Effect of male body mass index on clinical outcomes following assisted reproductive technology: a meta-analysis

Obesity and male fertility disorders

Often associated with obesity, male infertility represents a widespread condition that challenges the wellbeing of the couple. In this article, we provide a comprehensive and critical analysis of studies exploring the association between obesity and male reproductive function, to evaluate the frequency of this association, and establish the effects of increased body weight on conventional and biofunctional sperm parameters and infertility. In an attempt to find possible molecular markers of infertility in obese male patients, the numerous mechanisms responsible for infertility in overweight/obese patients are reviewed in depth. These include obesity-related functional hypogonadism, insulin resistance, hyperinsulinemia, chronic inflammation, adipokines, irisin, gut hormones, gut microbiome, and sperm transcriptome. According to meta-analytic evidence, excessive body weight negatively influences male reproductive health. This can occurr through a broad array of molecular mechanisms. Some of these are not yet fully understood and need to be further elucidated in the future. A better understanding of the effects of metabolic disorders on spermatogenesis and sperm fertilizing capacity is very useful for identifying new diagnostic markers and designing therapeutic strategies for better clinical management of male infertility.

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.

Sperm DNA damage: The possible link between obesity and male infertility, an update of the current literature

Obesity prevalence worldwide is increasing significantly. Whilst maternal obesity has clear detrimental impacts on fertility, pregnancy and foetal outcomes, more recently there has been an increasing focus on the role of paternal obesity in human fertility. Recent meta-analyses have indicated that obesity in men negatively affects basic sperm parameters such as sperm count, concentration and motility, increases the incidence of infertility and reduces the chances of conception. Sperm DNA damage, typically characterised by DNA strand breaks and oxidation of DNA nucleotides, is a specialised marker of sperm quality that has been independently associated with recurrent miscarriage, reduced assisted reproduction success and increased mutational loads in subsequent offspring. Whilst, there are still conflicting data in humans as to the association of obesity in men with sperm DNA damage, evidence from rodent models is clear, indicating that male obesity increases sperm DNA damage. Human data are often conflicting because of the large heterogeneity amongst studies, the use of body mass index as the indicator of obesity and the methods used for detection of sperm DNA damage. Furthermore, comorbidities of obesity (i.e., heat stress, adipokines, insulin resistance, changes in lipids, hypogonadism and obstructive sleep apnoea) are also independently associated with increased sperm DNA damage that is not always modified in men with obesity, and as such may provide a causative link to the discrepancies amongst human studies. In this review, we provide an update on the literature regarding the associations between obesity in men and fertility, basic sperm parameters and sperm DNA damage. We further discuss potential reasons for the discrepancies in the literature and outline possible direct and indirect mechanisms of increased sperm DNA damage resulting from obesity. Finally, we summarise intergenerational obesity through the paternal linage and how sperm DNA damage may contribute to the transmission.

Male obesity: Associated effects on fertility and the outcomes of offspring

Obesity rates are increasing globally, making it imperative to comprehend the effects of parental obesity on human reproduction. This review aims to highlight the impact of male obesity on reproductive and offspring outcomes. Male obesity has been shown to affect fertility through various mechanisms, including changes in semen quality, difficulty with natural conception, and worsened assisted reproductive technology outcomes. The evidence regarding the impact of male obesity on success of sperm retrieval is conflicting, but all aforementioned adverse effects may be modifiable with weight loss. Moreover, paternal obesity may influence atypical offspring outcomes, such as placental abnormalities and disruptions in fetal development, which may be moderated by epigenetic pathways. Further research is needed to fully understand the complex relationships and underlying mechanisms involved. Gaining more insight into the impact of male obesity on fertility and offspring outcomes can aid in the development of targeted interventions to improve family planning and the health of future generations.

