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Maternal vitamin D levels during pregnancy may be important for reproductive health in male offspring by regulating cell proliferation and differentiation during development. We conducted a follow-up study of 827 young men from the Fetal Programming of Semen Quality (FEPOS) cohort, nested in the Danish National Birth Cohort to investigate if maternal vitamin D levels were associated with measures of reproductive health in adult sons. These included semen characteristics, testes volume, and reproductive hormone levels and were analysed according to maternal vitamin D (25(OH)D3) levels during pregnancy. In addition, an instrumental variable analysis using seasonality in sun exposure as an instrument for maternal vitamin D levels was conducted. We found that sons of mothers with vitamin D levels  75 nmol/L. Continuous models, spline plots and an instrumental variable analysis supported these findings. Low maternal vitamin D levels were associated with lower testes volume and lower total sperm count with indications of dose-dependency. Maternal vitamin D level above 75 nmol/L during pregnancy may be beneficial for testes function in adult sons.

IntroductionTo date, the evidence for an association between perfluoroalkyl substances (PFAS) exposure and attention deficit and hyperactivity disorder (ADHD) is inconclusive.ObjectiveWe investigated the association between early life exposure to perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), and ADHD in a collaborative study including nine European population-based studies, encompassing 4,826 mother-child pairs.MethodsConcentrations of PFOS and PFOA were measured in maternal serum/plasma during pregnancy, or in breast milk, with different timing of sample collection in each cohort. We used a validated pharmacokinetic model of pregnancy and lactation to estimate concentrations of PFOS and PFOA in children at birth and at 3, 6, 12, and 24 months of age. We classified ADHD using recommended cutoff points for each instrument used to derive symptoms scores. We used multiple imputation for missing covariates, logistic regression to model the association between PFAS exposure and ADHD in each study, and combined all adjusted study-specific effect estimates using random-effects meta-analysis.ResultsA total of 399 children were classified as having ADHD, with a prevalence ranging from 2.3% to 7.3% in the studies. Early life exposure to PFOS or PFOA was not associated with ADHD during childhood [odds ratios (ORs) ranging from 0.96 (95% CI: 0.87, 1.06) to 1.02 (95% CI: 0.93, 1.11)]. Results from stratified models suggest potential differential effects of PFAS related to child sex and maternal education.ConclusionWe did not identify an increased prevalence of ADHD in association with early life exposure to PFOS and PFOA. However, stratified analyses suggest that there may be an increased prevalence of ADHD in association with PFAS exposure in girls, in children from nulliparous women, and in children from low-educated mothers, all of which warrant further exploration. https://doi.org/10.1289/EHP5444.

Background: Poor male fecundity is of concern, and a prenatal origin has been proposed. Folate, a methyl donor involved in DNA methylation, is essential for normal fetal development by regulating gene expression during different periods of fetal development. Thus, prenatal exposure to low maternal folate intake might have a programing function of the developing reproductive organs. Objectives: To examine the association between maternal intake of folate from diet and folic acid from supplements during pregnancy and markers of fecundity in young men. Materials and methods: We conducted a follow‐up study using a Danish mother–son cohort of 787 young men born 1998–2000. Percentage differences in semen characteristics, testes volume, and reproductive hormone levels were analyzed according to total folate calculated as dietary folate equivalents from diet and supplements in midpregnancy, using multivariable negative binomial regression models. Total folate was analyzed in quintiles, continuous per standard deviation decrease (SD: 318 μg/day) and as restricted cubic splines. Results: Low maternal intake of total folate was associated with lower total sperm count (−5% (95% confidence intervals [CI]: −11%; 2%)), a lower proportion of non‐progressive and immotile spermatozoa (−5% [95% CI: −8%; −3%]), and lower testes volume (−4% [95% CI: −6%; −2%]) per SD decrease in total folate intake. Spline plots supported these findings. Discussion: The finding of a lower proportion of non‐progressive and immotile spermatozoa, and hence a higher proportion of motile spermatozoa, in men of mothers with a lower intake of total folate in midpregnancy was surprising and may be a chance finding. Conclusion: Lower maternal intake of total folate in midpregnancy was associated with lower sperm count and lower testes volume, however, also with a lower proportion of non‐progressive and immotile spermatozoa in adult men. Whether this actually affects the ability to obtain a pregnancy warrants further investigation. [ABSTRACT FROM AUTHOR]

