Obese women exhibit differences in ovarian metabolites, hormones, and gene expression compared with moderate-weight women

Ovarian aging: energy metabolism of oocytes

In women who are getting older, the quantity and quality of their follicles or oocytes and decline. This is characterized by decreased ovarian reserve function (DOR), fewer remaining oocytes, and lower quality oocytes. As more women choose to delay childbirth, the decline in fertility associated with age has become a significant concern for modern women. The decline in oocyte quality is a key indicator of ovarian aging. Many studies suggest that age-related changes in oocyte energy metabolism may impact oocyte quality. Changes in oocyte energy metabolism affect adenosine 5'-triphosphate (ATP) production, but how related products and proteins influence oocyte quality remains largely unknown. This review focuses on oocyte metabolism in age-related ovarian aging and its potential impact on oocyte quality, as well as therapeutic strategies that may partially influence oocyte metabolism. This research aims to enhance our understanding of age-related changes in oocyte energy metabolism, and the identification of biomarkers and treatment methods.

The protective effects of some herbs on mitigating HFD-induced obesity via enhancing biochemical indicators and fertility in female rats

The potential of plant-based diets and drugs to prevent and control obesity has been attributed to the presence of several biologically active phytochemicals. The study aimed to assess herb consumption's impact on alleviating the risks and hazards associated with obesity induced by a high-fat diet (HFD) and the promotion of fertility. Eighty rats were allocated into four distinct groups. Group 1 (G1) was provided with a basal diet and acted as the control group. Group 2 (G2) was provided with an HFD. Group 3 (G3) was provided with HFD supplemented with chia seeds and Hibiscus sabdariffa L. The fourth group of subjects was provided with HFD supplemented with Foeniculum vulgare (fennel) and Coriandrum sativum L. (coriander). The feeding session was sustained for 10 weeks, and the biochemical parameters were evaluated. The administration of Foeniculum vulgare (fennel) and Coriandrum sativum L. (coriander) (G4) resulted in a more significant reduction in all biochemical parameters compared to G3, which received a diet consisting of chia seeds and Hibiscus sabdariffa L. Additionally, the average number of embryonic lobes and the average number of offspring after birth were found to be considerably more significant in the normal control group (G1) and group (G4) compared to the HFD group (G2) and group (G3) (P < 0.01). Group 4 (G4) was administered a diet enriched with Foeniculum vulgare (fennel) and Coriandrum sativum L. (coriander), which demonstrated superior outcomes in many biochemical indicators and the promotion of fertility in obese female rats.

The impact of obesity on reproductive health and metabolism in reproductive-age females

Obesity is a highly prevalent chronic disease that impacts >40% of reproductive-aged females. The pathophysiology of obesity is complex and can be understood simply as a chronic energy imbalance whereby caloric intake exceeds caloric expenditure with an energy surplus stored in adipose tissue. Obesity may be categorized into degrees of severity as well as different phenotypes on the basis of metabolic health and underlying pathophysiology. Obesity and excess adiposity have a significant impact on fertility and reproductive health, with direct effects on the hypothalamic-pituitary-ovarian axis, the ovary and oocyte, and the endometrium. There are significant adverse pregnancy outcomes related to obesity, and excess weight gain before, during, and after pregnancy that can alter the lifelong risk for metabolically unhealthy obesity. Given the high prevalence and pervasive impact of obesity on reproductive health, there is a need for better and individualized care for reproductive-aged females that considers obesity phenotype, underlying pathophysiology, and effective and sustainable interventions to treat obesity and manage weight gain before, during, and after pregnancy.

Normal weight obesity is associated with lower AFC and adverse IVF outcomes

Background

Body weight could be classified into underweight, normal weight and overweight according to percentage of body fat (%BF), and normal weight obesity (NWO) is defined as a normal BMI but a high %BF. While the impact of NWO in women fecundity remain unknow. Therefore, this study aimed to investigate the associations between %BF and reproductive outcomes among in vitro fertilization (IVF) women with normal BMI.

Methods

A total of 469 women were included in this study and were classified into low %BF, normal %BF and high %BF according to previous study. Multivariate generalized regression models were employed to evaluate the associations of %BF with ovarian reserve parameters, IVF outcomes and early pregnancy outcomes. We further run sensitivity analyses by restricted the analysis to young women and those only with tubal factor, respectively.

Results

About 32.2% of normal BMI women were misclassified according %BF, with 16.4% of them were low %BF and 15.8% were high %BF. The high %BF group had significantly lower antral follicle count (AFC) than normal %BF groups, and the AFC showed a tendency of decrease as %BF increased. In sensitivity analysis in young women, high %BF group also had significantly lower number of good-quality embryos when compared to normal %BF groups. The results expanded to all IVF outcomes when analysis restricted to tubal factor women.

Conclusion

In summary, misclassifications of body weight status based on BMI are common according to %BF, and NWO is associated with adverse reproductive outcomes.

Urinary biomarkers of drinking-water disinfection byproducts in relation to diminished ovarian reserve risk: A case-control study from the TREE cohort

BACKGROUND

Disinfection byproducts (DBPs) as ovarian toxicants have been documented in toxicological studies. However, no human studies have explored the effects of exposure to DBPs on diminished ovarian reserve (DOR).

OBJECTIVE

To assess whether urinary biomarkers of exposure to drinking-water DBPs were associated with DOR risk.

METHODS

A total of 311 women undergoing assisted reproductive technology were diagnosed with DOR in the Tongji Reproductive and Environmental (TREE) cohort from December 2018 to August 2021. The cases were matched to the controls with normal ovarian reserve function by age in a ratio of 1:1. Urinary trichloroacetic acid (TCAA) and dichloroacetic acid (DCAA) were quantified as biomarkers of drinking-water DBP exposures. The conditional logistic regression and restricted cubic spline (RCS) were used to explore urinary biomarkers of drinking-water DBP exposures in associations with the risk of DOR.

RESULTS

Elevated urinary DCAA levels were associated with higher DOR risk [adjusted odds ratio (OR) = 1.87; 95 % confidence interval (CI): 1.16, 3.03 for the highest vs. lowest quartiles; P for trend = 0.016]. The association was confirmed in the RCS model, with a linear dose-response curve (P for overall association = 0.029 and P for non-linear association = 0.708). The subgroup analysis by age and body mass index (BMI) showed that urinary DCAA in association with DOR risk was observed among women ≥35 years old and leaner women (BMI < 24 kg/m2), but the group differences were not statistically significant. Moreover, a U-shaped dose-response curve between urinary TCAA and DOR risk was estimated in the RCS model (P for overall association = 0.011 and P for non-linear association = 0.004).

CONCLUSIONS

Exposure to drinking-water DBPs may contribute to the risk of DOR among women undergoing assisted reproductive technology.

Association of metabolic-dysfunction associated steatotic liver disease with polycystic ovary syndrome

Non-alcoholic fatty liver disease (NAFLD), which has a prevalence of over 25% in adults, encompasses a wide spectrum of liver diseases. Metabolic-dysfunction associated steatotic liver disease (MASLD), the new term for NAFLD, is characterized by steatotic liver disease accompanied by cardiometabolic criteria, showing a strong correlation with metabolic diseases. Polycystic ovary syndrome (PCOS) is a common reproductive endocrine disease affecting 4-21% of women of reproductive age. Numerous studies have indicated that NAFLD and PCOS often occur together. However, as MASLD is a new term, there is still a lack of reports describing the effects of MASLD on the development of PCOS. In this review article, we have summarized the complex and multifaceted connections between MASLD and PCOS. Understanding the pathogenesis and treatment methods could not only guide the clinical prevention, diagnosis, and treatment of PCOS in patients with MASLD, but also increase the clinical attention of reproductive doctors to MASLD.

Association between oocyte donors' or recipients' body mass index and clinical outcomes after first single blastocyst transfers-the uterus is the most affected

OBJECTIVE

To assess whether high body mass index (BMI) in either oocyte donors or recipients is associated with poorer outcomes after the first single blastocyst transfer.

DESIGN

Retrospective study including 1,394 first blastocyst single embryo transfers (SETs) conducted by 1,394 recipients during oocyte donation cycles with the gametes retrieved from 1,394 women (January 2019-July 2021). Four BMI clusters were defined for both donors and recipients (underweight: <18.5 kg; normal weight: 18.5-24.9 kg; overweight: 25-29.9 kg; and obese: ≥30 kg).

SETTING

Network of private IVF centers.

PATIENTS

A total of 1,394 recipients aged 42.4 ± 4.0 and with a BMI of 23.2 ± 3.8 kg/m2, and 1,394 donors aged 26.1 ± 4.2 and with a BMI of 21.9 ± 2.5 kg/m2.

INTERVENTION

All oocytes were vitrified at 2 egg banks and warmed at 8 in vitro fertilization clinics that were part of the same network. Intracytoplasmic sperm injection, blastocyst culture, and either fresh or vitrified-warmed SETs were conducted. Putative confounders were investigated, and the data were adjusted through regression analyses.

MAIN OUTCOME MEASURES

The primary outcome was the live birth rate (LBR) per SET according to donors' and/or recipients' BMI. The main secondary outcome was the miscarriage rate (<22 gestational weeks) per clinical pregnancy.

RESULTS

The LBR per blastocyst SET showed no significant association with donors' BMI. Regarding recipients' BMI, instead, the multivariate odds ratio was significant in obese vs. normal-weight recipients (0.58, 95% confidence interval, 0.37-0.91). The miscarriage rate per clinical pregnancy was also significantly associated with recipients' obesity, with a multivariate odds ratio of 2.31 (95% confidence interval, 1.18-4.51) vs. normal-weight patients. A generalized additive model method was used to represent the relationship between predicted LBR or miscarriage rates and donors' or recipients' BMI; it pictured a scenario where the former outcome moderately but continuously decreases with increasing recipients' BMI to then sharply decline in the BMI range of 25-35 kg/m2. The miscarriage rate, instead, increases almost linearly with respect to both donors' and recipients' increasing BMI.

