Paternal metabolic and cardiovascular risk factors for fetal growth restriction: a case-control study

Relationship between paternal excessive weight and neonatal anthropometry in a clinical trial of nutritional counseling for pregnant women with overweight

BACKGROUND/OBJECTIVES

Human studies suggest that fathers with obesity influence infant growth and development. This study aimed to evaluate the relationship between paternal body mass index (BMI) and waist circumference (WC) with neonatal anthropometry and adiposity.

METHODS

This study is a cohort nested in a randomized controlled clinical trial of nutritional counseling for pregnant women with overweight. In total, 89 partner-pregnant woman-neonate triads were included. Paternal anthropometric measurements were taken at the time of the interview. Secondary data related to birth were obtained through access to the health information systems. Neonatal skinfold thickness was assessed and the adiposity was estimated using a predictive anthropometric model. Pearson's correlation and adjusted multivariate linear regression models were employed to evaluate the relationship between paternal BMI and WC with neonatal anthropometric measurements and adiposity.

RESULTS

In total, 57.0% of the fathers presented a BMI ≥ 25 kg/m² and 14.6% a waist circumference ≥102 cm. The mean ± SD birth weight of the newborns (g) was 3357 ± 538. Paternal BMI and WC were inversely correlated with head circumference at birth [r = -0.31 (p = 0.004), r = -0.23 (p = 0.03), respectively]. Paternal BMI was also inversely correlated with the birth weight standardized by gestational age (z-score) [r = -0.23 (p = 0.03)]. In adjusted multivariate linear regression models, the paternal BMI (kg/m²) was inversely associated with the head circumference at birth (cm) [β = -0.07 (95% CI -0.15; -0.001) p = 0.04].

CONCLUSION

The data suggest that paternal excessive weight have a negative effect on fetal development, as assessed by anthropometric measurements. The inverse association between paternal BMI and the head circumference at birth was independent of confounders. Future studies with larger sample sizes are necessary to confirm or refute such hypotheses.

Maternal Ezh1/2 deficiency impairs the function of mitochondria in mouse oocytes and early embryos

Maternal histone methyltransferase is critical for epigenetic regulation and development of mammalian embryos by regulating histone and DNA modifications. Here, we reported a novel mechanism by revealing the critical effects of maternal Ezh1/2 deletion on mitochondria in MII oocytes and early embryos in mice. We found that Ezh1/2 knockout in mouse MII oocytes impaired the structure of mitochondria and decreased its number, but membrane potential and respiratory function of mitochondrion were increased. The similar effects of Ezh1/2 deletion have been observed in 2-cell and morula embryos, indicating that the effects of maternal Ezh1/2 deficiency on mitochondrion extend to early embryos. However, the loss of maternal Ezh1/2 resulted in a severe defect of morula: the number, membrane potential, respiratory function, and ATP production of mitochondrion dropped significantly. Content of reactive oxygen species was raised in both MII oocytes and early embryos, suggesting maternal Ezh1/2 knockout induced oxidative stress. In addition, maternal Ezh1/2 ablation interfered the autophagy in morula and blastocyst embryos. Finally, maternal Ezh1/2 deletion led to cell apoptosis in blastocyst embryos in mice. By analyzing the gene expression profile, we revealed that maternal Ezh1/2 knockout affected the expression of mitochondrial related genes in MII oocytes and early embryos. The chromatin immunoprecipitation-polymerase chain reaction assay demonstrated that Ezh1/2 directly regulated the expression of genes Fxyd6, Adpgk, Aurkb, Zfp521, Ehd3, Sgms2, Pygl, Slc1a1, and Chst12 by H3K27me3 modification. In conclusion, our study revealed the critical effect of maternal Ezh1/2 on the structure and function of mitochondria in oocytes and early embryos, and suggested a novel mechanism underlying maternal epigenetic regulation on early embryonic development through the modulation of mitochondrial status.

Unlocking the Path to Healthier Families: The Untapped Potential of Men's Preconception Health

This debate paper explores the necessity of introducing a comprehensive primary care model for men's preconception health. It highlights the importance of a holistic approach that includes risk assessment, health promotion, and clinical and psychological interventions. Despite the current limited focus on male preconception health in primary care, there is evidence suggesting a growing awareness among men about the importance of optimizing their health before conception. The paper stresses the importance of such a model in addressing various aspects of men's well-being, family dynamics, and overall reproductive health outcomes. It also acknowledges potential limitations and considerations related to implementing this crucial healthcare approach.

The influence of insulin-related genetic variants on fetal growth, fetal blood flow, and placental weight in a prospective pregnancy cohort

The fetal insulin hypothesis proposes that low birthweight and type 2 diabetes (T2D) in adulthood may be two phenotypes of the same genotype. In this study we aimed to explore this theory further by testing the effects of GWAS-identified genetic variants related to insulin release and sensitivity on fetal growth and blood flow from week 20 of gestation to birth and on placental weight at birth. We calculated genetic risk scores (GRS) of first phase insulin release (FPIR), fasting insulin (FI), combined insulin resistance and dyslipidaemia (IR + DLD) and insulin sensitivity (IS) in a study population of 665 genotyped newborns. Two-dimensional ultrasound measurements with estimation of fetal weight and blood flow were carried out at week 20, 25, and 32 of gestation in all 665 pregnancies. Birthweight and placental weight were registered at birth. Associations between the GRSs and fetal growth, blood flow and placental weight were investigated using linear mixed models. The FPIR GRS was directly associated with fetal growth from week 20 to birth, and both the FI GRS, IR + DLD GRS, and IS GRS were associated with placental weight at birth. Our findings indicate that insulin-related genetic variants might primarily affect fetal growth via the placenta.

