A Hollow TFG Condensate Spatially Compartmentalizes the Early Secretory Pathway.

In the early secretory pathway, endoplasmic reticulum (ER) and Golgi membranes form a nearly spherical interface. In this ribosome-excluding zone, bidirectional transport of cargo coincides with a spatial segregation of anterograde and retrograde carriers by an unknown mechanism. We show that at physiological conditions, Trk-fused gene (TFG) self-organizes to form a hollow, anisotropic condensate that matches the dimensions of the ER-Golgi interface. Regularly spaced hydrophobic residues in TFG control the condensation mechanism and result in a porous condensate surface. We find that TFG condensates act as a molecular sieve, enabling molecules corresponding to the size of anterograde coats (COPII) to access the condensate interior while restricting retrograde coats (COPI). We propose that a hollow TFG condensate structures the ER-Golgi interface to create a diffusion-limited space for bidirectional transport. We further propose that TFG condensates optimize membrane flux by insulating secretory carriers in their lumen from retrograde carriers outside TFG cages.

Birth by caesarean section and semen quality in adulthood: a Danish population-based cohort study.

BACKGROUND: The caesarean section (CS) rate has increased worldwide and there is an increasing public and scientific interest in the potential long-term health consequences for the offspring. CS is related to persistent aberrant microbiota colonization in the offspring, which may negatively interfere with sex hormone homeostasis and thus potentially affect the reproductive health. It remains unknown whether adult sons' semen quality is affected by CS. We hypothesize that CS is associated with lower semen quality. METHODS: This study was based on the Fetal Programming of Semen Quality cohort (FEPOS, enrolled from 2017 to 2019) nested within the Danish National Birth Cohort (DNBC, enrolled from 1996 to 2002). A total of 5697 adult sons of mothers from the DNBC were invited to the FEPOS cohort, and 1044 young men participated in this study. Information on mode of delivery was extracted from the Danish Medical Birth Registry, and included vaginal delivery, elective CS before labor, emergency CS during labor and unspecified CS. The young men provided a semen sample for analysis of semen volume, sperm concentration, motility and morphology. Negative binomial regression models were applied to examine the association between CS and semen characteristics with estimation of relative differences in percentages with 95% confidence intervals (CIs). RESULTS: Among included sons, 132 (13%) were born by CS. We found a slightly lower non-progressive sperm motility (reflecting higher progressive sperm motility) among sons born by CS compared to sons born by vaginal delivery [relative difference (95% CI): - 7.5% (- 14.1% to - 0.4%)]. No differences were observed for other sperm characteristics. When CS was further classified into elective CS, emergency CS and unspecified CS in a sensitivity analysis, no significant differences in non-progressive motility were observed among sons born by any of the three types of CS compared to sons born vaginally. CONCLUSIONS: This large population-based cohort study found no significant evidence for an adverse effect on semen quality in adult sons born by CS.

Caesarean section is one of the most frequently used interventions during childbirth and global cesarean delivery rates continue to increase. The rising cesarean delivery rate has been reported to be related with series of adverse health outcomes in children, such as asthma, allergies, obesity, diabetes and even poor emotional, behavioral and educational outcomes. Still, it remains unknown whether children's reproductive health is affected by this delivery mode.Based on data from the Fetal Programming of Semen Quality cohort (FEPOS,) nested within the Danish National Birth Cohort, we have therefore analyzed the potential effect of caesarean section on son's semen quality in 1044 young men. We found a slightly higher progressive sperm motility among sons born by caesarean section compared to sons born by vaginal delivery. No differences, however, were observed for semen volume, sperm concentration and morphology between the two delivery modes.The FEPOS cohort is the largest population-based male offspring cohort worldwide. This is the first study aiming to examine the association between caesarean section and semen quality in adulthood. Although the findings need to be confirmed in other studies, it is reassuring that this large population-based cohort study finds no significant evidence for an adverse effect on semen quality in adult sons born by caesarean section.

Exome-informed formulations of food proteins enhance body growth and feed conversion efficiency in ad libitum-fed mice.

