced obese Swiss mice to restore metabolic health and oocyte quality?

SUMMARY ANSWER

Metabolic health and oocyte developmental competence was already significantly improved in the calorie-restricted group after 2 weeks, while obese mice that underwent diet normalization showed improved metabolic health after 2 weeks and improved oocyte quality after 4 weeks.

WHAT IS KNOWN ALREADY

Maternal obesity is linked with reduced metabolic health and oocyte quality; therefore, infertile obese women are advised to lose weight before conception to increase pregnancy chances. However, as there are no univocal guidelines and the specific impact on oocyte quality is not known, strategically designed studies are needed to provide fundamental insights in the importance of the type and duration of the dietary weight loss strategy for preconception metabolic health and oocyte quality.

STUDY DESIGN, SIZE, DURATION

Outbred female Swiss mice were fed a control (CTRL) or high-fat/high-sugar (HF/HS) diet. After 7 weeks, some of the HF mice were put on two different PCCIs, resulting in four treatment groups: (i) only control diet for up to 11 weeks (CTRL_CTRL), (ii) only HF diet for up to 11 weeks (HF_HF), (iii) switch at 7 weeks from an HF to an ad libitum control diet (HF_CTRL) and (iv) switch at 7 weeks from an HF to a 30% calorie-restricted control diet (HF_CR) for 2 or 4 weeks. Metabolic health and oocyte quality were assessed at 2 and 4 weeks after the start of the intervention (n = 8 mice/treatment/time point).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Changes in body weight were recorded. To study the impact on metabolic health, serum insulin, glucose, triglycerides, total cholesterol and alanine aminotransferase concentrations were measured, and glucose tolerance and insulin sensitivity were analyzed at PCCI Weeks 2 and 4. The quality of in vivo matured oocytes was evaluated by assessing intracellular lipid droplet content, mitochondrial activity and localization of active mitochondria, mitochondrial ultrastructure, cumulus cell targeted gene expression and oocyte in vitro developmental competence.

MAIN RESULTS AND THE ROLE OF CHANCE

Significant negative effects of an HF/HS diet on metabolic health and oocyte quality were confirmed (P < 0.05). HF_CTRL mice already showed restored body weight, serum lipid profile and glucose tolerance, similar to the CTRL_CTRL group after only 2 weeks of PCCI (P < 0.05 compared with HF_HF) while insulin sensitivity was not improved. Oocyte lipid droplet volume was reduced at PCCI Week 2 (P < 0.05 compared with HF_HF), while mitochondrial localization and activity were still aberrant. At PCCI Week 4, oocytes from HF_CTRL mice displayed significantly fewer mitochondrial ultrastructural abnormalities and improved mitochondrial activity (P < 0.05), while lipid content was again elevated. The in vitro developmental capacity of the oocytes was improved but did not reach the levels of the CTRL_CTRL mice. HF_CR mice completely restored cholesterol concentrations and insulin sensitivity already after 2 weeks. Other metabolic health parameters were only restored after 4 weeks of intervention with clear signs of fasting hypoglycemia. Although all mitochondrial parameters in HF_CR oocytes stayed aberrant, oocyte developmental competence in vitro was completely restored already after 2 weeks of intervention.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

In this study, we applied a relevant HF/HS Western-type diet to induce obesity in an outbred mouse model. Nevertheless, physiological differences should be considered when translating these results to the human setting. However, the in-depth study and follow-up of the metabolic health changes together with the strategic implementation of specific PCCI intervals (2 and 4 weeks) related to the duration of the mouse folliculogenesis (3 weeks), should aid in the extrapolation of our findings to the human setting.

WIDER IMPLICATIONS OF THE FINDINGS

Our study results with a specific focus on oocyte quality provide important fundamental insights to be considered when developing preconception care guidelines for obese metabolically compromised women wishing to become pregnant.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Flemish Research Fund (FWO-SB grant 1S25020N and FWO project G038619N). The authors declare there are no conflicts of interest.

Is the Association between Age and Fertility Problems Modified by Diet Quality? Findings from a National Study of Reproductive Age Women in Australia

Background: Increasing age is a strong risk factor for infertility, and there is accumulating evidence of the importance of a healthier diet for fertility. Whether a healthier diet modifies the association between increasing age and infertility has not been investigated. This study aimed to (i) examine if better diet quality could help reduce age-related infertility; and (ii) assess whether changes in diet quality over time are associated with fertility problems. Methods: Data were from Surveys 3 and 5 of the 1973−1978 birth cohort of the Australian Longitudinal Study on Women’s Health. Cross-sectional analysis with multivariable generalized linear models were used to examine the association between age and fertility status, adjusted for various confounders. Multiplicative and additive effect modification by diet quality was assessed, with additive effect modification evaluated with the relative risk for interaction (RERI). Results: In total, 3387 women were included from Survey 3 (age range 24−31 years) and 5614 women from Survey 5 (age range 30−38 years); 588 (17.4%) and 1321 (23.4%) self-reported to have fertility problems in the respective surveys. In Survey 3, compared to younger women with a good-quality diet, older women with a poor-quality diet had a 43% increased risk for fertility problems, with risk increasing after further adjustment for BMI (RR: 1.59; 95% CI: 1.07, 2.37) and PCOS (RR: 1.74; 95% CI: 1.15, 2.62). In Survey 5 in younger women (<33.9 years), there was no association between diet quality and risk for infertility problems. The RERI (across different adjusted models) was between −0.08 (−0.70, 0.55) to −0.39 (−1.40, 0.62) in survey 3 and 0.07 (−0.17, 0.31) to 0.08 (−0.17, 0.32) in Survey 5. Conclusions: There is little evidence to suggest effect modification on the effect of age and fertility problems with diet quality.

Sugar-sweetened beverage intake in relation to reproductive parameters in young men

BACKGROUND

There has been a decrease in sperm concentration in recent years. Concurrently, there were important dietary changes, including an increase in sugar-sweetened beverage intake (SSB). The relation between SSB and male reproduction functions in humans are barely described in the literature.

METHODS

Cross-sectional study with 209 participants (18-23 years old) recruited during one year in Murcia, Spain. All men provided semen and blood samples the same day. SSB consumption was evaluated using a 101-item validated food frequency questionnaire. Reproductive hormones were analysed from serum samples, obtaining levels of follicle-stimulating hormone, inhibin B, luteinizing hormone, estradiol, and testosterone. The evaluation of semen analysis followed the WHO guidelines and consisted of seminal volume, sperm concentration, total sperm count, percentage of morphologically normal sperm, and percentage of motile sperm. SSB intake association with semen parameters and hormone levels were examined using multiple linear regression.

