Associations between follicular fluid trace elements and ovarian response during in vitro fertilization

INTRODUCTION

Exposure to trace elements has been associated with ovarian response in experimental studies. We conducted a hypothesis-generating study of associations between ovarian follicular fluid (FF) trace elements and measures of ovarian response among women using in vitro fertilization (IVF).

METHODS

We collected ovarian FF specimens from 56 women. We determined concentrations (μg/L) of 11 trace elements using inductively coupled plasma-tandem mass spectrometry. We estimated associations between women's FF trace elements per interquartile range difference, and measures of ovarian response using linear (peak estradiol (E2), baseline anti-mullerian hormone (AMH), and follicle stimulating hormone (FSH)) and negative binomial (baseline antral follicle count (AFC) and oocyte count) regression, adjusting for confounding factors. We used principal component analysis (PCA) to estimate the associations of the FF trace elements mixture. We also explored FF oxidative stress enzymes as causal mediators of the associations.

RESULTS

Higher FF cobalt was associated with greater peak E2 (mean difference = 351.48 pg/mL; 95%CI: 21.76, 724.71) and AFC (rate ratio = 1.14; 95%CI: 1.01, 1.28), and higher FF copper was associated with greater peak E2 (mean difference = 335.66 pg/mL; 95%CI: 81.77, 753.08) and oocyte count (rate ratio = 1.19; 95%CI: 1.02, 1.43). Higher FF mercury was also associated with greater peak E2 (mean difference = 410.70 pg/mL; 95%CI: 61.90, 883.39). Higher FF lead was associated with lesser AFC (rate ratio = 0.85; 95%CI: 0.73, 0.98). Using PCA, the mixture of Sr, Hg, and As was associated with higher peak estradiol, AFC, and oocyte count. FF glutathione peroxidase, paraoxonase, and arylesterase activities were inconsistent mediators of the associations, but the effect estimates were imprecise.

CONCLUSION

Our results suggest that essential and non-essential trace elements in FF were associated with ovarian response during IVF.

Exploratory cohort study into underlying mechanism of differences in estrogen metabolism between Asian and Caucasian women during assisted reproductive technology treatment

Objective

Explore whether racial differences in prevalence of CYP1A2∗1F polymorphism underlies estrogen metabolism differences among Asians and Caucasians.

Design

Prospective cohort study.

Setting

University-based fertility practice.

Patients

Asian or Caucasian patients who underwent ovarian stimulation (OS) or programmed cycle frozen embryo transfer (FET) between October 2019 and April 2021.

Interventions

None.

Main Outcome Measures

Trigger-day serum E2 per oocyte retrieved in OS cycles, and E2 on day of lining check in FET cycles.

Results

Seventy-one participants were enrolled, 55 in OS group (29 Caucasian and 26 Asian) and 16 in FET group (10 Caucasian and 6 Asian). Peak E2 per oocyte retrieved in the OS group (n = 48) differed by race, with significantly lower levels in Caucasians compared with Asians (177.5 ± 64.2 vs. 261.1 ± 139.5 pg/mL). Prevalence of CYP1A2∗1F polymorphism did not significantly differ by race. Compared using Kruskal-Wallis test, peak E2 per oocyte retrieved did not differ by CYP1A2∗1F genotype. In multivariate linear regression model, adjusting for body mass index, caffeine intake, and self-reported race, there remained no significant correlation. In FET group, serum E2 on day of lining check was also not significantly different by CYP1A2∗1F genotype.

Conclusions

Although a consistent difference in serum E2 between Asians and Caucasians undergoing OS was noted, the CYP1A2∗1F polymorphism is unlikely the primary driver of this difference.

Toxic elements in follicular fluid adversely influence the likelihood of pregnancy and live birth in women undergoing IVF

STUDY QUESTION

Are follicular fluid (FF), arsenic (As), mercury (Hg), cadmium (Cd) and lead (Pb) concentrations associated with IVF outcomes among women undergoing IVF?

SUMMARY ANSWER

There was a non-linear association between higher FF Hg concentration and a lower likelihood of biochemical pregnancy and live birth. Higher FF Pb concentration was also associated with a lower probability of live birth.

WHAT IS KNOWN ALREADY

Previous research suggests that toxic elements may affect fertility among couples conceiving with and without assistance. However, the results have been inconsistent, possibly related in part to exposure misclassification. Very few studies have used ovarian FF to measure toxic elements, as it requires an invasive collection procedure, yet it may offer a more accurate estimate of a biologically effective dose than blood or urine.

STUDY DESIGN SIZE DURATION

This is a prospective study of 56 women undergoing IVF, from October 2015 to June 2017. FF was collected for analysis on the day of oocyte retrieval.

PARTICIPANTS/MATERIALS SETTING METHODS

As, Cd, Hg and Pb were determined in 197 FF specimens, using inductively coupled plasma tandem mass spectrometry. FF glutathione peroxidase, glutathione reductase, total glutathione-S-transferase, superoxide dismutase, arylesterase and paraoxonase (PON1p) activities were measured using kinetic enzyme assays.

MAIN RESULTS AND THE ROLE OF CHANCE

Non-linear associations were detected, in which the probabilities of biochemical pregnancy (P = 0.05) and live birth (P = 0.05) were lower in association with FF Hg greater than ∼0.51 µg/l Hg, adjusted for age, race, cigarette smoking and recent seafood consumption. Higher FF Pb was also associated with a lower likelihood of live birth (relative risk (RR) = 0.68, 95% CI: 0.46, 1.00; P = 0.05). We also found a suggestive, although imprecise, antagonizing mediating effect of PON1p activity on the association between FF Pb and live birth (-28.3%; 95% CI: -358%, 270%).

LIMITATIONS REASONS FOR CAUTION

The results should be interpreted judiciously given the limited sample size and difficulty accounting for correlated data in generalized additive models and mediation analyses. Additionally, women undergoing IVF are highly selected with respect to age and socioeconomic status, and so the generalizability of the results may be limited.

WIDER IMPLICATIONS OF THE FINDINGS

Overall, the results suggest that FF Hg was associated with a lower likelihood of biochemical pregnancy and live birth, with a potential threshold effect, and that higher FF Pb was associated with a lower probability of live birth. These results may help to guide clinical recommendations for limiting the exposure of patients to Hg and Pb and ultimately improve IVF success rates.

STUDY FUNDING/COMPETING INTERESTS

This work was funded in part by the National Institute of Environmental Health Sciences (NIEHS), grant number 1R56ES023886-01, to the University at Albany (M.S.B.), and in part by the National Institute of Environmental Health Sciences (NIEHS), grant number 1U2CES026542-01, to the Wadsworth Center (P.J.P.). The authors declare no competing interests.

TRIAL REGISTRATION NUMBER

N/A.

