Infertility among women exposed prenatally to diethylstilbestrol

Evidence of binding between diethylstilbestrol (DES) and the goldfish (Carassius auratus) membrane progesterone receptor α

BACKGROUND

In a previous study, diethylstilbestrol (DES) was shown to induce oocyte maturation in fish. In the present study, the interaction of DES on goldfish membrane progesterone receptor α (GmPRα) was investigated using a competitive binding assay with radiolabeled steroids. The results indicate that DES exerts its effects on membrane progesterone receptor alpha (mPRα) and induces oocyte maturation through nongenomic steroid mechanisms. This study provides empirical data that demonstrate the binding between DES and GmPRα.

METHODS

Binding of DES to GmPRα was achieved by using radiolabeled DES and recombinant GmPRα expressed in culture cells or purified GmPRα proteins that coupled to graphene quantum dots (GQDs). Additionally, the competitive binding of fluorescently labeled progesterone to GmPRα-expressing cells was evaluated.

RESULTS

Although significant nonspecific binding of radiolabeled DES to the cell membrane that expresses GmPRα has been observed, specific binding of DES to GmPRα has been successfully identified in the presence of digitonin. Furthermore, the specific binding of DES to GmPRα was confirmed by a binding assay using GQD-GmPRα. The radiolabeled DES was shown to bind to GQD-GmPRα. Additionally, the competition for the binding of fluorescently labeled progesterone to GmPRα-expressing cells was achieved with the DES.

CONCLUSIONS

The results of the experiments revealed that DES binds to GmPRα. Thus, it can be concluded that DES induces goldfish oocyte maturation by binding to GmPRα.

Transcriptional profiling of the developing rat ovary following intrauterine exposure to the endocrine disruptors diethylstilbestrol and ketoconazole

Exposure to endocrine-disrupting chemicals (EDCs) during development may cause reproductive disorders in women. Although female reproductive endpoints are assessed in rodent toxicity studies, a concern is that typical endpoints are not sensitive enough to detect chemicals of concern to human health. If so, measured endpoints must be improved or new biomarkers of effects included. Herein, we have characterized the dynamic transcriptional landscape of developing rat ovaries exposed to two well-known EDCs, diethylstilbestrol (DES) and ketoconazole (KTZ), by 3' RNA sequencing. Rats were orally exposed from day 7 of gestation until birth, and from postnatal day 1 until days 6, 14 or 22. Three exposure doses for each chemical were used: 3, 6 and 12 µg/kg bw/day of DES; 3, 6, 12 mg/kg bw/day of KTZ. The transcriptome changed dynamically during perinatal development in control ovaries, with 1137 differentially expressed genes (DEGs) partitioned into 3 broad expression patterns. A cross-species deconvolution strategy based on a mouse ovary developmental cell atlas was used to map any changes to ovarian cellularity across the perinatal period to allow for characterization of actual changes to gene transcript levels. A total of 184 DEGs were observed across dose groups and developmental stages in DES-exposed ovaries, and 111 DEGs in KTZ-exposed ovaries across dose groups and developmental stages. Based on our analyses, we have identified new candidate biomarkers for female reproductive toxicity induced by EDC, including Kcne2, Calb2 and Insl3.

Classical toxicity endpoints in female rats are insensitive to the human endocrine disruptors diethylstilbestrol and ketoconazole

Developmental exposure to endocrine disrupting chemicals can have negative consequences for reproductive health in both men and women. Our knowledge about how chemicals can cause adverse health outcomes in females is, however, poorer than our knowledge in males. This is possibly due to lack of sensitive endpoints to evaluate endocrine disruption potential in toxicity studies. To address this shortcoming we carried out rat studies with two well-known human endocrine disruptors, diethylstilbestrol (DES) and ketoconazole (KTZ), and evaluated the sensitivity of a series of endocrine related endpoints. Sprague-Dawley rats were exposed orally from gestational day 7 until postnatal day 22. In a range-finding study, disruption of pregnancy-related endpoints was seen from 0.014 mg/kg bw/day for DES and 14 mg/kg bw/day for KTZ, so doses were adjusted to 0.003; 0.006; and 0.0012 mg/kg bw/day DES and 3; 6; or 12 mg/kg bw/day KTZ in the main study. We observed endocrine disrupting effects on sensitive endpoints in male offspring: both DES and KTZ shortened anogenital distance and increased nipple retention. In female offspring, 0.0012 mg/kg bw/day DES caused slightly longer anogenital distance. We did not see effects on puberty onset when comparing average day of vaginal opening; however, we saw a subtle delay after exposure to both chemicals using a time-curve analysis. No effects on estrous cycle were registered. Our study shows a need for more sensitive test methods to protect the reproductive health of girls and women from harmful chemicals.

