Does obesity compromise ovarian reserve markers? A clinician’s perspective

Single-cell RNA sequencing reveals the effects of high-fat diet on oocyte and early embryo development in female mice

BACKGROUND

Obesity is a global health issue with detrimental effects on various human organs, including the reproductive system. Observational human data and several lines of animal experimental data suggest that maternal obesity impairs ovarian function and early embryo development, but the precise pathogenesis remains unclear.

METHODS

We established a high-fat diet (HFD)-induced obese female mouse model to assess systemic metabolism, ovarian morphology, and oocyte function in mice. For the first time, this study employed single-cell RNA sequencing to explore the altered transcriptomic landscape of preimplantation embryos at different stages in HFD-induced obese mice. Differential gene expression analysis, enrichment analysis and protein-protein interactions network analysis were performed.

RESULTS

HFD-induced obese female mice exhibited impaired glucolipid metabolism and insulin resistance. The ovaries of HFD mice had a reduced total follicle number, an increased proportion of atretic follicles, and irregular granulosa cell arrangement. Furthermore, the maturation rate of embryonic development by in vitro fertilization of oocytes was significantly decreased in HFD mice. Additionally, the transcriptional landscapes of preimplantation embryos at different stages in mice induced by different diets were significantly distinguished. The maternal-to-zygotic transition was also affected by the failure to remove maternal RNAs and to turn off zygotic genome expression.

CONCLUSIONS

HFD-induced obesity impaired ovarian morphology and oocyte function in female mice and further led to alterations in the transcriptional landscape of preimplantation embryos at different stages of HFD mice.

Study of Sonographic Indicators of Ovarian Reserves in Women With WHO-Defined Anovulatory Disorders

Depending on the age of the wife or female partner, infertility is defined as the inability of a couple to achieve conception after 12 months if the age is ≤35 years and six months if the age is ≥35 years. About half of female infertility is attributed to ovulatory dysfunction, and the rest is either due to tubal and pelvic pathology or problems such as thyroid disease or anatomic abnormalities. Ovulatory disorders are one of the major factors for infertility problems in couples. Ultrasound monitoring of ovarian follicle growth plays a pivotal role in infertility treatment. The total number of small antral follicles in both ovaries is an important predictive parameter of the ovarian induction cycle, whereas ovarian volume is the parameter most easily assessed by ultrasound. The purpose of this study is to analyze the sonographic indicators of infertility (antral follicle count and ovarian volume) in four World Health Organization (WHO)-defined anovulatory groups and compare the same with that of healthy fertile women.

Ultrasonographic criteria in the diagnosis of polycystic ovary syndrome: a systematic review and diagnostic meta-analysis

BACKGROUND

Polycystic ovary morphology (PCOM) on ultrasonography is considered as a cardinal feature of polycystic ovarian syndrome (PCOS). Its relevance as a diagnostic criterion for PCOS was reaffirmed in the most recent International Evidence-Based Guideline for the Assessment and Management of PCOS. However, there remains a lack of clarity regarding the best practices and specific ultrasonographic markers to define PCOM.

OBJECTIVE AND RATIONALE

The aim of this systematic review and diagnostic meta-analysis was to assess the diagnostic accuracy of various ultrasonographic features of ovarian morphology in the diagnosis of PCOS.

SEARCH METHODS

Relevant studies published from 1 January 1990 to 12 June 2023 were identified by a systematic search in PubMed, Web of Science, Scopus, CINAHL, and CENTRAL. Studies that generated diagnostic accuracy measures (e.g. proposed thresholds, sensitivity, specificity) for PCOS using the following ultrasonographic markers met criteria for inclusion: follicle number per ovary (FNPO) or per single cross-section (FNPS), ovarian volume (OV), and stromal features. Studies on pregnant or post-menopausal women were excluded. Risk of bias and applicability assessment for diagnostic test accuracy studies were determined using the QUADAS-2 and QUADAS-C tool for a single index test or between multiple index tests, respectively. Diagnostic meta-analysis was conducted using a bivariate model of pooled sensitivity and specificity, and visualized using forest plots and summary receiver-operating characteristic (SROC) curves.