CONCLUSION

Obesity mostly affects the uterus, especially because of higher miscarriage rates. Yet, poorer outcomes can be appreciated already with a BMI of 25 kg/m2 in both oocyte donors and recipients. Finer markers of nutritional homeostasis are therefore desirable; recipients should be counseled about poorer expected outcomes in cases of overweight and obesity; and oocyte banks should avoid assigning oocytes from overweight donors to overweight and obese recipients.

The impact of increasing body mass index on in vitro fertilization treatment, obstetrical, and neonatal outcomes

BACKGROUND

Citing the risks of administering anesthesia to patients with obesity, few fertility centers offer in vitro fertilization as a treatment modality for patients with body mass indexes ≥40 kg/m2. Although previous studies have assessed clinical pregnancy and cumulative live birth rates in patients who spontaneously conceive with body mass indexes ≥50 kg/m2, there is a paucity of in vitro fertilization, obstetrical, and neonatal outcome data in patients with severe obesity who conceive after in vitro fertilization.

OBJECTIVE

This study aimed to evaluate the impact of increasing body mass index on in vitro fertilization, obstetrical, and neonatal outcomes in patients with obesity undergoing in vitro fertilization.

STUDY DESIGN

This was a retrospective cohort study within an academic fertility center including 2069 fresh in vitro fertilization/intracytoplasmic sperm injection and frozen embryo transfer cycles from January 1, 2012 to April 30, 2020; this cohort was used to determine in vitro fertilization treatment outcomes. A second embedded cohort of 867 fresh in vitro fertilization/intracytoplasmic sperm injection and frozen embryo transfer cycles that resulted in ongoing clinical pregnancies and deliveries within a single tertiary hospital system was used to determine pregnancy, maternal, and neonatal outcomes. All patients with a body mass index ≥40 kg/m2 underwent consultation with a maternal-fetal medicine specialist before starting treatment and a preoperative evaluation with an anesthesiologist before oocyte retrieval. Cycles were grouped by body mass index at cycle start (30-34.9, 35-39.9, 40-44.9, 45-49.9, and ≥50 kg/m2). Log-binomial regression and Poisson regression with an offset were fitted with body mass index of 30 to 34.9 kg/m2 as the reference group, adjusting for potential confounders including oocyte age, patient age, embryo quality, transfer type, and coexisting comorbidities. The primary outcome was live birth rate. Secondary outcomes included fertilization rate, blastulation rate, miscarriage rate, incidence of preeclampsia with severe features, gestational diabetes, labor induction, cesarean delivery, preterm delivery, and birthweight.

RESULTS

There were 2069 fresh in vitro fertilization/intracytoplasmic sperm injection and frozen embryo transfer cycle starts from January 1, 2012 to April 30, 2020. Of these, 1008 cycles were in the 30 to 34.9 kg/m2 group, 547 in the 35 to 39.9 kg/m2 group, 277 in the 40 to 44.9 kg/m2 group, 161 in the 45 to 49.9 kg/m2 group, and 76 in the ≥50 kg/m2 body mass index group. Live birth rate was not significantly different between groups. The body mass index ≥50 kg/m2 group was significantly more likely to experience preeclampsia with severe features when compared with the 30 to 34.9 kg/m2 body mass index group (absolute risk reduction, 2.75; 95% confidence interval, 1.13-6.67). Fertilization rate, blastulation rate, miscarriage rate, incidence of gestational diabetes, labor induction, cesarean delivery, preterm delivery, and neonatal birthweights were not significantly different between groups.

CONCLUSION

Among patients with body mass indexes from 30 to 60 kg/m2 who conceived via in vitro fertilization and received comprehensive prenatal care at a tertiary care hospital, in vitro fertilization, obstetrical, and neonatal outcomes were largely comparable. These data support a collaborative care approach with maternal-fetal medicine specialists and skilled anesthesiologists, reinforcing the notion that in vitro fertilization should not be withheld as a treatment modality from patients with obesity.

Frozen embryo transfer outcomes decline with increasing female body mass index in female but not male factor infertility: analysis of 56,564 euploid blastocyst transfers

OBJECTIVE

To evaluate the association of body mass index (BMI) with cycle outcomes after euploid frozen blastocyst transfer.

DESIGN

Retrospective cohort study.

SETTING

Not applicable.

PATIENT(S)

A total of 56,564 first single autologous euploid frozen embryo transfers from the 2016-2019 Society for Assisted Reproductive Technology database were analyzed using BMI and using World Health Organization BMI cohorts. Subanalyses were performed on cycles among patients with a sole diagnosis of polycystic ovary syndrome (PCOS) (n = 4,626) and among patients with only a male factor (n = 10,854).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy, pregnancy loss, and live birth (LB).

RESULT(S)

Success rates and adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for all outcomes were most favorable among those with normal BMI and progressively worsened with increasing BMI. These trends persisted among patients with PCOS for clinical pregnancy (aOR, 0.99; 95% CI, 0.98-0.997), pregnancy loss (aOR, 1.02; 95% CI, 1.01-1.04), and LB (aOR, 0.98; 95% CI, 0.97-0.99), but not among patients with a male factor only for clinical pregnancy (aOR, 1.00; 95% CI, 0.99-1.01), pregnancy loss (aOR, 1.01; 95% CI, 0.99-1.03), or LB (aOR, 0.99; 95% CI, 0.98-1.00).

CONCLUSION(S)

In the largest cohort to date, increasing BMI was associated with decreased pregnancy and LB and increased pregnancy loss after euploid frozen embryo transfers among the entire cohort and among patients with a sole diagnosis of PCOS; however, these results were attenuated among patients with a sole diagnosis of male factor infertility, suggesting that associated female infertility diagnoses and not BMI alone may underlie this trend.

Chrysoeriol Improves the Early Development Potential of Porcine Oocytes by Maintaining Lipid Homeostasis and Improving Mitochondrial Function

Our previous study established that chrysoeriol (CHE) can reduce reactive oxygen species (ROS) accumulation, apoptosis, and autophagy in vitro culture (IVC) of porcine embryos. However, the role of CHE in oocyte maturation and lipid homeostasis is unclear. Herein, we aimed to elucidate the effect of CHE on porcine oocyte competence in vitro maturation (IVM) and subsequent embryo development. The study chooses parthenogenetic activated porcine oocytes as the research model. The study revealed that the cumulus expansion index and related gene expressions are significantly elevated after supplementing 1 μM CHE. Although there were no significant differences in nuclear maturation and cleavage rates, the blastocyst formation rate and total cell numbers were significantly increased in the 1 μM CHE group. In addition, CHE improved the expression of genes related to oocyte and embryo development. ROS was significantly downregulated in all CHE treatment groups, and intracellular GSH (glutathione) was significantly upregulated in 0.01, 0.1, and 1 μM CHE groups. The immunofluorescence results indicated that mitochondrial membrane potential (MMP) and lipid droplet (LD), fatty acid (FA), ATP, and functional mitochondria contents significantly increased with 1 μM CHE compared to the control. Furthermore, CHE increased the expression of genes related to lipid metabolism, mitochondrial biogenesis, and β-oxidation.

Intra-ovarian inflammatory states and their associations with embryo quality in normal-BMI PCOS patients undergoing IVF treatment

BACKGROUND

Polycystic ovary syndrome (PCOS) is the main cause of anovulatory infertility in women of reproductive age, and low-grade chronic inflammation plays a key role in the occurrence and development of PCOS. However, obesity, as a likely confounding factor, can affect the inflammatory state of PCOS patients.

OBJECTIVE

The aim of this study was to comprehensively investigate intra-ovarian inflammatory states and their impact on embryo quality in PCOS patients with a normal BMI undergoing IVF treatment.

METHODS

DIA-mass spectrometry-based proteomics and bioinformatic analysis were combined to comprehensively profile the protein expression of granulosa cells (GCs) from 5 normal-BMI PCOS patients and 5 controls. Thirty-four cytokines were further systematically detected in follicular fluid (FF) from 32 age- and BMI-matched normal-BMI patients using Luminex liquid chip suspension technology. Next, the differentially expressed cytokines were evaluated by enzyme-linked immunosorbent assay (ELISA) in 24 newly recruited subjects, and the relationship between these cytokines and embryo quality in PCOS patients was analysed. Finally, these cytokine levels were compared and evaluated in PCOS patients with different androgen levels.

RESULTS

Proteomic analysis showed that the suppression of substance metabolism and steroid biosynthesis, more interestingly, resulted in an enhanced immune and inflammatory response in the GCs of normal-BMI PCOS patients and prompted the involvement of cytokines in this process. Luminex analysis further showed that FF macrophage inflammatory protein-1 beta (MIP-1β) and stromal cell-derived factor-1 alpha (SDF-1α) levels were significantly increased in normal-BMI PCOS patients compared to controls (P = 0.005; P = 0.035, respectively), and the ELISA results were consistent with these findings. Besides, FF MIP-1β showed an inverse correlation with the number of D3 good-quality embryos and the good-quality blastocyst rate in patients with PCOS (P = 0.006; P = 0.003, respectively), which remained significant after correction for multiple comparisons. Moreover, SDF-1α levels had no relationship with embryo development in PCOS patients. Additionally, SDF-1α levels were significantly lower in PCOS patients with high androgen levels than in controls (P = 0.031).

CONCLUSIONS

Local ovarian inflammation was present in normal-BMI PCOS patients, affecting follicular development, and FF MIP-1β may be a potential biomarker associated with embryo quality in normal-BMI PCOS patients.

Association between waist circumference and female infertility in the United States

BACKGROUND

Obesity has significant implications for fertility and reproductive health. However, evidences linking abdominal obesity to female infertility were limited and inconclusive. Our objective was to figure out the potential relationship between waist circumference (WC) and infertility among women of childbearing age in the United States using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

Our cross-sectional study included 3239 female participants aged 18-45 years. To explore the independent relationship between WC and female infertility, the weighted multivariable logistic regression and smoothed curve fitting were performed. Interaction and subgroup analyzes were then conducted for secondary analysis.

