Effect of increasing paternal body mass index on pregnancy and live birth rates in couples undergoing intracytoplasmic sperm injection

A ripple effect? The impact of obesity on sperm quality and function

Infertility affects approximately 15% of couples trying to conceive. Male-related causes account for roughly 50% of cases, with obesity emerging as a possible significant factor. Obesity, defined as a body mass index of 30.0 or higher, has become a widespread epidemic associated with numerous health issues, including a decrease of fertility. This review discusses the relationship between obesity and male infertility, particularly focusing on sperm quality and function. An overview of the literature suggests that obesity may influence the male reproductive system via disruptions in hormonal profiles, oxidative stress, and inflammation, leading to changes in sperm parameters. Several studies have discussed if obesity causes a decrease in sperm concentration, motility, and normal morphology, so far without a consensus being reached. However, available evidence suggests an impairment of sperm function in obese men, due to an increase in DNA damage and oxidative stress, impaired mitochondrial function and acrosome reaction in response to progesterone. Finally, the relationship between obesity and assisted reproductive technologies outcomes remains debatable, with conflicting evidence regarding the influence on fertilisation, pregnancy, and live birth rates. Therefore, the actual impact of obesity on human spermatozoa still needs to be clarified, due to the multiple factors potentially in play.

Effect of Paternal Body Mass Index on In Vitro Fertilization and Neonatal Outcomes among Oligozoospermia and Asthenospermia Patients

PURPOSE

Male overweight and obesity could affect sperm quality and reproductive health. However, the impact of body mass index (BMI) on assisted reproductive technology (ART) outcomes in oligospermia and/or asthenospermia patients is yet lacking. This study aims to assess the impact of paternal BMI on ART and neonatal outcomes among oligozoospermia and/or asthenospermia patients undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI).

MATERIALS AND METHODS

In this study, 2,075 couples undergoing their first fresh embryo transfer between January 2015 and June 2022 were recruited. Following the World Health Organization's (WHO's) categories, couples were stratified into three cohorts based on paternal BMI: normal weight (18.5-24.9 kg/m²), overweight (25.0-29.9 kg/m²), and obese (≥30.0 kg/m²). Modified Poisson regression models were used to assess the associations of paternal BMI with fertilization, in vitro embryonic development, and pregnancy outcomes. Logistic regression models were performed to investigate the associations of paternal BMI with pregnancy loss and neonatal outcomes. Furthermore, stratified analyses were performed based on fertilization methods, male infertility cause, and maternal BMI.

RESULTS

Higher paternal BMI is associated with a lower likelihood of achieving normal fertilized (p-trend=0.002), Day 3 transferable (p-trend=0.007), and high-quality embryos (p-trend=0.046) in IVF cycles, rather than in ICSI cycles. Paternal BMI of oligospermia or asthenospermia was negatively correlated with day 3 transferable (p-trend=0.013 and 0.030) and high-quality embryos (p-trend=0.024 and 0.027). Moreover, for neonatal outcomes, paternal BMI was positively associated with macrosomia (p-trend=0.019), large for gestational age (LGA) (p-trend=0.031), and very LGA (p-trend=0.045).

CONCLUSIONS

Our data suggested that higher paternal BMI was associated with fetal overgrowth, reduced fertilization, and embryonic development potential. Among males with oligospermia and/or asthenospermia, the impact of overweight and obesity on the choice of fertilization method and the long-term effects on their offspring need to be further investigated.