OUTCOMES

From a total of 2197 records initially identified, 31 studies were included. Data from five and two studies were excluded from the meta-analysis due to duplicate study populations or limited data for the index test, leaving 24 studies. Pooled results of 20 adult studies consisted of 3883 control participants and 3859 individuals with PCOS. FNPO was the most accurate diagnostic marker (sensitivity: 84%, CI: 81-87%; specificity: 91%, CI: 86-94%; AUC: 0.905) in adult women. OV and FNPS had similar pooled sensitivities (OV: 81%, CI: 76-86%; FNPS: 81%, CI: 70-89%) but inferior pooled specificities (OV: 81%, CI: 75-86%; FNPS: 83%, CI: 75-88%) and AUCs (OV: 0.856; FNPS: 0.870) compared to FNPO. Pooled results from four adolescent studies consisting of 210 control participants and 268 girls with PCOS suggested that OV may be a robust ultrasonographic marker for PCOS diagnosis albeit the current evidence remains limited. The majority of the studies had high risk of bias for the patient selection (e.g. lack of randomized/consecutive patient selection) and index test (e.g. lack of pre-proposed thresholds for comparison) domains across all ultrasonographic markers. As such, diagnostic meta-analysis was unable to determine the most accurate cutoff for ultrasonographic markers to diagnose PCOS. Subgroup analysis suggested that stratification based on previously proposed diagnostic thresholds, age, BMI, or technology did not account for the heterogeneity in diagnostic accuracy observed across the studies. Studies that diagnosed PCOS using the Rotterdam criteria had improved sensitivity for FNPO. Studies from North America had lower diagnostic accuracy when compared to Asian studies (FNPO: sensitivity) and European studies (OV: specificity, diagnostic odds ratio and positive likelihood ratio). Geographic differences in diagnostic accuracy may potentially be due to differences in age, BMI, and diagnostic criteria of the PCOS group across regions.

WIDER IMPLICATIONS

This diagnostic meta-analysis supports the use of FNPO as the gold standard in the ultrasonographic diagnosis of PCOS in adult women. OV and FNPS provide alternatives if total antral follicle counts cannot be accurately obtained. Our findings support the potential for ultrasonographic evidence of PCOM in adolescents as more data becomes available. Subgroup analysis suggests the need to investigate any relative contributions of geographical differences on PCOS phenotypes. These findings may provide the basis for the development of strategies and best practices toward a standardized definition of PCOM and a more accurate ultrasonographic evaluation of PCOS.

Assessment of Nutritional Status and Its Influence on Ovarian Reserve: A Systematic Review

BACKGROUND

Nowadays, there is a growing interest in the relationship among lifestyle, reproductive health, and fertility. Recent investigations highlight the influence of environmental and lifestyle factors such as stress, diet, and nutritional status on reproductive health. The aim of this review was to determine the influence of nutritional status on ovarian reserve in order to improve the reproductive health of women of childbearing age.

METHODS

A systematic literature review was carried out following the PRISMA method. The quality of the studies was assessed using the Cochrane Collaboration Risk of Bias tool. Data were extracted, and the results were summarized into two blocks: according to the technique used to assess ovarian reserve and nutritional status; according to the results found in the relationship between ovarian reserve and nutritional status.

RESULTS

A total of 22 articles involving 5929 women were included. In 12 of the included articles (54.5%), a relationship between nutritional status and ovarian reserve was demonstrated. In seven publications (31.8%), the increased body mass index (BMI) led to a decrease in ovarian reserve, two of them (0.9%) in patients with polycystic ovary syndrome, showing a decrease only if BMI > 25. In two articles (0.9%), there was a negative relationship between ovarian reserve and waist-to-hip ratio, and in one (0.45%), a positive relationship was shown between ovarian reserve and testosterone levels, the latter being related to body mass index. In five articles (22.7%), body mass index was used as a confounder and was negatively related to ovarian reserve, and in another four (18%), no correlation was found.

CONCLUSIONS

Ovarian reserve appears to be influenced by nutritional status. A high body mass index has a negative impact on the ovary, decreasing antral follicle count and anti-Müllerian hormone. Oocyte quality is compromised, increasing the rate of reproductive problems and the demand for assisted reproductive techniques. Further studies are needed to understand which dietary factors have the greatest effect on ovarian reserve in order to promote reproductive health.