Background: Prenatal exposures may contribute to male infertility in adult life, but large-scale epidemiological evidence is still lacking. The Fetal Programming of Semen quality (FEPOS) cohort was founded to provide means to examine if fetal exposures can interfere with fetal reproductive development and ultimately lead to reduced semen quality and reproductive hormone imbalances in young adult men. Methods: Young adult men at least 18 years and 9 months of age born to women in the Danish National Birth Cohort living in relative proximity to Copenhagen or Aarhus and for whom a maternal blood sample and two maternal interviews during pregnancy were available were invited to FEPOS. Recruitment began in March 2017 and ended in December 2019. The participants answered a comprehensive questionnaire and underwent a physical examination where they delivered a semen, urine, and hair sample, measured their own testicular volume, and had blood drawn. Results: In total 21,623 sons fulfilled eligibility criteria of whom 5697 were invited and 1058 participated making the response rate 19%. Semen characteristics did not differ between sons from the Copenhagen and Aarhus clinics. When comparing the FEPOS semen parameters to similar cohorts, the median across all semen characteristics was slightly lower for FEPOS participants, although with smaller variation. Conclusion: With its 1058 young adult men, the FEPOS cohort is the largest population-based male-offspring cohort worldwide specifically designed to investigate prenatal determinants of semen quality. Wide-ranging information on maternal health, lifestyle, socioeconomic status, occupation, and serum concentrations of potential reproductive toxicants during pregnancy combined with biological markers of fertility in their sons collected after puberty allow for in-depth investigations of the 'fetal origins of adult disease hypothesis'. [ABSTRACT FROM AUTHOR]

BACKGROUND: Studies have reported some evidence of adverse effects of organochlorine exposures on child development, but the results have been inconsistent, and few studies have evaluated associations with child behavior. OBJECTIVE: We investigated the association between prenatal and early-life exposures to 2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153) and 1,1- dichloro-2,2-bis(p-chlorophenyl)-ethylene (p,p'-DDE) and behaviors in children between 5 and 9 y of age. METHODS: In the Biopersistent organochlorines in diet and human fertility: Epidemiologic studies of time to pregnancy and semen quality in Inuit and European populations (INUENDO) cohort, consisting of mother-child pairs from Greenland and Ukraine (n = 1,018), maternal serum PCB-153 and p,p'-DDE concentrations were measured during pregnancy, and cumulative postnatal exposures during the first 12 months after delivery were estimated using a pharmacokinetic model. Parents completed the Strengths and Difficulties Questionnaire (SDQ), and children's behaviors were dichotomized as abnormal (high) versus normal/borderline for five SDQ subscales and the total difficulties score. RESULTS: The total difficulties score, an overall measure of abnormal behavior, was not clearly associated with pre- or postnatal exposures to PCB-153 or to p,p'-DDE. However, pooled adjusted odds ratios (ORs) for high conduct problem scores with a doubling of exposure were 1.19 (95% CI: 0.99, 1.42) and 1.16 (95% CI: 0.96, 1.41) for pre- and postnatal PCB-153, respectively, and 1.25 (95% CI: 1.04, 1.51) and 1.24 (95% CI: 1.01, 1.51) for pre- and postnatal p,p'-DDE, respectively. Corresponding ORs for high hyperactivity scores were 1.24 (95% CI: 0.94, 1.62) and 1.08 (95% CI: 0.81, 1.45) for pre- and postnatal PCB-153, respectively, and 1.43 (95% CI: 1.06, 1.92) and 1.27 (95% CI: 0.93, 1.73) for pre- and postnatalp,p'-DDE, respectively. CONCLUSION: Prenatal and early postnatal exposures to p,p'-DDE and PCB-153 were associated with a higher prevalence of abnormal scores for conduct and hyperactivity at 5-9 y of age in our study population. These findings provide further support for the importance of minimizing organochlorine exposures to young children and to women of childbearing age. [ABSTRACT FROM AUTHOR]

BACKGROUND: More than 20 years ago, it was hypothesized that exposure to prenatal and early postnatal environmental xenobiotics with the potential to disrupt endogenous hormone signaling might be on the causal path to cryptorchidism, hypospadias, low sperm count and testicular cancer. Several consensus statements and narrative reviews in recent years have divided the scientific community and have elicited a call for systematic transparent reviews. We aimed to fill this gap in knowledge in the field of male reproductive disorders. OBJECTIVE AND RATIONALE: The aim of this study was to systematically synthesize published data on the risk of cryptorchidism, hypospadias, low sperm counts and testicular cancer following in utero or infant exposure to chemicals that have been included on the European Commission's list of Category 1 endocrine disrupting chemicals defined as having documented adverse effects due to endocrine disruption in at least one intact organism. SEARCH METHODS: A systematic literature search for original peer reviewed papers was performed in the databases PubMed and Embase to identify epidemiological studies reporting associations between the outcomes of interest and exposures documented by biochemical analyses of biospecimens including maternal blood or urine, placenta or fat tissue as well as amnion fluid, cord blood or breast milk; this was followed by meta-analysis of quantitative data. OUTCOMES: The literature search resulted in 1314 references among which we identified 33 papers(28 study populations) fulfilling the eligibility criteria. These provided 85 risk estimates of links between persistent organic pollutants and rapidly metabolized compounds (phthalates and Bisphenol A) and male reproductive disorders. The overall odds ratio (OR) across all exposures and outcomes was 1.11 (95% CI 0.91-1.35). When assessing four specific chemical subgroups with sufficient data for meta-analysis for all outcomes, we found that exposure to one of the four compounds, p,p'-DDE, was related to an elevated risk: OR 1.35 (95% CI 1.04-1.74). The data did not indicate that this increased risk was driven by any specific disorder. WIDER IMPLICATIONS: The current epidemiological evidence is compatible with a small increased risk of male reproductive disorders following prenatal and postnatal exposure to some persistent environmental chemicals classified as endocrine disruptors but the evidence is limited. Future epidemiological studies may change the weight of the evidence in either direction. No evidence of distortion due to publication bias was found, but exposure-response relationships are not evident. There are insufficient data on rapidly metabolized endocrine disruptors and on specific exposure-outcome relations. A particular data gap is evident with respect to delayed effects on semen quality and testicular cancer. Although high quality epidemiological studies are still sparse, future systematic and transparent reviews may provide pieces of evidence contributing to the narrative and weight of the evidence assessments in the field. [ABSTRACT FROM AUTHOR]