RESULTS

Men in the highest quartile of the SSB intake had a higher percentage of morphologically normal sperm, 37.4% [6.1, 68.3] (p, trend=0.047) and higher estradiol levels (9.5% [-3.5, 22.5] (p, trend=0.047) than those in the first quartile. SSB intake was unrelated to other semen quality parameters or reproductive hormone levels.

CONCLUSIONS

Our results indicate that sperm morphology and estradiol levels may be associated with sugar-sweetened beverage intake. These findings might be explained by physiological metabolism homeostasis, though more studies are required to confirm these results and draw conclusions in other male populations.

Beverage intake and ovarian reserve among women from a fertility center

OBJECTIVE

To evaluate the associations of caffeinated, alcoholic, and sweetened beverage intakes with antral follicle count (AFC), a well-accepted biomarker of ovarian reserve.

DESIGN

Observational prospective cohort study.

SETTING

Fertility center at an academic hospital.

PATIENTS

This study includes 567 women seeking fertility care at the Massachusetts General Hospital who participated in the Environment and Reproductive Health Study.

INTERVENTION

None. Women self-reported consumption of caffeinated (coffee, tea, soda), alcoholic (wine, beer, liquor), sugar-sweetened, and artificially sweetened beverages using a validated food-frequency questionnaire.

MAIN OUTCOME MEASURE

Antral follicle count was assessed using a transvaginal ultrasound performed on the 3rd day of an unstimulated menstrual cycle or on the 3rd day of a progesterone withdrawal bleed.

RESULTS

Median (interquartile range) age and AFC were 35.0 (32.0-38.0) years and 13.0 (9.0-18.0), respectively. Median (range) intake of caffeinated, alcoholic, sugar-sweetened, and artificially sweetened beverages in servings/day were 1.08 (0-7.08), 0.35 (0-3.84), 0.04 (0-4.80), and 0.04 (0-7.50), respectively. All examined beverages were unrelated to AFC. The multivariable adjusted mean AFC (95% confidence interval) for women in the top and bottom quartiles of intake were 13.8 (13.0-14.7) and 13.8 (12.9-14.7) for caffeinated beverages; 13.8 (13.0-14.7) and 13.8 (13.0-14.6) for alcoholic beverages; 13.5 (12.6-14.4) and 13.3 (12.4-14.2) for sugar-sweetened beverages; and 13.2 (12.4-14.1) and 13.4 (12.6-14.3) for artificially sweetened beverages.

CONCLUSION

Low-to-moderate intakes of caffeinated, alcoholic, sugar-sweetened, and artificially sweetened beverages were unrelated to ovarian reserve, as measured by AFC, in a cohort of women seeking fertility care.

Sugar Consumption Is Negatively Associated with Semen Quality

Recently, in parallel to decrease in semen quality, the consumption of sugar has risen sharply. This provided the rationale to study the association between whole dietary sugar consumption and semen quality. Our aim was to investigate the association between sugar consumption and semen quality. The final cross-sectional study population (n = 280 of initial n = 593, after applying inclusion and exclusion criteria) attending routine semen analysis at sperm bank laboratory was subject to semen quality analysis according to WHO criteria (volume, sperm concentration, total sperm count, percentage total motility, and percentage normal morphology) and filled food frequency questionnaire (FFQ) and lifestyle questionnaire. Associations between consumed sugars and semen quality were analyzed using multivariate regression adjusted to relevant cofounders for 2 food components containing sugar including soft drinks (SoftD) and total added sugar to food products (SugProd). We found negative association between higher consumption of dietary sugar in all 2 dietary sub-categories and sperm concentration. Significant sperm concentration decrements of 18% and 23% were associated with SoftD median consumption of 0.2 drinks/day (IQR; 0.1-0.5 drinks/day). Significant sperm concentration decrements of 15% and 17% were associated with median SugProd consumption of 25 teaspoons of added sugar/day (IQR; 19-31 teaspoons of added sugar/day). In conclusion, our study findings demonstrate that sugar consumption is negatively associated with sperm concentration.

Effects of mobile phone use on semen parameters: a cross-sectional study of 1634 men in China

Mobile phones play an irreplaceable role in modern people's lives. However, the radiofrequency electromagnetic radiation produced by mobile phones has also caused increasing concern. A cross-sectional study was conducted to investigate the effect of radiofrequency electromagnetic radiation produced by mobile phones on semen parameters in 1634 men who underwent semen examination at the Department of Reproductive Endocrinology, Women's Hospital, School of Medicine, Zhejiang University, China. Analysis of variance and multivariate linear regression were used to explore differences among different groups. A P <0.05 was considered statistically significant. The results showed significant associations among different groups of daily mobile phone use time and daily duration of phone calls in the percentage of progressively motile spermatozoa (P =0.004 and P =0.007), rapid progressively motile spermatozoa (P =0.012 and P =0.006) and total motile spermatozoa (P =0.004 and P =0.046). After adjustments for the confounding effects of age and body mass index by multiple linear regression, the results showed that the daily duration of mobile phone use had a negative effect on sperm motility. However, there was no statistically significant correlation between daily phone call duration and sperm motility. Therefore, the daily duration of mobile phone use may negatively affect sperm motility and impair male fertility.

Environmental factors in declining human fertility

A severe decline in child births has occurred over the past half century, which will lead to considerable population declines, particularly in industrialized regions. A crucial question is whether this decline can be explained by economic and behavioural factors alone, as suggested by demographic reports, or to what degree biological factors are also involved. Here, we discuss data suggesting that human reproductive health is deteriorating in industrialized regions. Widespread infertility and the need for assisted reproduction due to poor semen quality and/or oocyte failure are now major health issues. Other indicators of declining reproductive health include a worldwide increasing incidence in testicular cancer among young men and alterations in twinning frequency. There is also evidence of a parallel decline in rates of legal abortions, revealing a deterioration in total conception rates. Subtle alterations in fertility rates were already visible around 1900, and most industrialized regions now have rates below levels required to sustain their populations. We hypothesize that these reproductive health problems are partially linked to increasing human exposures to chemicals originating directly or indirectly from fossil fuels. If the current infertility epidemic is indeed linked to such exposures, decisive regulatory action underpinned by unconventional, interdisciplinary research collaborations will be needed to reverse the trends.