RESULTS

WC was positively associated with female infertility independent of BMI after adjusting for BMI and other potential confounders. In fully adjusted model, for every 1cm increase in waist circumference, the risk of infertility increased by 3% (OR = 1.03, 95% CI: 1.01-1.06). When WC was divided into five equal groups, women in the highest quintile had 2.64 times risk of infertility than that in the lowest quintile (OR = 2.64, 95% CI: 1.31-5.30). Smooth curve fitting revealed a non-linear but positively dose-dependent relationship between WC and female infertility. Furthermore, we found an inverted U-shaped relationship (turning point: 113.5 cm) between WC and female infertility in participants who had moderate recreational activities and a J-shaped relationship (turning point: 103 cm) between WC and female infertility in participants who had deficient recreational activities.

CONCLUSIONS

Waist circumference is a positive predictor of female infertility, independent of BMI. Moderate recreational activities can lower the risk of female infertility associated with abdominal obesity.

Sex hormone-binding globulin improves lipid metabolism and reduces inflammation in subcutaneous adipose tissue of metabolic syndrome-affected horses

Equine metabolic syndrome (EMS) is a steadily growing endocrine disorder representing a real challenge in veterinary practice. As a multifactorial condition, EMS is characterized by three main metabolic abnormalities including insulin resistance, increased adiposity or obesity and hoof laminitis. Adipose tissue dysfunction is recognized as a core pathophysiological determinant of EMS, as it strongly participates to lipotoxicity and systemic metaflammation, both of which have been closely linked to the development of generalized insulin resistance. Besides, sex hormone binding globulin (SHBG) is an important sex steroids transporters that has been recently proposed as an important metabolic mediator. Therefore, the aim of this study was to verify whether SHBG treatment may ameliorate subcutaneous adipose tissue metabolic failure under EMS condition in terms of lipidome homeostasis, lipid metabolism programs, insulin signalling and local inflammation. Subcutaneous adipose tissue (SAT) biopsies were collected post-mortem from healthy (n = 3) and EMS (n = 3) slaughtered horses. SHBG protein has been applied to SAT samples from EMS horses for 24 h at a final concentration of 50 nM, while control groups (healthy and untreated EMS) were cultured in the presence of SHBG-vehicle only. Tissues from all groups were afterwards secured for downstream analysis of gene expression using RT-qPCR, protein levels by Western blot and ELISA assay and lipidomics through GC-MS technique. Obtained results showcased that SHBG intervention efficiently normalized the altered fatty acids (FAs) profiles by lowering the accumulation of saturated and trans FAs, as well as the pro-inflammatory arachidonic and linoleic acids. Moreover, SHBG showed promising value for the regulation of adipocyte lipolysis and engorgement by lowering the levels of perilipin-1. SHBG exerted moderated effect toward SCD1 and FASN enzymes expression, but increased the LPL abundance. Interestingly, SHBG exhibited a negative regulatory effect on pro-adipogenic stimulators and induced higher expression of KLF3, IRF3 and β-catenin, known as strong adipogenesis repressors. Finally, SHBG protein showed remarkable ability in restoring the insulin signal transduction, IR/IRS/Pi3K/AKT phosphorylation events and GLUT4 transporter abundance, and further attenuate pro-inflammatory response by lowering IL-6 tissue levels and targeting the PDIA3/ERK axis. Overall, the obtained data clearly demonstrate the benefice of SHBG treatment in the regulation of adipose tissue metabolism in the course of EMS and provide new insights for the development of molecular therapies with potential translational application to human metabolic disorders.

Determining the best method for evaluating obesity and the risk for non-communicable diseases in women of childbearing age by measuring the body mass index, waist circumference, waist-to-hip ratio, waist-to-height ratio, A Body Shape Index, and hip index

OBJECTIVE

Non-communicable diseases (NCDs) are linked to excessive adiposity and anthropometric indices can be used to identify those at risk. The aim of this study was to evaluate the precision of anthropometric indices in identifying obesity and risk factors for NCDs and to investigate the emergence of obesity-related NCDs in young women in Sri Lanka.

METHODS

We recruited 282 women 18 to 35 y of age from suburban and rural areas in Sri Lanka. We measured the women's height, weight, body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), A Body Shape Index(ABSI), hip circumference (HC), hip index (HI), anthropometric risk index (ARI), fasting serum glucose, fasting serum insulin, homeostatic model assessment for insulin resistance, cholesterol, high-density lipoprotein, low-density lipoprotein, triacylglycerols, and ovulatory gonadal hormones (progesterone, testosterone). Comparisons were made between women with normal BMI and those who were overweight or obese using anthropometric and biochemical characteristics.

RESULTS

The prevalence of obesity was highest in WC and in receiver operating characteristic analysis, BMI, WC, and WHtR showed higher sensitivity and lower 1-specificity as indicators of obesity. BMI had an area under the curve (AUC) of 1.000 with 100% sensitivity and 0% 1-specificity. WC had an AUC of 0.941 with 80% sensitivity and 13.4% 1-specificity. Additionally, WHtR showed a 0.974 AUC, 92.1% sensitivity, and 4.9% 1-specificity. The correlations between body size and shapes were assessed among the study participants using Pearson's correlation. More than other measures, WC and WHtR showed a significant correlation with BMI with P < 0.05 (r = 0.888 and 0.737, respectively). Although ABSI and BMI showed only a weak correlation (P = 0.006, r = 0.162), WHR and BMI showed a moderate correlation (P = 0.001, r = 0.477). Although HI demonstrated a negative association with BMI (P = 0.618, r = -0.030), HC exhibited a strong association (P = 0.001, r = 0.749). A significant association with higher odds ratios was found for obesity-related NCD risk factors such as hypertension, homeostatic model assessment for insulin resistance, hypercholesterolemia, altered ovulatory hormones with these (BMI, WC, WHR, WHtR, ABSI, HI) obesity-assessing criteria (P < 0.05). A significant correlation between WC and hypertriacylglycerolmia (P = 0.001, r = 0.781, odds ratio, >16) was identified. A positive correlation was observed between all MS components and ARI, indicating that ARI may serve as a potential indicator of cardiometabolic risk.

CONCLUSION

BMI, WC, WHtR, and HC are intercorrelated anthropometric measurements that can be used either alone or in combination to define obesity and detect the risk for NCDs, including diabetes mellitus, cardiovascular disease, and infertility. On the other hand, BMI, ABSI, and HI are designed to be mutually independent indices and have the advantage of combining the separate risks to generate an overall ARI. Furthermore, ARI appears to be a highly effective predictor of cardiovascular disease.

Effects of pulsatile intravenous follicle-stimulating hormone treatment on ovarian function in women with obesity

OBJECTIVE

To establish conditions for effective hypothalamic suppression in women with normal and high body mass index (BMI) and test the hypothesis that intravenous (IV) administration of pulsatile recombinant follicle-stimulating hormone (rFSH) can overcome the clinically evident dysfunctional pituitary-ovarian axis in women with obesity.

DESIGN

Prospective interventional study.

SETTING

Academic medical center.

PATIENT(S)

Twenty-seven normal-weight women and 27 women with obesity, who were eumenorrheic and aged 21-39 years.

INTERVENTION(S)

Two-day frequent blood sampling study, in early follicular phase, before and after cetrorelix suppression of gonadotropins and exogenous pulsatile IV rFSH administration.

MAIN OUTCOME MEASURE(S)

Serum inhibin B and estradiol (E2) levels (basal and rFSH stimulated).

RESULT(S)

A modified gonadotropin-releasing hormone antagonism protocol effectively suppressed production of endogenous gonadotropins in women with normal and high BMIs, providing a model to address the functional role of FSH in the hypothalamic-pituitary-ovarian axis. The IV rFSH treatment resulted in equivalent serum levels and pharmacodynamics in normal-weight women and those with obesity. However, women with obesity exhibited reduced basal levels of inhibin B and E2 and a significantly decreased response to FSH stimulation. The BMI was inversely correlated with serum inhibin B and E2. In spite of this observed deficit in ovarian function, pulsatile IV rFSH treatment in women with obesity resulted in E2 and inhibin B levels comparable with those in normal-weight women, in the absence of exogenous FSH stimulation.

CONCLUSION(S)

Despite normalization of FSH levels and pulsatility by exogenous IV administration, women with obesity demonstrate ovarian dysfunction with respect to E2 and inhibin B secretion. Pulsatile FSH can partially correct the relative hypogonadotropic hypogonadism of obesity, thereby providing a potential treatment strategy to mitigate some of the adverse effects of high BMI on fertility, assisted reproduction, and pregnancy outcomes.

CLINICAL TRIAL REGISTRATION NUMBER

ClinicalTrials.gov #NCT02478775.

Influence of maternal obesity on embryonic vitrification injury and subsequent pregnancy outcomes: A retrospective cohort study

Background

We previously reported that obese mice had significantly high lipid content in embryos, and excessive lipids are detrimental to embryonic development. However, whether maternal obesity has an effect on embryonic vitrification injury and subsequent pregnancy outcomes is still controversial. This study was conducted to clarify the influence of maternal obesity on embryonic vitrification injury and subsequent pregnancy outcomes by in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

Methods

We retrospectively collected medical record of IVF/ICSI patients from reproductive medicine centers in two tertiary hospitals. The patients were classified into a low-weight group (<18.5 kg/m2), normal-weight group (18.5-23.9 kg/m2), overweight group (24.0-27.9 kg/m2) and obese group (≥28.0 kg/m2) according to their body mass index (BMI). Multivariable logistic regression analysis was performed to compare pregnancy outcomes in fresh and frozen embryo transfer among different BMI groups to define the correlation between BMI and embryonic vitrification injury.

Results

A total of 44 773 women among 20-40 years old were recruited in this study, of which 27 797 underwent their first fresh embryo transfer and 16 976 underwent their first frozen embryo transfer. For fresh embryo transfer, there was no significant difference in the clinical pregnancy rate, live birth rate, and miscarriage rate of 4 BMI groups. For frozen-thawed embryo transfer, there was a significant increase in the clinical pregnancy rate of the overweight group (AOR = 1.14, 95% CI: 1.05-1.25) and the obese group (AOR = 1.24, 95% CI: 1.03-1.50), while the miscarriage rate (AOR = 1.42, 95% CI: 1.05-1.92) also showed a significant increase in the obese group compared to the normal-weight group.

Conclusion

This study provided a new understanding of the effect of maternal obesity on embryonic vitrification injury. Maternal obesity does not worsen the outcome of IVF/ICSI, particularly in the frozen-thawed group.