Paternal Obesity Induced by High-Fat Diet Impairs the Metabolic and Reproductive Health of Progeny in Rats

Due to the increased incidence of obesity, it is of great importance to identify all the possible consequences in those who suffer from it and their descendants. This study aimed to investigate how paternal obesity, resulting from an 18-week high-fat diet (HFD), affects the metabolic and reproductive health of offspring. In the fathers (F0 generation), the HFD led to significant weight gain, primarily due to increased visceral fat. It also resulted in impaired glucose control and reduced insulin sensitivity. Furthermore, F0 males from the HFD group had reduced sperm concentration and lower sperm viability but were still able to sire litters. F1 offspring were monitored during 18 weeks; F1 offspring from obese fathers displayed increased body weight during the experimental window, especially in males, without significant metabolic disturbances. Additionally, F1 males showed reduced sperm viability, indicating potential reproductive implications. On the other hand, F1 females showed normal estrous cycle patterns but had a reduced number of primordial follicles, suggesting a decrease in their follicular reserve and reproductive potential. This study highlights that metabolic and reproductive issues may be passed down to future generations through the paternal line.

Congenital male genital malformations and paternal health: An analysis of the US claims data

OBJECTIVE

To investigate the potential association between paternal health and male genital malformations in the offspring.

MATERIALS AND METHODS

We analyzed data from 2007 to 2016 derived from the IBM MarketScan Research database, which reports on reimbursed private healthcare claims in the United States. The association between paternal comorbidities (defined as individual and combined measures) and genital malformations in male offspring was analyzed.

RESULTS

Of 376,362 male births, 22% of fathers had at least one component of metabolic syndrome (≥1) prior to conception. Totals of 2880 cases of cryptorchidism (0.77%) and 2651 cases of hypospadias (0.70%) were identified at birth. While 0.76% of sons born to fathers with no metabolic syndrome components were diagnosed with cryptorchidism, 0.82% of sons with fathers with multiple metabolic syndrome components had cryptorchidism. Similarly, 0.69% versus 0.88% of sons had hypospadias when fathers had 0 or 2+ components of metabolic syndrome. After adjusting for maternal and paternal factors, the odds of a son being diagnosed with hypospadias increased with two or more paternal metabolic syndrome components (Odds ratio [95% confidence interval]: 1.27 [1.10-1.47]). Specific components of paternal metabolic syndrome were not generally more associated with a son's genital malformations. When we performed a subgroup analysis where genital malformations were defined based on surgical correction, the association with hypospadias persisted.

CONCLUSIONS

Fathers with multiple components of metabolic syndrome in the preconception period were observed to be at increased risk for having sons born with hypospadias. The results support the association between a man's andrological and overall health.

Placenta-specific Slc38a2/SNAT2 knockdown causes fetal growth restriction in mice

Fetal growth restriction (FGR) is a complication of pregnancy that reduces birth weight, markedly increases infant mortality and morbidity and is associated with later-life cardiometabolic disease. No specific treatment is available for FGR. Placentas of human FGR infants have low abundance of sodium-coupled neutral amino acid transporter 2 (Slc38a2/SNAT2), which supplies the fetus with amino acids required for growth. We determined the mechanistic role of placental Slc38a2/SNAT2 deficiency in the development of restricted fetal growth, hypothesizing that placenta-specific Slc38a2 knockdown causes FGR in mice. Using lentiviral transduction of blastocysts with a small hairpin RNA (shRNA), we achieved 59% knockdown of placental Slc38a2, without altering fetal Slc38a2 expression. Placenta-specific Slc38a2 knockdown reduced near-term fetal and placental weight, fetal viability, trophoblast plasma membrane (TPM) SNAT2 protein abundance, and both absolute and weight-specific placental uptake of the amino acid transport System A tracer, 14C-methylaminoisobutyric acid (MeAIB). We also measured human placental SLC38A2 gene expression in a well-defined term clinical cohort and found that SLC38A2 expression was decreased in late-onset, but not early-onset FGR, compared with appropriate for gestational age (AGA) control placentas. The results demonstrate that low placental Slc38a2/SNAT2 causes FGR and could be a target for clinical therapies for late-onset FGR.

Effect of Preconception Care Intervention on Maternal Nutritional Status and Birth Outcome in a Low-Resource Setting: Proposal for a Nonrandomized Controlled Trial

BACKGROUND

The provision of preconception care approaches such as maternal assessments and education on healthy lifestyle (including physical activity, nutrition, and dietary supplements such as folic acid), general and sexual health, avoidance of high-risk behavior, and immunizations has been shown to identify and reduce the risk of adverse birth outcomes through appropriate management and preventive measures.

OBJECTIVE

The goal of the study is to determine the effect of an integrated preconception care intervention on delivery outcomes, which is a novel challenge for lowering unfavorable birth outcomes in India's low-resource setting. The main objectives are to investigate the relationship of birth outcomes to both maternal and paternal preconception health and determine the effect of preconception care intervention on improvement of maternal nutritional status and reduction of the risk of adverse birth outcomes such as prematurity, low birth weight, and maternal and neonatal complications.

METHODS

A nonrandomized controlled trial design will be used for comparing 2 groups: preconception care with a standard maternal health care (MHC) program and an integrated MHC program (without preconception care). Two rural field areas of Khordha district, Odisha, will be selected for conducting the study. The study will enroll 782 married women between the ages of 18 and 35 years with their spouses, with 391 women in each group. The couples will receive preconception care based on their health circumstances, and they will be followed up at 3-month intervals before pregnancy. Following pregnancy, they will be followed up for 8 prenatal monitoring and care visits as well as 6 weeks after delivery as part of the standard MCH program. The preconception care intervention package includes couples counseling, contraceptive education and distribution, sex education, lifestyle modification, and nutritional supplementation of iron and folic acid, along with multivitamins if needed.

RESULTS

The proposal was approved by the institutional ethical committee for conducting the study in June 2020 (Ref No: T/EMF/Nursing/20/6). Participants were enrolled in phase 1 in April 2021, phase 2 of offering preconception services will begin in August 2021, and study outcomes will be measured from 2023 to 2024.

CONCLUSIONS

Through preconception care and counseling, the eligible couples will recognize, embrace, and implement the actions to improve their preconception health. Finally, it is expected that maternal and paternal health will have a significant impact on enhancing maternal nutritional status and birth outcomes.