Dietary patterns are associated with improved ovarian reserve in overweight and obese women: a cross-sectional study of the Lifestyle and Ovarian Reserve (LORe) cohort

BACKGROUND

Growing evidence suggests that adherence to certain dietary patterns is associated with improved fecundity and reproductive outcomes in the general population and infertile couples assisted reproductive treatments. The objective of this study was to assess if dietary patterns are associated with ovarian reserve in reproductive age women without a history of infertility.

METHODS

This was a cross-sectional study of 185 women in the Lifestyle and Ovarian Reserve (LORe) cohort. Women aged 18-44 without a history of infertility were recruited from the local community at an academic medical center. Subjects completed validated food frequency and physical activity questionnaires to assess patterns over the year prior to presentation. Dietary patterns including a Western (including meat, refined carbohydrates, high-calorie drinks), prudent (including fruits, vegetables, olive oil and nuts), fertility (lower intake of trans fat with higher intake of monounsaturated fatty acids, increased intake of plant based protein, high-fat dairy, lower glycemic load carbohydrates and supplemental iron) and profertility diet (PFD) (characterize by whole grains, soy and seafood, low pesticide residue produce, supplemental folic acid, B12 and vitamin D) were identified through principal component analysis. Main outcome measures were serum antimullerian hormone concentration (AMH) (ng/mL) and antral follicle count (AFC) obtained by transvaginal ultrasound.

RESULTS

After stratifying by BMI, adjusting for age, smoking and physical activity, dietary patterns were not associated with ovarian reserve in normal weight women. Increased adherence to a profertility diet in overweight and obese women (BMI ≥ 25 kg/m²) was associated with a significantly higher AMH. Women in the third and fourth quartiles of PFD adherence had a mean AMH concentration of 1.45 ng/mL (95%CI 0.33-2.56, p = 0.01) and 1.67 ng/mL (95%CI 0.60-2.74, p = 0.003) higher than women in the lowest quartile respectively. The highest adherence to PFD was also associated with a higher AFC in women with a BMI ≥ 25 kg/m² (β = 7.8, 95%CI 0.003-15.34, p < 0.05). Other common dietary patterns were not significantly associated with ovarian reserve.

CONCLUSIONS

Increased adherence to a profertility diet is associated with improved markers of ovarian reserve in overweight and obese women. These findings provide novel insight on potential modifiable lifestyle factors associated with ovarian reserve.

Prepregnancy adherence to plant-based diet indices and exploratory dietary patterns in relation to fecundability

BACKGROUND

Modest associations have been reported between specific food groups or nutrients and fecundability [measured by time to pregnancy (TTP)]. Examining overall diets provides a more holistic approach towards understanding their associations with fecundability. It is not known whether plant-based diets indices or exploratory dietary patterns are associated with fecundability.

OBJECTIVES

We examine the associations between adherence to 1) plant-based diet indices; and 2) exploratory dietary patterns and fecundability among women planning pregnancy.

METHODS

Data were analyzed from the Singapore Preconception Study of Long-Term Maternal and Child Outcomes (S-PRESTO) study. Prepregnancy diet was assessed using a semi-quantitative FFQ from which the overall, healthful, and unhealthful plant-based diet indices (oPDI, hPDI, and uPDI, respectively) were calculated. Exploratory dietary patterns were derived using factor analysis based on 44 predefined food groups. Participants were categorized into quintiles based on their dietary pattern scores. TTP (expressed in menstrual cycles) was ascertained within a year from the prepregnancy dietary assessment. Discrete-time proportional hazard models, adjusted for confounders, were used to estimate fecundability ratios (FRs) and 95% CIs, with FR > 1 indicating a shorter TTP.

RESULTS

Among 805 women, 383 pregnancies were confirmed by ultrasound scans. Compared with women in the lowest quintile, those in the highest quintile of the uPDI had reduced fecundability (FR of Q5 compared with Q1, 0.65; 95% CI, 0.46-0.91; P trend, 0.009). Conversely, greater adherence to the hPDI was associated with increased fecundability (1.46; 95% CI, 1.02-2.07; P trend, 0.036). The oPDI was not associated with fecundability. Among the 3 exploratory dietary patterns, only greater adherence to the Fast Food and Sweetened Beverages (FFSB) pattern was associated with reduced fecundability (0.61; 95% CI, 0.40-0.91; P trend, 0.018).

CONCLUSIONS

Greater adherence to the uPDI or the FFSB dietary pattern was associated with reduced fecundability among Asian women. Greater adherence to the hPDI may be beneficial for fecundability, though this requires confirmation by future studies.

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.

Consumption of Sugar-Sweetened or Artificially Sweetened Beverages and Semen Quality in Young Men: A Cross-Sectional Study

BACKGROUND

Existing literature suggests that frequent consumption of sugar-sweetened drinks may be associated with lower semen quality. Studies performed in mice suggest a dose-response relationship between intake of saccharin or aspartame, two artificial sweeteners, and sperm and testis function.

METHODS

A cross-sectional study based on data from The Fetal Programming of Semen Quality (FEPOS) Cohort, including 1047 young men (mean age = 19 years) was performed. Each male participant completed an online questionnaire on health, health behavior and diet, and provided a semen sample. The associations between consumption of sugar-sweetened or artificially sweetened beverages (moderate ≥ 3 days/week; infrequent < 3 days/week) and semen quality were analyzed using a multivariable, negative, binomial regression model.

RESULTS

Sugar-sweetened or artificially sweetened beverage consumption was not strongly associated with either semen volume, sperm concentration, total sperm count or total motility in young men. The proportion of morphologically normal sperm was 11% lower (0.89 (95% CI 0.76, 1.04)) for moderate (≥3 days/week) consumption of artificially sweetened beverages relative to infrequent (<3 days/week).

CONCLUSION

Consumption of sugar-sweetened or artificially sweetened beverages, at the levels present in this study had limited effect on the measured markers of semen quality in young men.

A dietary score representing the overall relation of men's diet with semen quality in relation to outcomes of infertility treatment with assisted reproduction

Objective

To examine the impact of men's diet on outcomes of infertility treatment with assisted reproductive technology (ART) using an empirical score representing the relation of diet with semen quality.

Design

Prospective cohort study.

Setting

Fertility center at an academic medical center.

Patients

We included 296 men (688 semen samples) to identify an empirical dietary pattern and 231 couples (406 ART cycles) to investigate the association of this diet pattern with ART outcomes.

Interventions

Men's diet was assessed at baseline using a validated questionnaire. An empirical dietary pattern reflecting the overall relation of diet with semen quality was identified using reduced rank regression.

Main Outcome Measures

The primary outcome was live birth per treatment cycle. The secondary outcomes were fertilization, implantation, and clinical pregnancy.