The Role of Lifestyle and Dietary Factors in the Development of Premature Ovarian Insufficiency

Premature ovarian insufficiency (POI) is a condition that arises from dysfunction or early depletion of the ovarian follicle pool accompanied by an earlier-than-normal loss of fertility in young women. Oxidative stress has been suggested as an important factor in the decline of fertility in women and POI. In this review, we discuss the mechanisms of oxidative stress implicated in ovarian ageing and dysfunction in relation to POI, in particular mitochondrial dysfunction, apoptosis and inflammation. Genetic defects, autoimmunity and chemotherapy, are some of the reviewed hallmarks of POI that can lead to increased oxidative stress. Additionally, we highlight lifestyle factors, including diet, low energy availability and BMI, that can increase the risk of POI. The final section of this review discusses dietary factors associated with POI, including consumption of oily fish, mitochondria nutrient therapy, melatonin, dairy and vitamins that can be targeted as potential interventions, especially for at-risk women and in combination with personalised nutrition. Understanding the impact of lifestyle and its implications for POI and oxidative stress holds great promise in reducing the burden of this condition.

Effects of body mass index and insulin resistance on first-time assisted conception and perinatal outcomes in young polycystic ovary syndrome patients

Objective

The objective of the study was to explore the effect of body mass index (BMI) and insulin resistance (IR) levels on first-time assisted conception results and perinatal outcomes in young polycystic ovary syndrome (PCOS) patients.

Design

This was a single-center, retrospective, observational cohort study.

Patients

Young women with PCOS undergoing their first embryo transfer were included in the study.

Main outcome measure

Early pregnancy loss rate was the main outcome measure.

Results

The early pregnancy loss rate in the overweight + insulin resistance group (OW+IR group) was significantly higher than that in the non-overweight + non-insulin resistance group (NOW+NIR group) (18.16% vs. 9.02%, Bonferroni correction, P = 0.012). The early pregnancy loss rate in the non-overweight + insulin resistance group (NOW+IR group) and overweight + non-insulin resistance group (OW+NIR group) (18.18% and 17.14%, respectively) were also higher than that in the NOW+NIR group (6.07%), but the difference was not statistically significant (Bonferroni correction, all P > 0.05). No significant difference was found in clinical pregnancy rate, live birth rate, and macrosomia rate (all P > 0.05). After adjusting for confounding factors, BMI and IR levels were identified as independent risk factors for early pregnancy loss rate.

Conclusion

BMI and IR levels are independent risk factors for early pregnancy loss in young PCOS patients during the first embryo transfer cycle. Multiple indicators should be considered when assessing pregnancy outcomes, which will promote individualized pregnancy guidance and treatment procedures for PCOS patients.

Mitochondrial dysfunction in the offspring of obese mothers and it's transmission through damaged oocyte mitochondria: Integration of mechanisms

In vivo and in vitro studies demonstrate that mitochondria in the oocyte, are susceptible to damage by suboptimal pre/pregnancy conditions, such as obesity. These suboptimal conditions have been shown to induce mitochondrial dysfunction (MD) in multiple tissues of the offspring, suggesting that mitochondria of oocytes that pass from mother to offspring, can carry information that can programme mitochondrial and metabolic dysfunction of the next generation. They also suggest that transmission of MD could increase the risk of obesity and other metabolic diseases in the population inter- and trans-generationally. In this review, we examined whether MD observed in offspring tissues of high energetic demand, is the result of the transmission of damaged mitochondria from obese mothers' oocytes to the offspring. The contribution of genome-independent mechanisms (namely mitophagy) in this transmission were also explored. Finally, potential interventions aimed at improving oocyte/embryo health were investigated, to see if they may provide an opportunity to halter the generational effects of MD.

Obesity and In Vitro Fertilization

Obesity is a highly prevalent chronic disease with a significant effect on reproductive-age women. The clinical implications of obesity on fertility and pregnancy are well studied citing ovulatory dysfunction, hormonal imbalances, higher miscarriage rates, and increased maternal and neonatal risks. For this reason, many patients with obesity seek reproductive specialists to help build their families. Despite this literature base, the effect of weight loss interventions prior to assisted reproductive technology (ART) is lacking. This review aims to outline the impact of obesity on ART, specifically in vitro fertilization (IVF). Response differences to treatment protocols compared with normal weight counterparts, limitations of access to care, and the mixed results of weight-reduction strategies prior to fertility treatment will be addressed. The known data surrounding benefits of lifestyle modification, pharmacologic therapies, and surgical interventions for obesity prior to IVF are outlined and found to emphasize a need for further research to determine the optimal approach for infertility patients with obesity.

Impact of polyunsaturated fatty acid supplementation on assisted reproductive technology outcomes: a systematic review

This review explores the impact of polyunsaturated fatty acid (PUFA) supplementation in women undergoing assisted reproductive technology (ART) on reproductive outcomes. A systematic search of English peer-reviewed journals was carried out using MEDLINE, EMBASE, and the Cochrane Library to identify articles published from January 1978 to 2021. The primary outcomes assessed included pregnancy and live birth rates. Secondary outcome measures included: (i) implantation rate; (ii) fertilisation rate; (iii) number of oocytes retrieved; (iv) number of metaphase II (MII) oocytes; (v) blastocyst conversion; and (vi) embryo quality. A total of 4 randomised control trials (RCTs) met the inclusion criteria. There is a lack of high-quality research to support widespread dietary supplementation with PUFAs in women undergoing ART. Prior to its clinical recommendation, there is a need for well-designed RCTs to facilitate an in-depth understanding of PUFA supplementation in women undergoing ART.

Effect of High Fat Diet on Disease Development of Polycystic Ovary Syndrome and Lifestyle Intervention Strategies

Polycystic ovary syndrome (PCOS) is a prevalent endocrine and metabolic disorder that affects premenopausal women. The etiology of PCOS is multifaceted, involving various genetic and epigenetic factors, hypothalamic-pituitary-ovarian dysfunction, androgen excess, insulin resistance, and adipose-related mechanisms. High-fat diets (HFDs) has been linked to the development of metabolic disorders and weight gain, exacerbating obesity and impairing the function of the hypothalamic-pituitary-ovarian axis. This results in increased insulin resistance, hyperinsulinemia, and the release of inflammatory adipokines, leading to heightened fat synthesis and reduced fat breakdown, thereby worsening the metabolic and reproductive consequences of PCOS. Effective management of PCOS requires lifestyle interventions such as dietary modifications, weight loss, physical activity, and psychological well-being, as well as medical or surgical interventions in some cases. This article systematically examines the pathological basis of PCOS and the influence of HFDs on its development, with the aim of raising awareness of the connection between diet and reproductive health, providing a robust approach to lifestyle interventions, and serving as a reference for the development of targeted drug treatments.

The Role of Maternal Preconception Adiposity in Human Offspring Sex and Sex Ratio

We evaluated relationships between preconception adiposity and human offspring sex and sex ratio. Using data from a prospective preconception cohort nested within a randomized controlled trial based at 4 US clinical sites (2006-2012), we used logistic regression to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for male:female sex ratio, and log-identity regression to estimate risk differences (RDs) and 95% CIs for male and female livebirth according to preconception adiposity measures. Inverse-probability weights accounted for potential selection bias. Among 603 women attempting pregnancy, there were meaningful reductions in sex ratio for the highest category of each adiposity measure. The lowest sex ratios were observed for obesity (body mass index of ≥30, calculated as weight (kg)/height (m)2, OR = 0.48, 95% CI: 0.26, 0.88) relative to normal body mass index, and the top tertiles (tertile 3) of serum leptin (OR = 0.50, 95% CI: 0.32, 0.80) and skinfold measurements (OR = 0.50, 95% CI: 0.32, 0.79) relative to the lowest tertiles. Reductions were driven by 11-15 fewer male livebirths per 100 women (for obesity, RD = -15, 95% CI: -23, -6.7; for leptin tertile 3, RD = -11, 95% CI: -20, -3.2; and for skinfolds tertile 3, RD = -11, 95% CI: -19, -3.3). We found that relationships between preconception adiposity measures and reduced sex ratio were driven by a reduction in male births.

Maternal obesity and ovarian failure: is leptin the culprit?

At the time of its discovery and characterization in 1994, leptin was mostly considered a metabolic hormone able to regulate body weight and energy homeostasis. However, in recent years, a great deal of literature has revealed leptin's pleiotropic nature, through its involvement in numerous physiological contexts including the regulation of the female reproductive tract and ovarian function. Obesity has been largely associated with infertility, and leptin signalling is known to be dysregulated in the ovaries of obese females. Hence, the disruption of ovarian leptin signalling was shown to contribute to the pathophysiology of ovarian failure in obese females, affecting transcriptional programmes in the gamete and somatic cells. This review attempts to uncover the underlying mechanisms contributing to female infertility associated with obesity, as well as to shed light on the role of leptin in the metabolic dysregulation within the follicle, the effects on the oocyte epigenome, and the potential long-term consequence to embryo programming.

Contribution of key elements of nutritional metabolism to the development of cystic ovarian disease in dairy cattle

The alteration of signaling molecules involved in the general metabolism of animals can negatively influence reproduction. In dairy cattle, the development of follicular cysts and the subsequent appearance of ovarian cystic disease (COD) often lead to decreased reproductive efficiency in the herd. The objective of this review is to summarize the contribution of relevant metabolic and nutritional sensors to the development of COD in dairy cows. In particular, we focus on the study of alterations of the insulin signaling pathway, adiponectin, and other sensors and metabolites relevant to ovarian functionality, which may be related to the development of follicular persistence and follicular formation of cysts in dairy cattle. The results of these studies support the hypothesis that systemic factors could alter the local scenario in the follicle, generating an adverse microenvironment for the resumption of ovarian activity and possibly leading to the persistence of follicles and to the development and recurrence of COD.

The effect of metabolic syndrome on controlled ovarian stimulation outcome in infertile women with polycystic ovary syndrome undergoing assisted reproductive technology cycles

Objective

To evaluate the effect of metabolic syndrome (MetS) diagnosis on oocyte quality and pregnancy outcomes in infertile women with polycystic ovary syndrome (PCOS) who undergoing antagonist-controlled ovarian stimulation (COS) and in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) cycles.