The impact of obesity and metabolic health on male fertility: a systematic review

The impact of paternal obesity and metabolic disease on semen quality and fertility outcomes is not fully appreciated. With increasing obesity rates, researchers have studied the intricate relationship between paternal body mass index, metabolic health, and male fertility. This systematic review identified 112 articles in the MEDLINE database between 2013 and 2023 that investigated the effects of body mass index, diabetes, metabolic syndrome, exercise, weight loss medication, or bariatric surgery on semen parameters, sperm quality, or fertility outcomes. This review suggests that obesity, diabetes, and metabolic syndrome have a negative impact on various parameters of male fertility, from semen quality to sperm deoxyribonucleic acid integrity. There is also mounting evidence that male obesity is correlated negatively with live births via both natural conception and assisted reproductive technologies. Lifestyle interventions, such as physical exercise, generally appear to improve male fertility markers; however, the type and intensity of exercise may play a crucial role. Pharmacologic treatments for weight loss, such as metformin and glucagon-like peptide 1 agonists, present a more complex picture, with studies suggesting both beneficial and detrimental effects on male reproductive health. Similarly, surgical interventions, such as gastric bypass surgery, show promise in improving hormonal imbalances but have mixed effects on semen parameters. Future research is needed to clarify these associations and inform clinical guidelines. In the interim, health practitioners should incorporate these insights into clinical practices, encouraging proactive lifestyle changes and providing targeted treatments to improve male reproductive health.

A short-term high-fat diet alters rat testicular activity and blood-testis barrier integrity through the SIRT1/NRF2/MAPKs signaling pathways

Background

Overweight/obesity are metabolic disorder resulting from behavioral, environmental, and heritable causes. WHO estimates that 50% of adults and 30% of children and adolescents are overweight or obese, and, in parallel, an ongoing decline in sperm quality and male fertility has been described. Numerous studies demonstrated the intimate association between overweight/obesity and reproductive dysfunction due to a highly intricate network of causes not yet completely understood. This study expands the knowledge on the impact of a short-term high-fat diet (st-HFD) on rat testicular activity, specifically on steroidogenesis and spermatogenesis, focusing on the involved molecular mechanisms related to mitochondrial dynamics, blood-testis barrier (BTB) integrity, and SIRT1/NRF2/MAPKs pathways.

Methods

Ten adult Male Wistar rats were divided into two groups of five and treated with a standard diet or an HFD for five weeks. At the end of the treatment, rats were anesthetized and sacrificed by decapitation. Blood was collected for serum sex hormone assay; one testis was stored at -80ÅãC for western blot analysis, and the other, was fixed for histological and immunofluorescence analysis.

Results

Five weeks of HFD results in reduced steroidogenesis, increased apoptosis of spermatogenic cells, and altered spermatogenesis, as highlighted by reduced protein levels ofmeiotic and post-meiotic markers. Further, we evidenced the compromission of the BTB integrity, as revealed by the downregulation of structural proteins (N-Cadherin, ZO-1, occludin, connexin 43, and VANGL2) other than the phosphorylation of regulative kinases (Src and FAK). At the molecular level, the impairment of mitochondrial dynamics (fission, fusion, andbiogenesis), and the dysregulation of the SIRT1/NRF2/MAPKs signaling pathways, were evidenced. Interestingly, no change was observed in the levels of pro-inflammatory markers (TNFα, NF-kB, and IL-6).

Conclusions

The combined data led us to confirm that overweight is a less severe state than obesity. Furthermore, understanding the molecular mechanisms behind the association between metabolic disorders and male fertility could improve the possibility of identifying novel targets to prevent and treat fertility disorders related to overweight/obesity.

Novel Insights into circRNA Saga Coming from Spermatozoa and Epididymis of HFD Mice

