Subfecundity in overweight and obese couples

Obesity and Reproduction

OBJECTIVE

To provide a comprehensive review and evidence-based recommendations for the delivery of fertility care to women with obesity.

OUTCOMES

The impact of obesity on fertility, fertility treatments, and both short and long-term maternal fetal outcomes was carefully considered.

EVIDENCE

Published literature was reviewed through searches of MEDLINE and CINAHL using appropriate vocabulary and key words. Results included systematic reviews, clinical trials, observational studies, clinical practice guidelines, and expert opinions.

VALUES

The Canadian Fertility & Andrology Society (CFAS) is a multidisciplinary, national non-profit society that serves as the voice of reproductive specialists, scientists, and allied health professionals working in the field of assisted reproduction in Canada. The evidence obtained for this guideline was reviewed and evaluated by the Clinical Practice Guideline (CPG) Committee of the CFAS under the leadership of the principal authors.

BENEFITS, HARMS, AND COSTS

The implementation of these recommendations should assist clinicians and other health care providers in counselling and providing reproductive care to women with obesity.

VALIDATION

This guideline and its recommendations have been reviewed and approved by the membership, the CPG Committee and the Board of Directors of the CFAS.

SPONSORS

Canadian Fertility & Andrology Society.

RECOMMENDATIONS

Twenty-one evidence based recommendations are provided. These recommendations specifically evaluate the impact of obesity on natural fertility, fertility treatments, and maternal-fetal outcomes. Strategies to lose weight and BMI cut-offs are also addressed.

Preconception blood pressure and time to pregnancy among couples attempting to conceive their first pregnancy

BACKGROUND

The association of abnormal blood pressure levels (including hypertension and prehypertension) with reduced fecundability among young childbearing-age couples is not yet elucidated completely.

OBJECTIVE

The purpose of this study was to investigate the association between abnormal preconception blood pressure level and time to pregnancy among couples who are attempting to conceive their first pregnancy.

STUDY DESIGN

A total of 2,234,350 eligible couples (with no previous gravidity and whose female partners were 20-49 years old) participated in the National Free Preconception Check-up Projects from January 1, 2015, to December 31, 2016. Each couples' preconception blood pressure levels were measured, and time to pregnancy was recorded. Cox models for discrete survival time were used to estimate fecundability odds ratios and their corresponding 95% confidence intervals after adjustment for age, ethnicity, educational level, occupation, household registration, region, tobacco exposure, alcohol intake, body mass index, duration of marriage of the couples, and fasting plasma glucose levels of the female partner.

RESULTS

Compared with normotensive women, those women with hypertension (systolic blood pressure ≥140 mm Hg or diastolic blood pressure ≥90 mm Hg) had a 21% lower pregnancy rate (fecundability odds ratio, 0.79; 95% confidence interval, 0.78-0.81). A similar finding was found among men (fecundability odds ratio, 0.89; 95% confidence interval, 0.88-0.90). Prehypertension (systolic blood pressure between 120 and 139 mm Hg, and/or a diastolic blood pressure between 80 and 89 mm Hg) in both male and female partners was associated slightly with reduced fecundability odds ratios. Compared with couples in which both partners were normotensive, the pregnancy rate was reduced by 27% (fecundability odds ratio, 0.73; 95% confidence interval, 0.69-0.77) among couples in which both partners had hypertension.

CONCLUSION

Abnormal preconception blood pressure levels were associated with prolonged time to pregnancy among couples who were attempting to conceive their first pregnancy; the mechanism is worth further investigation.

Association between peri-conceptional bisphenol A exposure in women and men and time to pregnancy-The HOPE study

BACKGROUND

Bisphenol A (BPA) is a non-persistent endocrine-disrupting chemical with nearly ubiquitous, involuntary exposure. Previous studies have shown that BPA causes reproductive dysfunction in animal models, but there are limited data regarding the effects of BPA exposure on time to pregnancy (TTP) in humans.

OBJECTIVE

To evaluate whether peri-conceptional BPA exposure of women and men is associated with couples' TTP.

METHODS

A total of 164 heterosexual couples (164 women; 163 men) who have available BPA information as well as time to pregnancy from the Home Observation of Peri-conceptional Exposures (HOPE) Study were included and were followed up to 12 months. Women collected first-morning urine samples starting at the beginning of the fertile window and continued until the onset of menses or 18 days after the estimated day of ovulation (EDO+18 days). The time to pregnancy (TTP) after the enrolment was self-reported and used for the analysis. Discrete-time Cox proportional hazards models were performed to generate fecundability odds ratio (FOR) between BPA and TTP after adjusting for education and age, accounting for right censoring and prior number of cycles trying to conceive.

RESULTS

Among 164 couples, 125 couples became pregnant during the study. There was no association between TTP and peri-conceptional BPA exposure for both men (FOR 1.02, 95% CI 0.72, 1.47) and women (FOR 1.07, 95% CI 0.75, 1.53) after adjusting for education and age.

CONCLUSIONS

No association was found between peri-conceptional BPA exposure and fecundability in this preconception cohort of relatively young, healthy pregnancy planners.

The role of environmental factors and lifestyle on male reproductive health, the epigenome, and resulting offspring

Many environmental and genetic variables affect male reproductive health. Some of these factors, however, interfere not only with fertility, but also the non-genomic materials within spermatozoa that can cause phenotypic changes in the offspring, and in some cases, multiple generations. This intergenerational and transgenerational inheritance is due to epigenetic modifications, which is a complex adjunct to traditional Mendelian genetics whose influence on a wide range of human diseases is an active area of research. As the epigenome is a gestalt of individual exposures to the world, ongoing research is evaluating the scope of environmental impacts on the epigenome, as well as its mechanisms for adjusting the phenotypic expression of the organism without changing the code itself. Of particular interest is how these traits are passable to subsequent generations. This article will cover the latest data concerning how the overall quality of nutrition and lifestyle of an individual has been demonstrated to have a significant effect on male reproductive health, and how the accumulation of these modifications are risk factors for the health of their offspring.

Metabolic syndrome and smoking are independent risk factors of male idiopathic infertility

Background

Overweight and obesity are known to impact male fertility and are commonly associated with abdominal obesity and metabolic disorders. The association between abdominal obesity or metabolic syndrome with male reproduction has not been fully investigated. Moreover, many factors may interfere with the evaluation of the impact of metabolic syndrome on male fertility. Thus, tobacco is known to alter the spermatic parameters and phenomena linking smoking with metabolic syndrome are therefore complex. The main objective of this study has been to investigate the potential association of metabolic syndrome with male idiopathic infertility given smoking status.