Obesity and male infertility

The worldwide prevalence of obesity is increasing among both sexes, with associated impacts on chronic health and medical comorbidities. Similarly, the effects of obesity on reproductive health are increasingly being recognized. Adiposity is associated with reduced fertility in men, with a complex and multifactorial etiology. The reported effects of obesity on semen parameters and impaired fertility are contrasting, with some studies showing a clear reduction in reproductive outcomes associated with increased body mass index, while others do not show such impacts. These controversies may be due to the complex pathophysiology and interplay between gonadotropins and end organs, as well as genetic and epigenetic changes and oxidative stress on male fertility and function. These different aspects have led to heterogeneous participants in studies and varying implications for assisted reproductive outcomes as well as offspring health. Treatment modalities to manage obesity include lifestyle, medical, and surgical options, with emerging and effective medical treatments showing promise in reproductive outcomes.

The influence of male and female overweight/obesity on IVF outcomes: a cohort study based on registration in Western China

BACKGROUND

Overweight/obesity can affect fertility, increase the risk of pregnancy complications, and affect the outcome of assisted reproductive technology (ART). However, due to confounding factors, the accuracy and uniformity of published findings on IVF outcomes have been disputed. This study aimed to assess the effects of both male and female body mass index (BMI), individually and in combination, on IVF outcomes.

METHODS

This retrospective cohort study included 11,191 couples undergoing IVF. Per the Chinese BMI standard, the couples were divided into four groups: normal; female overweight/obesity; male overweight/obesity; and combined male and female overweight/obesity. The IVF outcomes of the four groups were compared and analysed.

RESULTS

Regarding the 6569 first fresh IVF-ET cycles, compared with the normal weight group, the female overweight/obesity and combined male/female overweight/obesity groups had much lower numbers of available embryos and high-quality embryos (p < 0.05); additionally, the fertilization (p < 0.001) and normal fertilization rates (p < 0.001) were significantly decreased in the female overweight/obesity group. The combined male/female overweight/obesity group had significant reductions in the available embryo (p = 0.002), high-quality embryo (p = 0.010), fertilization (p = 0.001) and normal fertilization rates (p < 0.001); however, neither male or female overweight/obesity nor their combination significantly affected the clinical pregnancy rate (CPR), live birth rate (LBR) or abortion rate (p > 0.05).

CONCLUSION

Our findings support the notion that overweight/obesity does not influence pregnancy success; however, we found that overweight/obesity affects the fertilization rate and embryo number and that there are sex differences.

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.

Effect of Female and Male Body Mass Index on Cumulative Live Birth Rates in the Freeze-all Strategy

CONTEXT

The impact of parental overweight/obese on cumulative live birth rate in in vitro fertilization/intracytoplasmic sperm injection using a freeze-all strategy is still unknown.

OBJECTIVE

To explore the effect of parental body mass index (BMI) on cumulative live birth rate (CLBR) in a freeze-all strategy over 1.5 years.

METHODS

This was a retrospective study in a tertiary care academic medical center; 23 482 patients (35 289 frozen-thawed embryo transfer cycles) were divided into 4 groups according to Asian BMI classification. The main outcome measure was CLBR.

RESULTS

Female overweight/obesity had a lower tendency in CLBR (groups 1-4: optimistic: 69.4%, 67.9%, 62.3%, and 65.7%; conservative: 62.9%, 61.1%, 55.4%, and 57.6%) and prolonged time (groups 1-4: 11.0, 12.2, 15.9, and 13.8 months for 60% CLBR in the optimistic method; 8.7, 9.5, 11.7, 11.0 months for 50% CLBR in the conservative method). The same trend to a lesser extent was also observed in male BMI groups. When combining parental BMI, "parental overweight/obesity" had lower CLBR and longer time for reaching CLBR >50% (optimistic: 4.5 months for 60% CLBR; conservative: 3 months for 50% CLBR), followed by "only female high BMI" (optimistic: 2.1 months for 60% CLBR; conservative: 1.7 months for 50% CLBR), while "only male high BMI" had no influence.

CONCLUSION

Our results showed the importance of parental BMI, female BMI, and male BMI on the 1.5-year CLBR using a freeze-all strategy; the time to reach the CLBR (60% in optimistic, 50% in conservative) for overweight and obese patients was several months, but it is not as long as losing weight.