Obesity is a pathophysiological disorder associated with adiposity accumulation, oxidative stress, and chronic inflammation state that is progressively increasing in younger population worldwide, negatively affecting male reproductive skills. An emerging topic in the field of male reproduction is circRNAs, covalently closed RNA molecules produced by backsplicing, actively involved in a successful spermatogenesis and in establishing high-quality sperm parameters. However, a direct correlation between obesity and impaired circRNA cargo in spermatozoa (SPZ) remains unclear. In the current work, using C57BL6/J male mice fed with a high-fat diet (HFD, 60% fat) as experimental model of oxidative stress, we investigated the impact of HFD on sperm morphology and motility as well as on spermatic circRNAs. We performed a complete dataset of spermatic circRNA content by a microarray strategy, and differentially expressed (DE)-circRNAs were identified. Using a circRNA/miRNA/target network (ceRNET) analysis, we identified circRNAs potentially involved in oxidative stress and sperm motility pathways. Interestingly, we demonstrated an enhanced skill of HFD sperm in backsplicing activity together with an inefficient epididymal circRNA biogenesis. Fused protein in sarcoma (FUS) and its ability to recruit quaking (QKI) could be involved in orchestrating such mechanism.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

The effect of obesity on human reproductive health and foetal life

Obesity in both women and men is regarded as one of the many factors that may contribute to impaired reproductive health. Obesity can be accompanied by several neuroendocrine and ovarian dysfunctions, including chronic oligo/anovulation, menstrual irregularities, subfertility, and the increased risk of pregnancy in women. Insulin resistance, elevated triglyceride and fatty acid levels, and the secretion of adipocytokines caused by the excessive accumulation of adipose tissue associated with obesity adversely affect reproductive functions. Alterations in sperm quality and motility and hormone levels related to a rise in body mass index (BMI) may predispose men to infertility. The mechanisms of action of obesity on male infertility include endocrinopathy, erectile dysfunction, epididymitis, increased leptin and adipocytes, increased aromatase, inflammatory cytokines secreted by fat tissue, and sperm DNA fragmentation. This study reports that an increased BMI may lead to low semen quality, poor sperm motility, and reduced fertilization rates in men as well as anovulation, pregnancy loss, diminished pregnancy, and low live birth rates in women. Having optimal weight with balanced nutrition enables one to maintain a continuity of reproductive health throughout the entire life cycle, which is extremely important in terms of having a healthy embryo, including pre-foetal life, in the continuity of pregnancy and having a live birth.

Obesity: A Doorway to a Molecular Path Leading to Infertility

The dramatic rise in obesity has recently made it a global health issue. About 1.9 billion were overweight, and 650 million global populations were obese in 2016. Obese women suffer longer conception time, lowered fertility rates, and greater rates of miscarriage. Obesity alters hormones such as adiponectin and leptin, affecting all levels within the hypothalamic-pituitary-gonadal axis. Advanced glycation end products (AGEs) and monocyte chemotactic protein-1 (MCP-1) are inflammatory cytokines that may play an important role in the pathophysiology of ovarian dysfunction in obesity. In obese males, there are altered sperm parameters, reduced testosterone, increased estradiol, hypogonadism, and epigenetic modifications transmitted to offspring. The focus of this article is on the possible adverse effects on reproductive health resulting from obesity and sheds light on different molecular pathways linking obesity with infertility in both female and male subjects. Electronic databases such as Google Scholar, Embase, Science Direct, PubMed, and Google Search Engine were utilized to find obesity and infertility-related papers. The search strategy is detailed in the method section. Even though multiple research work has shown that obesity impacts fertility in both male and female negatively, it is significant to perform extensive research on the molecular mechanisms that link obesity to infertility. This is to find therapeutics that may be developed aiming at these mechanisms to manage and prevent the negative effects of obesity on the reproductive system.

Impact of paternal body mass index on assisted reproduction treatment outcomes: An updated systematic review and meta-analysis

AIM

The aim was to provide updated evidence on the association of male body mass index (BMI) with outcomes of assisted reproduction technology (ART).

METHODS

PubMed, Embase, and Scopus databases were systematically searched. The review included observational studies in patients undergoing ART, that is, either in-vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) and compared rate of clinical pregnancy and live birth based on different categories of male BMI. Quality of the pooled findings was assessed using the GRADE criteria.