TRIAL REGISTRATION

Clinical Trials Registry-India CTRI/2021/04/032836; http://ctri.nic.in/Clinicaltrials/pmaindet2.php?trialid=48239&EncHid=&userName=CTRI/2021/04/032836.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/28148.

Two decades since the fetal insulin hypothesis: what have we learned from genetics?

In 1998 the fetal insulin hypothesis proposed that lower birthweight and adult-onset type 2 diabetes are two phenotypes of the same genotype. Since then, advances in research investigating the role of genetics affecting insulin secretion and action have furthered knowledge of fetal insulin-mediated growth and the biology of type 2 diabetes. In this review, we discuss the historical research context from which the fetal insulin hypothesis originated and consider the position of the hypothesis in light of recent evidence. In summary, there is now ample evidence to support the idea that variants of certain genes which result in impaired pancreatic beta cell function and reduced insulin secretion contribute to both lower birthweight and higher type 2 diabetes risk in later life when inherited by the fetus. There is also evidence to support genetic links between type 2 diabetes secondary to reduced insulin action and lower birthweight but this applies only to loci implicated in body fat distribution and not those influencing insulin resistance via obesity or lipid metabolism by the liver. Finally, we also consider how advances in genetics are being used to explore alternative hypotheses, namely the role of the maternal intrauterine environment, in the relationship between lower birthweight and adult cardiometabolic disease.

Association between preconception paternal health and pregnancy loss in the USA: an analysis of US claims data

STUDY QUESTION

Is preconception paternal health associated with pregnancy loss?

SUMMARY ANSWER

Poor preconception paternal health is associated with a higher risk of pregnancy loss as confirmed in sensitivity analyses accounting for maternal age and health.

WHAT IS KNOWN ALREADY

Preconception paternal health can negatively impact perinatal outcomes.

STUDY DESIGN, SIZE, DURATION

Retrospective cohort study of US insurance claims database from 2009 to 2016 covering 958 804 pregnancies.

PARTICIPANTS/MATERIALS, SETTING, METHODS

US insurance claims database including women, men and pregnancies within the USA between 2007 and 2016. Paternal preconception health status (e.g. metabolic syndrome diagnoses (MetS), Charlson comorbidity index (CCI) and individual chronic disease diagnoses) was examined in relation to pregnancy loss (e.g. ectopic pregnancy, miscarriage and stillbirth).

MAIN RESULTS AND THE ROLE OF CHANCE

In all, 958 804 pregnancies were analyzed. The average paternal age was 35.3 years (SD 5.3) and maternal age was 33.1 years (SD 4.4). Twenty-two percent of all pregnancies ended in a loss. After adjusting for maternal factors, the risk of pregnancy loss increased with increasing paternal comorbidity. For example, compared to men with no components of MetS, the risk of pregnancy loss increased for men with one (relative risk (RR) 1.10, 95% CI 1.09-1.12), two (RR 1.15, 95% CI 1.13-1.17) or three or more (RR 1.19, 95% CI 1.14-1.24) components. Specifically, less healthy men had a higher risk of siring a pregnancy ending in spontaneous abortion, stillbirth and ectopic pregnancies. Similar patterns remained with other measures of paternal health (e.g. CCI, chronic diseases, etc.). When stratifying by maternal age as well as maternal health, a similar pattern of increasing pregnancy loss risk for men with 1, 2 or 3+ MetS was observed. A statistically significant but weak association between timing of pregnancy loss and paternal health was found.

LIMITATIONS, REASONS FOR CAUTION

Retrospective study design covering only employer insured individuals may limit generalizability.

WIDER IMPLICATIONS OF THE FINDINGS

Optimization of a father's health may improve pregnancy outcomes.

STUDY FUNDING/COMPETING INTERESTS

National Institutes of Health National Center for Advancing Translational Science Clinical and Translational Science Award (UL1 TR001085). M.L.E. is an advisor for Sandstone Diagnostics, Dadi, Hannah and Underdog. No other competing interests were declared.

TRIAL REGISTRATION NUMBER

N/A.

Paternal metabolic and cardiovascular programming of their offspring: A systematic scoping review

BACKGROUND

There is lots of evidence that maternal peri-gestational metabolic, genomic and environmental conditions are closely linked to metabolic and cardiovascular outcomes in their offspring later in life. Moreover, there is also lotsof evidence that underlining mechanisms, such as molecular as well as epigenetic changes may alter the intrauterine environment leading to cardio-metabolic diseases in their offspring postnatal. But, there is also increasing evidence that cardio-metabolic diseases may be closely linked to their paternal metabolic risk factors, such as obesity, Type 2 Diabetes and other risk factors.

OBJECTIVE

To analyse the evidence as well as specific risk factors of paternal trans-generational programming of cardio-metabolic diseases in their offspring.

METHODS

Within a systematic scoping review, we performed a literature search in MEDLINE (PubMed) and EMBASE databases in August 2020 considering original research articles (2000-2020) that examined the impact of paternal programming on metabolic and cardiovascular offspring health. Epidemiological, clinical and experimental studies as well as human and animal model studies were included.

RESULTS

From n = 3.199 citations, n = 66 eligible studies were included. We selected n = 45 epidemiological as well as clinical studies and n = 21 experimental studies. In brief, pre-conceptional paternal risk factors, such as obesity, own birth weight, high-fat and low-protein diet, undernutrition, diabetes mellitus, hyperglycaemia, advanced age, smoking as well as environmental chemical exposure affect clearly metabolic and cardiovascular health of their offspring later in life.

CONCLUSIONS

There is emerging evidence that paternal risk factors, such as paternal obesity, diabetes mellitus, nutritional habits, advanced age and exposure to environmental chemicals or cigarette smoke, are clearly associated with adverse effects in metabolic and cardiovascular health in their offspring. Compared to maternal programming, pre-conceptional paternal factors might also have also a substantial effect in the sense of trans-generational programming of their offspring and need further research.