Results

Men had a median baseline age and body mass index of 36.8 years and 26.9 kg/m², respectively. Although the empirical diet pattern was significantly associated with all semen parameters, the empirical diet score was not related to any clinical outcome of infertility treatment after ART. The adjusted probabilities of relevant clinical outcomes in the lowest and highest quartiles of the empirical score were 0.62 (0.50-0.73) and 0.55 (0.45-0.66) for implantation, 0.57 (0.46-0.69) and 0.50 (0.40-0.61) for clinical pregnancy, and 0.49 (0.37-0.62) and 0.36 (0.25-0.48) for live birth. Analyses excluding couples with a diagnosis of male factor infertility and, separately, excluding intracytoplasmic sperm injection cycles yielded similar results.

Conclusions

A dietary score representing the overall association of diet with semen quality parameters was not associated with ART outcomes.

Female Fertility and the Nutritional Approach: The Most Essential Aspects

Infertility is an increasing problem that affects couples attempting pregnancy. A growing body of evidence points to a link between diet and female fertility. In fact, data show that a diet high in trans fats, refined carbohydrates, and added sugars can negatively affect fertility. Conversely, a diet based on the Mediterranean dietary patterns, i.e., rich in dietary fiber, omega-3 (ɷ-3) fatty acids, plant-based protein, and vitamins and minerals, has a positive impact on female fertility. An unhealthy diet can disrupt microbiota composition, and it is worth investigating whether the composition of the gut microbiota correlates with the frequency of infertility. There is a lack of evidence to exclude gluten from the diet of every woman trying to become pregnant in the absence of celiac disease. Furthermore, there are no data concerning adverse effects of alcohol on female fertility, and caffeine consumption in the recommended amounts also does not seem to affect fertility. On the other hand, phytoestrogens presumably have a positive influence on female fertility. Nevertheless, there are many unanswered questions with regard to supplementation in order to enhance fertility. It has been established that women of childbearing age should supplement folic acid. Moreover, most people experience vitamin D and iodine deficiency; thus, it is vital to control their blood concentrations and consider supplementation if necessary. Therefore, since diet and lifestyle seem to be significant factors influencing fertility, it is valid to expand knowledge in this area.

Association between intake of soft drinks and testicular function in young men

STUDY QUESTION

Is intake of sugar-sweetened beverages (SSB) or artificially sweetened beverages (ASB) associated with testicular function in young men?

SUMMARY ANSWER

Among young men unaware of their semen quality and reproductive hormone levels, intake of SSBs was associated with lower sperm concentration, lower total sperm count, and a lower ratio of serum inhibin-B/FSH.

WHAT IS KNOWN ALREADY

SSBs may adversely impact testicular function, but results are not consistent across studies. Moreover, the associations of ASB, energy-drinks or fruit juices with testicular function are unclear.

STUDY DESIGN, SIZE, DURATION

Young healthy men and unselected for fertility status men enrolled in a cross-sectional study between 2008 and 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 2935 young (median age: 19 years) men enrolled in the study. Intake of SSBs, ASBs, fruit juices, and energy-drinks was assessed with a validated food frequency questionnaire. Testicular function was assessed through conventional semen quality parameters (semen volume, sperm concentration, total count, motility and morphology), testicular volume assessed with ultrasound, and serum reproductive hormone concentrations (total testosterone, free testosterone, E2, inhibin-B, LH, FSH, sex hormone-binding globulin) were measured.

MAIN RESULTS AND THE ROLE OF CHANCE

In multivariable-adjusted analyses, men in the highest category of SSB intake (median: 1.1 servings (∼220 ml)/day) had a 13.2 million/ml lower median sperm concentration (95% CI: -21.0, -5.5) than non-consumers. A similar pattern was observed with total sperm count (-28 million (95% CI: -48, -9)), serum inhibin-B (-12 pg/ml (95% CI: -21, -4)), and inhibin-B/FSH ratio (-9 (95% CI: -18, 0)). The adjusted median difference in sperm concentration and inhibin-B associated with increasing SSB intake by 1 serving (∼200ml)/day at the expense of water was -3.4 million sperm/ml (95% CI: -5.8, -1.0) and -7 pg/ml (95% CI: -11, -3), respectively.

LIMITATIONS, REASONS FOR CAUTION

Inferring causality is limited owing to the cross-sectional design. We adjusted for a number of potential confounders but cannot exclude that unmeasured lifestyle and behavior associated with soft drink intake is associated with testicular function in these young men.

WIDER IMPLICATIONS OF THE FINDINGS

In the largest study to date, intake of SSBs was associated with lower sperm concentration, total sperm count, and serum inhibin-B/FSH ratio, consistent with a direct suppressive effect of SSB intake on testicular function among otherwise healthy men, potentially affecting fertility. However, the observed association between higher SSB intake and lower semen quality does not necessarily imply a decrease in fertility.

STUDY FUNDING/COMPETING INTEREST(S)

Supported by research from the Danish Council for Strategic Research (2101-08-0058), Independent Research Fund Denmark (8020-00218B), European Union (212844), the Kirsten and Freddy Johansen's Foundation (95-103-72087), the Research Fund of the Capital Region of Denmark (A6176), and the NIH (P30DK046200). The authors report no conflict of interest.

TRIAL REGISTRATION NUMBER

N/A.

Maternal lifestyle and nutritional habits are associated with oocyte quality and ICSI clinical outcomes

RESEARCH QUESTION

Do maternal lifestyle factors influence the incidence of oocyte dimorphisms and outcomes of intracytoplasmic sperm injection (ICSI) cycles?

DESIGN

A total of 752 female patients undergoing an ICSI cycle at a private university-affiliated IVF centre from January 2015 to December 2019 were included in this historical cohort study. Before starting ovarian stimulation, participants completed a questionnaire on cigarette smoking habits, consumption of alcoholic beverages, refined sugar, artificial sweeteners, soft drinks, fruits, legumes and vegetables, milk and dairy, and meat, as well as exercise frequency over the past 6 months. Oocyte morphology was evaluated before ICSI. The influence of maternal lifestyle factors on the incidence of oocyte dimorphisms and ICSI outcomes was evaluated by multivariate general linear models and generalized linear models, adjusted for potential confounders. The main outcome measures were the incidence of oocyte dimorphisms per cycle and clinical outcomes.