Variability of essential and non-essential trace elements in the follicular fluid of women undergoing in vitro fertilization (IVF)

Both essential and non-essential elements have been associated with female reproductive function in epidemiologic investigations, including among IVF populations. To date, most investigators have used blood or urine to assess biomarkers of exposure, with few employing ovarian follicular fluid (FF). FF may offer a more direct "snapshot" of the oocyte microenvironment than blood or urine, however previous studies report follicle-to-follicle variability in FF constituents that may contribute to exposure misclassification. Our objectives were to investigate sources of trace element variability, to estimate FF biomarker reliability among women undergoing IVF (n = 34), and to determine the minimum number of follicles required to estimate subject-specific mean concentrations. We measured As, Hg, Cd, Pb, Cu, Mn, Se, and Zn in FF samples using inductively coupled plasma tandem mass spectrometry. Inter-subject (between-women) variability contributed most of the variability in FF element concentrations, with ovarian, follicular, and analytical as smaller sources of variability. The proportion of variability attributable to sources between-follicles differed by age, body mass index (BMI), race, and cigarette smoking for Cu, Se, and Zn, by BMI and cigarette smoking for As, by primary infertility diagnosis for Hg, Cu, Se, and Zn, and by ovarian stimulation protocol for Mn and Se. Four to five individual follicles were sufficient to estimate subject-specific mean Cu, Se, and Zn concentrations, while >14 were necessary for As, Hg, Cd, Pb, and Mn. Overall, our results suggest that FF is a suitable source of biomarkers of As and Hg exposure in ovarian follicles. Although limited in size, our study offers the most comprehensive exploration of biological variation in FF trace elements to date and may provide guidance for future studies of ovarian trace element exposures.

A pilot investigation of couple-level phthalates exposure and in vitro fertilization (IVF) outcomes

Phthalates are reproductive toxicants in experimental animal studies and exposure has been associated with infertility in human populations, although the results have been inconsistent. To help to address the data gap, we conducted a hypothesis-generating investigation of associations between urinary phthalate metabolites and reproductive outcomes among women (n = 56) and their male partners (n = 43) undergoing in vitro fertilization (IVF). Urine was collected from participants on the day of oocyte retrieval. Samples were analyzed for a series of phthalates, MEP, MBP, MPP, MHxP, MEHP, MEHHP, MECPP, MiNP, MiDP, MCHP, and MBzP, using liquid chromatography-tandem mass spectrometry. We employed Poisson regression with robust variance estimation to estimate associations between urinary phthalate levels and biochemical pregnancy and live birth, adjusted for partner's concentration and confounding factors. Doublings in women's MBP (relative risk (RR) = 0.32, 95 % CI: 0.13, 0.78), and men's MEHP (RR = 0.28, 95 % CI: 0.09, 0.83), were associated with a lower likelihood for pregnancy. Doublings in women's (RR = 0.08, 95 % CI: 0.01, 0.67) and men's (RR = 0.13, 95 % CI: 0.02, 0.92) MHxP were associated with a lower likelihood of live birth. Our results suggest that phthalate exposure may impact IVF outcomes, and underscore the importance of including male partners when investigating the impact of phthalate exposure on IVF. These results also suggest that clinical recommendations should include male partners for limiting phthalate exposure. Still, a larger and more comprehensive investigation is necessary to more definitively assess the risks.

Seafood consumption is associated with higher follicular fluid arsenic (As) and mercury (Hg) concentrations in women undergoing in vitro fertilization (IVF)

Human exposure to non-essential toxic metals such as cadmium (Cd), mercury (Hg), and lead (Pb), and metalloids such as arsenic (As) commonly occurs through diet. Toxic trace element exposures have been reported in association with fertility and fecundity in epidemiologic studies even at low to moderate levels. While most previous studies employed blood and urine biomarkers of exposure, few have assessed toxic trace elements in ovarian follicular fluid (FF), which surrounds the developing oocyte and hence may better reflect concentrations potentially affecting reproductive outcomes. Our objective was to identify dietary predictors of FF toxic trace elements in n = 56 women (mean age: 38.3 years) undergoing in vitro fertilization (IVF) at the University of California at San Francisco. We determined As, Hg, Cd, and Pb in 197 FF specimens, collected on the day of oocyte retrieval, using inductively coupled plasma tandem mass spectrometry. A comprehensive food frequency questionnaire was used to assess the weekly and annual dietary "patterns" of participants. Consumption of specific seafood items and turkey were correlated with individual FF toxic trace elements. We also found that each unit higher seafood consumption in the past week dominated by mollusks, shrimp, and bass was associated with 60% higher FF As (95% confidence interval (CI): 25%, 105%) and FF Hg (95%CI: 7%, 136%) concentrations. Higher annual seafood consumption dominated by urchin, crab, and trout was associated with 16% higher FF As (95%CI: -2%, 38%) and 31% higher FF Hg (95%CI: 7%, 60%) concentrations per unit intake. No associations were noted between diet and Cd and Pb levels in FF. Overall, our results suggest that higher seafood consumption contributes to elevated levels of As and Hg in FF. These findings are consistent with previous IVF studies that assessed toxic trace element exposures in blood and urine. To our knowledge, this is the first study to report that diet might be a source of As, Hg, Cd, and Pb in FF.

Sources of exposure to urinary phthalates among couples undergoing infertility treatment

Phthalates have been implicated as reproductive toxicants in animal models and in human populations. This study examined associations between potential exposure sources and urinary phthalate metabolite concentrations among women (n = 56) and their male partners (n = 43) undergoing in vitro fertilization (IVF). On the day of oocyte retrieval, participants provided urine samples and completed questionnaires detailing use of personal care products (PCPs), and consumption of medications, foods, and beverages in the preceding 24 h. Urine was analyzed for MEP, MBP, MPP, MHxP, MEHP, MEHHP, MECPP, MiNP, MiDP, MCHP, and MBzP, via liquid chromatography-tandem mass spectrometry. We employed principal component analysis (PCA) to summarize exposure sources and regression models to estimate associations between exposure patterns and urinary phthalate metabolites, adjusted for confounding variables. Among women, application of more body washes and eye creams, and consumption of more supplements, was associated with greater urinary MECPP [relative difference = 1.36 (95% CI: 1.28, 1.45)] and the molar sum of DEHP metabolites, including MEHP, MEHHP, and MECPP [∑DEHP; 1.26 (95% CI: 1.17, 1.34)]. Among men, consumption of more supplements and allergy medications was associated with greater urinary MECPP, MEHHP, and ∑DEHP [relative difference = 1.13 (95% CI: 1.02, 1.23)] concentrations. Identifying differences in sources of phthalate exposure may help clinicians to intervene to reduce exposure as part of a comprehensive strategy to help improve IVF outcomes.

Preconception serum lipids and lipophilic micronutrient levels are associated with live birth rates after IVF

RESEARCH QUESTION

Is a mixture of preconception serum lipids and lipophilic micronutrients associated with clinical pregnancy and live births?

DESIGN

In this prospective cohort study, blood serum was collected on the day of oocyte retrieval for 180 women undergoing IVF at an academic reproductive health centre. Concentrations of lipids (phospholipids, total cholesterol, high- and low-density lipoproteins, and triglycerides) and lipophilic micronutrients (α-, δ-, and γ-tocopherols, retinol, β- and α-carotenes, β-cryptoxanthin, lutein and lycopene) were determined using diagnostic reagent kits and high-performance liquid chromatography. Poisson regression was used with robust variance estimation to evaluate changes in Z-scores for the mixture of serum lipid and lipophilic micronutrient concentrations as predictors of embryo implantation, clinical pregnancy and live birth, adjusted for age, body mass index (BMI), race, smoking status, infertility diagnosis, ovarian stimulation protocol and other measured lipid and lipophilic micronutrient concentrations.