Methods

This prospective cohort study was conducted from November 2019 to November 2020 across two university-affiliated infertility centers in Iran. The PCOS diagnosis was defined according to the Rotterdam criteria. The patients prior to IVF/ICSI cycles were evaluated for MetS diagnosis. MetS was detected according to the National Cholesterol Education Program/Adult Treatment Panel III with the presence of at least three or more of the specific clinical criteria. The cycle outcomes were compared between MetS and non-MetS groups.

Results

Overall, 68 eligible infertile PCOS patients with MetS diagnosis and 126 without MetS participated. The MetS diagnosis was associated with the increased requirement of gonadotropins and the COS duration significantly (P = 0.001). Although the total numbers of retrieved and MII oocytes, obtained and topquality embryos as well as clinical pregnancy and live birth rates in the MetS group were lower than those of in the non-MetS group, the differences were not statistically significant (P > 0.05). In followup of the obstetrics complications, the rate of preeclampsia was significantly higher in patients with MetS (P = 0.02).

Conclusion

MetS diagnosis in PCOS patients was associated with non-significant poor COS and pregnancy outcome. Further studies with larger sample sizes are recommended to clarify the risk of MetS in patients undergoing ART cycles.

Correlations between salivary- and blood-derived gonadal hormone assessments and implications for inclusion of female participants in research studies

Even in the 21st century, female participants continue to be underrepresented in human physiology research. This underrepresentation is attributable in part to the perception that the inclusion of females is more time consuming, less convenient, and more expensive relative to males because of the need to account for the menstrual cycle in cardiovascular study designs. Accounting for menstrual cycle-induced fluctuations in gonadal hormones is important, given established roles in governing vascular function and evidence that failure to consider gonadal hormone fluctuations can result in misinterpretations of biomarkers of cardiovascular disease. Thus, for cardiovascular researchers, the inclusion of females in research studies implies a necessity to predict, quantify, and/or track indexes of menstrual cycle-induced changes in hormones. It is here that methodologies are lacking. Gold standard measurement requires venous blood samples, but this technique is invasive and can become both expensive and technically preclusive when serial measurements are required. To this end, saliva-derived measures of gonadal hormones provide a means of simple, noninvasive hormone tracking. To investigate the feasibility of this technique as a means of facilitating research designs that take the menstrual cycle into account, the purpose of this review was to examine literature comparing salivary and blood concentrations of the primary gonadal hormones that fluctuate across the menstrual cycle: estradiol and progesterone. The data indicate that there appear to be valid and promising applications of salivary gonadal hormone monitoring, which may aid in the inclusion of female participants in cardiovascular research studies.

Obese outbred mice only partially benefit from diet normalization or calorie restriction as preconception care interventions to improve metabolic health and oocyte quality

STUDY QUESTION

Can diet normalization or a calorie-restricted diet for 2 or 4 weeks be used as a preconception care intervention (PCCI) in Western-type diet-induced obese Swiss mice to restore metabolic health and oocyte quality?

SUMMARY ANSWER

Metabolic health and oocyte developmental competence was already significantly improved in the calorie-restricted group after 2 weeks, while obese mice that underwent diet normalization showed improved metabolic health after 2 weeks and improved oocyte quality after 4 weeks.

WHAT IS KNOWN ALREADY

Maternal obesity is linked with reduced metabolic health and oocyte quality; therefore, infertile obese women are advised to lose weight before conception to increase pregnancy chances. However, as there are no univocal guidelines and the specific impact on oocyte quality is not known, strategically designed studies are needed to provide fundamental insights in the importance of the type and duration of the dietary weight loss strategy for preconception metabolic health and oocyte quality.

STUDY DESIGN, SIZE, DURATION

Outbred female Swiss mice were fed a control (CTRL) or high-fat/high-sugar (HF/HS) diet. After 7 weeks, some of the HF mice were put on two different PCCIs, resulting in four treatment groups: (i) only control diet for up to 11 weeks (CTRL_CTRL), (ii) only HF diet for up to 11 weeks (HF_HF), (iii) switch at 7 weeks from an HF to an ad libitum control diet (HF_CTRL) and (iv) switch at 7 weeks from an HF to a 30% calorie-restricted control diet (HF_CR) for 2 or 4 weeks. Metabolic health and oocyte quality were assessed at 2 and 4 weeks after the start of the intervention (n = 8 mice/treatment/time point).

PARTICIPANTS/MATERIALS, SETTING, METHODS

Changes in body weight were recorded. To study the impact on metabolic health, serum insulin, glucose, triglycerides, total cholesterol and alanine aminotransferase concentrations were measured, and glucose tolerance and insulin sensitivity were analyzed at PCCI Weeks 2 and 4. The quality of in vivo matured oocytes was evaluated by assessing intracellular lipid droplet content, mitochondrial activity and localization of active mitochondria, mitochondrial ultrastructure, cumulus cell targeted gene expression and oocyte in vitro developmental competence.

MAIN RESULTS AND THE ROLE OF CHANCE

Significant negative effects of an HF/HS diet on metabolic health and oocyte quality were confirmed (P < 0.05). HF_CTRL mice already showed restored body weight, serum lipid profile and glucose tolerance, similar to the CTRL_CTRL group after only 2 weeks of PCCI (P < 0.05 compared with HF_HF) while insulin sensitivity was not improved. Oocyte lipid droplet volume was reduced at PCCI Week 2 (P < 0.05 compared with HF_HF), while mitochondrial localization and activity were still aberrant. At PCCI Week 4, oocytes from HF_CTRL mice displayed significantly fewer mitochondrial ultrastructural abnormalities and improved mitochondrial activity (P < 0.05), while lipid content was again elevated. The in vitro developmental capacity of the oocytes was improved but did not reach the levels of the CTRL_CTRL mice. HF_CR mice completely restored cholesterol concentrations and insulin sensitivity already after 2 weeks. Other metabolic health parameters were only restored after 4 weeks of intervention with clear signs of fasting hypoglycemia. Although all mitochondrial parameters in HF_CR oocytes stayed aberrant, oocyte developmental competence in vitro was completely restored already after 2 weeks of intervention.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

In this study, we applied a relevant HF/HS Western-type diet to induce obesity in an outbred mouse model. Nevertheless, physiological differences should be considered when translating these results to the human setting. However, the in-depth study and follow-up of the metabolic health changes together with the strategic implementation of specific PCCI intervals (2 and 4 weeks) related to the duration of the mouse folliculogenesis (3 weeks), should aid in the extrapolation of our findings to the human setting.

WIDER IMPLICATIONS OF THE FINDINGS

Our study results with a specific focus on oocyte quality provide important fundamental insights to be considered when developing preconception care guidelines for obese metabolically compromised women wishing to become pregnant.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by the Flemish Research Fund (FWO-SB grant 1S25020N and FWO project G038619N). The authors declare there are no conflicts of interest.

Obesity-related alterations in protein expression in human follicular fluid from women undergoing in vitro fertilization

OBJECTIVE

To compare the proteomic composition of follicular fluid from women with normal weight vs. women with obesity but without a history of polycystic ovary syndrome or known ovarian dysfunction undergoing in vitro fertilization.

DESIGN

Cross-sectional.

SETTING

Academic medical center.

PATIENT(S)

Eight women with normal weight and 8 women with obesity undergoing in vitro fertilization and without a history of polycystic ovary syndrome, ovulatory dysfunction, diminished ovarian reserve, or known endometriosis were included in the analysis.

INTERVENTION(S)

Not applicable.

MAIN OUTCOME MEASURE(S)

Proteomic assessment using liquid chromatography-mass spectrometry analysis.

RESULT(S)

The mean age of women with normal weight was similar to that of women with obesity (32.9 vs. 32.6 years, not significant). The mean body mass index of women with normal weight was 21.2 kg/m² compared with a body mass index of 37.1 kg/m² in women with obesity. A total of 1,174 proteins were identified with ≥2 peptides present. Twenty-five proteins were found to be significantly altered in the follicular fluid from women with obesity. Of these 25 proteins, 19 were up-regulated and 6 were down-regulated. Notably, C-reactive protein was 11-fold higher in the follicular fluid from women with obesity than in the follicular fluid from women with normal weight.

CONCLUSION(S)

Obesity is associated with dysregulation at the level of the follicle, including alterations in proteins related to inflammation and metabolism. These include proteins with emerging roles in energy homeostasis and follicular regulation.

Parental Programming of Offspring Health: The Intricate Interplay between Diet, Environment, Reproduction and Development

As adults, our health can be influenced by a range of lifestyle and environmental factors, increasing the risk for developing a series of non-communicable diseases such as type 2 diabetes, heart disease and obesity. Over the past few decades, our understanding of how our adult health can be shaped by events occurring before birth has developed into a well-supported concept, the Developmental Origins of Health and Disease (DOHaD). Supported by epidemiological data and experimental studies, specific mechanisms have been defined linking environmental perturbations, disrupted fetal and neonatal development and adult ill-health. Originally, such studies focused on the significance of poor maternal health during pregnancy. However, the role of the father in directing the development and well-being of his offspring has come into recent focus. Whereas these studies identify the individual role of each parent in shaping the long-term health of their offspring, few studies have explored the combined influences of both parents on offspring well-being. Such understanding is necessary as parental influences on offspring development extend beyond the direct genetic contributions from the sperm and oocyte. This article reviews our current understanding of the parental contribution to offspring health, exploring some of the mechanisms linking parental well-being with gamete quality, embryo development and offspring health.