Molecular Mechanisms Underlying the Relationship between Obesity and Male Infertility

In recent decades, the worldwide prevalence of obesity has risen dramatically and is currently estimated to be around 20%. Obesity is linked to an increased risk of comorbidities and premature mortality. Several studies have shown that obesity negatively impacts male fertility through various mechanisms. This review aims to investigate the molecular mechanisms through which obesity impairs male reproduction, including obesity-associated hypogonadism and its effects on spermatogenesis, chronic inflammation, and oxidative stress. Obesity negatively impacts both conventional and biofunctional sperm parameters, and it also induces epigenetic changes that can be transferred to offspring. Moreover, obesity-related diseases are linked to a dysregulation of adipocyte function and micro-environmental inflammatory processes. The dysregulated adipokines significantly influence insulin signaling, and they may also have a detrimental effect on testicular function. Sirtuins can also play an important role in inflammatory and metabolic responses in obese patients. Understanding the molecular mechanisms that are involved in obesity-induced male infertility could increase our ability to identify novel targets for the prevention and treatment of obesity and its related consequences.

Association of parental prepregnancy BMI with neonatal outcomes and birth defect in fresh embryo transfer cycles: a retrospective cohort study

Background

Parental body mass index (BMI) is associated with pregnancy outcomes. But the effect of parental prepregnancy BMI on offspring conceived via in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI), especially the birth defect, remains to be determined. This study aimed to investigate the associations of parental prepregnancy BMI with neonatal outcomes and birth defect in fresh embryo transfer cycles.

Methods

We conducted a retrospective cohort study including 5741 couples in their first fresh IVF/ICSI cycles admitted to Women’s Hospital, School of Medicine, Zhejiang University from January 2013 to July 2016. The primary outcome was birth defects, which was classified according to the International Classification of Diseases, 10th Revision. Secondary outcomes included preterm delivery rate, infant gender, birth weight, small-for-gestational age (SGA) and large-for-gestational age (LGA). Multilevel regression analyses were used to assess the associations of parental prepregnancy BMI with neonatal outcomes and birth defect.

Results

In singletons, couples with prepregnancy BMI ≥25 kg/m² had higher odds of LGA than those with BMI < 25 kg/m². The birth defect rate was significantly higher when paternal prepregnancy BMI ≥25 kg/m² in IVF cycles (aOR 1.82, 95% CI 1.06–3.10) and maternal BMI ≥25 kg/m² in ICSI cycles (aOR 4.89, 95% CI 1.45–16.53). For subcategories of birth defects, only the odds of congenital malformations of musculoskeletal system was significantly increased in IVF offspring with paternal BMI ≥25 kg/m² (aOR 4.55, 95% CI 1.32–15.71). For twins, there was no significant difference among four groups, except for the lower birth weight of IVF female infants.

Conclusions

Parental prepregnancy BMI ≥25 kg/m² is associated with higher incidence of LGA in IVF/ICSI singletons. Paternal prepregnancy BMI ≥25 kg/m² was likely to have higher risk of birth defect in IVF offspring than those with BMI < 25 kg/m², particularly in the musculoskeletal system. It is essential for overweight or obesity couples to lose weight before IVF/ICSI treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-04261-y.

Potential Adverse Effects of Female and Male Obesity on Fertility: A Narrative Review

CONTEXT

Despite several studies documenting that obesity affects female and male fertility and leads to multiple adverse reproductive outcomes, the mechanisms involved are not elucidated. We aimed to summarize the potential adverse effects of female and male obesity, as well as the impact of weight loss on their fertility status.

EVIDENCE ACQUISITION

This review summarizes papers investigating the potential adverse effects of female and male obesity and the impact of weight-loss interventions on fertility among reproductive age populations. PubMed, Scopus, Web of Science, and Google Scholar databases were searched for retrieving studies published up to November 2019 on obesity/overweight among reproductive age populations.