RESULTS

A total of 19 studies were included in the review. Among subjects undergoing IVF, there were no significant differences in the rates of clinical pregnancy among overweight (odds ratio [OR] 1.38, 95% confidence interval [CI]: 0.65, 2.96) and obese (OR 1.86, 95% CI: 0.75, 4.58) BMI, compared to normal male BMI. Similarly, there were no significant differences in the rates of live birth among overweight (OR 1.04, 95% CI: 0.97, 1.13) and obese BMI (OR 0.90, 95% CI: 0.69, 1.18) when compared to males with normal BMI. Further, among those undergoing ICSI, there were no significant differences in the odds of clinical pregnancy among overweight (OR 0.98, 95% CI: 0.73, 1.33) and obese (OR 0.89, 95% CI: 0.62, 1.29). The odds of live births among overweight (OR 0.97, 95% CI: 0.89, 1.05) and obese (OR 0.95, 95% CI: 0.84, 1.07) male BMI were statistically similar to males with normal BMI undergoing ICSI.

CONCLUSIONS

The low to very low-quality findings suggest no significant association of overweight and obese BMI with clinical pregnancy and live birth rates among couples undergoing either IVF or ICSI.

Abnormal BMI in Male and/or Female Partners Are Deleterious for Embryonic Development and Pregnancy Outcome During ART Process: A Retrospective Study

OBJECTIVE

To investigate the effect of BMI in male and/or female partners on embryo development and clinical pregnancy outcome during ART.

METHODS

Data of 11,130 cycles between January 2018 and December 2020 were retrospectively analyzed. They were divided into Group A, B, C, and D based on couples' BMI values, also were divided into Group I, II, III and IV in IVF cycles and Group i, ii, iii, and iv in ICSI cycles. After grouping, inter-group indicators comparisons and logistic regression analysis were performed.

RESULTS

In IVF cycles, CPR in Group I and Group III were higher than Group IV. In Group III, it was higher than Group II. The AR in Group IV was higher, but the LBR was lower than Group I, Group II, and Group III. Logistic regression analysis results suggested that AR in Group IV was higher than that in Group I in IVF cycles, whereas LBR was lower.In ICSI cycles, high-quality embryo rate in Group i and Group ii were both higher than that in Group iii and Group iv. The CPR in Group i was higher than Group ii and Group iv, and in Group iii was higher than Group ii and Group iv. The AR in Group i was lower than Group iii and Group iv, and AR in Group ii was lower than Group iv. LBR, in Group I it was higher than Group ii, Group iii, and Group iv. Logistic regression analysis results suggested CPR in Group ii was significantly lower than that in Group i. AR in Group iii was considerably higher than that in Group i. LBR in Group ii and Group iv were significantly lower than that in Group i.

CONCLUSION

Female higher BMI was not conducive to the formation of high-quality embryos in ICSI cycle. Female and/or male BMI affected AR and LBR more than CPR not only in IVF cycles, but also in ICSI cycles.

A higher preconceptional paternal body mass index influences fertilization rate and preimplantation embryo development

Background

Obesity is a worldwide problem affecting the health of millions of people throughout the life course. Studies reveal that obesity impairs sperm parameters and epigenetics, potentially influencing embryonic development.

Objective

To investigate the association between preconceptional paternal body mass index (BMI) and embryo morphokinetics using a time‐lapse incubator and in vitro fertilization (IVF) and intracytoplasmic sperm injection (ICSI) outcomes.

Materials and methods

Participants were recruited from a tertiary hospital in this prospective periconceptional cohort study. A total of 211 men were included: 86 with normal weight (BMI < 25.0), 94 overweight (BMI 25–29.9), and 41 obese (BMI ≥ 30). These men were part of a couple that underwent IVF/ICSI treatment with ejaculated sperm after which 757 embryos were cultured in a time‐lapse incubator. The main outcome parameters consisted of fertilization rate, embryo developmental morphokinetics, embryo quality assessed by a time‐lapse prediction algorithm (KIDScore), and live birth rate.