Optical imaging detects metabolic signatures associated with oocyte quality

Oocyte developmental potential is intimately linked to metabolism. Existing approaches to measure metabolism in the cumulus oocyte complex (COC) do not provide information on the separate cumulus and oocyte compartments. Development of an assay that achieves this may lead to an accurate diagnostic for oocyte quality. Optical imaging of the autofluorescent cofactors NAD(P)H and FAD provides a spatially resolved indicator of metabolism via the optical redox ratio ($\mathrm{FAD}/\left[\mathrm{NAD}\left(\mathrm{P}\right)\mathrm{H}+\mathrm{FAD}\right]$). This may provide an assessment of oocyte quality. Here, we determined whether the optical redox ratio is a robust methodology for measuring metabolism in the cumulus and oocyte compartments compared with oxygen consumption in the whole COC. We also determined whether optical imaging could detect metabolic differences associated with poor oocyte quality (etomoxir-treated). We used confocal microscopy to measure NAD(P)H and FAD, and extracellular flux to measure oxygen consumption. We found that the optical redox ratio was an accurate reflection of metabolism in the oocyte compartment when compared with oxygen consumption (whole COC). Etomoxir-treated COCs showed significantly lower levels of NAD(P)H and FAD compared to control. While confocal imaging demonstrated the premise, we validated this approach using hyperspectral imaging, which is clinically compatible due to its low energy dose. This confirmed lower NAD(P)H and FAD in etomoxir-treated COCs. When comparing imaged vs non-imaged COCs, subsequent preimplantation development and post-transfer viability were comparable. Collectively, these results demonstrate that label-free optical imaging of metabolic cofactors is a safe and sensitive assay for measuring metabolism and has potential to assess oocyte developmental competence.

General infertility workup in times of high assisted reproductive technology efficacy

The assessments of oocyte quality and quantity and endocrine profile have traditionally been the cornerstone of the general workup of couples with infertility. Over the years, several clinical, hormonal, and functional biomarkers have been adopted to assess ovarian function and identify endocrine disorders before assisted reproductive technology. Furthermore, the genetic workup of patients has drastically changed, introducing novel markers. This not only allowed the prediction of response to ovarian stimulation but also contributed toward the development of a safer and more efficient management of women undergoing assisted reproductive technology. The scope of this review is to provide an overview of the current and novel strategies adopted for the assessment of ovarian function and ovulatory and endocrine disorders in women planning to conceive. Furthermore, it aims to provide an insight in the role of novel genetic biomarkers and use of expanded carrier screening as part of preliminary workup of women with infertility.

Early programming of reproductive health and fertility: novel neuroendocrine mechanisms and implications in reproductive medicine

BACKGROUND

According to the Developmental Origins of Health and Disease (DOHaD) hypothesis, environmental changes taking place during early maturational periods may alter normal development and predispose to the occurrence of diverse pathologies later in life. Indeed, adverse conditions during these critical developmental windows of high plasticity have been reported to alter the offspring developmental trajectory, causing permanent functional and structural perturbations that in the long term may enhance disease susceptibility. However, while solid evidence has documented that fluctuations in environmental factors, ranging from nutrient availability to chemicals, in early developmental stages (including the peri-conceptional period) have discernible programming effects that increase vulnerability to develop metabolic perturbations, the impact and eventual mechanisms involved, of such developmental alterations on the reproductive phenotype of offspring have received less attention.

OBJECTIVE AND RATIONALE

This review will summarize recent advances in basic and clinical research that support the concept of DOHaD in the context of the impact of nutritional and hormonal perturbations, occurring during the periconceptional, fetal and early postnatal stages, on different aspects of reproductive function in both sexes. Special emphasis will be given to the effects of early nutritional stress on the timing of puberty and adult gonadotropic function, and to address the underlying neuroendocrine pathways, with particular attention to involvement of the Kiss1 system in these reproductive perturbations. The implications of such phenomena in terms of reproductive medicine will also be considered.

SEARCH METHODS

A comprehensive MEDLINE search, using PubMed as main interface, of research articles and reviews, published mainly between 2006 and 2021, has been carried out. Search was implemented using multiple terms, focusing on clinical and preclinical data from DOHaD studies, addressing periconceptional, gestational and perinatal programming of reproduction. Selected studies addressing early programming of metabolic function have also been considered, when relevant.

OUTCOMES

A solid body of evidence, from clinical and preclinical studies, has documented the impact of nutritional and hormonal fluctuations during the periconceptional, prenatal and early postnatal periods on pubertal maturation, as well as adult gonadotropic function and fertility. Furthermore, exposure to environmental chemicals, such as bisphenol A, and maternal stress has been shown to negatively influence pubertal development and gonadotropic function in adulthood. The underlying neuroendocrine pathways and mechanisms involved have been also addressed, mainly by preclinical studies, which have identified an, as yet incomplete, array of molecular and neurohormonal effectors. These include, prominently, epigenetic regulatory mechanisms and the hypothalamic Kiss1 system, which likely contribute to the generation of reproductive alterations in conditions of early nutritional and/or metabolic stress. In addition to the Kiss1 system, other major hypothalamic regulators of GnRH neurosecretion, such as γ-aminobutyric acid and glutamate, may be targets of developmental programming.

WIDER IMPLICATIONS

This review addresses an underdeveloped area of reproductive biology and medicine that may help to improve our understanding of human reproductive disorders and stresses the importance, and eventual pathogenic impact, of early determinants of puberty, adult reproductive function and fertility.

Metabolic health status and fecundability in a Singapore preconception cohort study

BACKGROUND

Obesity compromises metabolic health and female fertility, yet not all obese women are similar in metabolic status. The extent to which fecundability is influenced by the metabolic health status of women who are overweight or obese before conception is unknown.

OBJECTIVE

This study aimed to: (1) determine the metabolic health status, and (2) examine the association between metabolic health status and fecundability of overweight and obese women trying to conceive in the Singapore PREconception Study of long-Term maternal and child Outcomes cohort study.

STUDY DESIGN

We conducted a prospective preconception cohort study of Asian women (Chinese, Malay, and Indian) aged 18 to 45 years trying to conceive who were treated from 2015 to 2017 in KK Women's and Children's Hospital in Singapore (n=834). We defined women to have metabolically unhealthy status if they: (1) met 3 or more modified Joint Interim Statement metabolic syndrome criteria; or (2) had homeostasis model assessment-insulin resistance index ≥2.5. Body mass index was categorized as normal (18.5-22.9 kg/m2), overweight (23-27.4 kg/m2), or obese (≥27.5 kg/m2) on the basis of cutoff points for Asian populations. Fecundability was measured by time to pregnancy in menstrual cycles within a year of enrolment. Discrete-time proportional hazards models were used to estimate fecundability odds ratios, with adjustment for confounders and accounting for left truncation and right censoring.

RESULTS

Of 232 overweight women, 28 (12.1%) and 25 (10.8%) were metabolically unhealthy by metabolic syndrome ≥3 criteria and homeostasis model assessment-insulin resistance ≥2.5, respectively. Of 175 obese women, 54 (30.9%) and 93 (53.1%) were metabolically unhealthy by metabolic syndrome ≥3 criteria and homeostasis model assessment-insulin resistance ≥2.5, respectively. Compared with metabolically healthy normal-weight women, lower fecundability was observed in metabolically unhealthy overweight women on the basis of metabolic syndrome criteria (fecundability odds ratios, 0.38 [95% confidence interval, 0.15-0.92]) and homeostasis model assessment-insulin resistance (fecundability odds ratios, 0.68 [95% confidence interval, 0.33-1.39]), with metabolic syndrome criteria showing a stronger association. Metabolically unhealthy obese women showed lower fecundability than the healthy normal-weight reference group by both metabolic syndrome (fecundability odds ratios, 0.35; 95% confidence interval, 0.17-0.72) and homeostasis model assessment-insulin resistance criteria (fecundability odds ratios, 0.43; 95% confidence interval, 0.26-0.71). Reduced fecundability was not observed in overweight or obese women who showed healthy metabolic profiles by either definition.

CONCLUSION

Overweight or obesity was not synonymous with having metabolic syndrome or insulin resistance. In our preconception cohort, metabolically unhealthy overweight and obese women showed reduced fecundability, unlike their counterparts who were metabolically healthy. These findings suggest that metabolic health status, rather than simply being overweight and obese per se, plays an important role in fecundability.

Impairment of endometrial decidual reaction in early pregnant mice fed with high fat diet

OBJECTIVE

To investigate the effect of obesity induced by high fat diet on decidual reaction of endometrium in mice, and the effect of high fat treatment on decidual reaction of endometrial stromal cells.

METHODS

Twelve 4-week-old healthy C57BL/6J female mice were randomly divided into high fat diet group and control group with 6 mice in each group. They were fed with high fat diet (22 kJ/g) or normal diet (16 kJ/g) for 12 weeks, respectively. The body weight of mice was measured every week. After feeding for 12 weeks, the body length and width of mice were measured, and the levels of fasting serum triglyceride and total cholesterol were determined. Then the mice were mated with healthy C57BL/6J male mice, and the uterine tissues were collected on the seventh day of pregnancy. The decidual cells and collagen fibers in mouse endometrium was observed by HE staining and Masson staining respectively. The expression of decidual reaction related proteins in mouse endometrium were detected by immunohistochemistry and Western blotting. Mouse endometrial stromal cells (mESCs) were isolated and treated with the oleic acid and palmitic acid in vitro, and the decidual reaction was induced with estradiol and progesterone. The accumulation of lipid droplets in mESCs was observed by oil red O and Bodipy staining. The cytoskeleton of mESCs was observed by phalloidin staining. The levels of decidual reaction related genes and proteins were detected by real-time fluorescence quantitative PCR and Western blotting.

RESULTS

After feeding for 12 weeks, the body weight of mice in the high fat group was significantly higher than that in the control group ( P<0.01), and there was no significant difference in body length between two groups ( P>0.05), but the body width of mice in the high fat group was significantly larger than that in the control group ( P<0.01), and the levels of serum triglyceride and total cholesterol were significantly higher than those in the control group (Both P<0.05). The number of embryo implantation in the high fat group was significantly less than that in the control group ( P<0.01). The differentiation of mESCs to decidual cells in high fat group was slow and abnormal. The expression levels of decidual reaction markers bone morphogenetic protein (BMP)2 and homeobox A10 (HOXA10) were lower than those in the control group, and there was significant difference in the expression level of HOXA10 ( P<0.01). The results of oil red O and Bodipy staining in mESCs showed that after high fat treatment, the accumulation of lipid droplets increased significantly, phalloidin staining showed abnormal cytoskeleton morphology. The expression levels of decidual reaction related genes dtprp, HOXA10 and proteins BMP2, HOXA10 and cyclooxygenase (COX)2 were significantly lower than those in the control group ( P<0.05).