Materiel and methods

The data of this study concerned infertile (n = 96) and fertile (n = 100) men under 45 years of age who have been recruited in the ALIFERT case-control study. Body mass index and waist circumference were measured. Serum triglycerides, cholesterol (total, high density lipoprotein, and low density lipoprotein cholesterol) and fasting blood glucose were assayed. Metabolic syndrome has been diagnosed in the presence of at least three of the following criteria: increased waist circumference, high triglycerides, fasting glucose or arterial blood pressure and low high density lipoprotein cholesterol.

Results

The present study reports that infertile men are in poorer health condition compared to fertile men and are more often smokers. The results of this study suggested metabolic syndrome and smoking to be independent risk factor for idiopathic infertility.

Conclusions

Metabolic syndrome and smoking should systematically be checked at the beginning of medical care in infertile males and personal and multifaceted coaching should be proposed to deal jointly with smoking and metabolic disorders.

Trial registration

NCT01093378 ALIFERT. Registered: March 25, 2010.

Obesity and Hypogonadism-A Narrative Review Highlighting the Need for High-Quality Data in Adolescents

The prevalence of obesity continues to rise in adult and pediatric populations throughout the world. Obesity has a direct impact on all organ systems, including the reproductive system. This review summarizes current knowledge about the effects of obesity on the male reproductive system across age, highlighting the need for more data in children and adolescents. Male hypogonadism is commonly seen in patients with obesity and affects the onset, duration, and progression of puberty. Different pathophysiologic mechanisms include increased peripheral conversion of testosterone to estrone and increased inflammation due to increased fat, both of which lead to suppression of the hypothalamic-pituitary-gonadotropin (HPG) axis and delayed development of secondary sexual characteristics in adolescent males. Evaluation of the HPG axis in obesity includes a thorough history to exclude other causes of hypogonadism and syndromic associations. Evaluation should also include investigating the complications of low testosterone, including increased visceral fat, decreased bone density, cardiovascular disease risk, and impaired mood and cognition, among others. The mainstay of treatment is weight reduction, but medications such as testosterone and clomiphene citrate used in adults, remain scarcely used in adolescents. Male hypogonadism associated with obesity is common and providers who care for adolescents and young adults with obesity should be aware of its impact and management.

Sedentary behavior, physical inactivity and body composition in relation to idiopathic infertility among men and women

BACKGROUND

Physical activity (PA) and sedentary behavior have inconsistent effects on fertility. High body mass index is associated with infertility but to our knowledge, very few studies have explored body composition in association to fertility.

OBJECTIVE

To assess the association between physical inactivity, sedentary behavior, body composition and idiopathic infertility in French men and women.

DESIGN

We conducted a case-control multicentric observational study. 159 infertile (79 men and 80 women) and 143 fertile (72 men and 71 women) were recorded in four fertility centers.

MAIN OUTCOME MEASURES

Participants completed self-administered questionnaires on sociodemographic and lifestyle characteristics, dietary intake, physical activity and sedentary behavior. Anthropometrics were measured, and bioelectrical impedance analysis was used to estimate body composition. Multivariable logistic regression was used to analyze the association of fertility with PA level and sedentary behavior.

RESULTS

In men, being physically inactive (Odd ratio [OR] 2.20; 95% confidence interval [CI], 1.06, 4.58) and having fat mass greater than the reference values for their age (OR 2.83; 95%CI, 1.31, 6.10) were positively associated with infertility. Sedentary behavior and fat-free mass were not related to infertility in men. In women, sedentary behavior (OR 3.61; 95%CI, 1.58, 8.24), high body fat (OR 3.16; 95%CI, 1.36, 7.37) and low fat-free mass (OR 2.65; 95%CI, 1.10, 6.37) were associated with infertility. PA level was not associated with fertility in women.

CONCLUSIONS

This study suggests that sedentary behavior and physical inactivity would represent two independent risk factors associated with infertility. The various elements that make up physical activity (frequency, intensity, time, and type of exercise) and the interrupting time spent sitting should be considered. Body composition variation should be explored further in relation to the biological pathways involved in idiopathic infertility. Moreover, the improvement of lifestyle factors should be considered in infertility treatment.

How much does obesity affect the male reproductive function?

Obesity is considered a worldwide epidemic disease. Many pathological conditions have been associated to obesity but the evidence relating to impaired fertility in males with obesity are contrasting. The aim of this review was to evaluate the interplay between obesity and male fertility, analyzing evidence from in vitro and in vivo studies to clinical trials. Obesity seems to be responsible of secondary hypogonadism. Here, we propose a new classification including central, peripheral and testicular factors that may affect the hypothalamic-pituitary-gonadal axis. Moreover, some studies demonstrated a direct action of obesity on sperm count and sperm characteristics, mediated by impaired Sertoli cells function, increased scrotal temperature, oxidative stress and accumulation of toxic substances and liposoluble endocrine disruptors in fat tissue. Recent studies have explored obesity-related epigenetic effects in sperm cells which may cause diseases in offspring. Moreover, not only in females but also males, obesity has been linked to reduced outcomes of in vitro fertilization, with a reduction of pregnancy rate and an increase of pregnancy loss. Finally, we reviewed the effects of weight modifications through diet or bariatric surgery on obesity-related reproductive dysfunction. In this regard, several studies have demonstrated that weight loss has been associated with a restoration of gonadal hormones levels.

Male partners of subfertile couples in which the spouse is obese display adverse weight and lifestyle associated with reduced sperm quality

OBJECTIVES

To assess: 1-the spousal concordance of lifestyle and anthropometric characteristics between partners of infertile couples in which the woman is obese; and 2-in men, the influence of these characteristics on their conventional seminal parameters.

DESIGN

Cross-sectional study.

SETTING

Fertility clinic of the Centre hospitalier universitaire de Sherbrooke, Canada, between January 2012 and February 2015.

PATIENTS

97 infertile heterosexual couples in which women were obese and seeking fertility treatments.

INTERVENTION

Not applicable.

MAIN OUTCOME MEASURES

Weight and percentage of fat mass were evaluated using a scale with foot-to-foot bio-impedance. Abdominal obesity was estimated with waist circumference and lifestyle habits, by a self-reported questionnaire. Seminal parameters were analysed and collected according to the WHO guidelines (Kruger's strict criteria for seminal morphology).

RESULTS

There was a significant spousal concordance for the percentage of fat mass, leisure activities and overall nutritional quality. Accordingly, male participants displayed anthropometric and lifestyle characteristics at higher risk than Canadian men of similar age. Moreover, BMI, daily consumption of fruits & vegetables and sleeping hours in men were independently associated to the total motile sperm count.