Results

A higher paternal BMI was associated with faster development of the preimplantation embryo, especially during the first cleavage divisions (t2: −0.11 h (p = 0.05) and t3: −0.19 h (p = 0.01)). Embryo quality using the KIDScore was not altered. The linear regression analysis, after adjustment for confounders (paternal age, ethnicity, smoking, alcohol use, education, total motile sperm count, and maternal age and BMI), showed an inverse association between paternal BMI and fertilization rate (effect estimate: −0.01 (p = 0.002)), but not with the live birth rate.

Discussion and conclusion

Our data demonstrate that a higher preconceptional paternal BMI is associated with a reduced fertilization rate in IVF/ICSI treatment. Our findings underline the importance of a healthy paternal weight during the preconception period.

Obesity and reproduction: a committee opinion

The purpose of this American Society for Reproductive Medicine Practice Committee report is to provide clinicians with principles and strategies for the evaluation and treatment of couples with infertility associated with obesity. This revised document replaces the Practice Committee document titled "Obesity and reproduction: an educational bulletin" last published in 2015 (Fertil Steril 2015;104:1116-26).

The Combined Impact of Female and Male Body Mass Index on Cumulative Pregnancy Outcomes After the First Ovarian Stimulation

Objectives

To evaluate the combined impact of male and female BMI on cumulative pregnancy outcomes after the first ovarian stimulation.

Design

Retrospective cohort study.

Setting

University-affiliated reproductive medicine center.

Patients

A total of 15,972 couples undergoing their first ovarian stimulations from June 2009 to June 2016 were included. During the follow-up period between June 2009 and June 2018, 14,182 couples underwent a complete ART cycle involving fresh embryo transfer and subsequent frozen embryo transfers (FETs) after their first ovarian stimulations. Patients with a BMI <24 kg/m2 served as the reference group. Patients with a BMI ≥ 24 kg/m2 were considered to be overweight, and those with a BMI ≥28 kg/m2 were considered to be obese.

Interventions

None.

Primary Outcome Measure

The primary outcome was the cumulative live birth rate (CLBR), which defined as the delivery of at least one live birth in the fresh or in the subsequent FET cycles after the first ovarian stimulation.

Results

In the analyses of females and males separately, compared with the reference group, overweight and obese females had a reduced CLBR (aOR 0.83, 95% CI 0.7.92 and aOR 0.76, 95% CI 0.64-0.90). Similarly, overweight males had a reduced CLBR (aOR 0.91, 95% CI 0.83-0.99) compared with that of the reference group. In the analyses of couples, those in which the male was in the reference or overweight group and the female was overweight or obese had a significantly lower CLBR than those in which both the male and female had a BMI <24 kg/m2.

Conclusions

The CLBR is negatively impacted by increased BMI in the female and overweight status in the male, both individually and together.

Inheritable testicular metabolic memory of high-fat diet causes transgenerational sperm defects in mice

The consumption of energy-dense diets has contributed to an increase in the prevalence of obesity and its comorbidities worldwide. The adoption of unhealthy feeding habits often occurs at early age, prompting the early onset of metabolic disease with unknown consequences for reproductive function later in life. Recently, evidence has emerged regarding the intergenerational and transgenerational effects of high-fat diets (HFD) on sperm parameters and testicular metabolism. Hereby, we study the impact of high-fat feeding male mice (F₀) on the testicular metabolome and function of their sons (F₁) and grandsons (F₂). Testicular content of metabolites related to insulin resistance, cell membrane remodeling, nutritional support and antioxidative stress (leucine, acetate, glycine, glutamine, inosine) were altered in sons and grandsons of mice fed with HFD, comparing to descendants of chow-fed mice. Sperm counts were lower in the grandsons of mice fed with HFD, even if transient. Sperm quality was correlated to testicular metabolite content in all generations. Principal Component Analysis of sperm parameters and testicular metabolites revealed an HFD-related phenotype, especially in the diet-challenged generation and their grandsons. Ancestral HFD, even if transient, causes transgenerational "inherited metabolic memory" in the testicular tissue, characterized by changes in testicular metabolome and function.