RESULTS

Each SD higher serum triglyceride concentration was associated with a lower chance of live birth (RR 0.54; 95% CI 0.33 to 0.90) whereas a 1 SD higher serum α-tocopherol concentration, as part of a mixture of serum lipids and lipophilic micronutrients, was associated with a higher likelihood for a live birth (RR 1.61; 95% CI 1.11 to 2.36). Serum β-carotene concentrations were associated with live birth in a non-linear fashion; low β-carotene was associated with a lower chance of live birth and high β-carotene with a higher chance of live birth.

CONCLUSION

Although components of a mixture of lipids and lipophilic micronutrients were associated with live birth outcomes after IVF, a larger investigation is necessary to fully evaluate the potential clinical implications.

Interpregnancy interval and singleton pregnancy outcomes after frozen embryo transfer

OBJECTIVE

To describe the relationship between interpregnancy interval (IPI) and perinatal outcomes in singleton live births after frozen embryo transfer (FET).

DESIGN

Retrospective analysis of the Society for Assisted Reproductive Technology Clinical Outcome Reporting System cohort including patients with a history of live birth from ART who returned for an FET cycle between 2004 and 2013.

SETTING

Not applicable.

PATIENT(S)

A total of 19,270 singleton live births from FET subsequent to a live birth.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Odds for preterm delivery (<37, <34, <28 weeks) and low birth weight (<2,500, <1,500 g) adjusted for age, body mass index, and history of prior preterm delivery.

RESULT(S)

Of 74,456 autologous FET cycles following an index live birth, 24,091 resulted in a repeat live birth, with 19,270 singleton live births. An IPI of <12 months occurred in 19% of cycles. Adjusted odds (aORs) for preterm delivery at <37 weeks were significantly increased for an IPI of <6 months (aOR 2.05, 95% confidence interval [CI] 1.48-2.84), 6 to <12 months (aOR 1.26, 95% CI 1.06-1.49), and 18 to <24 months (aOR 1.23, 95% CI 1.06-1.43) when compared with the reference interval of 12 to <18 months. Additionally, an IPI of <6 months was associated with increased odds for low birth weight (aOR 3.06, 95% CI 2.07-4.52) and very low birth weight (aOR 5.65, 95% CI 2.96-10.84) compared with an IPI of 12 to <18 months.

CONCLUSION(S)

In this nationally representative population, an interval from delivery to start of an FET cycle of <12 months is associated with increased odds for preterm delivery among singleton live births. Consistent with data for patients undergoing fresh IVF, the data support delaying FET 12 months from a live birth.

Decreased clinical pregnancy and live birth rates after short interval from delivery to subsequent assisted reproductive treatment cycle

STUDY QUESTION

Does the interval from delivery to initiation of a subsequent ART treatment cycle impact clinical pregnancy or live birth rates?

SUMMARY ANSWER

An interval from delivery to treatment start of <6 months or ≥24 months is associated with decreased likelihood of clinical pregnancy and live birth.

WHAT IS KNOWN ALREADY

Short interpregnancy intervals are associated with poor obstetric outcomes in the naturally conceiving population prompting birth spacing recommendations of 18-24 months from international organizations. Deferring a subsequent pregnancy attempt means a woman will age in the interval with an attendant decline in her fertility.

STUDY DESIGN, SIZE, DURATION

Retrospective analysis of the Society for Assisted Reproductive Technology Clinical Outcome Reporting System (SARTCORS) cohort containing 61 686 ART cycles from 2004 to 2013.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The delivery-to-cycle interval (DCI) was calculated for patients from SARTCORS with a history of live birth from ART who returned to the same clinic for a first subsequent treatment cycle. Generalized linear models were fit to determine the risk of clinical pregnancy and live birth by DCI with subsequent adjustment for factors associated with outcomes of interest. Predicted probabilities of clinical pregnancy and live birth were generated from each model.

MAIN RESULTS AND THE ROLE OF CHANCE

A DCI of <6 months was associated with a 5.6% reduction in probability of clinical pregnancy (40.1 ± 1.9 versus 45.7 ± 0.6%, P = 0.009) and 6.8% reduction in live birth (31.6 ± 1.7 versus 38.4 ± 0.6%, P = 0.001) per cycle start compared to a DCI of 12 to <18 months. A DCI of ≥24 months was associated with a 5.1% reduction in probability of clinical pregnancy (40.6 ± 0.5 versus 45.7 ± 0.6%, P < 0.001) and 5.7% reduction in live birth (32.7 ± 0.5 versus 38.4 ± 0.6%, P < 0.001) compared to 12 to <18 months.

LIMITATIONS, REASONS FOR CAUTION

The SART database is reliant upon self-report of many variables of interest including live birth. It remains unclear whether poorer outcomes are a result of residual confounding from factors inherent to the population with a very short or long DCI or the interval itself.

WIDER IMPLICATIONS OF THE FINDINGS

Birth spacing recommendations for naturally conceiving populations may not be generally applicable to patients with a history of infertility. Patients planning ART treatment should wait a minimum of 6 months, but not more than 24 months, from a live birth for optimization of clinical pregnancy and live birth rates.

STUDY FUNDING/COMPETING INTEREST(S)

National Center for Advancing Translational Sciences, National Institutes of Health, UCSF-CTSI Grant number UL1TR001872. The authors have no competing interests.

Ultra-trace element analysis of human follicular fluid by ICP-MS/MS: pre-analytical challenges, contamination control, and matrix effects

Follicular fluid (FF), which is the fluid that envelops the developing oocyte (egg cell) in the ovary, can be analyzed to assess trace element content as well as to determine potential exposure to toxic elements in women seeking in vitro fertilization (IVF) treatment. Such measurements may be useful in establishing associations with potential adverse effects on oocyte viability and subsequent pregnancy outcomes. The principal goal of this study was to leverage the next generation of inorganic mass spectrometry based on ICP-MS/MS to address the numerous analytical challenges of (ultra-)trace element analysis of human FF specimens. Ultra-trace element measurements are defined by the Clinical Laboratory Standards Institute as fluid concentrations below 10 μg L^-1 or tissue mass fractions below 1 μg g^-1. Stringent pre-analytical procedures were developed to minimize exogenous contamination during FF specimen collection and storage in a prospective study of 56 women seeking IVF treatment. ICP-MS/MS instrumental parameters were carefully optimized, and the method validated for 11 biologically important elements that included 4 at trace levels (Cu, Se, Sr, and Zn) and 7 at ultra-trace levels (As, Cd, Co, Mo, Mn, Hg, and Pb). Method limits of detection (LODs) for ultra-trace elements varied from 5.6 ng L^-1 for Cd to 0.11 μg L^-1 for Mo. A total of 197 human FF specimens were analyzed using the proposed ICP-MS/MS method with 84% of specimens detectable for Pb and 100% detectable for Co, Cu, Mn, Mo, Sr, and Zn. The method based on ICP-MS/MS was compared to a previous method developed for FF using SF-ICP-MS.

A higher prevalence of endometriosis among Asian women does not contribute to poorer IVF outcomes

PURPOSE

The purpose of the study was to determine whether diagnosis of endometriosis or endometriosis with endometrioma influences in vitro fertilization (IVF) outcomes in an ethnically diverse population.