CONCLUSION

This is the first study to report concordance for anthropometric and lifestyle characteristics between partners of infertile couples in which the woman is obese. These characteristics in men were more adverse than in the general population and were associated with reduced sperm quality. Altogether, our results suggest that male partners of infertile couples could benefit from participating in the lifestyle intervention that is already recommended for their spouse affected by obesity.

CAPSULE

Because partners of subfertile couples in which the woman is obese share adverse anthropometric and lifestyle characteristics, male partners should be implicated in lifestyle interventions already indicated for their spouse.

Fecundability among Danish women with a history of miscarriage: a prospective cohort study

OBJECTIVE

To examine the association between history of miscarriage and fecundability (the cycle-specific probability of conception).

DESIGN

Nationwide prospective cohort study using web-based questionnaires.

SETTING

Denmark, 2007-2012.

PARTICIPANTS

977 women attempting to conceive, not using fertility treatment, and with a reproductive history of only miscarriage or only live birth.

EXPOSURE AND OUTCOME MEASURES

Information on previous pregnancy outcomes, including miscarriage, came from self-report or from relevant registries. Participants were followed for up to 12 months or until they reported a pregnancy, stopped trying to conceive or started fertility treatment, whichever came first. We used Kaplan-Meier methods to estimate cumulative probabilities of conception for women whose reproductive history included only miscarriage or only live birth. Using proportional probabilities regression modelling, we computed fecundability ratios (FR) with 95% CI comparing women with a history of only miscarriage with women with a history of only live birth.

RESULTS

After adjustment for potential confounders, the cumulative probabilities of conception within 12 cycles of follow-up were 85% (95% CI 81% to 89%) for women with a history of 1 miscarriage, 85% (95% CI 73% to 92%) for women with a history of ≥2 miscarriages and 88% (95% CI 87% to 89%) for women whose reproductive history included only live birth. Adjusted FRs were 0.87 (95% CI 0.71 to 1.07) and 0.65 (95% CI 0.36 to 1.17) for women with a history of 1 and ≥2 miscarriages, respectively.

CONCLUSIONS

Our results indicate that women with a history of miscarriage may have slightly reduced fecundability compared with women with a history of only live birth. The reduction in fecundability was greater for women with repeated miscarriages, although the estimates were imprecise. Despite a potential delay in conception, women with previous miscarriage may have similar probability of pregnancy by 12 cycles of attempts to women with proven fertility.

Genetically Inherited Obesity and High-Fat Diet-Induced Obesity Differentially Alter Spermatogenesis in Adult Male Rats

Obesity is a multifactorial disorder with predominantly genetic and/or environmental causes. Our aim was to delineate effects of genetically inherited and high-fat diet-induced obesity on fertility and spermatogenesis using two Wistar rat models: genetically inherited obese (GIO) WNIN/Ob rats and diet-induced obese (DIO) rats, which received a high-fat diet. The terminal body weights were similar in both groups, but there was a significant difference in metabolic and hormone profiles between the groups. Fertility assessment revealed a significant decrease in the litter size due to increased pre- and postimplantation loss in the DIO group, whereas the rats in the GIO group were infertile due to lack of libido. Significantly decreased sperm counts were observed in the GIO group compared with the DIO group. Enumeration of testicular cells on the basis of ploidy and cell type-specific expression markers, to study the effect of obesity on spermatogenesis, demonstrated that the GIO and DIO states affected mitosis: spermatogonia and S-phase population were increased. However, distinctive effects were observed on meiosis and spermiogenesis in both the groups. Differential effects of GIO and DIO on fertility and spermatogenesis could be due to the significant difference in white adipose tissue accumulation between the groups and not due to high body weights. The differential effects of obesity suggest male obesity-induced infertility observed in humans could be a combination of genetic and environmental factors.

Obesity, fertility and pregnancy: can we intervene to improve outcomes?

Rates of obesity among women of reproductive age have risen dramatically in recent decades. Obesity impacts on health of women across their reproductive lifespan with adverse effects on not only fertility and short-term complications of pregnancy, but also on longer term health outcomes for both women and their children. This places considerable burden and cost on health services. Here, we review the evidence linking maternal obesity to adverse fertility, pregnancy and longer term health outcomes for women and their children. We discuss the outcomes of recent lifestyle, pharmacological and surgical intervention studies. As many of these studies have not shown a significant improvement in clinical outcomes, we discuss the need for better study design in future trials.

Effects of a preconception lifestyle intervention in obese infertile women on diet and physical activity; A secondary analysis of a randomized controlled trial

BACKGROUND

Lifestyle changes are notoriously difficult. Since women who intend to become pregnant are more susceptible to lifestyle advice, interventions during this time window might be more effective than interventions during any other period in life. We here report the effects of the first large preconception lifestyle intervention RCT on diet and physical activity in obese infertile women.

METHODS

In total, 577 women were randomized between a six-month lifestyle intervention program (intervention group; N = 290) or prompt infertility treatment (control group; N = 287). Self-reported dietary behaviors and physical activity were assessed at baseline, three, six and twelve months after randomization. Mixed models were used to analyze differences between groups.

RESULTS

Compared to the control group, the intervention group reduced their intake of sugary drinks at three months (-0.5 glasses/day [95% C.I. = -0.9;-0.2]), of savory snacks at three (-2.4 handful/week [-3.4;-1.4]) and at six months (-1.4 handful/week [-2.6;-0.2]), and of sweet snacks at three (-2.2 portion/week [-3.3;-1.0]) and twelve months after randomization (-1.9 portion/week [-3.5;-0.4]). Also, the intervention group was more moderate to vigorous physically active at three months after randomization compared to the control group (169.0 minutes/week [6.0; 332.1]).

CONCLUSION

Our study showed that obese infertile women who followed a six-month preconception lifestyle intervention program decreased their intake of high caloric snacks and beverages, and increased their physical activity. These changes in lifestyle may not only improve women's health but their offspring's health too.

Conditioning on Parity in Studies of Perfluoroalkyl Acids and Time to Pregnancy: An Example from the Danish National Birth Cohort

BACKGROUND

Previous studies have investigated the associations between perfluoroalkyl acids (PFAAs) in women and time to pregnancy (TTP). Inconsistent results may be explained by differences in conditioning on parity.

OBJECTIVES

We used causal directed acyclic graphs to illustrate potential confounding related to previous pregnancies and exposure measurement error due to differences in the interpregnancy interval in pregnancy-based studies that include parous women. We exemplified the potential importance of these issues using data from the Danish National Birth Cohort.