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.

Association Between Body Mass Index and Male Sperm Apoptosis and Apoptosis-Related Factors

BACKGROUND

Although obesity may affect reproductive functions, the molecular mechanisms of apoptosis-related biomarkers remain uncertain.

OBJECTIVE

To examine the effects of body mass index on sperm quality and apoptosis-related factors in seminal plasma of men.

METHODS

Data for 54 subfertile men were collected at our reproductive medical center. The men were divided into normal weight, overweight, and obese groups based on their body mass index (BMI). Sperm DNA fragmentation (sperm chromatin structure analysis), sperm apoptosis (annexin V), and sperm apoptosis-related factors (antibody array assay) were assessed and their relationships with BMI were analyzed.

RESULTS

BMI was not significantly related to age, duration of infertility, duration of sexual abstinence, semen volume, sperm concentration, or rate of normal sperm morphology (p > 0.05). However, progressive sperm motility was significantly reduced and the rates of sperm DNA fragmentation index (DFI) and sperm apoptosis were significantly increased in overweight and obese men compared with men with normal BMI. Fas/Fasl, Bcl-2/Bax, caspase-3, caspase-8, p53, and p21 were all upregulated in the overweight and obese groups. Protein function annotation by Gene Ontology analysis and Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that apoptosis-related factors were enriched in a network associated with activation of apoptotic signaling pathways, such as apoptosis and p53 signaling.

CONCLUSION

These data suggest that increased BMI is associated with increased sperm apoptosis and sperm DNA damage, as well as accelerated expression of apoptosis-related factors via the activation of apoptotic signaling pathways.

Obesity and male infertility: Mechanisms and management

Obesity is considered a global health problem affecting more than a third of the population. Complications of obesity include cardiovascular diseases, type 2 diabetes mellitus, malignancy (including prostatic cancer), neurodegeneration and accelerated ageing. In males, these further include erectile dysfunction, poor semen quality and subclinical prostatitis. Although poorly understood, important mediators of obesity that may influence the male reproductive system include hyperinsulinemia, hyperleptinemia, chronic inflammation and oxidative stress. Obesity is known to disrupt male fertility and the reproduction potential, particularly through alteration in the hypothalamic-pituitary-gonadal axis, disruption of testicular steroidogenesis and metabolic dysregulation, including insulin, cytokines and adipokines. Importantly, obesity and its underlying mediators result in a negative impact on semen parameters, including sperm concentration, motility, viability and normal morphology. Moreover, obesity inhibits chromatin condensation, DNA fragmentation, increases apoptosis and epigenetic changes that can be transferred to the offspring. This review discusses the impact of obesity on the male reproductive system and fertility, including associated mechanisms. Furthermore, weight management strategies, lifestyle changes, prescription medication, and complementary and alternative medicine in the management of obesity-induced subfertility is discussed.

Association between blood lipid level and embryo quality during in vitro fertilization

The aim of this study was to investigate the relationship between blood lipid level and the parameters of embryo morphology of in vitro fertilization (IVF).A total of 488 patients undergoing conventional IVF were divided into pregnant (n = 286) and nonpregnant (n = 202) groups. Levels of triglycerides (TG), total cholesterol (TC), high-density lipoproteins (HDL), low-density lipoprotein (LDL), lipoprotein (a), lipoprotein (b), and embryo outcomes were studied. Spearman correlation was performed to analyze the correlation between blood lipid levels and embryo quality in pregnant group.The normal fertilization rate and number of good quality embryos were higher than nonpregnant group (P < .05). TG, TC, and LDL levels were negatively correlated with number of normal fertilized oocytes, while TG, TC, and Lp(b) were negatively correlated with number of good quality embryos. TG level was negatively correlated with number of oocytes and cleavage embryos while HDL and Lp(a) were positively correlated with number of oocytes, normal fertilized oocytes and cleavage embryos (P < .05).TG, TC, LDL, and Lp(b) levels had negative correlation with embryo quality, while HDL and Lp(a) had positive correlation with the embryo quality. Our present findings showed blood lipid levels may provide certain reference for the prediction of IVF pregnancy outcome.