Background and Objectives: Survivors of spontaneous intracerebral hemorrhage (ICH) may have indications for statin therapy. The effect of statins on the risk of subsequent hemorrhagic and ischemic stroke (IS) in this setting is uncertain. We sought to determine the risk of any stroke (ischemic stroke, IS or recurrent ICH), IS, and recurrent ICH associated with statin use among ICH survivors., Methods: Using the Danish Stroke Registry, we identified all patients admitted to a hospital in Denmark (population 5.8 million) with a first-ever ICH between January 2003 and December 2021 who were aged 50 years or older and survived >30 days. Patients were followed up until August 2022. Within this cohort, we conducted 3 nested case-control analyses for any stroke, IS, and recurrent ICH. We matched controls for age, sex, time since first-ever ICH, and history of prior IS. The primary exposure was statin use before or on the date of subsequent stroke or the equivalent date in matched controls. Using conditional logistic regression, we calculated adjusted odds ratios (aORs) and corresponding 95% confidence intervals (CIs) for any stroke, IS, and recurrent ICH associated with statin exposure., Results: We identified 1,959 patients with any stroke (women 45.3%; mean [SD] age, 72.6 [9.7] years) who were matched to 7,400 controls; 1,073 patients with IS (women 42.0%; mean [SD] age, 72.4 [10.0] years) who were matched to 4,035 controls and 984 patients with recurrent ICH (women 48.7%; mean [SD] age, 72.7 [9.2] years) who were matched to 3,755 controls. Statin exposure was associated with a lower risk of both any stroke (cases 38.6%, controls 41.1%; aOR 0.88; 95% CI 0.78-0.99) and IS (cases 39.8%, controls 41.8%, aOR 0.79; 95% CI 0.67-0.92), but was not associated with recurrent ICH risk (cases 39.1%, controls 40.8%, aOR 1.05; 95% CI 0.88-1.24)., Discussion: Exposure to statins was not associated with an increased risk of recurrent ICH but was associated with a lower risk of any stroke, largely due to a lower risk of IS. Confirmation of these findings in randomized trials is needed., Classification of Evidence: This study provides Class III evidence that statin use in patients with ICH is associated with a lower risk of any stroke and IS and not with increased risk of recurrent ICH., (© 2023 American Academy of Neurology.)

Background: The negative impact of maternal smoking during pregnancy on offspring semen quality is well established. Less is known about the impact of paternal smoking., Methods: We estimated differences in semen parameters and testicle size according to paternal smoking in 772 adult sons of women enrolled in the Danish National Birth Cohort when pregnant. Parents' smoking was reported around gestational week 16, and analyses were adjusted for parents' ages at conception, maternal pre-pregnancy body mass index, maternal alcohol and caffeine intake, family occupational status, ejaculatory abstinence time, clinic of semen analysis, and season., Results: Sons of smoking fathers and non-smoking mothers had a 10% (95% confidence interval: -24%, 7%) lower semen concentration and 11% (95% confidence interval: -27%, 8%) lower sperm count than sons of non-smoking parents. Having two smoking parents was associated with 19% reduction in sperm count (95% confidence interval: -37%, 3%). Paternal smoking was not associated with volume, motility, or morphology. Adjusting for maternal smoking, paternal smoking was associated with a 26% increased risk of small testicular volume (95% confidence interval: 0.89, 1.78)., Discussion: Exclusion of sons with a history of testicular cancer, chemotherapy, orchiectomy, and with only one or no testicles may have caused us to underestimate associations if these men's reproductive health including semen quality are in fact more sensitive to paternal smoking., Conclusion: The study provides limited support for slightly lower sperm concentration and total sperm concentration in sons of smoking fathers, but findings are also compatible with no association., (© 2020 American Society of Andrology and European Academy of Andrology.)