The DNA methylome of human sperm is distinct from blood with little evidence for tissue-consistent obesity associations

Epidemiological research suggests that paternal obesity may increase the risk of fathering small for gestational age offspring. Studies in non-human mammals indicate that such associations could be mediated by DNA methylation changes in spermatozoa that influence offspring development in utero. Human obesity is associated with differential DNA methylation in peripheral blood. It is unclear, however, whether this differential DNA methylation is reflected in spermatozoa. We profiled genome-wide DNA methylation using the Illumina MethylationEPIC array in a cross-sectional study of matched human blood and sperm from lean (discovery n = 47; replication n = 21) and obese (n = 22) males to analyse tissue covariation of DNA methylation, and identify obesity-associated methylomic signatures. We found that DNA methylation signatures of human blood and spermatozoa are highly discordant, and methylation levels are correlated at only a minority of CpG sites (~1%). At the majority of these sites, DNA methylation appears to be influenced by genetic variation. Obesity-associated DNA methylation in blood was not generally reflected in spermatozoa, and obesity was not associated with altered covariation patterns or accelerated epigenetic ageing in the two tissues. However, one cross-tissue obesity-specific hypermethylated site (cg19357369; chr4:2429884; P = 8.95 × 10-8; 2% DNA methylation difference) was identified, warranting replication and further investigation. When compared to a wide range of human somatic tissue samples (n = 5,917), spermatozoa displayed differential DNA methylation across pathways enriched in transcriptional regulation. Overall, human sperm displays a unique DNA methylation profile that is highly discordant to, and practically uncorrelated with, that of matched peripheral blood. We observed that obesity was only nominally associated with differential DNA methylation in sperm, and therefore suggest that spermatozoal DNA methylation is an unlikely mediator of intergenerational effects of metabolic traits.

Paternal weight of ducks may have an influence on offspring' small intestinal function and cecal microorganisms

Background

In animals, many factors affect the small intestinal function and cecal microorganisms, including body weight and genetic background. However, whether paternal weight impacts the small intestinal function and cecal microorganisms remains unknown to date. The current study used Nonghua sheldrake to estimate the effect of paternal weight on the intestine of the offspring by evaluating differences in small intestinal morphology, digestive enzyme activity, and cecal microorganisms between the offspring of male parents with high body weight (group H) and that of male parents with low body weight (group L).

Results

The results of the analysis of small intestinal morphology showed that the villus height of the jejunum of group H ducks was higher than that of group L ducks, and the difference was significant for ducks at 10 weeks of age. Moreover, the villus height/crypt depth of the duodenum in group H significantly exceeded that of group L at a duck age of 2 weeks. The amylase activity in the jejunum content of group H exceeded that of group L at 5 and 10 weeks of age. Furthermore, the proportion of the Firmicutes to Bacteroidetes was significantly higher in group H (duck age of 2 weeks). Among the genera with a relative abundance exceeding 1%, the relative abundances of genera Desulfovibrio, Megamonas, Alistipes, Faecalibacterium, and Streptococcus observed in group H were significantly different between group H and group L.

Conclusions

For the first time, this study identifies the effect of paternal weight on offspring small intestinal function and cecal microorganisms. Consequently, this lays a foundation for further research on the relationship between male parents and offspring intestinal function.

Parental adiposity differentially associates with newborn body composition

BACKGROUND

Maternal obesity increases offspring's obesity risk. However, studies have not often considered maternal metabolic and exercise patterns as well as paternal adiposity as potential covariates.

OBJECTIVE

To assess the relationship between parental and newborn adiposity.

METHODS

Participants were mother-child pairs (n = 209) and mother-father-offspring triads (n = 136). Parental (during gestation) and offspring (2 weeks old) percent fat mass (FM) were obtained using air displacement plethysmography. Maternal race, age, resting energy expenditure (indirect calorimetry), physical activity (accelerometry), gestational weight gain (GWG), gestational age (GA), delivery mode, infant's sex and infant feeding method were incorporated in multiple linear regression analyses. The association between parental FM and offspring insulin-like growth factor 1 (IGF-1) was assessed at age 2 years.

RESULTS

Maternal adiposity was positively-associated with male (β = 0.11, P = .015) and female (β = 0.13, P = .008) infant FM, whereas paternal adiposity was negatively-associated with male newborn adiposity (β = -0.09, P = .014). Breastfeeding, female sex, GA and GWG positively associated with newborn adiposity. Vaginal and C-section delivery methods associated with greater adiposity than vaginal induced delivery method. Plasma IGF-1 of 2-year-old boys and girls positively associated with their respective fathers' and mothers' FM.

CONCLUSIONS

Maternal and paternal adiposity differentially associate with newborn adiposity. The mechanisms of this finding remain to be determined.

Paternal Environmental Toxicant Exposure and Risk of Adverse Pregnancy Outcomes

PURPOSE OF REVIEW

Current clinical efforts to predict and prevent preterm birth are primarily focused on the mother and have made minimal progress in improving outcomes. However, recent data indicate that paternal factors can also influence timing of birth. Herein, we will review recent human and murine data examining the contribution of the father to pregnancy outcomes with an emphasis on environmental exposures that can negatively impact fertility and the timing of birth.

RECENT FINDINGS

Human epidemiology studies now clearly indicate that a variety of paternal factors (age, race, weight, smoking status) can influence sperm quality, birth timing and, in some studies, offspring health. Utilizing a mouse model, our data have 57demonstrated that developmental exposure to the environmental toxicant TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin) is associated with a transgenerational reduction in sperm number and quality and an increased risk of preterm birth in an unexposed partner.

SUMMARY

Toxicant exposure history can clearly influence sperm quality in men and mice. Murine data further indicate that exposures which negatively affect sperm quality also impair placental function, potentially leading to preterm birth and other adverse outcomes. Of particular concern, these changes have been linked to epigenetic alterations within the male germ cell which can then be transmitted across multiple generations. Since it is not possible to prevent an ancestral toxicant exposure in a human population, identifying lifestyle modifications that can be implemented during the preconception period to improve sperm quality should be explored for the therapeutic potential to reduce the incidence of PTB and its sequelae.