Meeting requirements for dietary proteins, especially of essential amino acids (EAAs), is critical for the life-long health of living organisms. However, defining EAA targets for preparing biologically-matched nutrition that satisfies metabolic requirements for protein remains challenging. Previous research has shown the advantages of 'exome matching' in representing the specific requirement of dietary AAs, where the target dietary AA profile was derived from in silico translation of the genome of an organism, specifically responsible for protein expression (the 'exome'). However, past studies have assessed these effects in only one sex, for few parameters (body mass and composition), and have used purified diets in which protein is supplied as a mixture of individual AAs. Here, for the first time, we utilise a computational method to guide the formulation of custom protein blends and test if exome matching can be achieved at the intact protein level, through blending standard protein ingredients, ultimately leading to optimal growth, longevity and reproductive function. Mice were provided ad libitum (ad lib) access to one of the four iso-energetic protein-limited diets, two matched and two mis-matched to the mouse exome target, and fed at a fixed protein energy level of 6.2%. During or following 13-weeks of feeding, the food intake, body growth, composition and reproductive functions were measured. Compared to the two mis-matched diets, male and female animals on the exome-matched diet with protein digestibility correction applied, exhibited significantly improved growth rates and final body mass. The feed conversion efficiency in the same diet was also increased by 62% and 40% over the worst diets for males and females, respectively. Male, not female, exhibited higher accretion of lean body mass with the matched, digestibility-corrected diet. All reproductive function measures in both sexes were comparable among diets, with the exception of testicular daily sperm production in males, which was higher in the two matched diets versus the mis-matched diets. The results collectively demonstrate the pronounced advantages of exome-matching in supporting body growth and improving feed conversion efficiency in both sexes. However, the potential impact of this approach in enhancing fertility needs further investigation.

C. elegans epicuticlins define specific compartments in the apical extracellular matrix and function in wound repair.

The apical extracellular matrix (aECM) of external epithelia often contains lipid-rich outer layers that contribute to permeability barrier function. The external aECM of nematode is known as the cuticle and contains an external lipid-rich layer, the epicuticle. Epicuticlins are a family of tandem repeat proteins originally identified as components of the insoluble fraction of the cuticular aECM and thought to localize in or near epicuticle. However, there has been little in vivo analysis of epicuticlins. Here, we report the localization analysis of the three C. elegans epicuticlins (EPIC proteins) using fluorescent protein knock-ins to visualize endogenously expressed proteins, and further examine their in vivo function using genetic null mutants. By TIRF microscopy, we find that EPIC-1 and EPIC-2 localize to the surface of the cuticle in larval and adult stages in close proximity to the outer lipid layer. EPIC-1 and EPIC-2 also localize to interfacial cuticles and adult-specific cuticle struts. EPIC-3 expression is restricted to the stress-induced dauer stage, where it localizes to interfacial aECM in the buccal cavity. Strikingly, skin wounding in the adult induces epic-3 expression, and EPIC-3::mNG localizes to wound scars. Null mutants lacking one, two, or all three EPIC proteins display reduced survival after skin wounding yet are viable with low penetrance defects in epidermal morphogenesis. Our results suggest EPIC proteins define specific aECM compartments and have roles in wound repair.

Characteristics of Puberty in a Population-Based Sample of Danish Adolescents.

PURPOSE: To describe the duration, timing, tempo, and synchronicity of puberty, as well as the correlation between timing and tempo of puberty. METHODS: Overall, 15,819 of 22,439 invited children participated in the Puberty Cohort within the Danish National Birth Cohort. Participants completed a web-based questionnaire every 6 months through maturation with questions on current pubertal status. Girls reported current Tanner stage of breast and pubic hair development, and timing of menarche. Boys reported current Tanner stage of genital and pubic hair development, timing of first ejaculation, and vocal changes. While accounting for this interval-censored puberty information, we estimated the duration of puberty. Then, we used a nonlinear mixed effect growth model to estimate timing, tempo, synchronicity of puberty, and correlation between timing and tempo of puberty. RESULTS: In girls, the average duration of breast development was longer, whereas the average tempo was slower than pubic hair development. The average timing of breast development was earlier than the average timing of pubic hair development. The majority of girls had asynchronous puberty. In boys, the average duration was longer and average tempo slower for genital than pubic hair development. The average timing of genital and pubic hair development were comparable; hence, the majority had synchronous pubertal development. Adolescents who had earlier timing also tended to have a faster tempo. DISCUSSION: Being one of the largest puberty cohorts worldwide, these unique contemporary data can help physicians, parents, and children to understand and anticipate expected progression through pubertal development.