RESULTS

Lifestyle factors and nutritional habits such as cigarette smoking, and the consumption of alcohol, refined sugar and artificial sweeteners, were positively associated with incidence of several oocyte dimorphisms and negatively associated with the response to ovarian stimulation and embryo development. Negative relationships were also observed between these habits and clinical outcomes, apart from miscarriage rate, in which positive relationships were observed. Significant negative dose-dependent relationships between these habits and implantation rates were noted (P < 0.001). Alcoholic beverage consumption also showed inverse dose-dependent relationships with clinical pregnancy and live birth rates. Live birth rate was also negatively associated with cigarette smoking, in a dose-dependent manner.

CONCLUSIONS

Poor maternal habits were associated with reduced oocyte quality and ICSI outcomes in this study. Many of these associations were shown to be dose-dependent.

Men's dietary patterns in relation to infertility treatment outcomes among couples undergoing in vitro fertilization

PURPOSE(S)

To evaluate the relationship of men's dietary patterns with outcomes of in vitro fertilization (IVF).

METHODS

This is a prospective cohort study including 231 couples with 407 IVF cycles, presented at an academic fertility center from April 2007 to April 2018. We assessed diet with a validated food frequency questionnaire and identified Dietary Pattern 1 and Dietary Pattern 2 using principal component analysis. We evaluated adjusted probability of IVF outcomes across the quartiles of the adherence to two dietary patterns by generalized linear mixed models.

RESULTS

Men had a median age of 36.8 years and BMI of 26.9 kg/m2. Women's median age and BMI were 35.0 years and 23.1 kg/m2, respectively. Adherence to Dietary Pattern 1 (rPearson=0.44) and Dietary Pattern 2 (rPearson=0.54) was positively correlated within couples. Adherence to Dietary Pattern 1 was positively associated with sperm concentration. A 1-unit increase in this pattern was associated with a 13.33 (0.71-25.96) million/mL higher sperm concentration. However, neither Dietary Pattern 1 nor Dietary Pattern 2 was associated with fertilization, implantation, clinical pregnancy, or live birth probabilities.

CONCLUSIONS

Data-derived dietary patterns were associated with semen quality but unrelated to the probability of successful IVF outcomes.

Can Nutrition Help in the Treatment of Infertility?

Infertility is defined as the inability to conceive after 12 months of unprotected intercourse or six months for women aged 35 years or older. The physical, emotional, psychological, and financial statuses of infertile couples are tremendously affected especially after undergoing diagnostic and/or curative treatments. Human fertility is influenced by multiple factors including female or male, and modifiable or non-modifiable factors. There is growing evidence that nutri-tion may play an important role in adjusting fertility-related outcomes in both men and women. The objective of our study was to summarize the latest data on nutritional factors (specific food groups, nutrients, and nutritional supplements) that have an impact on female or male sexual and reproductive function. PubMed and Google Scholar platforms were used to collect appropriate articles for the review using several combinations of keywords (infertility, diet, dietary supplements, antioxidants, and beverages). Adherence to a healthy dietary pattern favoring fish, poultry, whole grains, fruits, vegetables, and healthy fats, was related to better fertility in both genders. Despite the multifactorial etiology of sexual infertility, nutrition may affect the sexual/reproductive function in both women and men.

Do dietary patterns and morbidities have a relationship with primary infertility among women? A study from NFHS-4 (2015-16), India

This study assessed the rate of primary infertility and its associated factors among 402,807 currently married women aged 20-49 years in India using National Family Health Survey-4 data collected in 2015-2016. Dietary patterns and selected morbidities were included as independent variables, and socioeconomic variables were considered as covariates. Bivariate and multivariate analyses were done to estimate the prevalence of primary infertility and assess its association with the selected variables, respectively. The rate of primary infertility among currently married women in India in 2015-16 was 1.9% and this was significantly associated with younger age (<35 years), higher age at marriage (≥18 years), urban residence, higher secondary or above education and poverty. The consumption of dairy products (OR = 0.79, CI = 0.73-0.86), dark green leafy vegetables (OR = 0.57, CI = 0.39-0.81) and fruit (OR = 0.88, CI = 0.77-1.01) significantly reduced the odds of primary infertility. Daily consumption of fish and aerated drinks was related to 1.06-1.21 times higher odds of primary infertility. Overweight/obesity, high blood pressure and high blood glucose levels were associated with 1.08-1.21 times elevated odds of primary infertility. Thyroid disorder (OR = 1.38, CI = 1.21-1.60), heart disease (OR = 1.17, CI = 1.16-1.19) and severe anaemia (OR = 1.24, CI = 1.00-1.53) were associated with an increased likelihood of primary infertility among women (OR 1.17-1.39, CI 1.00-1.60). The findings provide compelling evidence that primary infertility among women is related to dietary patterns and morbidities. Interventions and programmes targeting the promotion of healthy diets and lifestyles could be beneficial in addressing the issue of primary infertility among women.

Male cellular telephone exposure, fecundability, and semen quality: results from two preconception cohort studies

STUDY QUESTION

To what extent is exposure to cellular telephones associated with male fertility?

SUMMARY ANSWER

Overall, we found little association between carrying a cell phone in the front pants pocket and male fertility, although among leaner men (BMI <25 kg/m2), carrying a cell phone in the front pants pocket was associated with lower fecundability.

WHAT IS KNOWN ALREADY

Some studies have indicated that cell phone use is associated with poor semen quality, but the results are conflicting.

STUDY DESIGN, SIZE, DURATION

Two prospective preconception cohort studies were conducted with men in Denmark (n = 751) and in North America (n = 2349), enrolled and followed via the internet from 2012 to 2020.

PARTICIPANTS/MATERIALS, SETTING, METHODS

On the baseline questionnaire, males reported their hours/day of carrying a cell phone in different body locations. We ascertained time to pregnancy via bi-monthly follow-up questionnaires completed by the female partner for up to 12 months or until reported conception. We used proportional probabilities regression models to estimate fecundability ratios (FRs) and 95% confidence intervals (CIs) for the association between male cell phone habits and fecundability, focusing on front pants pocket exposure, within each cohort separately and pooling across the cohorts using a fixed-effect meta-analysis. In a subset of participants, we examined selected semen parameters (semen volume, sperm concentration and sperm motility) using a home-based semen testing kit.

MAIN RESULTS AND THE ROLE OF CHANCE

There was little overall association between carrying a cell phone in a front pants pocket and fecundability: the FR for any front pants pocket exposure versus none was 0.94 (95% CI: 0.0.83-1.05). We observed an inverse association between any front pants pocket exposure and fecundability among men whose BMI was <25 kg/m2 (FR = 0.72, 95% CI: 0.59-0.88) but little association among men whose BMI was ≥25 kg/m2 (FR = 1.05, 95% CI: 0.90-1.22). There were few consistent associations between cell phone exposure and semen volume, sperm concentration, or sperm motility.