Dioxin exposure associated with fecundability and infertility in mothers and daughters of Seveso, Italy

STUDY QUESTION

Is there an association between 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure and fecundability and infertility among Seveso women and their daughters?

SUMMARY ANSWER

TCDD exposure is associated with a decrease in fecundability and increased risk of infertility in women, as well as their daughters.

WHAT IS KNOWN ALREADY

In animal studies, maternal exposure to TCDD is associated with decreased fertility in offspring. Effects of TCDD are mediated by activation of the aryl hydrocarbon receptor (AHR) pathway.

STUDY DESIGN, SIZE, DURATION

The Seveso Women's Health Study (SWHS) has followed 981 women exposed to TCDD in a 1976 accident since 1996. In 2014, we initiated the Seveso Second Generation Study to follow-up their children.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We obtained information on pregnancy history including time of trying to conceive from SWHS women and their daughters who were 18 years or older. We considered TCDD exposure as initial 1976 serum TCDD concentration and estimated TCDD at pregnancy. We examined relationships of TCDD exposure with time to pregnancy (TTP, the monthly probability of conception within the first 12 months of trying) and infertility (≥12 months of trying to conceive). We also assessed contributions of polymorphisms in the AHR pathway via genetic risk score.

MAIN RESULTS AND THE ROLE OF CHANCE

Among SWHS women (n = 446), median TTP was 3 months and 18% reported taking ≥12 months to conceive. Initial 1976 TCDD (log10) was associated with longer TTP (adjusted fecundability odds ratio = 0.82; 95% CI 0.68-0.98) and increased risk of infertility (adjusted relative risk = 1.35; 95% CI 1.01-1.79). TCDD at pregnancy yielded similar associations. Among SWHS daughters (n = 66), median TTP was 2 months and 11% reported taking ≥12 months to conceive. Daughters showed similar, but non-significant, associations with maternal TCDD exposure.

LIMITATIONS, REASONS FOR CAUTION

A limitation of this study is time to pregnancy was reported retrospectively, although previous studies have found women are able to recall time to conception with a high degree of accuracy many years after the fact. The number of SWHS daughters who had a live birth was small and we were unable to examine fecundability of SWHS sons.

WIDER IMPLICATIONS OF THE FINDINGS

Consistent with previous findings in animal studies, our study found that TCDD exposure may be associated with decreased fertility in Seveso mothers and potentially in their daughters exposed in utero. There may be susceptible genetic subgroups. The literature has largely considered the genetics of the AHR pathway in the context of male fertility but not female fertility, despite strong biological plausibility. These findings should be replicated in larger populations and of different ancestry. Future studies in Seveso should examine the sons and the grandchildren of exposed mothers given the animal literature suggesting potential heritable epigenetic effects.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by grant numbers F06 TW02075-01 from the National Institutes of Health, R01 ES07171 and 2P30-ESO01896-17 from the National Institute of Environmental Health Sciences, R82471 from the U.S. Environmental Protection Agency and #2896 from Regione Lombardia and Fondazione Lombardia Ambiente, Milan, Italy. J.A. was supported by F31ES026488 from the National Institutes of Health. The authors declare they have no actual or potential competing financial interests.

TRIAL REGISTRATION NUMBER

N/A.

Putative adverse outcome pathways for female reproductive disorders to improve testing and regulation of chemicals

Modern living challenges female reproductive health. We are witnessing a rise in reproductive disorders and drop in birth rates across the world. The reasons for these manifestations are multifaceted and most likely include continuous exposure to an ever-increasing number of chemicals. The cause–effect relationships between chemical exposure and female reproductive disorders, however, have proven problematic to determine. This has made it difficult to assess the risks chemical exposures pose to a woman’s reproductive development and function. To address this challenge, this review uses the adverse outcome pathway (AOP) concept to summarize current knowledge about how chemical exposure can affect female reproductive health. We have a special focus on effects on the ovaries, since they are essential for lifelong reproductive health in women, being the source of both oocytes and several reproductive hormones, including sex steroids. The AOP framework is widely accepted as a new tool for toxicological safety assessment that enables better use of mechanistic knowledge for regulatory purposes. AOPs equip assessors and regulators with a pragmatic network of linear cause–effect relationships, enabling the use of a wider range of test method data in chemical risk assessment and regulation. Based on current knowledge, we propose ten putative AOPs relevant for female reproductive disorders that can be further elaborated and potentially be included in the AOPwiki. This effort is an important step towards better safeguarding the reproductive health of all girls and women.