METHODS

Women undergoing a first IVF cycle (n = 717) between January 1, 2008 and December 31, 2009, at a university-affiliated infertility clinic, were retrospectively assessed for an endometriosis diagnosis. Differences in prevalence of endometriosis by ethnicity were determined, as well as differences in IVF success by ethnicity, with a focus on country of origin for Asian women. A multivariate model was generated to assess the relative contributions of country of origin and endometriosis to chance of clinical pregnancy with IVF.

RESULTS

Endometriosis was diagnosed in 9.5% of participants; 3.5% also received a diagnosis of endometrioma. Endometriosis prevalence in Asian women was significantly greater than in Caucasians (15.7 vs. 5.8%, p < 0.01). Women of Filipino (p < 0.01), Indian (p < 0.01), Japanese (p < 0.01), and Korean (p < 0.05) origin specifically were more likely to have endometriosis than Caucasian women, although there was no difference in endometrioma presence by race/ethnicity. Oocyte quantity, embryo quality, and fertilization rates did not relate to endometriosis. Clinical pregnancy rates were significantly lower for Asian women, specifically in Indian (p < 0.05), Japanese (p < 0.05), and Korean (p < 0.05) women, compared to Caucasian women, even after controlling for endometriosis status.

CONCLUSIONS

The prevalence of endometriosis appears to be higher in Filipino, Indian, Japanese, and Korean women presenting for IVF treatment than for Caucasian women; however, the discrepancy in IVF outcomes was conditionally independent of the presence of endometriosis. Future research should focus on improving pregnancy outcomes for Asian populations whether or not they are affected by endometriosis, specifically in the form of longitudinal studies where exposures can be captured prior to endometriosis diagnoses and infertility treatment.

Associations between PON1 enzyme activities in human ovarian follicular fluid and serum specimens

The importance of high-density lipoprotein (HDL) particle components to reproduction is increasingly recognized, including the constituent paraoxonase 1 (PON1). However, the reliability characteristics of PON1 enzymes in ovarian follicular fluid (FF) as biomarkers for clinical and epidemiologic studies have not been described. Therefore, we characterized PON1 enzymes in FF and serum and assessed the impact of the PON1 Q192R polymorphism on associations between enzyme activities in two compartments. We also evaluated associations between HDL particle size and enzyme activities. We collected FF and serum from 171 women undergoing in vitro fertilization. PON1 activities were measured as paraoxonase and arylesterase activities, and HDL particle size was determined by ¹H NMR spectrometry. Reliability indices for PON1 activities were characterized and we evaluated HDL particle sizes as predictors of PON1 enzyme activities. We found that PON1 enzyme activities were correlated between compartments, but higher in serum than in FF. For FF, the index of individuality (II) was low and the coefficient of variation (CV%) was high for paraoxonase activity overall (0.12 and 11.51%, respectively). However, IIs increased (0.33–1.30) and CV%s decreased (5.58%-8.52%) when stratified by PON1 Q192R phenotype. The intraclass correlation coefficient (ICC) for FF paraoxonase activity was high overall (0.89) but decreased when stratified by PON1 Q192R phenotype (0.43–0.75). We found similar, although more modest, patterns for FF arylesterase activity. For enzyme activities in serum, ICCs were close to 1.00 across all phenotypes. Additionally, different HDL particle sizes predicted PON1 enzyme activities according to PON1 Q192R phenotype. Overall, stratification by PON1 Q192R phenotype improved the reliability characteristics of FF PON1 enzymes as biomarkers for use in clinical investigations but diminished usefulness for epidemiologic studies. Thus, we recommend stratification by PON1 Q192R phenotype for clinical but not epidemiologic investigations, when employing FF PON1 enzyme activity biomarkers.

Persistent organic pollutants (POPs) in human follicular fluid and in vitro fertilization outcomes, a pilot study

Persistent organic pollutants (POPs) are ubiquitously distributed among the U.S. population and adversely impact human reproduction. These compounds have been detected in human ovarian follicular fluid (FF), where they directly contact a developing oocyte. As a pilot investigation, we measured 43 polychlorinated biphenyl (PCB) congeners, p,p'-dichlorodiphenyltrichloroethane (DDT), and its persistent metabolite p,p'-dichlorodiphenyldichloroethylene (DDE) in residual FF collected from 32 women undergoing in vitro fertilization (IVF). We identified significant inverse associations between higher levels of PCB congeners and indicators of ovarian reserve (e.g., antral follicle count), follicular response to administered gonadotropins (e.g., peak estradiol, number of oocytes retrieved, endometrial thickness), intermediate IVF endpoints (e.g., oocyte fertilization and embryo quality), and clinical IVF outcomes (e.g., embryo implantation and live birth), after adjusting for body mass index, cigarette smoking, race, and age. Our results suggest that ongoing exposure to POPs impacts IVF and merit confirmation in a larger and more definitive future study.

Associations between follicular fluid high density lipoprotein particle components and embryo quality among in vitro fertilization patients

PURPOSE

Follicular redox balance is likely to be important for embryo quality during in vitro fertilization (IVF), and the anti-oxidative high desity lipoprotein (HDL) particle is the sole lipoprotein measured in follicular fluid (FF). Therefore, we investigated FF HDL particle components as predictors of embryo quality during IVF.

METHODS

Two research follicles collected from each participant were individually tracked, and 103 women having at least one developed embryo were included in the analysis. Concentrations of 15 non-cholesterol HDL particle components and 26 HDL-cholesterol (HDL-C) particle size subfractions were determined. Embryo quality was assessed for embryo cell number, embryo fragmentation, and embryo symmetry. Multivariable Poisson regression with a sandwich variance estimator was used to evaluate associations between HDL particle components and embryo quality, adjusted for covariates.

RESULTS

Higher γ-tocopherol concentration was associated with less embryo fragmentation (relative risk [RR] = 4.43; 95 % confidence interval [CI] 1.78, 11.06), and higher apolipoprotein A-1 concentration was associated with full embryo symmetry (RR = 3.92; 95 % CI 1.56, 9.90). Higher concentrations of HDL-C subfractions in the large and medium particle size ranges were associated with poorer embryo quality.

CONCLUSIONS

FF HDL lipophilic micronutrients and protein components, as well as HDL-C particle size, may be important predictors of embryo quality during IVF.

Variability in follicular fluid high density lipoprotein particle components measured in ipsilateral follicles

PURPOSE

The purpose of this study was to examine the biological variability of follicular fluid (FF) high density lipoprotein (HDL) particle components measured in ipsilateral ovarian follicles.

METHODS

We collected FF from two ipsilateral follicles among six women undergoing in vitro fertilization (IVF). We measured concentrations of 19 FF HDL particle components, including HDL cholesterol, free cholesterol, four cholesteryl esters, phospholipids, triglycerides, paraoxonase and arylesterase activities, apolipoproteins A-1 and A-2 (ApoA-1 and ApoA-2), and seven lipophilic micronutrients, by automated analysis and with high-performance liquid chromatography. We assessed biological variability using two-stage nested analysis of variance and compared values with those previously published for contralateral follicles.

RESULTS

For most FF HDL analytes, there was little variability between follicles relative to the variability between women (i.e., %σ(2) F:%σ(2) B <0.5). Intraclass correlation coefficients were >0.80 for HDL cholesterol (0.82), phospholipids (0.89), paraoxonase (0.96), and arylesterase (0.91) activities, ApoA-1 (0.89), and ApoA-2 (0.90), and single specimen collections were required to estimate the subject-specific mean, demonstrating sufficient reliability for use as biomarkers of the follicular microenvironment in epidemiologic and clinical studies.