LIMITATIONS, REASONS FOR CAUTION

Exposure to radiofrequency radiation from cell phones is subject to considerable non-differential misclassification, which would tend to attenuate the estimates for dichotomous comparisons and extreme exposure categories (e.g. exposure 8 vs. 0 h/day). Residual confounding by occupation or other unknown or poorly measured factors may also have affected the results.

WIDER IMPLICATIONS OF THE FINDINGS

Overall, there was little association between carrying one's phone in the front pants pocket and fecundability. There was a moderate inverse association between front pants pocket cell phone exposure and fecundability among men with BMI <25 kg/m2, but not among men with BMI ≥25 kg/m2. Although several previous studies have indicated associations between cell phone exposure and lower sperm motility, we found few consistent associations with any semen quality parameters.

STUDY FUNDING/COMPETING INTEREST(S)

The study was funded by the National Institutes of Health, grant number R03HD090315. In the last 3 years, PRESTO has received in-kind donations from Sandstone Diagnostics (for semen kits), Swiss Precision Diagnostics (home pregnancy tests), Kindara.com (fertility app), and FertilityFriend.com (fertility app). Dr. L.A.W. is a fibroid consultant for AbbVie, Inc. Dr. H.T.S. reports that the Department of Clinical Epidemiology is involved in studies with funding from various companies as research grants to and administered by Aarhus University. None of these studies are related to the current study. Dr. M.L.E. is an advisor to Sandstone Diagnostics, Ro, Dadi, Hannah, and Underdog. Dr. G.J.S. holds ownership in Sandstone Diagnostics Inc., developers of the Trak Male Fertility Testing System. In addition, Dr. G.J.S. has a patent pending related to Trak Male Fertility Testing System issued.

TRIAL REGISTRATION NUMBER

N/A.

Awareness of and reactions to the health harms of sugary drinks: An online study of U.S. parents

Evidence about the health problems associated with sugary drink consumption is well-established. However, little is known about which sugary drink health harms are most effective at changing consumers' behavior. We aimed to identify which harms people were aware of and most discouraged them from wanting to buy sugary drinks. Participants were a national convenience sample of diverse parents (n = 1,058), oversampled for Latino parents (48%). Participants rated a list of sugary drink-related health harms occurring in children (7 harms) and in adults (15 harms). Outcomes were awareness of each harm and how much each harm discouraged parents from wanting to purchase sugary drinks. Most participants were aware that sugary drinks contribute to tooth decay in children (75%) and weight gain in both children (73%) and adults (69%). Few participants were aware that sugary drinks contribute to adult infertility (16%), arthritis (18%), and gout (18%). All health harms were rated highly in terms of discouraging parents from wanting to buy sugary drinks (range: 3.59-4.11 on a 1-5 scale), with obesity, pre-diabetes, and tooth decay eliciting the highest discouragement ratings. Harm-induced discouragement was higher for participants who were aware of more health harms (B = 0.05, p < 0.0001), identified as female (B = 0.15 compared to male, p = 0.02), or had an annual household income of $50,000 or more (B = 0.16 compared to less than $50,000, p = 0.03). These findings suggest health messages focused on a variety of health harms could raise awareness and discourage sugary drink purchases.

Association of sugar-sweetened beverage intake with maternal postpartum weight retention

OBJECTIVE

During the perinatal period, modifiable behaviours contributing to excess weight gain, including sugar-sweetened beverage (SSB) intake, are understudied. We examined the extent to which perinatal SSB intake affects postpartum weight retention (PPWR).

DESIGN

We measured SSB intake frequency in the third trimester and 1-month postpartum using the NHANES Dietary Screener Questionnaire. We assessed the association between SSB intake and PPWR (difference between 6-month postpartum and pregravid weight) using multivariable regression adjusted for socio-demographic and anthropometric variables.

SETTING

Greater Boston area.

PARTICIPANTS

Three hundred forty-eight mother-infant pairs in the Rise and SHINE prospective birth cohort.

RESULTS

Mean age was 32·7 (sd 5·0) years; the sample was 47 % white, 32 % Hispanic, 14 % Asian and 7 % Black. Women reported mean daily SSB intake frequencies of 0·9 (sd 1·2) and 0·7 (sd 1·0) times/d in the third trimester and 1-month postpartum, respectively. At 6-month postpartum, average weight retention was 3·4 (sd 5·7) kg; 108 (sd 31 %) women had substantial PPWR, defined as a ≥ 5 kg increase between pregravid and 6-month postpartum weight. Each 1-time/d increment in SSB intake frequency during the third trimester (β = 0·46 kg (95 % CI, 0·07, 0·86)) and 1-month postpartum (β = 0·52 kg (95 % CI 0·03, 1·00)) was associated with higher weight retention at 6 months. Increased SSB intake frequency in the third trimester (OR: 1·37; 95 % CI 1·10, 1·75) and 1-month postpartum (OR: 1·17; 95 % CI 0·92, 1·52) resulted in higher odds of substantial PPWR.

CONCLUSIONS

SSB consumption during the perinatal period is associated with higher weight retention at 6-month postpartum. Avoiding SSB may reduce the risk of excess weight retention.

At-home sperm testing for epidemiologic studies: Evaluation of the Trak male fertility testing system in an internet-based preconception cohort

BACKGROUND

Semen quality assessment in population-based epidemiologic studies presents logistical and financial challenges due to reliance on centralised laboratory semen analysis. The Trak Male Fertility Testing System is an FDA-cleared and validated at-home test for sperm concentration and semen volume, with a research use only sperm motility test. Here we evaluate the Trak System's overall utility among men participating in Pregnancy Study Online (PRESTO), a web-based study of North American couples planning pregnancy.

METHODS

US male participants aged ≥21 years with ≤6 months of pregnancy attempt time at study enrolment were invited to participate in the semen testing substudy after completing their baseline questionnaire. Consenting participants received a Trak Engine (battery-powered centrifuge) and two test kits. Participants shared their test results via smartphone images uploaded to online questionnaires. Data were then linked with covariate data from the baseline questionnaire.

RESULTS

Of the 688 men invited to participate, 373 (54%) provided consent and 271 (73%) completed at least one semen test result. The distributions of semen volume, sperm concentration, motile sperm concentration, total sperm count, and total motile sperm count were similar to 2010 World Health Organization (WHO) semen parameter data of men in the general population. The overall usability score for the Trak System was 1.4 on a 5-point Likert scale (1 = Very Easy, 5 = Difficult), and 92% of participants believed they performed the test correctly and received an accurate result. Lastly, men with higher motile sperm count were more likely to report feeling "at ease" or "excited" following testing, while men with low motile sperm count were more likely to report feeling "concerned" or "frustrated." Overall, 91% of men reported they would like to test again.