Virtual Compared With In-Clinic Transvaginal Ultrasonography for Ovarian Reserve Assessment

OBJECTIVE

To evaluate noninferiority of virtual transvaginal ultrasonography compared with in-clinic ultrasonography for ovarian reserve assessment.

METHODS

We conducted a single-site, head-to-head crossover trial. Participants performed self-administered virtual transvaginal ultrasonography at home, guided by a remote-certified ultrasound technologist, then underwent transvaginal ultrasonography in-clinic with another ultrasound technologist. Participants were women in the greater Boston area interested in evaluating ovarian reserve and recruited through social media, health care referrals, and professional networks. The uterus and ovaries were captured in sagittal and transverse views. These randomized recordings were reviewed by two or three independent, blinded reproductive endocrinologists. The primary outcome was noninferiority of the rate of clinical quality imaging produced at home compared with in clinic. Sample size was selected for greater than 90% power, given the 18% noninferiority margin. Secondary outcomes included antral follicle count equivalency and net promoter score superiority.

RESULTS

Fifty-six women were enrolled from December 2020 to May 2021. Participants varied in age (19-35 years), BMI (19.5-33.9), and occupation. Ninety-six percent of virtual and 98% of in-clinic images met "clinical quality." The difference of -2.4% (97.5% CI lower bound -5.5%) was within the noninferiority margin (18%). Antral follicle counts were equivalent across settings, with a difference in follicles (0.23, 95% CI -0.36 to 0.82) within the equivalence margin (2.65). Virtual examinations had superior net promoter scores (58.1 points, 97.5% CI of difference 37.3-79.0, P<.01), indicating greater satisfaction with the virtual experience.

CONCLUSION

Virtual transvaginal ultrasonography remotely guided by an ultrasonography technologist is noninferior to in-clinic transvaginal ultrasonography for producing clinical quality images and is equivalent for estimating antral follicle count. Virtual transvaginal ultrasonography had superior patient satisfaction and has potential to significantly expand patient access to fertility care.

FUNDING SOURCE

This study was sponsored by Turtle Health.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, NCT04687189.

Are the body shape index, the body roundness index and waist-to-hip ratio better than BMI to predict recurrent pregnancy loss?

PURPOSE

Etiology could not be determined in approximately 50% of recurrent pregnancy loss cases, and it was named unexpected recurrent pregnancy loss(URPL). A body shape index(ABSI), body roundness index(BRI), and waist-to-hip ratio(WtHR) are new indexes that are superior to BMI in showing body fat distribution. We aimed to investigate the potency of ABSI, BRI, and WtHR in URPL, their superiority to BMI, and their suitability for clinical use.

METHODS

One hundred and thirty-eight patients between the ages of 20-40 who applied to our hospital for URPL between January 2016 and December 31, 2020 were included in our study. Weight, height, waist circumference, and hip circumference were measured, and indexes were calculated. Differences between the URPL and control groups were calculated using the IBM SPSS program.

RESULTS

There was a significant difference between the two groups for BRI, ABSI, and WtHR values, while there was no significant difference in BMI. BRI(4.4 ± 1.7vs3.9 ± 1.5), ABSI(0.08 ± 0.005 vs 0.078 ± 0.004), and WtHR(0.84 ± 0.06vs0.82 ± 0.05) values were higher in the URPL group. ROC analysis showed us that BRI, ABSI, and WtHR have a diagnostic value for URPL(P < .05). When indexes were above the cutoff values, RPL risk increased 3.59 times in ABSI, 2.26 times in BRI, and 2.9 times in WtHR(P < .05).

CONCLUSIONS

The relationship between obesity and URPL can be explained more clearly by using effective indexes that show body fat distribution rather than BMI. Ethics committee approval was obtained from Erzincan Binali Yildirim University in 14.01.2021. Clinical Research Ethics Committee no: 01/01.

Ultrasonographic features of ovarian morphology capture nutritional and metabolic influences on the reproductive axis: implications for biomarker development in ovulatory disorders

Ultrasonographic imaging of ovarian morphology is used widely to inform reproductive health status in women. Metabolic disturbances induced by a negative energy balance (e.g. undernutrition) or positive energy balance (e.g. overnutrition, obesity) are known to drive or exacerbate reproductive dysfunction. Whether the utility of ultrasonographic metrics of ovarian morphology could be extended as biomarkers that detect and monitor the integration of metabolic and reproductive dysfunction is an emerging research area, and recent evidence is discussed. We note that unique variations in ovarian morphology emerge across the adiposity spectrum and highlight the potential for reproductive and metabolic 'tipping points' upon which such morphological variations may be detected on ultrasonography.