CONCLUSIONS

These preliminary results raise the possibility for tighter regulation of HDL in follicles within the same ovary vs. between ovaries. Thus, collection of a single FF specimen may be sufficient to estimate HDL particle components concentrations within a single ovary. However, our results should be interpreted with caution as the analysis was based on a small sample.

Urine cortisol concentration as a biomarker of stress is unrelated to IVF outcomes in women and men

PURPOSE

Our primary objective was to assess associations between urine cortisol as a biomarker of psychological stress and in vitro fertilization (IVF) outcomes. A secondary objective was to assess associations between toxic metals and cortisol.

METHODS

Urine and blood specimens were collected from 52 women and 28 male partners completing a first IVF procedure, on the day of oocyte retrieval. Urine cortisol was measured with an enzyme-linked immunosorbent assay. Mercury (Hg), cadmium (Cd), and lead (Pb) were determined in blood and Cd in urine by inductively coupled plasma-mass spectrometry.

RESULTS

No associations were indicated for cortisol with IVF outcomes in multivariable regression models adjusted for covariates. However, we detected positive linear associations for cortisol and urine Cd (β = 9.96, 95%CI 1.52, 21.44) and blood Hg (β = 1.44, 95%CI 0.31, 3.18). An exploratory stratified analysis suggested a potential inverse association between urine cortisol and oocyte fertilization among women with low, but not high blood Hg.

CONCLUSION

While limited, these preliminary data suggest that psychological stress may not play a major role in IVF outcomes, which therefore could be one less concern for couples and their clinicians. Our data also raise the possibility for toxic metals to modify associations between cortisol and IVF outcomes among women. However, these preliminary results require corroboration in an experimental animal model and confirmation in a larger, more definitive observational study.

Toxic metals in seminal plasma and in vitro fertilization (IVF) outcomes

We measured toxic metals in seminal plasma collected from 30 men using vitro fertilization (IVF), to evaluate associations with semen quality and IVF outcomes. A doubling in Hg-adjusted Pb concentration was associated with 47% lower total motile sperm. Positive associations were suggested for Hg with pregnancy and live birth, adjusted for Cd or Pb. A negative association was suggested for Hg-adjusted Cd with pregnancy. These data add to evidence indicating that toxic metals impact IVF.

Conjugated bisphenol A in maternal serum in relation to miscarriage risk

OBJECTIVE

To examine the relationship between the maternal serum bisphenol A (BPA) concentration at the time of the missed menstrual cycle and miscarriage risk.

DESIGN

Retrospective cohort of prospectively collected serum samples.

SETTING

Academic fertility center.

PATIENT(S)

Women presenting for early pregnancy monitoring with singleton pregnancies.

INTERVENTION(S)

Stored serum samples from 4 to 5 weeks' gestation analyzed for conjugated serum BPA concentrations.

MAIN OUTCOME MEASURE(S)

Live birth, miscarriage, and chromosome content of miscarriage.

RESULT(S)

With the 115 women included in the study, there were 47 live births and 68 clinical miscarriages (46 aneuploid and 22 euploid). Median conjugated BPA concentrations were higher in the women who had miscarriages than in those who had live births (0.101 vs. 0.075 ng/mL). Women with the highest quartile of conjugated BPA had an increased relative risk of miscarriage (1.83; 95% CI, 1.14-2.96) compared with the women in the lowest quartile. We found a similar increase risk for both euploid and aneuploid miscarriages.

CONCLUSION(S)

Maternal conjugated BPA was associated with a higher risk of aneuploid and euploid miscarriage in this cohort. The impact of reducing individual exposure on future pregnancy outcomes deserves further study.

Bisphenol-A (BPA), BPA glucuronide, and BPA sulfate in midgestation umbilical cord serum in a northern and central California population

Bisphenol-A (BPA) is an endocrine disrupting chemical used in numerous consumer products, resulting in universal exposure in the United States. Prenatal exposure to BPA is associated with numerous reproductive and developmental effects in animals. However, little is known about human fetal exposure or metabolism of BPA during midgestation. In the present study, we present a new liquid chromatography-tandem mass spectrometry method to directly measure concentrations of BPA and two predominant metabolic conjugates-BPA glucuronide and BPA sulfate-in umbilical cord serum collected from elective second trimester pregnancy terminations. We detected at least one form of BPA in all umbilical cord serum samples: BPA (GM 0.16, range Collapse

Key Words Collapse

MESH Headings

• Adolescent
• Adult
• Animals
• Benzhydryl Compounds/blood
• California
• Chromatography, Liquid
• Environmental Pollutants/blood
• Female
• Fetus/metabolism
• Glucuronides/blood
• Humans
• Male
• Mass Spectrometry
• Middle Aged
• Phenols/blood
• Pregnancy
• Reference Standards
• Reproducibility of Results
• Sulfuric Acid Esters/blood
• Umbilical Cord/metabolism
• Young Adult

Collapse

Grants

• P20 ES018135 NIEHS NIH HHS
• R01 HD021341 NICHD NIH HHS
• R21 ES17763 NIEHS NIH HHS
• R37 HD021341 NICHD NIH HHS
• RD83467801 ORD VA
• R01 ES013527 NIEHS NIH HHS
• R01 HD031544 NICHD NIH HHS
• R01HD31544 NICHD NIH HHS
• R21 ES017763 NIEHS NIH HHS

Collapse

Affiliation(s)

Roy R. Gerona Department of Laboratory Medicine, University of California, San Francisco
Tracey J. Woodruff Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco
Carrie A. Dickenson Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco
Janet Pan Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco
Jackie M. Schwartz Program on Reproductive Health and the Environment, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco
Saunak Sen Department of Epidemiology and Biostatistics, University of California, San Francisco
Matthew M. Friesen Department of Laboratory Medicine, University of California, San Francisco
Victor Y. Fujimoto Department of Laboratory Medicine, University of California, San Francisco
Patricia A. Hunt

Collapse

Ethnic differences in assisted reproductive technologies outcomes

Disparities in assisted reproductive technologies (ARTs) outcomes have been identified among ethnic minorities when compared with their Caucasian counterparts. Minority ethnicity has been shown to be an independent predictor of lower clinical pregnancy and live birth rates in many studies. In this article, we seek to summarize the most recent literature on ethnic difference reported within ART outcomes. We will discuss potential reasons behind these disparities and further explore independent predictors and associations between ethnicity and ART success.

Bisphenol A and phthalates and endometriosis: the Endometriosis: Natural History, Diagnosis and Outcomes Study

OBJECTIVE

To explore the relation between bisphenol A and 14 phthalate metabolites and endometriosis.

DESIGN

Matched cohort design.

SETTING

Fourteen clinical centers.

PATIENT(S)

The operative cohort comprised 495 women undergoing laparoscopy/laparotomy, whereas the population cohort comprised 131 women matched on age and residence.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Surgically visualized or pelvic magnetic resonance imaging diagnosed endometriosis in the two cohorts, respectively.