Long-term outcomes of foreskin reconstruction in distal hypospadias; a cohort study spanning twenty years.

INTRODUCTION: Surgical correction of hypospadias aims to achieve normal functionality and appearance. This entails foreskin reconstruction (FR) in countries where the uncircumcised penis constitutes the norm. Long-term data are however scarce. OBJECTIVE: To investigate the long-term outcome of FR in cohort of patients operated for distal hypospadias combined with approximately 20 years after surgery. METHODS: The hospital management system was searched for patients operated for distal hypospadias in conjunction with FR between 1997 and 2004. Prospective participants were invited to participate in an online questionnaire. Signed consent allowed for extended medical chart review, with regards to hypospadias grade, surgical procedure and complications. RESULTS: Response rate of 44.6 %. For 113 participants, median age at primary surgery was 5.2 (1.0-15.5) years. Two-thirds had a distal meatus while the remaining, meatus was mid to distal shaft. Urethroplasties performed were mainly glanular approximation procedures and meatal based flap procedures in 85 %. Foreskin fistula developed in 15 % of cases. There was no significant relationship between urethroplasty procedure or meatal position and risk of foreskin complications. Three layer closure of foreskin resulted in significantly less complications than two layer closure. Twenty years on 95 % of the men still had an intact foreskin, of whom 16.8 % had received treatment for phimosis. Foreskin was retractable in 92.5 % and 74.7 % in the flaccid and erect states respectively. Ninety intact men had had their sexual debut and in those 23.3 % reported foreskin related issues with intercourse. Evolution of foreskin retractability can be seen in the figure. DISCUSSION: Current results show that three layer FR in conjunction with hypospadias surgery is feasible and that short-term complication rates were comparable with what has previously been published in the literature. Long-term results indicate that FR is durable with regards to anatomical reconstruction however foreskin function especially in relation to sexual function was compromised in about 25 %. Foreskin retractability after surgery predicted retractability in adulthood for the flaccid but not erect penis. Limitations of this study include the retrospective nature of data collection, and that the questionnaire used was not validated. We however achieved a decent response rate and were able to capture important long-term data. CONCLUSIONS: FR has an acceptable complication rate. Long-term results two decades on are remarkably durable with regards to the anatomical preservation of the prepuce, however functionality was compromised with regards to retractability and sexual function in approximately 25 %.

Nanoscale patterning of collagens in C. elegans apical extracellular matrix.

Apical extracellular matrices (aECMs) are complex extracellular compartments that form important interfaces between animals and their environment. In the adult C. elegans cuticle, layers are connected by regularly spaced columnar structures known as struts. Defects in struts result in swelling of the fluid-filled medial cuticle layer ('blistering', Bli). Here we show that three cuticle collagens BLI-1, BLI-2, and BLI-6, play key roles in struts. BLI-1 and BLI-2 are essential for strut formation whereas activating mutations in BLI-6 disrupt strut formation. BLI-1, BLI-2, and BLI-6 precisely colocalize to arrays of puncta in the adult cuticle, corresponding to struts, initially deposited in diffuse stripes adjacent to cuticle furrows. They eventually exhibit tube-like morphology, with the basal ends of BLI-containing struts contact regularly spaced holes in the cuticle. Genetic interaction studies indicate that BLI strut patterning involves interactions with other cuticle components. Our results reveal strut formation as a tractable example of precise aECM patterning at the nanoscale.

Sleep duration and biomarkers of fecundity in young men: a cross-sectional study from a population-based cohort.