High-fat diet leads to elevated lipid accumulation and endoplasmic reticulum stress in oocytes, causing poor embryo development

The present study was designed to investigate the effect of diet-induced obesity on endoplasmic reticulum (ER) stress in oocytes. Swiss albino mice (3 weeks old) were fed with a high-fat diet (HFD) for 8 weeks. Oocytes were assessed for lipid droplet accumulation, oxidative stress, ER stress and their developmental potential invitro. High lipid accumulation (P<0.01) and elevated intracellular levels of reactive oxygen species were observed in both germinal vesicle and MII oocytes of HFD-fed mice (P<0.05 and P<0.01 respectively compared with control). Further, expression of the ER stress markers X-box binding protein 1 (XBP1), glucose-regulated protein 78 (GRP78), activating transcription factor 4 (ATF4) and activating transcription factor 6 (ATF6) was significantly (P<0.001) higher in oocytes of the HFD than control group. Oocytes from HFD-fed mice exhibited poor fertilisation and blastocyst rates, a decrease in total cell number and high levels of DNA damage (P<0.01) compared with controls. In conclusion, diet-induced obesity resulted in elevated lipid levels and higher oxidative and ER stress in oocytes, which contributed to the compromised developmental potential of embryos.

Is ovarian reserve associated with body mass index and obesity in reproductive aged women? A meta-analysis

OBJECTIVE

The associations of body mass index (BMI) and obesity with ovarian reserve are controversial. This systematic review and meta-analysis was conducted to investigate the associations in reproductive-aged women.

METHODS

PubMed and Scopus were searched up to December, 2016. Original studies on the association of BMI with ovarian reserve markers, anti-Mullerian hormone (AMH), follicle-stimulating hormone (FSH), inhibin β, and antral follicle count (AFC), either according to BMI categories or a continuous variable, were selected. Analyses were stratified into three groups based on polycystic ovary syndrome (PCOS) and fertility status of women.

RESULTS

Of 4,055 records identified, 45 studies were eligible for inclusion. Comparing the obese with nonobese, the pooled mean differences (MDs) and 95% confidence intervals (CIs) were -1.08 (95% CIs -1.52, -0.63) ng/mL for AMH, -0.22 (95% CIs -0.39, -0.06) mIU/mL for FSH, -0.09 (95% CIs -0.60, 0.42) for AFC, and -21.06 (95% CIs -41.18, -0.85) pg/mL for inhibin β in overall populations. The MDs were significant for AMH in fertile non-PCOS and PCOS women, and for FSH only in PCOS women. Fisher's Z showed significant correlations of BMI with AMH in the overall populations (-0.15 [95% CIs -0.20, -0.11]) and in all subgroups, and with FSH in the fertile non-PCOS women (-0.16 [95% CIs -0.28, -0.04]).

CONCLUSION

Ovarian reserve markers of AMH and FSH are significantly lower in obese than in nonobese women, and BMI is negatively correlated with AMH in all study populations, and with FSH in fertile non-PCOS subgroups. PCOS and fertility status do not appear to affect the associations.

Exploring the Ovarian Reserve Within Health Parameters: A Latent Class Analysis

The process of ovarian aging is influenced by a complex and poorly understood interplay of endocrine, metabolic, and environmental factors. The purpose of this study was to explore the feasibility of using latent class analysis to identify subgroups based on cardiometabolic, psychological, and reproductive parameters of health and to describe patterns of anti-Müllerian hormone levels, a biomarker of the ovarian reserve, within these subgroups. Sixty-nine lean (body mass index [BMI] ⩽ 25 kg/m2) and severely obese (BMI ⩾ 40 kg/m2) postpartum women in Edinburgh, Scotland, were included in this exploratory study. The best fitting model included three classes: Class 1, n = 23 (33.5%); Class 2, n = 30 (42.2%); Class 3, n = 16 (24.3%). Postpartum women with lower ovarian reserve had less favorable cardiometabolic and psychological profiles. Examining the ovarian reserve within distinct subgroups based on parameters of health that affect ovarian aging may facilitate risk stratification in the context of ovarian aging.