METHODS

We used discrete time survival models to estimate associations between maternal plasma PFAAs in early pregnancy and TTP in 638 nulliparous and 613 parous women.

RESULTS

PFAA quartiles were not associated with the TTP in nulliparous women. In parous women, higher PFAA quartiles were associated with longer TTP. The strongest associations were estimated for perfluorohexane sulfonate and perfluorooctane sulfonate. PFAA concentrations were higher in women with longer interpregnancy intervals. Accounting for the interpregnancy interval attenuated the estimated associations.

CONCLUSIONS

Associations between PFAAs and TTP in parous women may be biased by confounders related to previous pregnancies and exposure measurement error. To avoid these biases, studies that include parous women may need to condition on a) common causes of PFAAs and the TTP in the index pregnancy, b) previous births (a descendant of a collider), c) PFAA levels or common causes of PFAA levels and the TTP in the previous pregnancy (to alleviate collider stratification bias caused by conditioning on previous births), and d) the interpregnancy interval (in pregnancy-based studies). Alternatives would be to restrict studies to nulliparous women or to use toxicokinetic modeling to correct exposure estimates in parous women. These recommendations may be extended to studies of other chemicals with similar toxicokinetic properties. https://doi.org/10.1289/EHP1493.

Recent advances in understanding the relationship between long- and short-term weight change and fertility

The impact of excess body weight on fertility is well recognized among both women attempting to conceive spontaneously and those attempting to conceive with medical assistance. Although many leading societies of reproductive medicine have proposed weight loss as a means to counteract the negative consequences of obesity on fertility, there is limited research on this topic. In this review, we provide a brief overview of the recent advances in the literature focused on how long- and short-term weight change affects fertility among women. Overall, despite initial hope that weight loss may be beneficial for fertility, two large well-conducted randomized controlled trials have consistently shown that short-term weight loss among overweight and obese women undergoing infertility treatment does not improve a woman's probability of live birth. The observational evidence among women attempting to conceive without medical assistance also suggests limited benefits of weight loss on fecundity or pregnancy loss. In contrast, substantial weight gain between consecutive pregnancies, in the year prior to pregnancy attempt, and throughout adulthood appears to be harmful for not only time to pregnancy but also pregnancy maintenance. Future research focused on efforts to prevent weight gain during adulthood is needed to better understand whether these types of interventions may have beneficial effects on fertility.

The impact of maternal lifestyle factors on periconception outcomes: a systematic review of observational studies

The main risk factors for important reproductive health issues such as subfertility and perinatal mortality largely originate in the periconception period. To evaluate associations between modifiable maternal lifestyle factors and periconception outcomes, a systematic search was conducted for relevant studies published from 1990 to February 2017 on Embase, Medline, Web of Science, Cochrane database, PubMed and Google Scholar. The initial search identified 6166 articles, of which 49 studies were eligible for inclusion. Fecundity (the capacity to have a live birth) showed significant inverse associations with smoking, alcohol use and poor diet. Studies regarding time to pregnancy showed a decline in fecundity ratios (the monthly conception rate among exposed relative to unexposed couples) with increasing body mass index (BMI). Furthermore, risk of first-trimester miscarriage was found to be increased in smokers, alcohol and caffeine consumers, and with increasing BMI. Vitamin supplement use showed a decrease in this risk. This review demonstrates that maternal modifiable lifestyle factors affect periconception outcomes. If couples planning a pregnancy are more aware and supported to adopt healthy lifestyles during the periconceptional 'window of opportunity', short-term reproductive health as well as health in later life and even of future generations can be further improved.

No independent associations between preconception paternal dietary patterns and embryonic growth; the Predict Study

BACKGROUND & AIM

Several studies show the importance of periconceptional maternal dietary patterns on human embryonic growth. Healthy paternal nutrition has been associated with better semen quality and fecundability, however, evidence on the impact on pregnancy outcome is limited. Therefore, the aim of this study was to investigate the association between preconception paternal dietary patterns and first trimester embryonic growth using the parameters longitudinal crown-rump length (CRL) and embryonic volume (EV).

METHODS

A total of 638 couples were enrolled in the Rotterdam Periconceptional Cohort and received longitudinal three dimensional transvaginal ultrasound scans from 7⁺⁰ up to 12⁺⁰ weeks of gestation. Virtual reality software was used to perform offline measurements of the embryonic CRL and EV. Food frequency questionnaires (FFQ) were used to estimate habitual food intake in couples. Principal component analysis (PCA) was performed to identify paternal and maternal dietary patterns. Linear mixed models adjusted for potential confounders were applied to analyze associations between paternal and maternal dietary patterns and embryonic growth parameters.

RESULTS

The paternal dietary patterns retrieved were identified as "Whole wheat grains and Vegetables", "Sauces and Snacks Refined Grains", "Fish and Legumes" and explained 27.5% of the total variance of the dietary intake. No significant additional effects, independent of maternal dietary patters and other maternal and paternal potential confounders, were shown of these paternal dietary patterns on embryonic growth in spontaneous or IVF/ICSI pregnancies.

CONCLUSION

No significant effects of paternal dietary patterns independent of maternal dietary patters and other parental potential confounders on embryonic growth parameters could be established in spontaneous or IVF/ICSI pregnancies. The biological importance of paternal nutrition on semen quality, however, supports the need of periconceptional tailored nutritional counselling of couples trying to conceive.

Oxidative Stress in the Male Germline: A Review of Novel Strategies to Reduce 4-Hydroxynonenal Production

Germline oxidative stress is intimately linked to several reproductive pathologies including a failure of sperm-egg recognition. The lipid aldehyde 4-hydroxynonenal (4HNE) is particularly damaging to the process of sperm-egg recognition as it compromises the function and the stability of several germline proteins. Considering mature spermatozoa do not have the capacity for de novo protein translation, 4HNE modification of proteins in the mature gametes has uniquely severe consequences for protein homeostasis, cell function and cell survival. In somatic cells, 4HNE overproduction has been attributed to the action of lipoxygenase enzymes that facilitate the oxygenation and degradation of ω-6 polyunsaturated fatty acids (PUFAs). Accordingly, the arachidonate 15-lipoxygenase (ALOX15) enzyme has been intrinsically linked with 4HNE production, and resultant pathophysiology in various complex conditions such as coronary artery disease and multiple sclerosis. While ALOX15 has not been well characterized in germ cells, we postulate that ALOX15 inhibition may pose a new strategy to prevent 4HNE-induced protein modifications in the male germline. In this light, this review focuses on (i) 4HNE-induced protein damage in the male germline and its implications for fertility; and (ii) new methods for the prevention of lipid peroxidation in germ cells.