Calretinin is a novel candidate marker for adverse ovarian effects of early life exposure to mixtures of endocrine disruptors in the rat

Disruption of sensitive stages of ovary development during fetal and perinatal life can have severe and life-long consequences for a woman’s reproductive life. Exposure to endocrine disrupting chemicals may affect ovarian development, leading to subsequent reproductive disorders. Here, we investigated the effect of early life exposure to defined mixtures of human-relevant endocrine disrupting chemicals on the rat ovary. We aimed to identify molecular events involved in pathogenesis of ovarian dysgenesis syndrome that have potential for future adverse outcome pathway development. We therefore focused on the ovarian proteome. Rats were exposed to a mixture of phthalates, pesticides, UV-filters, bisphenol A, butyl-paraben, and paracetamol during gestation and lactation. The chemicals were tested together or in subgroups of chemicals with anti-androgenic or estrogenic potentials at doses 450-times human exposure. Paracetamol was tested separately, at a dose of 360 mg/kg. Using shotgun proteomics on ovaries from pup day 17 offspring, we observed exposure effects on the proteomes. Nine proteins were affected in more than one exposure group and of these, we conclude that calretinin is a potential key event biomarker of early endocrine disruption in the ovary.

Implication of environmental estrogens on breast cancer treatment and progression

Breast cancer is the most diagnosed malignancy among women in the United States. Approximately 70% of breast tumors express estrogen receptor alpha and are deemed ER-positive. ER-positive breast tumors depend upon endogenous estrogens to promote ER-mediated cellular proliferation. Decades of research have led to a fundamental understanding of the role ER signaling in this disease and this knowledge has led to significant advancements in the clinical use of antiestrogens for breast cancer treatment. However, adjuvant breast cancer recurrence and metastatic disease progression due to endocrine therapy resistance are prominent and unresolved issues. The established role that estrogens play in breast cancer pathogenesis explains why some patients initially respond to endocrine therapy but also why a significant number of patients become refractory to antiestrogen treatment. It is been hypothesized that exposure to environmental steroid hormone mimics and/or acquired mechanisms of resistance may explain why endocrine therapy fails in a subset of breast cancer patients. This review will highlight: 1) the relationship between ER signaling and breast cancer pathogenesis, 2) the implication of environmental exposures on steroid hormone regulated processes including breast cancer, and 3) the unresolved issue of endocrine therapy resistance.

Maternal age at birth and daughters' subsequent childlessness

STUDY QUESTION

Does maternal age at a daughter's birth predict her subsequent probability of lifelong childlessness?

SUMMARY ANSWER

In this study population, women born to older mothers were more likely to be childless.

WHAT IS KNOWN ALREADY

Although maternal age at childbearing is increasing in many countries, there is limited evidence on whether being born to older parents may influence offspring fertility.

STUDY DESIGN SIZE AND DURATION

This analysis included 43 135 women from the US-based Sister Study, a cohort study of 50 884 sisters of women with breast cancer recruited between 2003 and 2009.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Participants had no breast cancer at baseline. Women were included in the analytic sample if they were born between 1930 and 1964 and were at least 44 years old at enrolment. Median age when reproductive history was last ascertained was 63.8 years. We estimated relative risks (RR) and 95% CI of lifelong childlessness as a function of maternal age at birth, using multivariable log-binomial models, including total number of siblings, birth order, socioeconomic indicators of the family of origin, race and birth cohort. We examined the association in different subgroups and in a sibling-matched analysis including 802 sister pairs discordant for childlessness.

MAIN RESULTS AND ROLE OF CHANCE

Compared with women born to 20-24-year-old mothers, those born to mothers aged 25-29, 30-34 and ≥35 years were more likely to be childless [RR (95% CI): 1.21 (1.14-1.29), 1.30 (1.22-1.39) and 1.40 (1.31-1.50), respectively]. The association was consistent in strata defined by birth cohort, number of siblings, birth order, and participant's educational level, as well as within sister pairs. Overall, we found weak evidence for an independent contribution of paternal age at birth to the daughter's probability of childlessness.