Obesity and anovulatory infertility: A review

This global overweight and obesity epidemics has become one of the largest public health problem worldwide and is increasingly more common among women in reproductive age. Along with the prevalence of overweight women, there is an increase in women with anovulatory infertility. Thus, we carried out a bibliographic research in the PubMed, Lilacs and SciELO databases, using the combinations in Portuguese, Spanish and English of the following descriptors: "Body Mass Index", "obesity", "overweight", "female infertility" and "anovulation". The aim of this study was to assess the effects of obesity on the ovulatory profile of infertile women in the available literature.

Anti-Müllerian Hormone Levels and Urinary Cortisol in Women With Chronic Abdominal Pain

OBJECTIVE

To explore the association of hypothalamic-pituitary-adrenal activity with ovarian functioning in women with and without chronic abdominal pain (CAP).

DESIGN AND SETTING

A secondary data analysis was performed with data from female participants in a natural history protocol at the National Institutes of Health.

PARTICIPANTS

A total of 36 women (age range = 19-39 years, mean = 27.11 years) were included in the study.

METHODS

This pilot study was conducted with a subset of participants enrolled in a natural history protocol conducted in the Hatfield Clinical Research Center at the National Institutes of Health. The parent study included participants with and without CAP who provided a 5-hour urine sample for determination of cortisol levels and serum samples for determination of circulating levels of cortisol, luteinizing hormone, and follicle-stimulating hormone. CAP was defined as presence or absence of chronic pain for at least 6 months and was determined via self-report.

RESULTS

Anti-Müllerian hormone (AMH) concentrations declined significantly with age as expected. When AMH levels were dichotomized as normal or abnormal (defined as higher or lower than age-specific normative ranges, respectively), there were significant associations between abnormal AMH levels and CAP and urine cortisol levels. Participants with CAP or low urine cortisol levels were significantly more likely to have abnormal AMH levels.

CONCLUSION

Results suggest that chronic abdominal pain and hypothalamic-pituitary-adrenal dysregulation may be associated with abnormal AMH levels.

Ethnicity or environment: effects of migration on ovarian reserve among Bangladeshi women in the United Kingdom

OBJECTIVE

To assess whether the quality of early childhood environments among different groups of Bangladeshi women, including migrants to the United Kingdom (UK), contributes to variation in ovarian reserve and the rate of reproductive aging in later life.

DESIGN

Cross-sectional study.

SETTING

Not applicable.

PATIENT(S)

A total of 179 healthy women volunteers aged 35-59 years were divided into four groups: [1] 36 Bangladeshis living in Sylhet, Bangladesh; [2] 53 Bangladeshis who migrated to the UK as adults; [3] 40 Bangladeshis who migrated to the UK as children aged 0-16 years; and [4] a reference group of 50 women of European origin living in London.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Levels of serum antimüllerian hormone, inhibin B, FSH, and E2, and anthropometrics derived from biomarkers; reproductive, demographic, and health variables from structured questionnaires.

RESULT(S)

Bangladeshi migrants who moved to the UK as children and European women had a highly significantly larger, age-related ovarian reserve compared with migrant Bangladeshis who had moved to the UK as adults or Bangladeshi women still living in Bangladesh. There were no other significant covariates in the model aside from age and menopausal status.

CONCLUSION(S)

The study points to the importance of childhood development in considering variation in ovarian reserve across different ethnic groups. Clinical studies and research in assisted reproductive technology have emphasized the role of genes or race in determining inter-population variation in ovarian reserve. Early life developmental factors should be given due consideration when evaluating inter-group differences in response to assisted reproductive technology.