CONCLUSIONS

The Trak System provides a simple and potentially cost-effective means of measuring important semen parameters and may be useful in population-based epidemiologic fertility studies.

Glycemic load, dietary fiber, and added sugar and fecundability in 2 preconception cohorts

BACKGROUND

Glycemic load (GL) reflects the quantity and quality of carbohydrates in the diet; dietary fiber and added sugar are components of GL. Few epidemiologic studies have assessed the association between these dietary factors and fecundability.

OBJECTIVE

We prospectively evaluated the associations of GL, total carbohydrates, dietary fiber, and added sugar with fecundability.

METHODS

Snart Foraeldre (SF) and Pregnancy Study Online (PRESTO) are parallel web-based prospective preconception cohorts of couples attempting to conceive in Denmark and North America. At baseline, female participants completed a web-based questionnaire on demographic and lifestyle factors and a validated FFQ. We calculated GL, total carbohydrate intake, total dietary fiber, carbohydrate-to-fiber ratio, and added sugar based on reported frequencies for individual foods, standard recipes for mixed foods, and average serving sizes. The analysis included 2709 SF participants and 4268 PRESTO participants. We used proportional probabilities regression models to estimate fecundability ratios (FR) and 95% CIs.

RESULTS

Compared with an average daily GL of ≤100, FRs for an average daily GL of ≥141 were 0.89 (95% CI: 0.73, 1.08) in SF and 0.87 (95% CI: 0.77, 0.98) in PRESTO participants. Compared with consuming ≤16 g/d of dietary fiber, FRs for consuming ≥25 g/d were 0.99 (95% CI: 0.81, 1.22) in SF and 1.06 (95% CI: 0.94, 1.20) in PRESTO. Compared with a carbohydrate-to-fiber ratio of ≤8, FRs for a ratio of ≥13 were 0.86 (95% CI: 0.73, 1.01) in SF and 0.87 (95% CI: 0.78, 0.98) in PRESTO. Compared with ≤27 g/d of added sugar, FRs for ≥72 g/d were 0.87 (95% CI: 0.68, 1.10) in SF and 0.86 (95% CI: 0.75, 0.99) in PRESTO participants.

CONCLUSIONS

Among women attempting to conceive in Denmark and North America, diets high in GL, carbohydrate-to-fiber ratio, and added sugar were associated with modestly reduced fecundability.

Emerging Trends in Research on Food Compounds and Women’s Fertility: A Systematic Review

Pro-healthy behaviours, including the diet, are significant factors in maintaining women’s fertility health. However, to improve the patient’s nutrition management, it is important to seek food-derived bioactive compounds to support fertility treatment. This review analysed recent studies of food compounds related to fertility, using databases including PubMed, Web of Science and Science Direct as well as PRISMA (preferred reporting items for systematic reviews) to ensure complete and transparent reporting of systematic reviews. This review lists foods associated with a higher birth rate, using original papers from the last five years (2015). The analysis included the impact of food compounds such as caffeine, fatty acids, folates and vitamin D, as well as the intake of fish, whole grains, dairy and soya. In addition, dietary patterns and total diet composition supporting women’s fertility were also analysed. The results will encourage further research on the relationship between food components and fertility.

Male alcohol consumption and fecundability

STUDY QUESTION

Does male alcohol consumption affect fecundability?

SUMMARY ANSWER

In data pooled across Danish and North American preconception cohort studies, we found little evidence of an association between male alcohol consumption and reduced fecundability.

WHAT IS KNOWN ALREADY

Experimental and clinical studies have shown that alcohol affects male reproductive physiology, mainly by altering male reproductive hormones and spermatogenesis. However, few epidemiologic studies have examined the association between alcohol consumption and male fertility.

STUDY DESIGN, SIZE, DURATION

Data were collected from two ongoing prospective preconception cohort studies: the Danish 'SnartForaeldre' (SF) study (662 couples) and the North American 'Pregnancy Study Online' (PRESTO) (2017 couples). Participants included in the current analysis were enrolled from August 2011 through June 2019 (SF) and from June 2013 through June 2019 (PRESTO).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Eligible men were aged ≥18 years in SF and ≥21 years in PRESTO, in a stable relationship with a female partner and not using contraception or receiving fertility treatment. In both cohorts, alcohol consumption/serving size was self-reported as number of beers (330 mL/12 oz.), glasses of white or red wine (120 mL/4 oz. each), dessert wine (50 mL/2 oz.) and spirits (20 mL/1.5 oz.). Overall alcohol consumption was categorized as none, 1-5, 6-13 and ≥14 standard servings per week. Total menstrual cycles at risk were calculated using data from female partners' follow-up questionnaires, which were completed every 8 weeks until self-reported pregnancy or 12 menstrual cycles, whichever came first. Analyses were restricted to couples that had been trying to conceive for ≤6 cycles at study entry. Proportional probability regression models were used to compute fecundability ratios (FRs) and 95% confidence interval (CIs). We adjusted for male and female age, female partner's alcohol consumption, intercourse frequency, previous history of fathering a child, race/ethnicity, education, BMI, smoking and consumption of sugar-sweetened beverages and caffeine.

MAIN RESULTS AND THE ROLE OF CHANCE

The cumulative proportion of couples who conceived during 12 cycles of follow-up were 1727 (64.5%). The median (interquartile range) of total male alcohol consumption was 4.5 (2.0-7.8) and 4.1 (1.0-8.6) standard servings per week in the SF and PRESTO cohorts, respectively. In pooled analyses, adjusted FRs for male alcohol consumption of 1-5, 6-13 and ≥14 standard servings per week compared with no alcohol consumption were 1.02 (95% CI: 0.90-1.17), 1.10 (95% CI: 0.96-1.27) and 0.98 (95% CI: 0.81-1.18), respectively. For SF, adjusted FRs of 1-5, 6-13 and ≥14 standard servings per week compared with no alcohol consumption were 0.97 (95% CI: 0.73-1.28), 0.81 (95% CI: 0.60-1.10) and 0.82 (95% CI: 0.51-1.30), respectively. For PRESTO, adjusted FRs of 1-5, 6-13 and ≥14 standard servings per week compared with no alcohol consumption were 1.02 (95% CI: 0.88-1.18), 1.20 (95% CI: 1.03-1.40) and 1.03 (95% CI: 0.84-1.26), respectively.