Paternal contributions to large-for-gestational-age term babies: findings from a multicenter prospective cohort study

We assessed whether paternal demographic, anthropometric and clinical factors influence the risk of an infant being born large-for-gestational-age (LGA). We examined the data on 3659 fathers of term offspring (including 662 LGA infants) born to primiparous women from Screening for Pregnancy Endpoints (SCOPE). LGA was defined as birth weight >90th centile as per INTERGROWTH 21st standards, with reference group being infants ⩽90th centile. Associations between paternal factors and likelihood of an LGA infant were examined using univariable and multivariable models. Men who fathered LGA babies were 180 g heavier at birth (P<0.001) and were more likely to have been born macrosomic (P<0.001) than those whose infants were not LGA. Fathers of LGA infants were 2.1 cm taller (P<0.001), 2.8 kg heavier (P<0.001) and had similar body mass index (BMI). In multivariable models, increasing paternal birth weight and height were independently associated with greater odds of having an LGA infant, irrespective of maternal factors. One unit increase in paternal BMI was associated with 2.9% greater odds of having an LGA boy but not girl; however, this association disappeared after adjustment for maternal BMI. There were no associations between paternal demographic factors or clinical history and infant LGA. In conclusion, fathers who were heavier at birth and were taller were more likely to have an LGA infant, but maternal BMI had a dominant influence on LGA.

Down-regulation of steroidogenesis-related genes and its accompanying fertility decline in streptozotocin-induced diabetic male rats: ameliorative effect of metformin

BACKGROUND

Metformin has long been used for glycemic control in diabetic state. Recently, other benefits of metformin beyond blood glucose regulation have emerged.

OBJECTIVES

To investigate the effect of metformin on the expression of testicular steroidogenesis-related genes, spermatogenesis, and fertility of male diabetic rats.

MATERIALS AND METHODS

Eighteen adult male Sprague Dawley rats were divided into three groups, namely normal control (NC), diabetic control (DC), and metformin-treated (300 mg/kg body weight/day) diabetic rats (D+Met). Diabetes was induced using a single intraperitoneal injection of streptozotocin (60 mg/kg b.w.), followed by oral treatment with metformin for four weeks.

RESULTS

Diabetes decreased serum and intratesticular testosterone levels and increased serum but not intratesticular levels of luteinizing hormone. Sperm count, motility, viability, and normal morphology were decreased, while sperm nuclear DNA fragmentation was increased in DC group, relative to NC group. Testicular mRNA levels of androgen receptor, luteinizing hormone receptor, cytochrome P450 enzyme (CYP11A1), steroidogenic acute regulatory (StAR) protein, 3β-hydroxysteroid dehydrogenase (HSD), and 17β-HSD, as well as the level of StAR protein and activities of CYP11A1, 3β-HSD, and 17β-HSD, were decreased in DC group. Similarly, decreased activities of epididymal antioxidant enzymes and increased lipid peroxidation were observed in DC group. Consequently, decreased litter size, fetal weight, mating and fertility indices, and increased pre- and post-implantation losses were recorded in DC group. Following intervention with metformin, we observed increases in serum and intratesticular testosterone levels, Leydig cell count, improved sperm parameters, and decreased sperm nuclear DNA fragmentation. Furthermore, mRNA levels and activities of steroidogenesis-related enzymes were increased, with improved fertility outcome.

DISCUSSION AND CONCLUSION

Diabetes mellitus is associated with dysregulation of steroidogenesis, abnormal spermatogenesis, and fertility decline. Controlling hyperglycemia is therefore crucial in preserving male reproductive function. Metformin not only regulates blood glucose level, but also preserves male fertility in diabetic state.

Early-Life Exposures and Risk of Diabetes Mellitus and Obesity

PURPOSE OF REVIEW

Type 2 diabetes is a growing concern worldwide with increasing incidence in youth. Development of preventive strategies in earlier stages of life is crucial. We aimed to examine epidemiological evidence of early-life exposures and their associations with childhood and later risk of obesity and diabetes, and to discuss potential mechanisms.

RECENT FINDINGS

Parental obesity and diabetes in the preconception period may influence offspring's obesity risk via epigenetic mechanisms influencing gametogenesis and early development that could have significant transgenerational effects. A more comprehensive understanding of these effects is needed to identify possible avenues for interventions in both fathers and mothers to be. In addition, current evidence suggests that growth and body weight trajectories in infancy and childhood are useful indicators of later obesity and type 2 diabetes. Moreover, the composition and variations in the microbiome in early life are associated with long-term health and could mediate associations between several early-life exposures and later risk of diseases. Altogether, the epidemiological evidence supports the need for preconception and early-life interventions to reduce the obesity and diabetes burden in later life.

Prophylaxis and treatment of foetal growth restriction

Foetal growth restriction (FGR) and associated placental pathologies such as pre-eclampsia and stillbirth arise in early pregnancy when inadequate remodelling of maternal spiral arteries leads to persistent high-resistance low-flow uteroplacental circulation. Current interventions concentrate on targeting the placental ischaemia-reperfusion injury and oxidative stress associated with an imbalance in angiogenic/anti-angiogenic factors. Recent meta-analyses confirm that aspirin modestly reduces the risk for small-for-gestational-age pregnancy in high-risk women. A dose of ≥100 mg starting by 16 weeks of gestation is recommended. In vitro and in vivo studies suggest that low-molecular-weight heparin may prevent FGR; further research is needed to confirm efficacy. Once FGR is diagnosed, no treatment will improve foetal growth. Potential FGR therapies such as phosphodiesterase type-5 inhibitors or maternal VEGF gene therapy aim to improve poor placentation and/or uterine blood flow. Melatonin, creatine and N-acetyl cysteine have potential as novel neuroprotective and cardioprotective agents in FGR.