Impact of maternal malnutrition during the periconceptional period on mammalian preimplantation embryo development

During episodes of undernutrition and overnutrition the mammalian preimplantation embryo undergoes molecular and metabolic adaptations to cope with nutrient deficits or excesses. Maternal adaptations also take place to keep a nutritional microenvironment favorable for oocyte development and embryo formation. This maternal-embryo communication takes place via several nutritional mediators. Although adaptive responses to malnutrition by both the mother and the embryo may ensure blastocyst formation, the resultant quality of the embryo can be compromised, leading to early pregnancy failure. Still, studies have shown that, although early embryonic mortality can be induced during malnutrition, the preimplantation embryo possesses an enormous plasticity that allows it to implant and achieve a full-term pregnancy under nutritional stress, even in extreme cases of malnutrition. This developmental strategy, however, may come with a price, as shown by the adverse developmental programming induced by even subtle nutritional challenges exerted exclusively during folliculogenesis and the preimplantation period, resulting in offspring with a higher risk of developing deleterious phenotypes in adulthood. Overall, current evidence indicates that malnutrition during the periconceptional period can induce cellular and molecular alterations in preimplantation embryos with repercussions for fertility and postnatal health.

[Impact of maternal overnutrition on the periconceptional period]

Overnutrition may lead to obesity. Maternal obesity may affect fertility not only via anovulation, but also through direct effects on oocytes and preimplantation embryos, indicating that the periconceptional period is sensitive to conditions of overnutrition. The periconceptional period includes from folliculogenesis to implantation. Animal model studies suggest that oocytes derived from obese females usually have a small size and mitochondrial abnormalities. These disruptions are probably induced by changes in the components of the ovarian follicular fluid. Experimental evidence also suggests that obesity may affect the microenvironment in oviducts and uterus, resulting in development of preimplantation embryos with reduced cell numbers and up-regulation of proinflammatory genes. However, further research is needed for in-depth characterization of the effects of maternal obesity during the periconceptional period.

Evaluation of the ovarian reserve function in patients with metabolic syndrome in relation to healthy controls and different age groups

OBJECTIVE

To evaluate the ovarian reserve function in female patients with metabolic syndrome (MetS).

METHODS

This study evaluated 136 subjects, 67 with MetS and 69 controls. Subjects were divided into three age groups. Group I included 49 subjects aged 20-29 years, 22 with MetS and 27 controls; group II included 45 subjects aged 30-39 years, 22 with MetS and 23 controls; and group III included 42 subjects aged 40-49 years, 23 with MetS and 19 controls. Demographic characteristics, anthropometrics, blood biochemistry, and gonadotrophic hormones were compared as total ovarian volume and antral follicle count on ovarian transvaginal ultrasonography.

RESULTS

Serum levels of FSH, LH, E2 and progesterone were similar in the MetS and control groups, while testosterone levels were significantly higher in MetS patients than controls, both in the overall population (p = 0.024) and in those aged 20-29 years (p = 0.018). Total ovarian volume was significantly lower in MetS patients than controls, in both the overall population (p = 0.003) and those aged 20-29 years (p = 0.018), while antral follicle counts were similar. Ovarian volume correlated positively with antral follicle count (AFC) (r = 0.37; p < 0.001) and negatively with age (r = 0.34; p < 0.001) and FSH concentration (r = 0.21; p = 0.013). AFC was negatively correlated with age (r = 0.36; p < 0.001).

CONCLUSION

Ovarian reserve function is significantly lower in MetS patients than in healthy control subjects, particularly in women aged 20-29 years.

Survey of the situation of infertile women seeking in vitro fertilization treatment in China

Background. In previous studies, people's knowledge of reproductive health and infertile women's psychological states was surveyed in several countries. However, there has been limited information concerning the psychological states of infertile women seeking treatment and the outcomes of in vitro fertilization (IVF) in China. Methods. Infertile women were asked to complete short questionnaires on the day that their oocytes were retrieved; these questionnaires covered the durations of their infertility, levels of education, sources of pressure, and psychological states. Data concerning IVF outcomes were provided by embryologists and clinicians. The correlations between the duration of infertility and educational level, psychological state and education level, and psychological state and outcome of IVF were analyzed in the cohort study. Results. The duration of infertility in more than half of the females was longer than 5 years. Compared with less-educated women, women with higher levels of education sought treatment earlier and their rates of depressive symptoms were lower. There is an association between negative emotions and outcome of IVF. Conclusions. The survey of the situations of infertile women seeking IVF treatment in China indicates the importance of popularizing knowledge concerning reproductive health. Improving medical conditions, reducing the costs of treatment, and developing social culture will aid in relieving the stress of infertile women and improving assisted reproductive treatment.