BACKGROUND: Poor male fecundity is of concern and warrants the identification of potential modifiable risk factors. Short and long sleep duration might be risk factors for poor male fecundity although evidence in this research field is inconsistent. OBJECTIVES: To investigate the association between sleep duration and biomarkers of male fecundity in young men. MATERIALS AND METHODS: We conducted a cross-sectional study of 1,055 young men from the Fetal Programming of Semen Quality (FEPOS) cohort, Denmark, 2017-2019. Sleep duration was obtained from an online survey answered by the participants prior to the clinical visit, where semen and blood samples were obtained, and testis volume was self-assessed using an Orchidometer. Percentage differences in semen characteristics, testes volume, and reproductive hormone levels were analysed according to sleep duration using multivariable negative binomial regression models. Sleep duration was dichotomised (recommended (6-9 h/night) versus deviant sleep) and visualised continuously as restricted cubic spline plots. RESULTS: Deviation from recommended sleep duration was associated with higher high DNA stainability (HDS) of 5% (95% CI: -1%; 13%), higher testosterone of 3% (95% CI: 0%; 7%) and higher free androgen index (FAI) of 6% (95% CI: 0%; 13%). The spline plots overall supported these results, suggesting u-shaped associations between sleep duration and HDS, testosterone and FAI, a linear association between sleep duration and semen volume and sex hormone binding globulin (SHBG) and an inverse u-shaped association with normal morphology. DISCUSSION: Information on sleep duration was obtained by self-report in broad categories with at least 3 h intervals. We were not able to investigate short or long sleep duration separately, since only few participants reported this. CONCLUSION: Sleep duration was associated with some biomarkers of fecundity in young men. Maintaining a recommended sleep duration may thus be beneficial for young men with regard to reproductive health.

Prenatal exposure to nitrosatable drugs and timing of puberty in sons and daughters: A nationwide cohort study.

BACKGROUND: N-nitroso compounds (NOCs) can be formed by endogenous reactions between nitrosatable drugs and nitrite. Animal studies have found that several NOCs are teratogenic, and epidemiological studies report associations between prenatal exposure to nitrosatable drugs and adverse birth outcomes. It is unknown whether prenatal exposure to nitrosatable drugs is harmful to the child's reproductive health, including pubertal development. OBJECTIVES: We investigated whether prenatal exposure to nitrosatable drugs was associated with timing of puberty and whether nitrate, nitrite and antioxidant intake modified any association. METHODS: The population-based Danish National Birth Cohort (DNBC) Puberty Cohort, which includes 15,819 children, was used to investigate the association between prenatal exposure to nitrosatable drugs and timing of puberty. Around gestational week 11 and gestational week 18, mothers provided information about drug use during pregnancy. The children's self-reported information on onset of pubertal milestones was collected every six months from 11 years of age and throughout puberty. To investigate potential effect modification by nitrite, nitrate and antioxidant intake, information on these factors was obtained from a food frequency questionnaire completed by the mothers in gestational week 25, and information on nitrate concentration in maternal drinking water at her residential address was obtained from monitoring data from public waterworks. Data were analysed using a multivariable regression model for interval-censored data estimating difference in months in timing of puberty between exposure groups. RESULTS: A total of 2,715 children were prenatally exposed to nitrosatable drugs. We did not find an association between prenatal exposure to nitrosatable drugs and timing of puberty. This finding was supported by null-findings in the following sub-analyses investigating: 1. subtypes of nitrosatable drugs (secondary and tertiary amines and amides), 2. dose-dependency (duration of drug intake), 3. effect modification by maternal intake of nitrate, nitrite, and antioxidants. 4. confounding by indication. CONCLUSIONS: Prenatal exposure to nitrosatable drugs was not associated with timing of puberty. Nitrosatable drugs are commonly used drugs in pregnancy, and further research is needed to allow firm conclusions on the potential effect of prenatal exposure to nitrosatable drugs on the child's reproductive health.

Parental age at birth and biomarkers of fecundity in young Danish men.

BACKGROUND: High parental age is associated with adverse birth and genetic outcomes, but little is known about fecundity in male offspring. OBJECTIVES: We investigated if high parental age at birth was associated with biomarkers of male fecundity in a large population-based sample of young men. MATERIALS AND METHODS: We conducted a study of 1057 men from the Fetal Programming of Semen Quality (FEPOS) cohort, a sub-cohort of sons born 1998-2000 into the Danish National Birth Cohort. Semen characteristics and reproductive hormone concentrations were measured in samples provided by the men 2017-2019. Testis volume was determined by self-measurement. Data on the parental age was drawn from registers. Adjusted relative difference in percentage with 95% confidence intervals were estimated for each outcome according to pre-specified maternal and paternal age groups (< 30 (reference), 30-34 and ≥ 35) as well as for combinations of parental age groups, using multivariable negative binomial regression models. RESULTS: We did not observe consistent associations between parental age and biomarkers of fecundity, although sons of mothers ≥ 35 years had lower sperm concentration (-15% (95% CI: -30, 3)) and total sperm count (-10% (95% CI: -25, 9)). The analysis with parental age combinations showed lower sperm concentration with high age of the parents (both ≥ 35 years: -27%, 95% CI: -40, -19) when compared to the reference where both parents were below 30 years. DISCUSSION AND CONCLUSION: We found no strong association between higher parental age and biomarkers of fecundity in young men. However, we cannot exclude poorer semen characteristics in sons born by older mothers or with high age of both parents.