[Semen quality and fertility: the role of the environment and health]

Sperm quality appears to be degrading over the past 40 years. Nowadays, more than 35 % of causes of male infertility are still idiopathic. More and more studies have suggested an impact of environment on sperm quality, essentially through epigenetic and hormonal changes. Recent studies in men with impaired sperm quality, have demonstrated epigenetic variations in sperm DNA. These modifications are responsible for modifications of the expression of transmissible genes to theiroffspring. Those transgenerational effects have been particularly illustrated in drosophila and caenorhabditis elegans. In humans, consequences of the environment on fertility have been studied in obese men, who present hypogonadotropic as well as hypergonadotropic hypogonadisms. Interestingly, recent studies have suggested a correlation between sperm quality and longevity. In summary, those environmental factors are the source of new causes of infertility.

Linking sleep disturbance to idiopathic male infertility

Recently published data suggests that male fertility has declined over the past four decades. The reasons for the decline are unclear with up to 50% of cases of male infertility remaining unexplained (idiopathic male infertility). Whilst environmental factors and rising rates of obesity have been implicated, there is now growing evidence that sleep disturbance may be an independent causative factor. Indeed, the prevalence of sleep disturbance appears to be increasing in parallel with deterioration in population sperm quality, a commonly used surrogate marker of male fertility. Although there is some understanding of the relationship between sleep, gonadal hormone secretion and sexual function, it remains to be seen whether sleep disturbance is implicated in idiopathic male infertility. This review will detail the current evidence supporting a link between sleep disturbance and male infertility. Potential mechanistic pathways will be proposed and evidence supporting these pathways will be discussed. Further research is needed in clarifying links between sleep disturbance and idiopathic male infertility. At present the only available treatment option for men with idiopathic infertility is assisted reproductive technology. Demonstration of a causative link between sleep disturbance and idiopathic male infertility may in the future lead to additional treatment options in selected cases.

Liver X Receptors: A Possible Link between Lipid Disorders and Female Infertility

A close relationship exists between cholesterol and female reproductive physiology. Indeed, cholesterol is crucial for steroid synthesis by ovary and placenta, and primordial for cell structure during folliculogenesis. Furthermore, oxysterols, cholesterol-derived ligands, play a potential role in oocyte maturation. Anomalies of cholesterol metabolism are frequently linked to infertility. However, little is known about the molecular mechanisms. In parallel, increasing evidence describing the biological roles of liver X receptors (LXRs) in the regulation of steroid synthesis and inflammation, two processes necessary for follicle maturation and ovulation. Both of the isoforms of LXRs and their bona fide ligands are present in the ovary. LXR-deficient mice develop late sterility due to abnormal oocyte maturation and increased oocyte atresia. These mice also have an ovarian hyper stimulation syndrome in response to gonadotropin stimulation. Hence, further studies are necessary to explore their specific roles in oocyte, granulosa, and theca cells. LXRs also modulate estrogen signaling and this could explain the putative protective role of the LXRs in breast cancer growth. Altogether, clinical studies would be important for determining the physiological relevance of LXRs in reproductive disorders in women.

Cost-effectiveness analysis of lifestyle intervention in obese infertile women

STUDY QUESTION

What is the cost-effectiveness of lifestyle intervention preceding infertility treatment in obese infertile women?

SUMMARY ANSWER

Lifestyle intervention preceding infertility treatment as compared to prompt infertility treatment in obese infertile women is not a cost-effective strategy in terms of healthy live birth rate within 24 months after randomization, but is more likely to be cost-effective using a longer follow-up period and live birth rate as endpoint.

WHAT IS KNOWN ALREADY

In infertile couples, obesity decreases conception chances. We previously showed that lifestyle intervention prior to infertility treatment in obese infertile women did not increase the healthy singleton vaginal live birth rate at term, but increased natural conceptions, especially in anovulatory women. Cost-effectiveness analyses could provide relevant additional information to guide decisions regarding offering a lifestyle intervention to obese infertile women.

STUDY DESIGN, SIZE, DURATION

The cost-effectiveness of lifestyle intervention preceding infertility treatment compared to prompt infertility treatment was evaluated based on data of a previous RCT, the LIFEstyle study. The primary outcome for effectiveness was the vaginal birth of a healthy singleton at term within 24 months after randomization (the healthy live birth rate). The economic evaluation was performed from a hospital perspective and included direct medical costs of the lifestyle intervention, infertility treatments, medication and pregnancy in the intervention and control group. In addition, we performed exploratory cost-effectiveness analyses of scenarios with additional effectiveness outcomes (overall live birth within 24 months and overall live birth conceived within 24 months) and of subgroups, i.e. of ovulatory and anovulatory women, women <36 years and ≥36 years of age and of completers of the lifestyle intervention. Bootstrap analyses were performed to assess the uncertainty surrounding cost-effectiveness.

PARTICIPANTS/MATERIALS, SETTINGS, METHODS

Infertile women with a BMI of ≥29 kg/m2 (no upper limit) were allocated to a 6-month lifestyle intervention programme preceding infertility treatment (intervention group, n = 290) or to prompt infertility treatment (control group, n = 287). After excluding women who withdrew informed consent or who were lost to follow-up we included 280 women in the intervention group and 284 women in the control group in the analysis.

MAIN RESULTS AND THE ROLE OF CHANCE

Total mean costs per woman in the intervention group within 24 months after randomization were €4324 (SD €4276) versus €5603 (SD €4632) in the control group (cost difference of -€1278, P < 0.05). Healthy live birth rates were 27 and 35% in the intervention group and the control group, respectively (effect difference of -8.1%, P < 0.05), resulting in an incremental cost-effectiveness ratio of €15 845 per additional percentage increase of the healthy live birth rate. Mean costs per healthy live birth event were €15 932 in the intervention group and €15 912 in the control group. Exploratory scenario analyses showed that after changing the effectiveness outcome to all live births conceived within 24 months, irrespective of delivery within or after 24 months, cost-effectiveness of the lifestyle intervention improved. Using this effectiveness outcome, the probability that lifestyle intervention preceding infertility treatment was cost-effective in anovulatory women was 40%, in completers of the lifestyle intervention 39%, and in women ≥36 years 29%.

LIMITATIONS, REASONS FOR CAUTION

In contrast to the study protocol, we were not able to perform the analysis from a societal perspective. Besides the primary outcome of the LIFEstyle study, we performed exploratory analyses using outcomes observed at longer follow-up times and we evaluated subgroups of women; the trial was not powered on these additional outcomes or subgroup analyses.