LIMITATIONS, REASONS FOR CAUTION

Male alcohol consumption was ascertained at baseline only, and we did not distinguish between regular and binge drinking. In addition, we had insufficient numbers to study the effects of specific types of alcoholic beverages. As always, residual confounding by unmeasured factors, such as dietary factors and mental health, cannot be ruled out. Comorbidities thought to play a role in the reproductive setting (i.e. cancer, metabolic syndrome) were not considered in this study; however, the prevalence of cancer and diabetes was low in this age group. Findings for the highest categories of alcohol consumption (6-13 and ≥14 servings/week) were not consistent across the two cohorts.

WIDER IMPLICATIONS OF THE FINDINGS

Despite little evidence of an association between male alcohol consumption and reduced fecundability in the pooled analysis, data from the Danish cohort might indicate a weak association between reduced fecundability and consumption of six or more servings per week.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the National Institutes of Health (R01-HD060680, R01-HD086742, R21-HD050264, R21-HD072326, R03-HD090315), the Novo Nordisk Foundation, Oticon Fonden, Politimester J.P.N. Colind og hustru Asmine Colinds mindelegat and Erna og Peter Houtveds studielegat. PRESTO receives in-kind donations from FertilityFriend.com, Kindara.com, Swiss Precision Diagnostics and Sandstone Diagnostics for the collection of data pertaining to fertility. Dr Wise serves as a consultant on uterine leiomyomata for AbbVie.com. All other authors declare no conflict of interest.

Preconception diet, fertility, and later health in pregnancy

PURPOSE OF REVIEW

Women should enter pregnancy in the best possible health. There is increasing recognition of the importance of nutrition for reproductive health; however, key dietary factors in relation to optimizing fertility are nonexistent. The purpose of this review is to investigate dietary factors, preconception, and the association with fertility and later health in pregnancy.

RECENT FINDINGS

This article summarizes recent literature assessing preconception dietary intake and the association with fertility, time to pregnancy, and also the relationship with polycystic ovary syndrome and gestational diabetes; these conditions associate with each other, and also with infertility. The impact of paternal diet is also reported.

SUMMARY

There is recent interest investigating diet and time to pregnancy, suggesting higher intakes of fruit, minimal intake of fast food and sugar sweetened beverages, and a diet lower in glycemic load, may improve time to pregnancy. There is minimal recent literature on paternal diet and impact on fertility. Present advice to women with polycystic ovary syndrome is in line with international recommendations for lifestyle management to improve reproductive outcomes; and for gestational diabetes, prepregnancy may be an optimal time to improve dietary intakes, particularly through consumption of an overall healthy dietary pattern or a Mediterranean-style dietary pattern.

A narrative review of the effects of sugar-sweetened beverages on human health: A key global health issue

The provision of healthy and safe food is vital for human health, and the addition of unnecessary sugars in foodstuffs is an important global issue, leading to multiple long- and short-term health issues and spiraling costs for individuals and governments alike. The negative effect of excess sugar consumption contributes to adverse health conditions, including obesity, type 2 diabetes, and poor oral health in both high and low resource settings. A key plank of governmental and health promotion bodies' nutritional guidance is to raise public awareness of "hidden" sugars, salt, and fats, such as found in processed foods and sugar-sweetened beverages (SSBs), and guide individuals to reduce their consumption. This rapid narrative review brings together some of the key issues identified in the literature around the consumption of SSBs, including patterns of consumption, the general impact on human health and nutrition, specific effects on oral health and the oral microbiome, and strategies to address over-consumption. The range of long-term adverse effects on health is often misunderstood or unknown by the public. However, some strategies have succeeded in reducing the consumption of SSBs, including public health strategies and interventions and the imposition of taxes or levies, and this article makes recommendations for action.

Caffeine, alcohol, smoking, and reproductive outcomes among couples undergoing assisted reproductive technology treatments

During the past decade, as the use of assisted reproductive technologies (ART) has continued to increase worldwide, research investigating whether modifiable lifestyle factors, such as alcohol, caffeine, and smoking, may affect ART outcomes has grown. Despite the vast literature, there is still uncertainty regarding the effects of some of these exposures on ART outcomes. The objective of this review is to summarize the epidemiologic literature on intakes of caffeine and alcohol, smoking, and reproductive outcomes among women undergoing ART. Of the five epidemiologic studies on caffeine intake and ART outcomes, only one found a significant negative effect of caffeine intake on live birth following ART. There have been six epidemiologic studies exploring whether alcohol intake is associated with fertility outcomes among women undergoing ART. Three studies assessed current alcohol consumption and observed a negative effect on outcomes such as fertilization, embryo quality, and implantation. When alcohol intake in the year before treatment was assessed, no relationships were observed with clinical outcomes following ART. Finally, numerous epidemiologic studies and a handful of meta-analyses have confirmed that female current smokers have worse ART outcomes compared with nonsmokers. Although former smokers tend to have better ART outcomes than current smokers, very few individual studies have investigated the influence of smoking cessation on ART outcomes. Literature on male smoking, drinking, and caffeine habits in relation to ART outcomes is even sparser and inconsistent, making it difficult to draw strong conclusions on that topic. In summary, there is little evidence supporting a detrimental effect of moderate caffeine intake on ART outcomes. Current consumption of alcohol may have a negative effect on ART outcomes, but at present the evidence is limited. Women who currently smoke cigarettes have been consistently found to have poorer ART outcomes, including reduced live birth rates, but a quantification of the benefits of smoking cessation is lacking.

Developmental Origins of Disease: Emerging Prenatal Risk Factors and Future Disease Risk

Purpose of review

Many of the diseases and dysfunctions described in the paradigm of the developmental origins of health and disease have been studied in relation to prenatal nutrition or environmental toxicant exposures. Here, we selectively review the current research on four exposures-two nutritional and two environmental-that have recently emerged as prenatal risk factors for long-term health outcomes.

Recent findings

Recent studies have provided strong evidence that prenatal exposure to (1) excessive intake of sugar-sweetened beverages, (2) unhealthy dietary patterns, (3) perfluoroalkyl substances, and (4) fine particulate matter, may increase risk of adverse health outcomes, such as obesity, cardiometabolic dysfunction, and allergy/asthma.

Summary

Emerging prenatal nutritional factors and environmental toxicants influence offspring long-term health. More work is needed to identify the role of paternal exposures and maternal exposures during the preconception period and to further elucidate causality through intervention studies. The ubiquity of these emerging nutritional and environmental exposures makes this area of inquiry of considerable public health importance.