RESULTS

The review of 68 studies revealed that female and male obesity/overweight increases the risk of sub-fecundity and infertility. The destructive effects of female obesity on reproduction are attributed to a variety of ovarian and extra-ovarian factors. In women with overweight or obesity, the time taken to conceive is longer, and they have a decreased fertility rate, increased requirement for gonadotropins, and higher miscarriage rate when compared to those with normal weight. Male obesity may lead to subfertility, mainly because of the disruption of the hypothalamus-pituitary-gonadal (HPG) axis, increased testicular temperature, impairment of the physical and molecular structure of sperm, decreased sperm quality, and erectile dysfunction due to peripheral vascular disease. Most studies recommend lifestyle interventions as first-line therapy in the general population of women and men with obesity and infertility.

CONCLUSIONS

This study shows the negative effects of female and male overweight and obesity on fertility. Therefore, educational interventions on the adverse effects of obesity and the benefits of weight reduction, such as increasing pregnancy rate, should be considered for couples seeking fertility.

Obesity with High Body Mass Index Does Not Influence Sperm Retrieval in Males with Azoospermia

BACKGROUND The aim of this study was to evaluate the influence of male body mass index (BMI) on the retrieval of sperm from azoospermic patients who were undergoing testicular sperm extraction (TESE). MATERIAL AND METHODS The study included retrospective data of male patients suffering from non-obstructive azoospermia (NOA). Age, BMI, testicular volumes, the serum concentration of the follicle-stimulating hormone (FSH), luteinizing hormone (LH), testosterone, and prolactin were investigated and collected. RESULTS A total of 75 azoospermic males were evaluated between 2014 and 2019, including 35 patients (46.7%) with positive sperm retrieval. The majority of patients (57.3%) had normal BMI (between 20 kg/m² and 25 kg/m²) or first degree obesity (from 25 kg/m² to 30 kg/m²). No statistically significant correlation between BMI and positive sperm retrieval or hormone levels (LH, FSH, SHBG, prolactin) were found. However, lower serum testosterone levels were observed in patients with higher BMI (P=0.035). Receiver operating characteristic curve analysis showed that none of the hormones could potentially predict the positive outcome of TESE. CONCLUSIONS The hormonal levels or patient's BMI could not predict positive sperm retrieval outcome, however a negative correlation between serum testosterone and BMI levels was calculated implicating influence on fertility.

Effect of paternal body mass index on neonatal outcomes of singletons after frozen-thawed embryo transfer cycles: analysis of 7,908 singleton newborns

OBJECTIVE

To investigate the effect of paternal body mass index (BMI) on neonatal outcomes of singletons after frozen-thawed embryo transfer (FET) cycles.

DESIGN

Retrospective cohort study.

SETTING

Tertiary-care academic medical center.

PATIENT(S)

A total of 7,908 singleton newborns were divided into four categories based on their paternal BMI: 284 (3.6%) infants were in the paternal underweight category, 4,678 (59.2%) infants were in the paternal normal weight category, 2,585 (32.7%) infants were in the paternal overweight category, and 361 (4.6%) infants were in the paternal obesity category. In addition, we included only infants of women with normal BMI (18.5 kg/m² ≤ BMI < 25 kg/m²).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Neonatal outcomes.

RESULT(S)

The rates of large for gestational age (LGA) infants were significantly higher among those in the paternal overweight and obesity categories than those in the paternal underweight categories. The rates of very LGA were higher among infants in the paternal overweight categories and lower among infants in the paternal underweight categories than the rates in normal controls. The rates of fetal macrosomia were higher among infants in the paternal overweight categories than among infants in the paternal normal weight categories. Compared with normal controls, Z-scores (gestational age- and sex-adjusted birthweight) were significantly higher among the infants in the paternal overweight and paternal obesity categories and significantly lower among the infants in the paternal underweight categories. A positive association was observed in a multiple linear regression model between paternal BMI and newborn birthweights after adjustment for several potential confounders.

CONCLUSION(S)

Paternal BMI had an independent impact on the birthweight of singletons born after FET cycles. Paternal overweight and paternal obesity were independent risk factors for having LGA infants after FET cycles. Furthermore, paternal overweight was an independent risk factor for fathering infants with macrosomia or very LGA infants after FET cycles.