Effects of obesity on sperm retrieval, early embryo quality and clinical outcomes in men with nonobstructive azoospermia undergoing testicular sperm aspiration-intracytoplasmic sperm injection cycles

The objective of this study was to assess the effects of body mass index (BMI) on sperm retrieval, early embryo quality and clinical outcomes in patients with nonobstructive azoospermia (NOA) undergoing testicular sperm aspiration-intracytoplasmic sperm injection (TESA-ICSI). A total of 3,005 infertile couples were evaluated between January 2010 and June 2017, including 1585 normal-weight (BMI < 25 kg/m² ), 847 overweight (BMI 25-29.99 kg/m² ) and 573 obese (BMI ≥ 30 kg/m² ) patients. We found no significant relationship between BMI and sperm retrieval rate (22.4%, 24.3% and 25.1%, p = 0.327) or sperm motility. Among the 705 patients with NOA who underwent TESA-ICSI cycles, obese individuals had lower T levels and higher E2 levels than normal-weight and overweight individuals. However, there were no significant differences in other male hormones (follicle stimulating hormone [FSH], luteinizing hormone [LH], or prolactin [PRL]) among the groups. We also found that the sperm parameters, embryo quality and clinical outcomes of patients with NOA undergoing TESA-ICSI were not influenced by high BMI levels. In conclusion, this study demonstrated a lack of obvious effects of obesity on sperm retrieval, early embryo quality and clinical outcomes in infertile men undergoing TESA-ICSI cycles, although T and E2 levels were affected.

The Effects of Maternal and Paternal Body Mass Index on Live Birth Rate after Intracytoplasmic Sperm Injection Cycles

Background

We designed the present study to evaluate the simultaneous effect of obesity in couples on in vitro fertilization/ intracytoplasmic sperm injection (IVF/ICSI) outcomes.

Materials and Methods

In this cross-sectional study, performed at Royan Institute between January 2013 and January 2014, we evaluated the recorded data of all patients during this time period. The study population was limited to couples who underwent ICSI or IVF/ICSI cycles with autologous oocytes and fresh embryo transfers. We recorded the heights and weights of both genders and divided them into groups according to body mass index (BMI). Multilevel logistic regression analysis was used to determine the odds ratio for live births following ICSI or IVF/ICSI.

Results

In total, 990 couples underwent IVF/ICSI cycles during the study period. Among the ovulatory women, a significant difference existed between the BMI groups. There was a 60% decrease [95% confidence interval (CI): 0.11-0.83] in the odds of a live birth among overweight subjects and 84% (95% CI: 0.02-0.99) decrease among obese subjects. Among the anovulatory women, the association between the BMI and live births presented no clear tendencies. We did not observe any significant relationship between male BMI and live birth rate. The results demonstrated no significant association between the couples' BMI and live birth rate.

Conclusion

Based on the present findings, increased female BMI independently and negatively influenced birth rates after ICSI. However, increased male BMI had no impact on live births after ICSI, either alone or combined with increased female BMI.

Body Mass Index Effects Kruger's Criteria in Infertile Men

Background

The aim of this study is to evaluate the relationship between sperm parameters and body mass index (BMI) in the male spouses with infertility complaints, who had reffered to our clinic.

Materials and Methods

The male spouses from 159 couples reffering to our clinic because of infertility, during a six-month period, were included in the study. In this prospective case control study, the included men were catego- rized as non-obese (BMI<25 kg/m²), overweight (BMI 25-29 kg/m²) and obese (BMI ≥30 kg/m²) according to their BMIs. The assessed sperm parameters consisted of; sperm concentration, Kruger morphology, progressive motility level, and volume pH levels. The statistical significant level was set as less than 0.05 .