CONCLUSION

Obesity induced by high fat diet and high fat treatment can impair the decidual reaction of endometrium and endometrial stromal cells in mice.

Melatonin Regulates Lipid Metabolism in Porcine Cumulus–Oocyte Complexes via the Melatonin Receptor 2

Previous studies suggest that the inclusion of melatonin (MTn) in in vitro maturation protocols improves the developmental competence of oocytes by scavenging reactive oxygen species (ROS). However, the molecular mechanisms integrating melatonin receptor (MT)-mediated lipid metabolism and redox signaling during in vitro cumulus–oocyte complex (COC) development still remain unclear. Here, we aimed to elucidate the potential role of MTn receptors in lipid metabolic adjustments during in vitro porcine COC development. We observed that MTn-mediated Gsα–cAMP/PKA signaling facilitated lipolysis primarily through the MT2 receptor and subsequently increased fatty acid (FA) release by hydrolyzing intracellular triglycerides (TGs) in cumulus cells. Furthermore, CD36 was a critical FA transporter that transported available FAs from cumulus cells to oocytes and promoted de novo TG synthesis in the latter. In addition, MTn regulated lipogenesis and intracellular lipolysis to maintain lipid homeostasis and limit ROS production, thereby supporting oocyte cytoplasmic maturation and the subsequent embryo development. Taken together, these findings provide insight into the possible mechanism integrating MT2-mediated lipid homeostasis and redox signaling, which limits ROS production during in vitro COC development. Therefore, understanding the dynamics of the interactions between lipid homeostasis and redox signaling driven by MT2 is necessary in order to predict drug targets and the effects of therapeutics used to improve female reproductive health.

Impact of obesity on medically assisted reproductive treatments

Increasing evidence has demonstrated that obesity impairs female fertility and negatively affects human reproductive outcome following medically assisted reproduction (MAR) treatment. In the United States, 36.5% of women of reproductive age are obese. Obesity results not only in metabolic disorders including type II diabetes and cardiovascular disease, but might also be responsible for chronic inflammation and oxidative stress. Several studies have demonstrated that inflammation and reactive oxygen species (ROS) in the ovary modify steroidogenesis and might induce anovulation, as well as affecting oocyte meiotic maturation, leading to impaired oocyte quality and embryo developmental competence. Although the adverse effect of female obesity on human reproduction has been an object of debate in the past, there is growing evidence showing a link between female obesity and increased risk of infertility. However, further studies need to clarify some gaps in knowledge. We reviewed the recent evidence on the association between female obesity and infertility. In particular, we highlight the association between fat distribution and reproductive outcome, and how the inflammation and oxidative stress mechanisms might reduce ovarian function and oocyte quality. Finally, we evaluate the connection between female obesity and endometrial receptivity.

Effect of orlistat intervention on in vitro fertilization/intracytoplasmic sperm injection outcome in overweight/obese infertile women

OBJECTIVE

This retrospective study sought to evaluate the effect of orlistat intervention on the outcome of in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) in overweight/obese infertile women.

METHODS

Twenty-nine overweight/obese patients undergoing IVF/ICSI for the first time were treated with orlistat intervention (orlistat group). Another 29 patients with matched age and body mass index (BMI) were included in the control group at a ratio of 1:1. Clinical data of both groups were collected, and the clinical baseline data, IVF/ICSI cycle information and embryo transfer outcome were compared between groups by Student's t-test or chi-square test when appropriate.

RESULTS

The 29 patients in the orlistat group completed 37 embryo transfer cycles, and the 29 subjects in the control group completed 38 embryo transfer cycles. There was no significant difference in the clinical baseline data or IVF/ICSI cycle data between the two groups (p > .05). In the end, 22 transfer cycles in orlistat group obtained clinical pregnancies, 5 obtained biochemical pregnancies and 10 had non-pregnancies. As for the control group, 15 transfer cycles obtained clinical pregnancies, 15 achieved biochemical pregnancies and 8 had non-pregnancies. The clinical pregnancy rate of the orlistat group was significantly higher than that of the control group (59.46% versus 39.47%, p = .004), but there was no significant difference in the live birth rate between the two groups (54.05% versus 36.84%, p > .05).

CONCLUSIONS

Orlistat intervention for overweight/obese infertile women receiving IVF/ICSI treatment will increase the clinical pregnancy rate, without affecting the total amount of gonadotropins, ovarian stimulation time or the follicular output rate (FORT).

Arachidonic Acid in Follicular Fluid of PCOS Induces Oxidative Stress in a Human Ovarian Granulosa Tumor Cell Line (KGN) and Upregulates GDF15 Expression as a Response

Polycystic ovarian ovary syndrome (PCOS) is the main cause of ovulatory infertility and a common reproductive endocrine disease of women in reproductive age. In addition, nearly half of PCOS patients are associated with obesity, and their total free fatty acids tend to increase. Arachidonic acid (AA) is a polyunsaturated fatty acid. Oxidation products of AA reacting with various enzymes[cyclooxygenases (COX), lipoxygenases (LOX), cytochrome P450s (CYP)] can change cellular mitochondrial distribution and calcium ion concentration, and increase reactive oxygen species (ROS) production. In this study, we analyzed the follicular fluid fatty acids and found higher levels of C20:4n6 (AA) in PCOS patients than in normal control subjects. Also, to determine whether AA induces oxidative stress (OS) in the human ovarian granulosa tumor cell line (KGN) and affects its function, we treated KGN cells with or without reduced glutathione (GSH) and then stimulated them with AA. The results showed that AA significantly reduced the total antioxidant capacity (TAC) and activity of antioxidant enzymes and increased the malondialdehyde (MDA), ROS and superoxide anion(O_2-)levels in KGN cells. In addition, AA was also found to impair the secretory and mitochondrial functions of KGN cells and induce their apoptosis. We further investigated the downstream genes affected by AA in KGN cells and its mechanism of action. We found that AA upregulated the expression of growth differentiation factor 15 (GDF15), which had a protective effect on inflammation and tissue damage. Therefore, we investigated whether AA-induced OS in KGN cells upregulates GDF15 expression as an OS response.Through silencing of GDF15 and supplementation with recombinant GDF15 (rGDF15), we found that GDF15, expressed as an OS response, protected KGN cells against AA-induced OS effects, such as impairment of secretory and mitochondrial functions and apoptosis. Therefore, this study suggested that AA might induce OS in KGN cells and upregulate the expression of GDF15 as a response to OS.

Extensive analysis of mitochondrial DNA quantity and sequence variation in human cumulus cells and assisted reproduction outcomes

STUDY QUESTION

Are relative mitochondrial DNA (mtDNA) content and mitochondrial genome (mtGenome) variants in human cumulus cells (CCs) associated with oocyte reproductive potential and assisted reproductive technology (ART) outcomes?

SUMMARY ANSWER

Neither the CC mtDNA quantity nor the presence of specific mtDNA genetic variants was associated with ART outcomes, although associations with patient body mass index (BMI) were detected, and the total number of oocytes retrieved differed between major mitochondrial haplogroups.

WHAT IS KNOWN ALREADY

CCs fulfil a vital role in the support of oocyte developmental competence. As with other cell types, appropriate cellular function is likely to rely upon adequate energy production, which in turn depends on the quantity and genetic competence of the mitochondria. mtDNA mutations can be inherited or they can accumulate in somatic cells over time, potentially contributing to aging. Such mutations may be homoplasmic (affecting all mtDNA in a cell) or they may display varying levels of heteroplasmy (affecting a proportion of the mtDNA). Currently, little is known concerning variation in CC mitochondrial genetics and how this might influence the reproductive potential of the associated oocyte.

STUDY DESIGN, SIZE, DURATION

This was a prospective observational study involving human CCs collected with 541 oocytes from 177 IVF patients. mtDNA quantity was measured in all the samples with a validated quantitative PCR method and the entire mtGenome was sequenced in a subset of 138 samples using a high-depth massively parallel sequencing approach. Associations between relative mtDNA quantity and mtGenome variants in CCs and patient age, BMI (kg/m2), infertility diagnosis and ART outcomes were investigated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Massively parallel sequencing permitted not only the accurate detection of mutations but also the precise quantification of levels of mutations in cases of heteroplasmy. Sequence variants in the mtDNA were evaluated using Mitomaster and HmtVar to predict their potential impact.

MAIN RESULTS AND THE ROLE OF CHANCE

The relative mtDNA CC content was significantly associated with BMI. No significant associations were observed between CC mtDNA quantity and patient age, female infertility diagnosis or any ART outcome variable. mtGenome sequencing revealed 4181 genetic variants with respect to a reference genome. The COXI locus contained the least number of coding sequence variants, whereas ATPase8 had the most. The number of variants predicted to affect the ATP production differed significantly between mitochondrial macrohaplogroups. The total number of retrieved oocytes was different between the H-V and J-T as well as the U-K and J-T macrohaplogroups. There was a non-significant increase in mtDNA levels in CCs with heteroplasmic mitochondrial mutations.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

Although a large number of samples were analysed in this study, it was not possible to analyse all the CCs from every patient. Also, the results obtained with respect to specific clinical outcomes and macrohaplogroups should be interpreted with caution due to the smaller sample sizes when subdividing the dataset.

WIDER IMPLICATIONS OF THE FINDINGS

These findings suggest that the analysis of mtDNA in CCs is unlikely to provide an advantage in terms of improved embryo selection during assisted reproduction cycles. Nonetheless, our data raise interesting biological questions, particularly regarding the interplay of metabolism and BMI and the association of mtDNA haplogroup with oocyte yield in ovarian stimulation cycles.

STUDY FUNDING/COMPETING INTEREST(S)

This study was funded by National Institutes of Health grant 5R01HD092550-02. D.J.N. and C.R. co-hold patent US20150346100A1 and D.J.N. holds US20170039415A1, both for metabolic imaging methods. D.W. receives support from the NIHR Oxford Biomedical Research Centre. The remaining authors have no conflicts of interest to declare.