WIDER IMPLICATIONS OF THE FINDINGS

Cost-effectiveness of a lifestyle intervention is more likely for longer follow-up times, and with live births conceived within 24 months as the effectiveness outcome. This effect was most profound in anovulatory women, in completers of the lifestyle intervention and in women ≥36 years old. This result indicates that the follow-up period of lifestyle interventions in obese infertile women is important. The scenario analyses performed in this study suggest that offering and reimbursing lifestyle intervention programmes in certain patient categories may be cost-effective and it provides directions for future research in this field.

STUDY FUNDING/COMPETING INTEREST(S)

The study was supported by a grant from ZonMw, the Dutch Organization for Health Research and Development (50-50110-96-518). The department of obstetrics and gynaecology of the UMCG received an unrestricted educational grant from Ferring pharmaceuticals BV, The Netherlands. B.W.J.M. is a consultant for ObsEva, Geneva.

TRIAL REGISTRATION NUMBER

The LIFEstyle RCT was registered at the Dutch trial registry (NTR 1530). http://www.trialregister.nl/trialreg/admin/rctview.asp?TC = 1530.

In Utero and Postnatal Exposure to High Fat, High Sucrose Diet Suppressed Testis Apoptosis and Reduced Sperm Count

Obesity affects male fertility and maternal diabetes affects the offspring sperm epigenome. However, the effects of in utero exposure to maternal glucose intolerance in combination with postnatal high fat, high sucrose (HFHS) diet consumption on offspring spermatogenesis is not clear. The present study was designed to test these effects. One week before and during pregnancy, dams were fed either control or HFHS diet to induce gestational glucose intolerance, and returned to standard diet during lactation. Male offspring from each maternal group were split into control and HFHS-fed groups for eight weeks prior to sacrifice at 11, 19 or 31 weeks of age, and reproductive tissues were harvested for analysis of testicular germ cell apoptosis and sperm output. Postnatal HFHS diet suppressed spermatogonia apoptosis in all age groups and maternal HFHS diet reduced testosterone levels at 11 weeks. At 31 weeks of age, the postnatal HFHS diet increased body weight, and reduced epididymis weight and sperm count. The combination of in utero and postnatal exposure impacted sperm counts most significantly. In summary, HFHS diet during pregnancy puts male offspring at greater risk of infertility, particularly when combined with postnatal high fat diet feeding.

Difference between Primary and Secondary Infertility in Morocco: Frequencies and Associated Factors

Background

The main objective of this survey was to determine the difference between primary and secondary infertility in Morocco and the associated factors among women, who are referred to public and private health centers in Morocco.

Materials and Methods

In this cross-sectional study, 619 infertile women referring to public and private health cent- ers in Marrakech-Safi region, were selected by simple random sampling method. This study was conducted between 1 October 2013 and 31 December 2015. Socio-economic status, demographic characteristics, couple’s age, nutritional status and other data related to both male and female reproductive organs were collected by a questionnaire. Logistic regression was used to identify the associated factors to infertility. Statistical significance was set at 0.05.

Results

The rates of primary and secondary infertility were 67.37, and 32.63%, respectively. Multivariate analysis identified a model with three significant predictive factors of secondary infertility: duration of marriage [odds ratio (OR)=12.263: 2.289-65.685], socio-economic status (OR=3.83: 1.011-14.70) and the ages of women (OR=1.268: 1.038-1.549).

Conclusion

The causes of primary and secondary infertility were not always a woman’s problem, but both man and woman contribute to infertility. Multiple regression analysis showed that women’s age, duration of marriage, and socio- economic status are predictive variables that decrease the chance of fertility among women with secondary infertility.

Impact of weight loss on sperm DNA integrity in obese men

The objective of the study was to determine whether weight loss in obese men improves their fertility with respect to DNA fragmentation index and morphology. Collected fertility parameters included DFI and morphology. Body mass index (BMI) was calculated for all patients with comparisons to their fertility parameters before and after weight loss using paired t test and chi-square tests. The mean BMI was significantly higher in group 1, before weight loss (33.18 kg/m2 ), than in group 2, after weight loss (30.43 kg/m2 ). Overall, 53.3% of men had DFI <20% while 43.8% had a DFI between 20% and 40%, and 2.9% of men had DFI >40%. The mean DFI of participants was higher before weight loss (20.2%) and had improved significantly after weight loss (17.5%) (p = <.001). The weight loss had significant positive correlation with percentage of DFI. There was a significant improvement in morphology after weight loss (p = <.05). In one of the largest cohorts of male fertility and obesity, DFI and morphology demonstrated significant relationship with adiposity, possibly contributing to subfertility in this population.

Effect of Body Mass Index on the Efficacy of Paracervical Block for Ultrasound-Guided Transvaginal Oocyte Retrieval as assessed by Requirement of Rescue Propofol

Background and Aims:

Oocyte retrieval is the only vital aspect of in vitro fertilization requiring anesthesia. Previous studies have shown the inconclusive role of paracervical block (PCB) in transvaginal oocyte retrieval (TVOR) under ultrasound guidance. This study was planned to observe the role and efficacy of PCB as measured by the amount of propofol used as rescue in patients undergoing TVOR and grading it on the basis of body mass index (BMI).

Methods:

This prospective, comparative study, conducted over 1 year, recruited 140 American Society of Anesthesiologists I and II patients and divided into two groups as follows: Group A received PCB with 20 ml of 1% lignocaine and Group B received no PCB. Total propofol consumed, BMI, time taken, oocytes retrieved, postprocedure visual analog scale score, and complications were noted. In both the groups, patients were then divided into underweight, normal, overweight, and obese according to BMI. Statistical analysis was done using Statistical Package Mini Tab Version 17.0. The primary objective was to study the efficacy of PCB as estimated by amount of propofol required during the procedure. The secondary aim was to assess the effect of BMI on the efficacy of PCB.

Results:

Propofol requirement was found to be significantly more (P < 0.05) in Group B patients (172.14 ± 64.15) in comparison to Group A (132.14 ± 66.11). Amount of propofol required in normal BMI and overweight patients was significantly higher in Group B. No significant difference was observed in underweight, and obese patients in both the groups.

Conclusion:

PCB reduces the consumption of propofol in normal BMI patients. Underweight and obese population do not benefit from PCB.