RESULT(S)

Odds ratios (OR) and 95% confidence intervals (CIs) were estimated using logistic regression adjusting for age, body mass index, and creatinine. In the population cohort, six phthalate metabolites-mono-n-butyl phthalate, mono-[(2-carboxymethyl) hexyl] phthalate, mono (2-ethyl-5-carboxyphentyl) phthalate, mono (2-ethylhexyl) phthalate, mono (2-ethyl-5-hydroxyhexyl) phthalate, and mono (2-ethyl-5-oxohexyl) phthalate-were significantly associated with an approximately twofold increase in the odds of an endometriosis diagnosis. Two phthalates were associated with endometriosis in the operative cohort when restricting to visualized and histologic endometriosis (monooctyl phthalate; OR 1.38; 95% CI 1.10-1.72) or when restricting comparison women to those with a postoperative diagnosis of a normal pelvis [mono (2-ethylhexyl) phthalate; OR 1.35; 95% CI 1.03-1.78].

CONCLUSION(S)

Select phthalates were associated with higher odds of an endometriosis diagnosis for women with magnetic resonance imaging-diagnosed endometriosis. The lack of consistency of findings across cohorts underscores the impact of methodology on findings.

A pilot study of seafood consumption and exposure to mercury, lead, cadmium and arsenic among infertile couples undergoing in vitro fertilization (IVF)

This cross-sectional pilot study was conducted to assess environmental exposures to toxic elements through seafood consumption, among infertile couples undergoing in vitro fertilization (IVF). Twenty-five women and 15 men completed a questionnaire, and provided biologic specimens for quantification of Hg, Pb, Cd, and As using ICP-MS. Consumption of 'mollusks' and 'shellfish' are associated with increased blood Hg. Other seafood consumption predicts blood Pb, and urine Cd and As. Though limited by small numbers and the cross-sectional design, these results suggest that consumption of specific seafood items increases exposure to toxic elements in couples undergoing IVF.

Risk factors associated with endometriosis: importance of study population for characterizing disease in the ENDO Study

OBJECTIVE

We sought to identify risk factors for endometriosis and their consistency across study populations in the Endometriosis: Natural History, Diagnosis, and Outcomes (ENDO) Study.

STUDY DESIGN

In this prospective matched, exposure cohort design, 495 women aged 18-44 years undergoing pelvic surgery (exposed to surgery, operative cohort) were compared to an age- and residence-matched population cohort of 131 women (unexposed to surgery, population cohort). Endometriosis was diagnosed visually at laparoscopy/laparotomy or by pelvic magnetic resonance imaging in the operative and population cohorts, respectively. Logistic regression estimated the adjusted odds ratios (AORs) and 95% confidence intervals (CIs) for each cohort.

RESULTS

The incidence of visualized endometriosis was 40% in the operative cohort (11.8% stage 3-4 by revised criteria from the American Society for Reproductive Medicine), and 11% stage 3-4 in the population cohort by magnetic resonance imaging. An infertility history increased the odds of an endometriosis diagnosis in both the operative (AOR, 2.43; 95% CI, 1.57-3.76) and population (AOR, 7.91; 95% CI, 1.69-37.2) cohorts. In the operative cohort only, dysmenorrhea (AOR, 2.46; 95% CI, 1.28-4.72) and pelvic pain (AOR, 3.67; 95% CI, 2.44-5.50) increased the odds of diagnosis, while gravidity (AOR, 0.49; 95% CI, 0.32-0.75), parity (AOR, 0.42; 95% CI, 0.28-0.64), and body mass index (AOR, 0.95; 95% CI, 0.93-0.98) decreased the odds of diagnosis. In all sensitivity analyses for different diagnostic subgroups, infertility history remained a strong risk factor.

CONCLUSION

An infertility history was a consistent risk factor for endometriosis in both the operative and population cohorts of the ENDO Study. Additionally, identified risk factors for endometriosis vary based upon cohort selection and diagnostic accuracy. Finally, endometriosis in the population may be more common than recognized.

Associations between toxic metals in follicular fluid and in vitro fertilization (IVF) outcomes

PURPOSE

We previously reported associations between trace concentrations of Hg, Cd and Pb in blood and urine and reproductive outcomes for women undergoing in-vitro fertilization (IVF). Here we assess measurements in single follicular fluid (FF) specimens from 46 women as a presumably more relevant marker of dose for reproductive toxicity.

METHODS

FF specimens were analyzed for Hg, Cd and Pb using sector field-inductively coupled plasma-mass spectrometry (SF-ICP-MS). Variability sources were assessed by nested ANOVA. Multivariable regression was used to evaluate associations for square root transformed metals with IVF outcomes, adjusting for confounders.

RESULTS

An inverse association is detected for FF Pb and fertilization (relative risk (RR) = 0.68, P = 0.026), although positive for Cd (RR = 9.05, P = 0.025). While no other statistically significant associations are detected, odds ratios (OR) are increased for embryo cleavage with Hg (OR = 3.83, P = 0.264) and Cd (OR = 3.18, P = 0.644), and for embryo fragmentation with Cd (OR = 4.08, P = 0.586) and Pb (OR = 2.22, P = 0.220). Positive estimates are observed for Cd with biochemical (RR = 19.02, P = 0.286) and clinical pregnancies (RR = 38.80, P = 0.212), yet with very low precision.

CONCLUSIONS

We have identified associations between trace amounts of Pb and Cd in FF from a single follicle, and oocyte fertilization. Yet, the likelihood of biological variation in trace element concentrations within and between follicles, coupled with levels that are near the limits of detection suggest that future work should examine multiple follicles using a 'one follicle-one oocyte/embryo' approach. A larger study is merited to assess more definitively the role that these environmental factors could play with respect to egg quality in IVF programs.

When genetic load does not correlate with phenotypic spectrum: lessons from the GnRH receptor (GNRHR)

CONTEXT

A broad spectrum of GnRH-deficient phenotypes has been identified in individuals with both mono- and biallelic GNRHR mutations.

OBJECTIVE

The objective of the study was to determine the correlation between the severity of the reproductive phenotype(s) and the number and functional severity of rare sequence variants in GNRHR.

SUBJECTS

Eight hundred sixty-three probands with different forms of GnRH deficiency, 46 family members and 422 controls were screened for GNRHR mutations. The 70 subjects (32 patients and 38 family members) harboring mutations were divided into four groups (G1-G4) based on the functional severity of the mutations (complete or partial loss of function) and the number of affected alleles (monoallelic or biallelic) with mutations, and these classes were mapped on their clinical phenotypes.

RESULTS

The prevalence of heterozygous rare sequence variants in GNRHR was significantly higher in probands vs. controls (P < 0.01). Among the G1-G3 groups (homozygous subjects with successively decreasing severity and number of mutations), the hypogonadotropic phenotype related to their genetic load. In contrast, subjects in G4, with only monoallelic mutations, demonstrated a greater diversity of clinical phenotypes.

CONCLUSIONS

In patients with GnRH deficiency and biallelic mutations in GNRHR, genetic burden defined by severity and dose is associated with clinical phenotype. In contrast, for patients with monoallelic GNRHR mutations this correlation does not hold. Taken together, these data indicate that as-yet-unidentified genetic and/or environmental factors may combine with singly mutated GNRHR alleles to produce reproductive phenotypes.

Race matters: a systematic review of racial/ethnic disparity in Society for Assisted Reproductive Technology reported outcomes

OBJECTIVE

To systematically review the reporting of race/ethnicity in Society for Assisted Reproductive Technology (SART) Clinic Outcome Reporting System (CORS) publications.

DESIGN

Systematic review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology of literature published in PubMed on race/ethnicity that includes data from SART CORS.