Maternal Intake of Vitamin D Supplements during Pregnancy and Pubertal Timing in Children: A Population-Based Follow-Up Study.

Maternal vitamin D may be important for several organ systems in the offspring, including the reproductive system. In this population-based follow-up study of 12,991 Danish boys and girls born 2000-2003, we investigated if maternal intake of vitamin D supplements during pregnancy was associated with pubertal timing in boys and girls. Information on maternal intake of vitamin D supplements was obtained by self-report in mid-pregnancy. Self-reported information on the current status of various pubertal milestones was obtained every six months throughout puberty. Mean differences in months at attaining each pubertal milestone and an average estimate for the mean difference in attaining all pubertal milestones were estimated according to maternal intake of vitamin D supplements using multivariable interval-censored regression models. Lower maternal intake of vitamin D supplements was associated with later pubertal timing in boys. For the average estimate, boys had 0.5 months (95% CI 0.1; 0.9) later pubertal timing per 5 µg/day lower maternal vitamin D supplement intake. Maternal intake of vitamin D supplements was not associated with pubertal timing in girls. Spline plots and sensitivity analyses supported the findings. Whether the observed association with boys' pubertal timing translates into an increased risk of disease in adulthood is unknown.

Roles for diacylglycerol in synaptic vesicle priming and release revealed by complete reconstitution of core protein machinery.

Here, we introduce the full functional reconstitution of genetically validated core protein machinery (SNAREs, Munc13, Munc18, Synaptotagmin, and Complexin) for synaptic vesicle priming and release in a geometry that enables detailed characterization of the fate of docked vesicles both before and after release is triggered with Ca2+. Using this setup, we identify new roles for diacylglycerol (DAG) in regulating vesicle priming and Ca2+-triggered release involving the SNARE assembly chaperone Munc13. We find that low concentrations of DAG profoundly accelerate the rate of Ca2+-dependent release, and high concentrations reduce clamping and permit extensive spontaneous release. As expected, DAG also increases the number of docked, release-ready vesicles. Dynamic single-molecule imaging of Complexin binding to release-ready vesicles directly establishes that DAG accelerates the rate of SNAREpin assembly mediated by chaperones, Munc13 and Munc18. The selective effects of physiologically validated mutations confirmed that the Munc18-Syntaxin-VAMP2 "template" complex is a functional intermediate in the production of primed, release-ready vesicles, which requires the coordinated action of Munc13 and Munc18.

Novel Roles for Diacylglycerol in Synaptic Vesicle Priming and Release Revealed by Complete Reconstitution of Core Protein Machinery.