Gene cascade analysis in human granulosa tumor cells (KGN) following exposure to high levels of free fatty acids and insulin

Maternal metabolic disorders such as obesity and diabetes are detrimental factors that compromise fertility and the success rates of medically assisted procreation procedures. During metabolic stress, adipose tissue is more likely to release free fatty acids (FFA) in the serum resulting in an increase of FFA levels not only in blood, but also in follicular fluid (FF). In humans, high concentrations of palmitic acid and stearic acid reduced granulosa cell survival and were associated with poor cumulus-oocyte complex (COC) morphology. Obesity and high levels of circulating FFA were also causatively linked to hampered insulin sensitivity in cells and compensatory hyperinsulinemia. To provide a global picture of the principal upstream signaling pathways and genomic mechanisms involved in this metabolic context, human granulosa-like tumor cells (KGN) were treated with a combination of palmitic acid, oleic acid, and stearic acid at the higher physiological concentrations found in the follicular fluid of women with a higher body mass index (BMI) (≥ 30.0 kg/m2). We also tested a high concentration of insulin alone and in combination with high concentrations of fatty acids. Transcription analysis by RNA-seq with a cut off for fold change of 1.5 and p-value 0.05 resulted in thousands of differentially expressed genes for each treatment. Using analysis software such as Ingenuity Pathway Analysis (IPA), we were able to establish that high concentrations of FFA affected the expression of genes mainly related to glucose and insulin homoeostasis, fatty acid metabolism, as well as steroidogenesis and granulosa cell differentiation processes. The combination of insulin and high concentrations of FFA affected signaling pathways related to apoptosis, inflammation, and oxidative stress. Taken together, our results provided new information on the mechanisms that might be involved in human granulosa cells exposed to high concentrations of FFA and insulin in the contexts of metabolism disorders.

Obesity and oocyte quality: Significant implications for ART and Emerging mechanistic insights

The prevalence of obesity in adults worldwide, and specifically in women of reproductive age, is concerning given the risks to fertility posed by the increased risk of type 2 diabetes, metabolic syndrome and other non-communicable diseases. Obesity has a multi-systemic impact in female physiology that is characterized by the presence of oxidative stress, lipotoxicity, and the activation of pro-inflammatory pathways, inducing tissue-specific insulin resistance and ultimately conducive to abnormal ovarian function. A higher body mass is linked to Polycystic Ovary Syndrome, dysregulated menstrual cycles, anovulation, and longer time to pregnancy, even in ovulatory women. In the context of ART, compared to women of normal BMI, obese women have worse outcomes in every step of their journey, resulting in reduced success measured as live birth rate. Even after pregnancy is achieved, obese women have a higher chance of miscarriage, gestational diabetes, pregnancy complications, birth defects, and most worryingly, a higher risk of stillbirth and neonatal death. The potential for compounding effects of ART on pregnancy complications and infant morbidities in obese women has not been studied. There is still much debate in the field on whether these poorer outcomes are mainly driven by defects in oocyte quality, abnormal embryo development or an unaccommodating uterine environment, however the clinical evidence to date suggests a combination of all three are responsible. Animal models of maternal obesity shed light on the mechanisms underlaying the effects of obesity on the peri-conception environment, with recent findings pointing to lipotoxicity in the ovarian environment as a key driver of defects in oocytes that have not only reduced developmental competence but long-lasting effects in offspring health.

Influence of maternal and paternal pre-conception overweight/obesity on offspring outcomes and strategies for prevention

Overweight, obesity, and their comorbidities remain global health challenges. When established early in life, overweight is often sustained into adulthood and contributes to the early onset of non-communicable diseases. Parental pre-conception overweight and obesity is a risk factor for overweight and obesity in childhood and beyond. This increased risk likely is based on an interplay of genetic alterations and environmental exposures already at the beginning of life, although mechanisms are still poorly defined. In this narrative review, potential routes of transmission of pre-conceptional overweight/obesity from mothers and fathers to their offspring as well as prevention strategies are discussed. Observational evidence suggests that metabolic changes due to parental overweight/obesity affect epigenetic markers in oocytes and sperms alike and may influence epigenetic programming and reprogramming processes during embryogenesis. While weight reduction in overweight/obese men and women, who plan to become pregnant, seems advisable to improve undesirable outcomes in offspring, caution might be warranted. Limited evidence suggests that weight loss in men and women in close proximity to conception might increase undesirable offspring outcomes at birth due to nutritional deficits and/or metabolic disturbances in the parent also affecting gamete quality. A change in the dietary pattern might be more advisable. The data reviewed here suggest that pre-conception intervention strategies should shift from women to couples, and future studies should address possible interactions between maternal and paternal contribution to longitudinal childhood outcomes. Randomized controlled trials focusing on effects of pre-conceptional diet quality on long-term offspring health are warranted.

High-sensitivity C-reactive protein is not independently associated with self-reported infertility in National Health and Nutrition Examination Survey 2015–2018 data

Objective

To study the association between high-sensitivity C-reactive protein (hs-CRP) and infertility among reproductive-age women while controlling for obesity and other metabolic markers. Previous studies found a link between infertility and cardiovascular diseases (CVDs). C-reactive protein is a sensitive marker of CVDs, and its levels are affected by obesity.

Design/Setting

We conducted a cross-sectional study using national data from 2015 through 2018.

Patients

A total of 940 women aged 20–45 years who self-reported infertility, had hs-CRP values measured, and did not have CRP >10 mg/L, asthma, arthritis, bronchitis, thyroid disease, bilateral oophorectomy, hysterectomy, and who were not breastfeeding or pregnant, premenarchal at the time of study or had menarche after the age of 20.

Interventions

N/A.

Main outcome measure(s)

Infertility status (ever reporting inability to conceive with 12 months of trying to become pregnant).

Results

In comparison to noninfertile women, self-reported infertile women had higher mean of hs-CRP (3.11 mg/L vs. 2.40 mg/L) and higher percentage of moderate/high hs-CRP values (77.0% vs 58.8%). However, after adjusting for metabolic markers, there was a nonsignificant association between moderate/high hs-CRP and self-reported infertility in the multivariable logistic regression analysis. Odds ratio estimates of the association between hs-CRP and infertility increased over 40% after removing obesity measures and/or high-density lipoprotein from regression models.

Conclusion

There was no association between hs-CRP and self-reported infertility after controlling for obesity measures and other risk factors for CVDs in a sample of U.S. women aged 20–45 years.

Breast Cancer Risk Factors and Circulating Anti-Müllerian Hormone Concentration in Healthy Premenopausal Women

CONTEXT

We previously reported that anti-Müllerian hormone (AMH), a marker of ovarian reserve, is positively associated with breast cancer risk, consistent with other studies.

OBJECTIVE

This study assessed whether risk factors for breast cancer are correlates of AMH concentration.

METHODS

This cross-sectional study included 3831 healthy premenopausal women (aged 21-57, 87% aged 35-49) from 10 cohort studies among the general population.

RESULTS

Adjusting for age and cohort, AMH positively associated with age at menarche (P < 0.0001) and parity (P = 0.0008) and inversely associated with hysterectomy/partial oophorectomy (P = 0.0008). Compared with women of normal weight, AMH was lower (relative geometric mean difference 27%, P < 0.0001) among women who were obese. Current oral contraceptive (OC) use and current/former smoking were associated with lower AMH concentration than never use (40% and 12% lower, respectively, P < 0.0001). We observed higher AMH concentrations among women who had had a benign breast biopsy (15% higher, P = 0.03), a surrogate for benign breast disease, an association that has not been reported. In analyses stratified by age (<40 vs ≥40), associations of AMH with body mass index and OCs were similar in younger and older women, while associations with the other factors (menarche, parity, hysterectomy/partial oophorectomy, smoking, and benign breast biopsy) were limited to women ≥40 (P-interaction < 0.05).

CONCLUSION

This is the largest study of AMH and breast cancer risk factors among women from the general population (not presenting with infertility), and it suggests that most associations are limited to women over 40, who are approaching menopause and whose AMH concentration is declining.

Impact of body mass index (BMI) on the success rate of fresh embryo transfer in women undergoing first in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment

OBJECTIVE

To investigate the impact of body mass index (BMI) on the success rate and prenatal outcomes of fresh embryo transfer in women undergoing their first in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) treatment.

METHODS

It is a post-hoc analysis of a prospective observational cohort study. 2569 Chinese women were grouped in quintiles of BMI and according to the official Chinese classification of body weight. IVF/ICSI and pregnancy outcomes were compared between groups.

RESULTS

BMI was not associated with IVF/ICSI pregnancy outcomes including hCG positive rate, clinical pregnancy rate, implantation rate, ectopic pregnancy rate, ongoing pregnancy rate, early miscarriage rate, and live birth rate. However, it was negatively related to some pregnancy complications such as gestational diabetes mellitus (GDM) and hypertension. Additionally, the proportion of Cesarean-section was increased with BMI. As for prenatal outcomes, the current results showed no statistical difference in the number of male and female newborn, the proportion of low live birth weight (<2500 g), macrosomia (≥4000 g) (both in all live birth and full-term live birth), and premature delivery (<37 weeks).

CONCLUSIONS

The current study showed that BMI was not associated with embryo transfer outcomes after fresh embryo transfer in women undergoing their first IVF/ICSI treatment, whereas BMI was associated with GDM and gestational hypertension.

Biological roles of l-carnitine in oocyte and early embryo development

Poor oocyte quality is responsible for female infertility. Multiple studies have been carried out to find supplements to enhance oocyte quality and mitigate infertility problems. l-carnitine and its derivatives have diverse roles in developing oocytes and early embryos. This review focuses on the in vitro and in vivo studies that using l-carnitine alone or in combination with other supplements for oocyte quality enhancement. The key roles of l-carnitine in oocyte quality and embryo growth were summarized, and the underlying mechanism was also elucidated. l-carnitine helps in the lipid metabolism process by controlling the transfer of fatty acids to mitochondria for β-oxidation. l-carnitine modulates glucose metabolism and enhances respiratory chain enzyme activity. Furthermore, it acts as an antioxidant to prevent oxidative damage and inhibit apoptosis, a signal in response to oxidative stress. Results show the potential of l-carnitine as a potential agent in assisted reproductive technology to improve oocyte quality and the subsequent embryonic development.

Obesity and reproduction: a committee opinion

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