Intracytoplasmic sperm injection for male infertility and consequences for offspring

Intracytoplasmic sperm injection (ICSI) has become the most commonly used method of fertilization in assisted reproductive technology. The primary reasons for its popularity stem from its effectiveness, the standardization of the procedure, which means that it can easily be incorporated into the routine practice of fertility centres worldwide, and the fact that it can be used to treat virtually all forms of infertility. ICSI is the clear method of choice for overcoming untreatable severe male factor infertility, but its (over)use in other male and non-male factor infertility scenarios is not evidence-based. Despite all efforts to increase ICSI efficacy and safety through the application of advanced sperm retrieval and cryopreservation techniques, as well as methods for selecting sperm with better chromatin integrity, the overall pregnancy rates from infertile men remain suboptimal. Treating the underlying male infertility factor before ICSI seems to be a promising way to improve ICSI outcomes, but data remain limited. Information regarding the health of ICSI offspring has accumulated over the past 25 years, and there are reasons for concern as risks of congenital malformations, epigenetic disorders, chromosomal abnormalities, subfertility, cancer, delayed psychological and neurological development, and impaired cardiometabolic profile have been observed to be greater in infants born as a result of ICSI than in naturally conceived children. However, as subfertility probably influences the risk estimates, it remains to be determined to what extent the observed adverse outcomes are related to parental factors or associated with ICSI.

Metabolically healthy and unhealthy obesity in erectile dysfunction and male infertility

Introduction: Metabolically unhealthy obesity (MUHO) is the most important preventable cardiovascular (CV) risk factor. Recently, the significance of metabolically healthy obesity (MHO) as a CV risk factor has raised increasing interest. MUHO is a known risk factor for erectile dysfunction (ED); however, the effect of MHO on ED has barely been investigated. This review aims at summarizing the evidence supporting the relation of MUHO and MHO to male sexual functioning and fertility. Areas covered: An extensive Medline search on obesity and ED or male infertility was conducted to summarize the role of MUHO or MHO on male sexual dysfunction and infertility. Expert opinion: Longitudinal studies have demonstrated that MHO causes vascular damage, which is consistent with the impairment in penile blood flows found in ED subjects. In this population, MHO is a predictor of CV events. The relationship between male infertility and MUHO is currently debated and data on MHO are almost completely lacking. The only available study did not find an association between obesity classes and semen parameters. Although the andrological correlates of MHO must be better assessed, in the current state, evidence suggests that MHO does not represent a benign condition and measures for improving lifestyle are mandatory.

High-fat diets reduce male reproductive success in animal models: A systematic review and meta-analysis

Sperm counts have shown a progressive decline across the world since the mid-1900s. Global rates of obesity have been climbing at a similarly alarming rate, suggesting that these two factors may be linked. However, studies examining the relationship between body mass index (BMI) and male fertility have produced conflicting results. These discrepancies among studies are commonly attributed to limitations that are inherent in human studies such as correlational data and confounding factors-limitations that are absent from animal studies. Hence, we conducted a systematic review and meta-analysis of animal studies that experimentally induced obesity with a high-fat diet and measured impacts on sperm traits and/or male fertility. Overall, we found strong, consistent evidence in animal studies that high-fat diets are detrimental for male fertility. Compared with controls, males fed a high-fat diet had smaller testes and sex accessory glands relative to body size, reduced semen quality, reduced mating success, and reduced fertilization success. This is the first time that experimental data of high-fat diet effects on male reproduction have been synthesized in a meta-analysis, and thus, our results provide novel insight to the complex question of how dietary-induced obesity affects male fertility. The strong negative effects detected in animal models suggest that the inconsistent results plaguing human studies are an artefact of limitations inherent in correlational studies rather than a true effect.