LIMITATIONS REASONS FOR CAUTION

All participants had at least one sister, and all information was self-reported. We had no knowledge of whether childlessness was intentional and found only a modest association between maternal age at birth and self-reported indicators of infertility. Still, the association with childlessness was highly consistent.

WIDER IMPLICATIONS OF THE FINDING

Given the widespread tendency to delay childbearing, evaluating the influence of maternal age at birth on offspring fertility is a public health priority.

STUDY FUNDING/COMPETING INTERESTS

This research was supported in part by the Intramural Research Programme of the NIH, National Institute of Environmental Health Sciences (Z01-ES044005). The authors report no conflict of interest.

Natural and environmental oestrogens induce TGFB1 synthesis in oviduct cells

Autocrine/paracrine factors generated in response to 17β-oestradiol (E2), within the oviduct, facilitate early embryo development for implantation. Since transforming growth factor beta 1 (TGFB1) plays a key role in embryo implantation, regulation of its synthesis by E2 may be of biological/pathophysiological relevance. Here, we investigated whether oviduct cells synthesize TGFB1 and whether E2 and environmental oestrogens (EOEs; xenoestrogens and phytoestrogens) modulate its synthesis. Under basal conditions, bovine oviduct cells (OCs; oviduct epithelial cells and oviduct fibroblasts; 1:1 ratio) synthesized TGFB1. E2 concentration-dependent induced TGFB1 levels in OCs and these effects were mimicked by some, but not all EOEs (genistein, biochanin A and 4-hydroxy-2',4',6'-trichlorobiphenyl, 4-hydroxy-2',4',6'-dichlorobiphenyl); moreover, EOEs enhanced (P < 0.05) the stimulatory effects of E2 on TGFB1 synthesis. The OCs expressed oestrogen receptors alpha and beta and aryl hydrocarbon; moreover, co-treatment with ER antagonist ICI182780 blocked the stimulatory effects of E2 and EOEs on TGFB1 synthesis. Treatment with non-permeable E2-BSA failed to induce TGFB1, thereby ruling out the involvement of membrane ERs. Cycloheximide (protein synthesis inhibitor) blocked E2-induced TGFB1 synthesis providing evidence for de novo synthesis. The stimulatory effects of E2 and EOEs, were inhibited (P < 0.05) by MAPK inhibitor (PD98059), whereas intracellular-Ca²⁺ chelator (BAPTA-AM) and adenylyl cyclase inhibitor (SQ22536) abrogated the effects of E2, but not EOEs, suggesting that post-ER effects of E2 and EOEs involve different pathways. Our results provide the first evidence that in OCs, E2 and EOEs stimulate TGFB1 synthesis via an ER-dependent pathway. Exposure of the oviduct to EOEs may result in continuous/sustained induction of TGFB1 levels in a non-cyclic fashion and may induce deleterious effects on reproduction.

Triclocarban and Triclosan Inhibit Human Aromatase via Different Mechanisms

Human aromatase (CYP19A1) is an important enzyme, which produces estrogen from androgen for maintaining the female reproductive function and pregnancy. Triclocarban and triclosan are antimicrobial chemicals added to personal care, household, and industrial products. They could be endocrine disruptors and may disrupt human CYP19A1 activity. In the present study, we investigated the effects of triclocarban and triclosan on estradiol production and human CYP19A1 activity in JEG-3 cells. Triclocarban and triclosan reduced estradiol production in JEG-3 cells. Triclocarban and triclosan inhibited human CYP19A1 with IC50 values of 15.81 and 6.26 μM, respectively. Triclosan competitively inhibited CYP19A1, while triclocarban noncompetitively inhibited this enzyme. Docking study showed that triclosan bound to the steroid-binding pocket of CYP19A1, while triclocarban was off this target, suggesting a different mechanism. In conclusion, triclocarban and triclosan are inhibitors of human CYP19A1.