SETTING

Not applicable.

PATIENT(S)

Not applicable.

INTERVENTION(S)

In vitro fertilization cycles reported to SART.

MAIN OUTCOME MEASURE(S)

Any outcomes reported in SART CORS.

RESULT(S)

Seven publications were identified that assessed racial/ethnic disparities in IVF outcomes using SART data. All reported a racial/ethnic disparity. However, more than 35% of cycles were excluded from analysis because of missing race/ethnicity data.

CONCLUSION(S)

Review of current publications of SART data suggests significant racial/ethnic disparities in IVF outcomes. However, the potential for selection bias limits confidence in these findings, given that fewer than 65% of SART reported cycles include race/ethnicity. Our understanding of how race/ethnicity influences ART outcome could be greatly improved if information on race/ethnicity was available for all reported cycles.

Persistent lipophilic environmental chemicals and endometriosis: the ENDO Study

BACKGROUND

An equivocal literature exists regarding the relation between persistent organochlorine pollutants (POPs) and endometriosis in women, with differences attributed to methodologies.

OBJECTIVES

We assessed the association between POPs and the odds of an endometriosis diagnosis and the consistency of findings by biological medium and study cohort.

METHODS

Using a matched cohort design, we assembled an operative cohort of women 18-44 years of age undergoing laparoscopy or laparotomy at 14 participating clinical centers from 2007 to 2009 and a population-based cohort matched on age and residence within a 50-mile catchment area of the clinical centers. Endometriosis was defined as visualized disease in the operative cohort and as diagnosed by magnetic resonance imaging in the population cohort. Logistic regression analysis was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for each POP in relation to an endometriosis diagnosis, with separate models run for each medium (omental fat in the operative cohort, serum in both cohorts) and cohort. Adjusted models included age, body mass index, breast-feeding conditional on parity, cotinine, and lipids.

RESULTS

Concentrations were higher in omental fat than in serum for all POPs. In the operative cohort, γ-hexachlorocyclohexane (γ-HCH) was the only POP with a significant positive association with endometriosis [per 1-SD increase in log-transformed γ-HCH: adjusted OR (AOR) = 1.27; 95% CI: 1.01, 1.59]; β-HCH was the only significant predictor in the population cohort (per 1-SD increase in log-transformed β-HCH: AOR = 1.72; 95% CI: 1.09, 2.72).

CONCLUSIONS

Using a matched cohort design, we found that cohort-specific and biological-medium-specific POPs were associated with endometriosis, underscoring the importance of methodological considerations when interpreting findings.

DNA methylation changes in whole blood is associated with exposure to the environmental contaminants, mercury, lead, cadmium and bisphenol A, in women undergoing ovarian stimulation for IVF

BACKGROUND

Changes in DNA methylation may play an important role in the deleterious reproductive effects reported in association with exposure to environmental pollutants. In this pilot study, we identify candidate methylation changes associated with exposure to pollutants in women undergoing in vitro fertilization (IVF).

METHODS

Blood and urine were collected from women on the day of oocyte retrieval. Whole blood was analyzed for mercury and lead, and urine for cadmium using inductively coupled plasma mass spectrometry. Unconjugated bisphenol A (BPA) was analyzed in serum using high-performance liquid chromatography with Coularray detection. Participants were dichotomized as higher or lower exposure groups by median concentrations. Using the Illumina GoldenGate Methylation Cancer Panel I, DNA methylation in whole blood from 43 women was assessed at 1505 CpG sites for association with exposure levels of each pollutant. Candidate CpG sites were identified using a Diff Score >|13| (P< 0.05) and an absolute difference >10% which were confirmed using bisulfite pyrosequencing.

RESULTS

Methylation of the GSTM1/5 promoter was increased for women with higher mercury exposure (P= 0.04); however, no correlation was observed (r= 0.17, P= 0.27). Reduced methylation was detected in the COL1A2 promoter in women with higher exposure to lead (P= 0.004), and an inverse correlation was observed (r = - 0.45, P= 0.03). Lower methylation of a promoter CpG site at the TSP50 gene was detected in women with higher BPA exposure (P= 0.005), and again an inverse correlation was identified (r = - 0.51, P= 0.001).

CONCLUSIONS

Altered DNA methylation at various CpG sites was associated with exposure to mercury, lead or BPA, providing candidates to be investigated using a larger study sample, as the results may reflect an independently associated predictor (e.g. socioeconomic status, diet, genetic variants, altered blood cell composition). Further studies accommodating variations in these factors will be needed to confirm these associations and identify their underlying causes.

Serum unconjugated bisphenol A concentrations in men may influence embryo quality indicators during in vitro fertilization

Here we assess bisphenol A (BPA) in couples undergoing in vitro fertilization (IVF) and indicators of embryo quality; embryo cell number (ECN) and embryo fragmentation score (EFS). Twenty-seven couples provided serum on the day of oocyte retrieval. Unconjugated BPA was measured by HPLC with Coularray detection. Odds ratios (OR) were generated using ordinal logistic regression including female and male BPA concentrations, age and race, and day of embryo transfer for ECN. Inverse associations are suggested for male BPA with ECN (OR=0.70, P=0.069), and EFS (OR=0.54, P=0.009), but not for women. Male BPA exposure may affect embryo quality during IVF.

Bisphenol A exposure reduces the estradiol response to gonadotropin stimulation during in vitro fertilization

OBJECTIVE

To investigate associations between serum bisphenol A (BPA) concentrations and follicular response to exogenous ovary stimulation.

DESIGN

Fasting serum was prospectively collected on the day of oocyte retrieval and assessed for unconjugated BPA using high-performance liquid chromatography with Coularray detection. Multivariable linear regression and negative binomial regression were used to assess associations between concentrations of BPA and outcome measures. Models were adjusted for race/ethnicity, antral follicle count at baseline, and cigarette smoking.

SETTING

A reproductive health center.

PATIENT(S)

Forty-four women undergoing IVF.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Peak E(2) level and the number of oocytes retrieved during IVF.

RESULT(S)

The median unconjugated serum BPA concentration is 2.53 ng/mL (range = 0.3-67.36 ng/mL). Bisphenol A is inversely associated with E(2) (β = -0.16; 95% confidence interval = -0.32, 0.01), as well as with E(2) normalized to the number of mature-sized follicles at the hCG trigger (β = -0.14; 95% confidence interval = -0.24, -0.03). No association is observed for BPA and the number of oocytes retrieved (adjusted risk ratio = 0.95; 95% confidence interval = 0.82, 1.10).

CONCLUSION(S)

Bisphenol A is associated with a reduced E(2) response during IVF. Although limited by the preliminary nature of this study, these results merit confirmation in a future comprehensive investigation.