The impact of sociodemographic characteristics, lifestyle, work exposure and medical history on semen parameters in young Chinese men: A cross-sectional study

There is an ongoing debate on the declining semen quality, and unfortunately, existing evidence is inconclusive and inconsistence. We evaluated the impact of sociodemographic characteristics, lifestyle, medical history and work exposure on semen quality. Univariate and multivariate analysis was used to investigate the association between different risk factors and semen quality parameters. Total sperm count (p = 0.041), sperm concentration (p = 0.007), normal morphology (p = 0.002), total motility (p = 0.004) and progressive motility (p = 0.009) decreased in men with varicocele. Sperm concentration increased in tea (p = 0.044); progressive and total motility increased in cola (p = 0.018, p = 0.012) consumers. Progressive and total motility decreased in urogenital surgery (p = 0.016, p = 0.014) and infection (p = 0.037, p = 0.022). However, age, coffee and alcohol drinking, physical activities, sleep duration and cell phone use were unrelated to any of semen parameters. Interestingly, semen volume (p < 0.0001), total sperm count (p < 0.0001) and concentration (p < 0.033) increased with longer abstinence period (>5 days); normal morphology (p = 0.013) improved in men with higher body mass index (BMI > 24), curvilinear velocity (p = 0.042) increased with smoking; semen volume (p = 0.050) increased in manual labourers. This study highlights the importance of sociodemographic characteristics, lifestyle, occupational exposure and medical history and provides time trends in semen quality, its clinical importance and direction for further research.

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.

The influence of obesity, smoking, and serum follicular stimulating hormone in azoospermic patients on testicular sperm extraction-intra cytoplasmic sperm injection outcomes: A retrospective cohort study

To examine the effect of serum follicle-stimulating hormone (sFSH) level, body-mass index (BMI) and smoking on Testicular Sperm Extraction-Intracytoplasmic Sperm Injection (TESE-ICSI), and pregnancy outcomes.In this retrospective study, data were extracted from files of 52 azoospermic men who underwent TESE and in-vitro fertilization (IVF)-ICSI in our IVF unit. Demographic information, treatment cycle follow-up and pregnancy outcomes were collected.Fifty-two patients underwent 79 TESE due to azoospermia in 143 IVF cycles. Smoking was found to significantly affect sperm motility in TESE specimens before freezing (45.5% vs 14.8%; P <.001); however, this finding did not influence the pregnancy rate. Male FSH was inversely correlated with testicle volume (r = -0.595, P <.0001). Body weight did not affect semen parameters after TESE or ICSI outcomes.Among azoospermic patients with extremely poor sperm quality, male BMI, male FSH or smoking did not have an adverse effect sperm parameters or pregnancy and delivery rates.

Variation of DNA Fragmentation Levels During Density Gradient Sperm Selection for Assisted Reproduction Techniques: A Possible New Male Predictive Parameter of Pregnancy?

Predicting the outcome of in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) is one main goal of the present research on assisted reproduction. To understand whether density gradient centrifugation (DGC), used to select sperm, can affect sperm DNA integrity and impact pregnancy rate (PR), we prospectively evaluated sperm DNA fragmentation (sDF) by TUNEL/PI, before and after DGC. sDF was studied in a cohort of 90 infertile couples the same day of IVF/ICSI treatment. After DGC, sDF increased in 41 samples (Group A, median sDF value: 29.25% [interquartile range, IQR: 16.01-41.63] in pre- and 60.40% [IQR: 32.92-93.53] in post-DGC) and decreased in 49 (Group B, median sDF value: 18.84% [IQR: 13.70-35.47] in pre- and 8.98% [IQR: 6.24-15.58] in post-DGC). PR was 17.1% and 34.4% in Group A and B, respectively (odds ratio [OR]: 2.58, 95% confidence interval [CI]: 0.95-7.04, P = 0.056). After adjustment for female factor, female and male age and female BMI, the estimated OR increased to 3.12 (95% CI: 1.05-9.27, P = 0.041). According to the subgroup analysis for presence/absence of female factor, heterogeneity in the association between the Group A and B and PR emerged (OR: 4.22, 95% CI: 1.16-15.30 and OR: 1.53, 95% CI: 0.23-10.40, respectively, for couples without, n = 59, and with, n = 31, female factor).This study provides the first evidence that the DGC procedure produces an increase in sDF in about half of the subjects undergoing IVF/ICSI, who then show a much lower probability of pregnancy, raising concerns about the safety of this selection procedure. Evaluation of sDF before and after DGC configures as a possible new prognostic parameter of pregnancy outcome in IVF/ICSI. Alternative sperm selection strategies are recommended for those subjects who undergo the damage after DGC.