Endothelial dysfunction in individuals born after fetal growth restriction: cardiovascular and renal consequences and preventive approaches

Individuals born after intrauterine growth restriction (IUGR) have an increased risk of perinatal morbidity/mortality, and those who survive face long-term consequences such as cardiovascular-related diseases, including systemic hypertension, atherosclerosis, coronary heart disease and chronic kidney disease. In addition to the demonstrated long-term effects of decreased nephron endowment and hyperactivity of the hypothalamic-pituitary-adrenal axis, individuals born after IUGR also exhibit early alterations in vascular structure and function, which have been identified as key factors of the development of cardiovascular-related diseases. The endothelium plays a major role in maintaining vascular function and homeostasis. Therefore, it is not surprising that impaired endothelial function can lead to the long-term development of vascular-related diseases. Endothelial dysfunction, particularly impaired endothelium-dependent vasodilation and vascular remodeling, involves decreased nitric oxide (NO) bioavailability, impaired endothelial NO synthase functionality, increased oxidative stress, endothelial progenitor cells dysfunction and accelerated vascular senescence. Preventive approaches such as breastfeeding, supplementation with folate, vitamins, antioxidants, L-citrulline, L-arginine and treatment with NO modulators represent promising strategies for improving endothelial function, mitigating long-term outcomes and possibly preventing IUGR of vascular origin. Moreover, the identification of early biomarkers of endothelial dysfunction, especially epigenetic biomarkers, could allow early screening and follow-up of individuals at risk of developing cardiovascular and renal diseases, thus contributing to the development of preventive and therapeutic strategies to avert the long-term effects of endothelial dysfunction in infants born after IUGR.

Effects of paternal obesity on growth and adiposity of male rat offspring

Emerging evidence suggests that paternal obesity plays an important role in offspring health. Our previous work using a rodent model of diet-induced paternal obesity showed that female offspring from high-fat diet (HFD)-fed fathers develop glucose intolerance due to impairment of pancreatic insulin secretion. Here, we focused on the health outcomes of male offspring from HFD-fed fathers. Male Sprague-Dawley rats (3 wk old) were fed control (CD-F0) or HFD (HFD-F0) for 12 wk before mating with control-fed females. Male offspring were fed control diets for up to 8 wk or 6 mo. Although male offspring from HFD-F0 did not develop any obvious glucose metabolism defects in this study, surprisingly, a growth deficit phenotype was observed from birth to 6 mo of age. Male offspring from HFD-F0 had reduced birth weight compared with CD-F0, followed by reduced postweaning growth from 9 wk of age. This resulted in 10% reduction in body weight at 6 mo with significantly smaller fat pads and skeletal muscles. Reduced circulating levels of growth hormone (GH) and IGF-I were detected at 8 wk and 6 mo, respectively. Expression of adipogenesis markers was decreased in adipose tissue of HFD-F0 offspring at 8 wk and 6 mo, and expression of growth markers was decreased in muscle of HFD-F0 offspring at 8 wk. We propose that the reduced GH secretion at 8 wk of age altered the growth of male offspring from HFD-F0, resulting in smaller animals from 9 wk to 6 mo of age. Furthermore, increased muscle triglyceride content and expression of lipogenic genes were observed in HFD-F0 offspring, potentially increasing their metabolic risk.

Delivery of small-for-gestational-age neonate and association with early-onset impaired maternal endothelial function

OBJECTIVE

Women who have delivered a small-for-gestational-age (SGA) infant are at an increased risk of developing cardiovascular disease (CVD) in later life. Endothelial dysfunction is a subclinical sign of early CVD. It is unknown whether women who have recently had a pregnancy complicated by SGA, in the absence of other maternal and fetal diseases, have subclinical endothelial dysfunction. Our aim was to assess maternal endothelial function 6 months after a pregnancy complicated by SGA.

METHODS

This was a case-control study conducted in a tertiary referral hospital in London, UK, over a 15-month period. Flow-mediated dilatation (FMD) of the brachial artery was measured in women 6.9 ± 2.5 months after childbirth. Forty-four women were included in the study, of whom 15 had a SGA neonate (mean ± SD customized birth centile of 1.9 ± 2.3) and 29 delivered an appropriately grown baby (mean ± SD customized birth centile of 47.5 ± 26.3). The primary continuous variable, FMD, was assessed in each group and compared using unpaired t-test.

RESULTS

Women who had a SGA neonate had lower postpartum FMD (6.79 ± 0.95%) than did those who had an appropriately grown offspring (10.26 ± 2.44% (95% CI for difference between groups, -5.37 to -1.57); P = 0.0007). There were no differences in postnatal maternal blood pressure, abdominal circumference, weight and glucose, insulin and lipid profiles between the two groups.

CONCLUSIONS

Women who had a pregnancy affected by SGA, probably due to placental failure in the absence of pre-eclampsia, have evidence of subclinical endothelial dysfunction within 6 months of childbirth. These women may benefit from lifestyle measures focused on the primary prevention of CVD. Further research in larger populations is needed to ascertain if such postpartum maternal endothelial dysfunction is a pregnancy-induced phenomenon or if it is related to the pre-existing maternal phenotype, and whether it persists long term. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Differential impact of maternal and paternal ethnicity on the pattern of fat distribution in infants at age 3 months

BACKGROUND

As ethnicity is typically recorded as a single demographic variable in clinical studies, little is known about the relative impact of maternal vs. paternal ethnicity on fat distribution.

OBJECTIVES

The objective of this study was to determine whether there is a differential impact of maternal and paternal ethnicity on infant adiposity.

METHODS

Three hundred fifty-five infants underwent anthropometric assessment at age 3 months, including skin-fold thickness (SFT) measurement at subscapular, suprailiac and triceps. Maternal (M) and paternal (P) ethnicity were classified as white (M = 241, P = 252), Asian (M = 50, P = 42) or other (M = 64, P = 61).