Results

The assessed group consisted of 159 patients applying to our clinic with infertility symptoms. Fifty-three non-obese, 53 overweight and 53 obese men were eligible for the study. There was statistically significant differences in sperm volume (P<0.001), progressive motility (P<0.001), postwash sperm count (P<0.001) and Kruger (P<0.001) morphology among the patient groups grouping according to the BMI levels.

Conclusion

In this study, increased BMI was associated with decreased semen quality, affecting volume, concentra- tion, and motility. further studies with a wider range of prospective cases need to be conducted in order to investigate the effects on male fertility in more detail.

Obesity and reproduction: a committee opinion

The purpose of this ASRM Practice Committee report is to provide clinicians with principles and strategies for the evaluation and treatment of couples with infertility associated with obesity. This revised document replaces the Practice Committee document titled, "Obesity and reproduction: an educational bulletin," last published in 2008 (Fertil Steril 2008;90:S21-9).

Paternal obesity negatively affects male fertility and assisted reproduction outcomes: a systematic review and meta-analysis

This systematic review investigated the effect of paternal obesity on reproductive potential. Databases searched were Pubmed, Ovid, Web of Science, Scopus, Cinahl and Embase. Papers were critically appraised by two reviewers, and data were extracted using a standardized tool. Outcomes were: likelihood of infertility, embryo development, clinical pregnancy, live birth, pregnancy viability, infant development, sperm; concentration, morphology, motility, volume, DNA fragmentation, chromatin condensation, mitochondrial membrane potential (MMP), and seminal plasma factors. Thirty papers were included, with a total participant number of 115,158. Obese men were more likely to experience infertility (OR = 1.66, 95% CI 1.53-1.79), their rate of live birth per cycle of assisted reproduction technology (ART) was reduced (OR = 0.65, 95% CI 0.44-0.97) and they had a 10% absolute risk increase of pregnancy non-viability. Additionally, obese men had an increased percentage of sperm with low MMP, DNA fragmentation, and abnormal morphology. Clinically significant differences were not found for conventional semen parameters. From these findings it can be concluded that male obesity is associated with reduced reproductive potential. Furthermore, it may be informative to incorporate DNA fragmentation analysis and MMP assessment into semen testing, especially for obese men whose results suggest they should have normal fertility.

Effect of male and female body mass index on pregnancy and live birth success after in vitro fertilization

OBJECTIVE

To assess the effects of both male and female body mass index (BMI), individually and combined, on IVF outcomes.

DESIGN

Prospective cohort study.

SETTING

University fertility center.

PATIENT(S)

All couples undergoing first fresh IVF cycles, 2005-2010, for whom male and female weight and height information were available (n = 721 couples).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Embryologic parameters, clinical pregnancy, and live birth incidence.

RESULT(S)

The average male BMI among the study population was 27.5 ± 4.8 kg/m(2) (range, 17.3-49.3 kg/m(2)), while the average female BMI (n = 721) was 25.2 ± 5.9 kg/m(2) (range, 16.2-50.7 kg/m(2)). Neither male nor female overweight (25-29.9 kg/m(2)), class I obese (30-34.9 kg/m(2)), or class II/III obese (≥35 kg/m(2)) status was significantly associated with fertilization rate, embryo score, or incidence of pregnancy or live birth compared with normal weight (18.5-24.9 kg/m(2)) status after adjusting for male and female age, partner BMI, and parity. Similar null findings were found between combined couple BMI categories and IVF success.

CONCLUSION(S)

Our findings support the notion that weight status does not influence fecundity among couples undergoing infertility treatment. Given the limited and conflicting research on BMI and pregnancy success among IVF couples, further research augmented to include other adiposity measures is needed.