Male Obesity: Epigenetic Origin and Effects in Sperm and Offspring

PURPOSE OF REVIEW

The prevalence of obesity has increased substantially in the current generations of Western countries, and the burden of obesity-related complications has been growing steadily. In men, obesity is not only a major risk factor for serious chronic diseases, concern is growing that the reproductive capacity, and more particularly, their offspring's health may be affected. Obesity-related impaired spermatogenesis is associated with a decrease in microscopic and molecular sperm characteristics and pregnancy success. We hypothesize that epigenetics is an important mediator explaining interactions between an obesogenic environment and sperm/offspring outcomes.

RECENT FINDINGS

Recent studies have explored inter- and transgenerational epigenetic effects in sperm cells and in offspring. Father-to-child effects have been reported in relation to preconceptional nutritional and life-style related factors.

SUMMARY

Here, we summarize the current understanding about obesity and molecular or epigenetic underlying mechanisms in sperm. We identify the obesogenic environment of the father before conception as a potential origin of health or disease in the offspring and include it as part of a new concept, the Paternal Origins of Health and Disease (POHaD).

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.

Lactobacillus rhamnosus PB01 (DSM 14870) supplementation affects markers of sperm kinematic parameters in a diet-induced obesity mice model

Probiotics have been proposed as alternatives to pharmacological products in several medical conditions including the modulation of obesity, which is frequently associated with poor semen quality. However, effects of probiotics on male fertility have been less investigated. This study assessed the effect of Lactobacillus rhamnosus PB01 (DSM-14870) on sperm kinematic parameters in Normal-weight (NW) and diet-induced obese (DIO) models. NW and DIO C57BL/6NTac mice were divided into two subgroups with or without a single daily dose (1x109CFU) of L. rhamnosus for four weeks. Sperm motility and kinematics together with blood lipid profiles and reproductive hormone levels were assessed using the sperm class analyzer system. Probiotic supplementation increased serum testosterone, LH and FSH levels in both NW and DIO groups resulting in significantly (P<0.05) higher velocity (VSL, VCL and VAP) and percentages of progressively motile sperm and significantly lower percentages of immotile sperm. Other kinematic parameters (Lin, STR, ALH and BCF) were also increased in both probiotic supplemented DIO and NW groups at the 10% level of significance. Probiotic supplemented DIO mice demonstrated significantly higher percentages of progressively motile sperm versus DIO controls. This study demonstrated the potential of L. rhamnosus PB01 as a regulatory agent with positive effects on weight loss and reproductive-hormones, significantly improving sperm motility and kinematic parameters in male DIO models.

Responding to Infertility: Lessons From a Growing Body of Research and Suggested Guidelines for Practice

Infertility is a common, yet often misunderstood, experience. Infertility is an important topic for family scientists because of its effects on families; its relevance to research in related areas, such as fertility trends and reproductive health; and its implications for practitioners who work with individuals and couples experiencing infertility. In this review, we focus on common misperceptions in knowledge and treatment of infertility and highlight insights from recent research that includes men, couples, and people with infertility who are not in treatment. The meaning of parenthood, childlessness, awareness of a fertility problem, and access to resources are particularly relevant for treatment seeking and psychosocial outcomes. On the basis of insights from family science research, we provide specific guidelines for infertility practice within broader social contexts such as trends in health care, education, employment, and relationships. Guidelines are presented across three areas of application: infertility education for individuals, families, and practitioners; steps to support the emotional well-being of those affected by infertility; and understanding of treatment approaches and their implications for individuals and couples.

Couples' body composition and time-to-pregnancy

STUDY QUESTION

Is couples' body compositions associated with reduced fecundity as measured by a longer time-to-pregnancy (TTP)?

SUMMARY ANSWER

Couples whose BMI are within obese class II (≥35 kg/m2) have a longer TTP in comparison to leaner (BMI < 25 kg/m2) couples, observed only when both partner's BMI was jointly modeled.

WHAT IS KNOWN ALREADY

Extremes of BMI have been associated with a longer TTP and with less successful assisted reproductive technology (ART) outcomes. To our knowledge, the association between measured adiposity in both partners of the couple and prospectively measured TTP has not been investigated despite pregnancy being a couple-dependent outcome.

STUDY DESIGN, SIZE, DURATION

Prospective cohort with preconception recruitment of 501 couples trying for pregnancy and recruited from 16 counties in Michigan and Texas between 2005 and 2009. Couples were followed daily for up to a year of trying or until a hCG pregnancy.

PARTICIPANTS/MATERIALS, SETTING, METHODS

In-home standardized anthropometric assessment of couples upon enrollment included measured height and weight using calibrated stadiometers and scales, and measured waist and hip circumferences. Discrete-time Cox regression was used to estimate fecundability odds ratios (FORs) and 95% CIs, controlling for potential confounders including age, number of days of vigorous physical activity, serum cotinine concentration, race, education, free cholesterol levels for each partner in partner-specific models and for both partners in couple-based models as well as average acts of intercourse per menstrual cycle and menstrual cycle regularity.

MAIN RESULTS AND THE ROLE OF CHANCE

Neither male nor female partner's BMI was associated with TTP when modeled individually. However, obese class II (BMIs ≥ 35.0 kg/m2) couples experienced a reduction in fecundability in both unadjusted (FOR = 0.45; 95% CI: 0.23, 0.89) and adjusted analyses (aFOR = 0.41; 95% CI: 0.17, 0.98) resulting in a longer TTP in comparison to couples with normal BMI (<25 kg/m2). Female partners' waist circumference ≥88.6 cm was associated with a significant reduction in fecundability in the unadjusted model (FOR = 0.64; 95% CI: 0.48, 0.86) but not in the adjusted model (aFOR = 0.77; 95% CI: 0.55, 1.08) in comparison to females with a smaller (<80 cm) circumference.

LIMITATIONS, REASONS FOR CAUTION

BMI and waist circumference are proxy measures of body composition and residual confounding cannot be eliminated. Findings may not be generalizable to clinical populations.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first cohort study known to us with preconception enrollment of couples who underwent standardized anthropometric assessment and for whom TTP was prospectively measured. The findings underscore the importance of considering both partners' body composition for fecundity outcomes and preconception guidance.