Biomonitoring for exposure to multiple trace elements via analysis of urine from participants in the study of metals and assisted reproductive technologies (SMART)

Humans are exposed to concentrations of multiple trace elements through a variety of background sources; many are suspected reproductive toxicants. Prior to investigating associations between trace elements and human reproductive health, potential biomarkers of exposure should be characterized by sources of variability in the population at risk. Factors influencing elemental exposure should also be identified to ensure their consideration as potential confounding variables. The principal aim of this study is to characterize sources of variability for 19 trace elements measured in urine specimens collected from 55 women and 36 male partners completing a 1st cycle of in vitro fertilization (IVF). Urine specimens were analyzed using a biomonitoring method based on inductively coupled plasma-mass spectrometry (ICP-MS). Randomly selected urine specimens (∼6%) were analyzed in duplicate, and these data were used to characterize sources of variability. Nine trace elements including As, Ba, Cd, Cs, Co, Cu, Mn, Mo, and Zn, were quantified in most specimens, indicating their utility in future epidemiologic studies of trace elements exposure and IVF outcomes. With few exceptions, normalizing urine using the traditional creatinine-correction procedure, or an alternative approach based on a linear regression model, increased residual variability only slightly. Sex and race appear to be important factors to consider in epidemiologic studies conducted in this population. Urine concentrations for most elements are similar to those reported in the 2005-2006 National Health and Nutrition Examination Survey (NHANES); however, differences in others may indicate regional trends or a unique exposure history for this infertile study population.

Asian ethnicity and fecundability in women with spontaneous conceptions

Asian women do not have decreased fecundability compared with Caucasian women when assessing time to pregnancy in spontaneous conceptions.

Incidence of endometriosis by study population and diagnostic method: the ENDO study

OBJECTIVE

To estimate the incidence of endometriosis in an operative cohort of women seeking clinical care and in a matched population cohort to delineate more fully the scope and magnitude of endometriosis in the context of and beyond clinical care.

DESIGN

Matched-exposure cohort design.

SETTING

Surgical centers in the Salt Lake City, Utah, and San Francisco, California, areas.

PATIENT(S)

The operative cohort comprised 495 women undergoing laparoscopy/laparotomy between 2007 and 2009, and the population cohort comprised 131 women from the surgical centers' catchment areas.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Incidence of endometriosis by diagnostic method in the operative cohort and by pelvic magnetic resonance imaged (MRI) disease in the population cohort.

RESULT(S)

Endometriosis incidence in the operative cohort ranged by two orders of magnitude by diagnostic method: 0.7% for only histology, 7% for only MRI, and 41% for visualized disease. Endometriosis staging was skewed toward minimal (58%) and mild disease (15%). The incidence of MRI-diagnosed endometriosis was 11% in the population cohort.

CONCLUSION(S)

Endometriosis incidence is dependent on the diagnostic method and choice of sampling framework. Conservatively, 11% of women have undiagnosed endometriosis at the population level, with implications for the design and interpretation of etiologic research.

Toxic trace metals and embryo quality indicators during in vitro fertilization (IVF)

Trace exposures to the toxic metals mercury (Hg), cadmium (Cd) and lead (Pb) may interfere with in vitro fertilization (IVF). The aim of this study is to explore biologically plausible hypotheses concerning associations between metals and embryo quality indicators during IVF. For 24 female patients, a multivariable ordinal logistic regression model suggests a 75% reduction in the odds for higher embryo cell cleavage per μg/dL increase in blood Pb (adjusted odds ratio (aOR) 0.25, 95% confidence interval (CI) 0.07-0.86). For 15 male partners, each μg/L increase in blood Hg (aOR 0.60, 95% CI 0.45-0.79) and μg/dL increase in blood Pb (aOR 0.58, 95% CI 0.37-0.91) is associated with a decrease in the analogous odds. Embryo fragmentation is reduced by higher blood Hg (aOR 0.85, 95% CI 0.72-1.00), but increased by higher blood Pb (aOR 1.47, 95% CI 1.11-1.94) in men. The magnitude of these suggested effects warrants confirmation in a larger study.

Racial and ethnic disparities in benign gynecologic conditions and associated surgeries

Common gynecologic conditions and surgeries may vary significantly by race or ethnicity. Uterine fibroid tumors are more prevalent in black women, and black women may have larger, more numerous fibroid tumors that cause worse symptoms and greater myomectomy complications. Some, but not all, studies have found a higher prevalence of endometriosis among Asian women. Race and ethnicity are also associated with hysterectomy rate, route, and complications. Overall, the current literature has significant deficits in the identification of racial and ethnic disparities in the incidence of fibroid tumors, endometriosis, and hysterectomy. Further research is needed to better define racial and ethnic differences in these conditions and to examine the complex mechanisms that may result in associated health disparities.

Recent cadmium exposure among male partners may affect oocyte fertilization during in vitro fertilization (IVF)

Purpose

We recently reported evidence suggesting associations between urine cadmium concentrations, reflecting long-term exposure, measured in 25 female patients (relative risk = 1.41, P = 0.412) and 15 of their male partners (relative risk = 0.19, P = 0.097) and oocyte fertilization in vitro. Blood cadmium concentrations reflect more recent exposure.

Methods

We here incorporate those measures into our prior data set and employ multivariable log-binomial regression models to generate hypotheses concerning the relative effects of long-term and recent cadmium exposure on oocyte fertilization in vitro.

Results

No association is indicated for blood cadmium from women and oocyte fertilization, adjusted for urine cadmium and creatinine, blood lead and mercury, age, race/ethnicity and cigarette smoking (relative risk = 0.88, P = 0.828). However, we suggest an inverse adjusted association between blood cadmium from men and oocyte fertilization (relative risk = 0.66, P = 0.143).

Conclusions

These results suggest that consideration of long-term and recent exposures are both important for assessing the effect of partner cadmium levels on oocyte fertilization in vitro.

Are there ethnic differences in pregnancy rates in African-American versus white women undergoing frozen blastocyst transfers?

OBJECTIVE

To determine whether frozen-thawed blastocyst transfer pregnancy rates (PR) are lower in African-American compared with white women.

DESIGN

Retrospective review of frozen blastocyst cycles.

SETTING

University-based assisted reproductive technology (ART) program.

PATIENT(S)

All patients who underwent a frozen blastocyst transfer between 2003 and 2008.

INTERVENTION

None.

MAIN OUTCOME MEASURE(S)

Live birth rate.

RESULT(S)

One hundred sixty-nine patients underwent transfer of a frozen-thawed blastocyst. African-American women had a higher incidence of leiomyoma (40% vs. 10%) and tubal and uterine factor infertility. There was no difference in the live birth rate for African-American patients (28.0%) compared with white patients (30.2%). Of the patients who underwent a frozen-thawed blastocyst transfer, 58% (n=98) had their fresh, autologous IVF cycle, which produced the cryopreserved blastocyst, at Walter Reed Medical Center. A higher peak serum E2 level was noted in African-American patients (5,355 pg/mL) compared with white patients (4,541 pg/mL). During the fresh cycle, the live birth rates between African-American and white patients were significantly different at 16.7% versus 39.7%, respectively.

CONCLUSION(S)

Live birth rates after frozen blastocyst transfer are not different between African-American and white women despite a fourfold higher incidence of leiomyomas in African-American women.

Racial and ethnic disparities in reproductive endocrinology and infertility

This review examines racial and ethnic disparities in reproductive health focusing on 3 key topical areas: (1) infertility, (2) polycystic ovarian syndrome, and (3) reproductive aging. We report that an increasing body of knowledge points toward reduced infertility access and in vitro fertilization outcomes in Asian, black, and Hispanic women compared with white women. There are differences in the reproductive and metabolic phenotypes of Asian, black, and Hispanic women presenting with the polycystic ovarian syndrome compared with white women. Reproductive aging differences appear to exist in all racial and ethnic groups. Awareness of racial and ethnic disparities is critical to a complete understanding of the health issues facing women of reproductive age.