RESULTS

Infants with either Asian mother (compared with white) or Asian father (compared with white) had increased subscapular, suprailiac and triceps SFT (all P < 0.05). On logistic regression analysis, however, only maternal Asian ethnicity (compared with white) independently predicted the likelihood of an infant being in the highest tertile for SFT at subscapular (odds ratio [OR] = 2.72, 95% confidence interval 1.17-6.34, P = 0.02), suprailiac (OR = 3.56, 1.51-8.42, P = 0.004) and triceps (OR = 3.26, 1.40-7.55, P = 0.005). In contrast, paternal Asian ethnicity was independently associated with sum of SFT only (OR = 2.46, 1.02-5.97, P = 0.04).

CONCLUSION

Maternal and paternal Asian ethnicity have differential effects on infant fat distribution. Future clinical studies on obesity and fat composition should consider the distinct contributions of both parents to the ethnic classification of participants.

Advancing age increases sperm chromatin damage and impairs fertility in peroxiredoxin 6 null mice

Due to socioeconomic factors, more couples are choosing to delay conception than ever. Increasing average maternal and paternal age in developed countries over the past 40 years has raised the question of how aging affects reproductive success of males and females. Since oxidative stress in the male reproductive tract increases with age, we investigated the impact of advanced paternal age on the integrity of sperm nucleus and reproductive success of males by using a Prdx6(-/-) mouse model. We compared sperm motility, cytoplasmic droplet retention sperm chromatin quality and reproductive outcomes of young (2-month-old), adult (8-month-old), and old (20-month-old) Prdx6(-/-) males with their age-matched wild type (WT) controls. Absence of PRDX6 caused age-dependent impairment of sperm motility and sperm maturation and increased sperm DNA fragmentation and oxidation as well as decreased sperm DNA compaction and protamination. Litter size, total number of litters and total number of pups per male were significantly lower in Prdx6(-/-) males compared to WT controls. These abnormal reproductive outcomes were severely affected by age in Prdx6(-/-) males. In conclusion, the advanced paternal age affects sperm chromatin integrity and fertility more severely in the absence of PRDX6, suggesting a protective role of PRDX6 in age-associated decline in the sperm quality and fertility in mice.

Novel DNA methylation profiles associated with key gene regulation and transcription pathways in blood and placenta of growth-restricted neonates

Fetal growth is determined by the feto-placental genome interacting with the maternal in utero environment. Failure of this interplay leads to poor placental development and fetal growth restriction (FGR), which is associated with future metabolic disease. We investigated whether whole genome methylation differences existed in umbilical cord blood and placenta, between gestational-matched, FGR, and appropriately grown (AGA) neonates. Using the Infinium HumanMethylation450 BeadChip®, we found that DNA from umbilical cord blood of FGR born at term (n = 19) had 839 differentially methylated positions (DMPs) that reached genome-wide significance compared with AGA (n = 18). Using gestational age as a continuous variable, we identified 76,249 DMPs in cord blood (adj. P < 0.05) of which 121 DMPs were common to the 839 DMPs and were still evident when comparing 12 FGR with 12 AGA [39.9 ± 1.2 vs. 40.0 ± 1.0 weeks (mean ± SD), respectively]. A total of 53 DMPs had a β methylation difference >10% and 25 genes were co-methylated more than twice within 1000 base pairs. Gene Ontology (GO) analysis of DMPs supported their involvement in gene regulation and transcription pathways related to organ development and metabolic function. A similar profile of DMPs was found across different cell types in the cord blood. At term, no DMPs between FGR and AGA placentae reached genome-wide significance, validated with an external dataset. GO analysis of 284 pre-term, placental DMPs associated with autophagy, oxidative stress and hormonal responses. Growth restricted neonates have distinct DNA methylation profiles in pre-term placenta and in cord blood at birth, which may predispose to future adult disease.

Relationships of maternal and paternal anthropometry with neonatal body size, proportions and adiposity in an Australian cohort

The patterns of association between maternal or paternal and neonatal phenotype may offer insight into how neonatal characteristics are shaped by evolutionary processes, such as conflicting parental interests in fetal investment and obstetric constraints. Paternal interests are theoretically served by maximizing fetal growth, and maternal interests by managing investment in current and future offspring, but whether paternal and maternal influences act on different components of overall size is unknown. We tested whether parents' prepregnancy height and body mass index (BMI) were related to neonatal anthropometry (birthweight, head circumference, absolute and proportional limb segment and trunk lengths, subcutaneous fat) among 1,041 Australian neonates using stepwise linear regression. Maternal and paternal height and maternal BMI were associated with birthweight. Paternal height related to offspring forearm and lower leg lengths, maternal height and BMI to neonatal head circumference, and maternal BMI to offspring adiposity. Principal components analysis identified three components of variability reflecting neonatal “head and trunk skeletal size,” “adiposity,” and “limb lengths.” Regression analyses of the component scores supported the associations of head and trunk size or adiposity with maternal anthropometry, and limb lengths with paternal anthropometry. Our results suggest that while neonatal fatness reflects environmental conditions (maternal physiology), head circumference and limb and trunk lengths show differing associations with parental anthropometry. These patterns may reflect genetics, parental imprinting and environmental influences in a manner consistent with parental conflicts of interest. Paternal height may relate to neonatal limb length as a means of increasing fetal growth without exacerbating the risk of obstetric complications. Am J Phys Anthropol 156:625–636, 2015.

Paternal race/ethnicity and very low birth weight

BACKGROUND

The purpose was to examine the association between paternal race/ethnicity and very low birth weight stratified by maternal race/ethnicity.

METHODS

Birth data for Tarrant County, Texas 2006-2010 were analyzed. Very low birth weight was dichotomized as yes (<1,500 g) and no (≥1,500 g). Paternal race/ethnicity was categorized as Caucasian, African American, Hispanic, other, and missing. Missing observations (14.7%) were included and served as a proxy for fathers absent during pregnancy. Potential confounders included maternal age, education, and marital status, plurality, previous preterm birth, sexually transmitted disease during pregnancy, smoking during pregnancy, and Kotelchuck Index of prenatal care. Logistic regressions were stratified by maternal race/ethnicity. Odds ratios and 95% confidence intervals were calculated.