Here we introduce the full functional reconstitution of genetically-validated core protein machinery (SNAREs, Munc13, Munc18, Synaptotagmin, Complexin) for synaptic vesicle priming and release in a geometry that enables detailed characterization of the fate of docked vesicles both before and after release is triggered with Ca 2+ . Using this novel setup, we discover new roles for diacylglycerol (DAG) in regulating vesicle priming and Ca 2+- triggered release involving the SNARE assembly chaperone Munc13. We find that low concentrations of DAG profoundly accelerate the rate of Ca 2+ -dependent release, and high concentrations reduce clamping and permit extensive spontaneous release. As expected, DAG also increases the number of ready-release vesicles. Dynamic single-molecule imaging of Complexin binding to ready-release vesicles directly establishes that DAG accelerates the rate of SNAREpin assembly mediated by Munc13 and Munc18 chaperones. The selective effects of physiologically validated mutations confirmed that the Munc18-Syntaxin-VAMP2 'template' complex is a functional intermediate in the production of primed, ready-release vesicles, which requires the coordinated action of Munc13 and Munc18. SIGNIFICANCE STATEMENT: Munc13 and Munc18 are SNARE-associated chaperones that act as "priming" factors, facilitating the formation of a pool of docked, release-ready vesicles and regulating Ca 2+ -evoked neurotransmitter release. Although important insights into Munc18/Munc13 function have been gained, how they assemble and operate together remains enigmatic. To address this, we developed a novel biochemically-defined fusion assay which enabled us to investigate the cooperative action of Munc13 and Munc18 in molecular terms. We find that Munc18 nucleates the SNARE complex, while Munc13 promotes and accelerates the SNARE assembly in a DAG-dependent manner. The concerted action of Munc13 and Munc18 stages the SNARE assembly process to ensure efficient 'clamping' and formation of stably docked vesicles, which can be triggered to fuse rapidly (∼10 msec) upon Ca 2+ influx.

Maternal intake of folate and folic acid during pregnancy and pubertal timing in girls and boys: A population-based cohort study.

BACKGROUND: Folate is essential for normal foetal development as it plays an important role for gene expression during different periods of foetal development. Thus, prenatal exposure to folate may have a programming effect on pubertal timing. OBJECTIVES: To study the association between maternal intake of folate during pregnancy and pubertal timing in girls and boys. METHODS: We studied 6585 girls and 6326 boys from a Danish population-based Puberty Cohort, 2000-2021. Information on maternal intake of folate from diet and folic acid from supplements was obtained from a food-frequency questionnaire in mid-pregnancy, and total folate was calculated as dietary folate equivalents. Information on age at menarche in girls, age at first ejaculation and voice break in boys, and Tanner stages, acne and axillary hair in both girls and boys was obtained every 6 months throughout puberty. We estimated mean monthly differences according to exposure groups for each pubertal milestone in addition to a combined estimate for the average age at attaining all pubertal milestones using multivariable interval-censored regression models. Total folate was analysed in quintiles, continuous and as restricted cubic splines. RESULTS: Maternal intake of total folate in mid-pregnancy was not associated with pubertal timing in girls (combined estimate for overall pubertal timing per standard deviation (SD 325 µg/day) decrease in maternal intake of total folate: -0.14 months (95% confidence interval [CI] -0.51, 0.22)). Boys had slightly later overall pubertal timing per standard deviation (SD 325 µg/day) decrease in maternal intake of total folate (combined estimate: 0.40 months, 95% CI 0.01, 0.72). Spline plots supported these findings. CONCLUSIONS: Prenatal exposure to low maternal intake of total folate in mid-pregnancy was not associated with pubertal timing in girls but associated with slightly later pubertal timing in boys. This minor delay is likely not of clinical importance.

The estimated effect of season and vitamin D in the first trimester on pubertal timing in girls and boys: a cohort study and an instrumental variable analysis.

BACKGROUND: Season of birth has been associated with age at menarche. Maternal vitamin D levels in pregnancy may explain this effect. We investigated whether the season of first trimester or maternal 25-hydroxyvitamin D3 [25(OH)D3] levels were associated with pubertal timing in children. METHODS: We conducted a follow-up study of 15 819 children born in 2000-03 from the Puberty Cohort, nested in the Danish National Birth Cohort (DNBC). Mean differences in attaining numerous pubertal markers, including a combined estimate for the average age at attaining all pubertal markers, were estimated for low (November-April) relative to high (May-October) sunshine exposure season in the first trimester using multivariable interval-censored regression models. Moreover, we conducted a two-sample instrumental variable analysis using season as an instrument for maternal first-trimester 25(OH)D3 plasma levels obtained from a non-overlapping subset (n = 827) in the DNBC. RESULTS: For the combined estimate, girls and boys of mothers who had their first trimester during November-April had earlier pubertal timing than girls and boys of mothers whose first trimester occurred during May-October: -1.0 months (95% CI: -1.7 to -0.3) and -0.7 months (95% CI: -1.4 to -0.1), respectively. In the instrumental variable analysis, girls and boys also had earlier pubertal timing: respectively, -1.3 months (95% CI: -2.1 to -0.4) and -1.0 months (95% CI: -1.8 to -0.2) per SD (22 nmol/L) decrease in 25(OH)D3. CONCLUSIONS: Both first pregnancy trimester during November-April and lower 25(OH)D3 were associated with earlier pubertal timing in girls and boys.