STUDY FUNDING/COMPETING INTEREST(S)

Supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (Contracts #N01-HD-3-3355, N01-HD-3-3356 and N01-HD-3-3358). The authors have no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

The Society for Translational Medicine: clinical practice guidelines for sperm DNA fragmentation testing in male infertility

Sperm DNA fragmentation (SDF) testing has been emerging as a valuable tool for male fertility evaluation. While the essential role of sperm DNA integrity in human reproduction was extensively studied, the clinical indication of SDF testing is less clear. This clinical practice guideline provides recommendations of clinical utility of the test supported by evidence. It is intended to serve as a reference for fertility specialists in identifying the circumstances in which SDF testing should be of greatest clinical value. SDF testing is recommended in patients with clinical varicocele and borderline to normal semen parameters as it can better select varicocelectomy candidates. Outcomes of natural pregnancy and assisted reproductive techniques (ART) can be predicted by result of SDF tests. High SDF is also linked with recurrent pregnancy loss (RPL) and failure of ART. Result of SDF testing may change the management decision by selecting the most appropriate ART with the highest success rate for infertile couples. Several studies have demonstrated the benefit in using testicular instead of ejaculated sperm in men with high SDF, oligozoospermia or recurrent in vitro fertilization (IVF) failure. Infertile men with modifiable lifestyle factor may benefit from SDF testing by reinforcing risk factor modification and monitoring patient's progress to intervention.

Cardiovascular risk factors among women with self-reported infertility

Background

Amongst women with certain types of ovulatory disorder infertility, the studies are conflicting whether there is an increased risk of long-term cardiovascular disease risk. This paper evaluates the associations of several CVD risk factors among Framingham women with self-reported infertility.

Methods

Women who completed the Framingham Heart Study Third Generation and Omni Cohort 2 Exam 2 (2008–2011), and reported on past history of infertility and current cardiovascular disease status were included in this cross-sectional study. Directly measured CVD risk factors were: resting blood pressure, fasting lipid levels, fasting blood glucose, waist circumference, and body mass index (BMI). Multivariable models adjusted for age, smoking, physical activity, and cohort. Generalized estimating equations adjusted for family correlations. We performed sensitivity analyses to determine whether the association between infertility and CVD risk factors is modified by menopausal status and menstrual cycle length.

Results

Comparing women who self-reported infertility to those who did not, there was an average increase in BMI (β = 1.03 kg/m², 95% CI: 0.18, 1.89), waist circumference (β = 3.08 in., 95% CI: 1.06, 5.09), triglycerides (β = 4.47 mg/dl, 95% CI:−1.54, 10.49), and a decrease in HDL cholesterol (β = −1.60 mg/dl, 95% CI: −3.76, 0.56). We estimated that infertile premenopausal women have an increased odds of obesity (BMI ≥ 30 kg/m²) (OR = 1.56, 95% CI: 1.11, 4.49) and diabetes (OR = 1.96, 95% CI: 0.86, 4.49).

Conclusions

BMI and waist circumference were the most strongly correlated CVD risk factors amongst women reporting a history of infertility.

Urinary Concentrations of Parabens and Other Antimicrobial Chemicals and Their Association with Couples' Fecundity

BACKGROUND

Human exposure to parabens and other antimicrobial chemicals is continual and pervasive. The hormone-disrupting properties of these environmental chemicals may adversely affect human reproduction.

OBJECTIVE

We aimed to prospectively assess couples' urinary concentrations of antimicrobial chemicals in the context of fecundity, measured as time to pregnancy (TTP).

METHODS

In a prospective cohort of 501 couples, we examined preconception urinary chemical concentrations of parabens, triclosan and triclorcarban in relation to TTP; chemical concentrations were modeled both continuously and in quartiles. Cox's proportional odds models for discrete survival time were used to estimate fecundability odds ratios (FORs) and 95% confidence intervals (CIs) adjusting for a priori-defined confounders. In light of TTP being a couple-dependent outcome, both partner and couple-based exposure models were analyzed. In all models, FOR estimates < 1.0 denote diminished fecundity (longer TTP).

RESULTS

Overall, 347 (69%) couples became pregnant. The highest quartile of female urinary methyl paraben (MP) concentrations relative to the lowest reflected a 34% reduction in fecundity (aFOR = 0.66; 95% CI: 0.45, 0.97) and remained so when accounting for couples' concentrations (aFOR = 0.63; 95% CI: 0.41, 0.96). Similar associations were observed between ethyl paraben (EP) and couple fecundity for both partner and couple-based models (p-trend = 0.02 and p-trend = 0.05, respectively). No associations were observed with couple fecundity when chemicals were modeled continuously.

CONCLUSIONS

Higher quartiles of preconception urinary concentrations of MP and EP among female partners were associated with reduced couple fecundity in partner-specific and couple-based exposure models.

Body mass index effects sperm quality: a retrospective study in Northern China

Excess weight and obesity have become a serious problem in adult men of reproductive age throughout the world. The purpose of this retrospective study was to assess the relationships between body mass index and sperm quality in subfertile couples in a Chinese Han population. Sperm analyses were performed and demographic data collected from 2384 male partners in subfertile couples who visited a reproductive medical center for treatment and preconception counseling. The subjects were classified into four groups according to their body mass index: underweight, normal, overweight, and obese. Of these subjects, 918 (38.3%) had a body mass index of >25.0 kg m-0 2 . No significant differences were found between the four groups with respect to age, occupation, level of education, smoking status, alcohol use, duration of sexual abstinence, or the collection time of year for sperm. The results clearly indicated lower sperm quality (total sperm count, sperm concentration, motile sperm, relative amounts of type A motility, and progressive motility sperm [A + B]) in overweight and obese participants than in those with normal body mass index. Normal sperm morphology and sperm volume showed no clear difference between the four groups. This study indicates that body mass index has a negative effect on sperm quality in men of subfertile couples in a Northern Chinese population. Further study should be performed to investigate the relationship between body mass index and sperm quality in a larger population.

Effects of apelin on reproductive functions: relationship with feeding behavior and energy metabolism

Apelin is an adipose tissue derived peptidergic hormone. In this study, 40 male Sprague-Dawley rats were used (four groups; n = 10). Apelin-13 at three different dosages (1, 5 and 50 μg/kg) was given intraperitoneally while the control group received vehicle the same route for a period of 14 days. In results, apelin-13 caused significant decreases in serum testosterone, luteinizing hormone and follicle-stimulating hormone levels (p < 0.05). Administration of apelin-13 significantly increased body weights, food intake, serum low-density lipoprotein and total cholesterol levels (p < 0.05), but caused significant decreases in high-density lipoprotein levels (p < 0.05). Serum glucose and triglyceride levels were not significantly altered by apelin-13 administration. Significant decreases in both uncoupling protein (UCP)-1 levels in the white and brown adipose tissues and UCP-3 levels in the biceps muscle (p < 0.05) were noted. The findings of the study suggest that apelin-13 may not only lead to obesity by increasing body weight but also cause infertility by suppressing reproductive hormones.