RESULTS

Of 145,054 births, 60,156 (41.5%) were Caucasian, 22,306 (15.4%) African American, 54,553 (37.6%) Hispanic, and 8,039 (5.5%) other mothers. There were 2,154 (1.5%) very low birth weights total, with 3.1% for African American mothers and 1.2% for all other race/ethnicities. Among Caucasian mothers, African American paternal race was associated with increased odds of very low birth weight (OR = 1.52; 95% CI:1.08-2.14). Among Hispanic mothers, African American paternal race (OR = 1.66; 95% CI:1.01-2.74) and missing paternal race/ethnicity (OR = 1.65; 95% CI:1.15-2.36) were associated with increased odds of very low birth weight.

CONCLUSIONS

Paternal race/ethnicity is an important predictor of very low birth weight among Caucasian and Hispanic mothers. Future research should consider paternal race/ethnicity and further explore the association between paternal characteristics and very low birth weight.

Impact of maternal and paternal preconception health on birth outcomes using prospective couples' data in Add Health

PURPOSE

Retrospective studies of preconception health have demonstrated that parents' health conditions and behaviors can impact a newborn's birth outcomes and, subsequently, future health status. This study sought to examine the impact of preconception health, measured prospectively, among both mothers and fathers, on two important birth outcomes: birthweight and gestational age.

METHODS

Data came from Add Health (the National Longitudinal Study of Adolescent Health), which included interviews with original participants and a subsample of their partners in 2001-02. In 2008, the original respondents again completed an interview for Add Health. For 372 eligible infants born to these couples, birth outcomes (measured in 2008) were regressed on preconception health conditions and behaviors among non-pregnant heterosexual partners (measured in 2001-02).

RESULTS

Mean birthweight was 3,399 g, and mean gestational age was 39 weeks. Birthweight was higher for infants born to mothers with diabetes or high blood pressure, and for mothers who drank alcohol at least once per month, and lower for infants born to fathers with diabetes (p < 0.05). Infant gestational age was marginally lower for infants born to mothers with higher levels of depression (p < 0.10), and lower for infants born to fathers with diabetes and with higher levels of fast food consumption (p < 0.05).

CONCLUSIONS

Both maternal and paternal preconception health conditions and behaviors influenced infant birth outcomes. Interventions to promote preconception health should focus on prevention of diabetes and high blood pressure, as well as minimizing consumption of alcohol and fast food.

Early developmental conditioning of later health and disease: physiology or pathophysiology?

Extensive experimental animal studies and epidemiological observations have shown that environmental influences during early development affect the risk of later pathophysiological processes associated with chronic, especially noncommunicable, disease (NCD). This field is recognized as the developmental origins of health and disease (DOHaD). We discuss the extent to which DOHaD represents the result of the physiological processes of developmental plasticity, which may have potential adverse consequences in terms of NCD risk later, or whether it is the manifestation of pathophysiological processes acting in early life but only becoming apparent as disease later. We argue that the evidence suggests the former, through the operation of conditioning processes induced across the normal range of developmental environments, and we summarize current knowledge of the physiological processes involved. The adaptive pathway to later risk accords with current concepts in evolutionary developmental biology, especially those concerning parental effects. Outside the normal range, effects on development can result in nonadaptive processes, and we review their underlying mechanisms and consequences. New concepts concerning the underlying epigenetic and other mechanisms involved in both disruptive and nondisruptive pathways to disease are reviewed, including the evidence for transgenerational passage of risk from both maternal and paternal lines. These concepts have wider implications for understanding the causes and possible prevention of NCDs such as type 2 diabetes and cardiovascular disease, for broader social policy and for the increasing attention paid in public health to the lifecourse approach to NCD prevention.

Second trimester postload glucose level as an important predictor of low birth weight infants: Tanaka Women's Clinic Study

Although it is well known that the maternal prepregnancy BMI is a strong contributor to fetal growth, our results showed that a low postload glucose level, although within normal range, independent of maternal BMI was strongly associated with an increased risk of low birth weight births among Japanese mothers.

Parental diabetes and birthweight in 236 030 individuals in the UK biobank study

Background The UK Biobank study provides a unique opportunity to study the causes and consequences of disease. We aimed to use the UK Biobank data to study the well-established, but poorly understood, association between low birthweight and type 2 diabetes.

Methods We used logistic regression to calculate the odds ratio for participants’ risk of type 2 diabetes given a one standard deviation increase in birthweight. To test for an association between parental diabetes and birthweight, we performed linear regression of self-reported parental diabetes status against birthweight. We performed path and mediation analyses to test the hypothesis that birthweight partly mediates the association between parental diabetes and participant type 2 diabetes status.

Results Of the UK Biobank participants, 277 261 reported their birthweight. Of 257 715 individuals of White ethnicity and singleton pregnancies, 6576 had type 2 diabetes, 19 478 reported maternal diabetes (but not paternal), 20 057 reported paternal diabetes (but not maternal) and 2754 participants reported both parents as having diabetes. Lower birthweight was associated with type 2 diabetes in the UK Biobank participants. A one kilogram increase in birthweight was associated with a lower risk of type 2 diabetes (odds ratio: 0.74; 95% CI: 0.71, 0.76; P = 2 × 10⁻⁵⁷). Paternal diabetes was associated with lower birthweight (45 g lower; 95% CI: 36, 54; P = 2 × 10⁻²³) relative to individuals with no parental diabetes. Maternal diabetes was associated with higher birthweight (59 g increase; 95% CI: 50, 68; P = 3 × 10⁻³⁷). Participants’ lower birthweight was a mediator of the association between reported paternal diabetes and participants’ type 2 diabetes status, explaining 1.1% of the association, and participants’ higher birthweight was a mediator of the association between reported maternal diabetes and participants’ type 2 diabetes status, explaining 1.2% of the association.

Conclusions Data from the UK Biobank provides the strongest evidence by far that paternal diabetes is associated with lower birthweight, whereas maternal diabetes is associated with increased birthweight. Our findings with paternal diabetes are consistent with a role for the same genetic factors influencing foetal growth and type 2 diabetes.