Timing of puberty in relation to semen characteristics, testicular volume, and reproductive hormones: a cohort study.

OBJECTIVE: To investigate whether the timing of puberty is associated with semen characteristics, testicular volume, and reproductive hormone levels. DESIGN: Cohort study. SETTING: Not applicable. PATIENTS: The Danish National Birth Cohort and its subcohort, the Fetal Programming of Semen Quality cohort of 1,058 young men. INTERVENTION(S): Self-reported information on the timing (younger, same age, older than peers) of the pubertal markers: voice break (primary exposure), pubic hair growth, regular shaving, and axillary hair growth. MAIN OUTCOME MEASURES(S): We estimated the relative differences with 95% confidence intervals for semen characteristics (semen volume, sperm concentration, total sperm count, sperm motility, percentage of morphologically normal spermatozoa), testicular volume, and reproductive hormones (follicle stimulating hormone [FSH], luteinizing hormone, sex hormone-binding globulin [SHBG], testosterone, estradiol, and free androgen index [FAI]) obtained at a median age of 19.2 years according to timing of pubertal development. RESULT(S): Compared with men reporting voice break "same age as peers," men reporting voice break "older than peers" tended to have lower total sperm count (-12% [-25%, 4%]) and lower percent morphologically normal spermatozoa (-10% [-20%, 2%]), whereas men reporting voice break "younger than peers" tended to have a lower proportion of nonprogressive and immotile spermatozoa (-6% [-13%, 1%]) and larger testicular volume (7% [1%, 13%]). The pattern was less consistent for the other pubertal markers. For reproductive hormones, voice break "older than peers" tended to have higher FSH levels (24% [-1%, 55%]), higher SHBG levels (7% [0, 15%]), lower estradiol levels (-14% [-23%, -5%]), and lower FAI (-8% [-14%, -1%]), whereas voice break "younger than peers" tended to have higher luteinizing hormone levels (4% [-2%, 11%]), higher testosterone levels (5% [0%, 11%]), higher estradiol levels (17% [6%, 29%]), and higher FAI (4% [-2%, 11%]). When the categorical pubertal markers were analyzed as a linear term to assess dose dependence, older age at pubertal development was associated with higher FSH levels, higher SHBG levels, lower testosterone levels, lower estradiol levels, and lower FAI for most pubertal markers. CONCLUSION(S): These results lend weak support to the hypothesis that older age at pubertal development is associated with markers of reduced male fecundity, especially reproductive hormone levels, although associations with semen characteristics and testicular volume were statistically insignificant.

Maternal alcohol intake in early pregnancy and biomarkers of fecundity in adult sons: A cohort study.

Male fecundity may be largely determined through fetal programming and therefore potentially be sensitive to exposure to maternal alcohol intake during pregnancy. We investigated whether maternal alcohol intake in early pregnancy was associated with biomarkers of fecundity in adult sons. In total, 1058 sons from the Fetal Programming of Semen Quality (FEPOS) cohort nested in the Danish National Birth Cohort (DNBC) provided blood and semen samples at around 19 years of age. Information on maternal weekly average alcohol intake (0 drinks [ref], >0-1 drinks, >1-3 drinks, >3 drinks) and binge drinking episodes (intake of ≥5 drinks on one occasion: (0 [ref], 1-2, ≥3 episodes)) was self-reported at around gestational week 17. Outcomes included semen characteristics, testes volume and reproductive hormones. We found some small tendencies towards lower semen characteristics and an altered hormone level profile in sons of mother who had an intake of > 3 drinks/week in early pregnancy and sons of mother who had ≥ 3 episodes of binge drinking in pregnancy. However, the effect estimates were overall small and inconsistent and with no indication of a dose dependent association. Due to the limited number of mothers with a high weekly alcohol intake, we cannot exclude whether prenatal exposure to higher doses than 4.5 drinks/week of alcohol in early pregnancy might have a detrimental effect on the biomarkers of fecundity in adult sons..