Emergent contaminants in the wastewater effluents of two highly populated tropical cities

Exposure to the anthropogenic chemicals known as endocrine disrupting compounds (EDCs) may result in negative biological effects. Low levels of EDCs in the environment aggravate the problem as exposure is constant. Urban areas concentrate pollution as greater volumes are released from human activities. Water for public supply is particularly vulnerable as the sewage treatment facilities may not eliminate EDCs. The goal was to assess estrogenicity and effectiveness of removal of phthalates in primary and tertiary wastewater treatment facilities in urban cities in the tropical island of Puerto Rico. A yeast bioassay used to measure estrogenicity showed higher removal with tertiary treatment. However, results in the picomolar range suggest low doses of estrogenic compounds were being released to receiving waters. For the phthalates, solid phase extraction and gas chromatography-mass spectrometry analyses revealed removals ranging from 42.9% to 92.4% with tertiary treatment. More than 90% removal was achieved for benzylbutyl phthalate, dibutyl phthalate and bis-2-ethylhexyl phthalate. However, concentrations ranging from 0.86 to 1.29 ppm for the phthalates in the outflow were detected even at the tertiary waste water treatment plant effluent implying failure of EDC removal. These results can assist managers in evaluating pollution control technologies to ameliorate the impacts of EDCs in the tropics.

Environmental influences on ovarian dysgenesis - developmental windows sensitive to chemical exposures

A woman's reproductive health and ability to have children directly affect numerous aspects of her life, from personal well-being and socioeconomic standing, to morbidity and lifespan. In turn, reproductive health depends on the development of correctly functioning ovaries, a process that starts early during fetal life. Early disruption to ovarian programming can have long-lasting consequences, potentially manifesting as disease much later in adulthood. A growing body of evidence suggests that exposure to chemicals early in life, including endocrine-disrupting chemicals, can cause a range of disorders later in life, such as those described in the ovarian dysgenesis syndrome hypothesis. In this Review, we discuss four specific time windows during which the ovary is particularly sensitive to disruption by exogenous insults: gonadal sex determination, meiotic division, follicle assembly and the first wave of follicle recruitment. To date, most evidence points towards the germ cell lineage being the most vulnerable to chemical exposure, particularly meiotic division and follicle assembly. Environmental chemicals and pharmaceuticals, such as bisphenols or mild analgesics (including paracetamol), can also affect the somatic cell lineages. This Review summarizes our current knowledge pertaining to environmental chemicals and pharmaceuticals, and their potential contributions to the development of ovarian dysgenesis syndrome. We also highlight knowledge gaps that need addressing to safeguard female reproductive health.

Human UDP-Glucuronosyltransferases 1A1, 1A3, 1A9, 2B4 and 2B7 are Inhibited by Diethylstilbestrol

Inhibition of UDP-glucuronosyltransferases (UGTs) can result in many undesired side effects. Diethylstilbestrol (DES), a synthetic oestrogen famous for its multiple toxicities, was once widely administered to women in high dosages and now still gains application in clinics. This study investigated in vitro inhibitory effects of DES on catalytic activities of human UGTs, aiming at disclosing new potential toxic mechanisms on the basis of interactions between DES and metabolizing enzymes. DES (10 μM) could decrease activities of UGT1A1, 1A3, 1A9, 2B4 and 2B7 in catalysing 4-methylumbelliferone (4-Mu) glucuronidation. Further kinetic analyses showed that inhibition of these UGTs followed competitive (UGT1A1 and 1A9), mixed (UGT1A3 and 2B4) and non-competitive (UGT2B7) mechanisms, with K_i values ranging from 0.91 to 4.1 μM. The inhibition potentials of UGT1A9 and 2B7 in human liver microsomes (HLM) were further tested by employing propofol and zidovudine as probe substrates, respectively. The inhibition of human liver microsomal UGT1A9 followed mixed mechanism, with the K_i value of 3.5 μM and α of 4.1. On the other hand, DES displayed non-competitive inhibition against UGT2B7 in HLM, with the K_i value of 9.8 μM. The risks of in vivo inhibition of human UGTs were also predicted by calculation of plasma C/K_i values. Results suggest that DES can trigger in vivo inhibition of UGT1A1, 1A3, 1A9, 2B4 and 2B7 after the intravenous administration in high doses.

Obesogens: an emerging threat to public health

Endocrine disrupting chemicals (EDCs) are defined as exogenous chemicals, or mixtures of chemicals, that can interfere with any aspect of hormone action. The field of endocrine disruption is historically rooted in wildlife biology and reproductive endocrinology where EDCs are demonstrated contributors to infertility, premature puberty, endometriosis, and other disorders. Recently, EDCs have been implicated in metabolic syndrome and obesity. Adipose tissue is a true endocrine organ and, therefore, an organ that is highly susceptible to disturbance by EDCs. A subset of EDCs, called "obesogens," promote adiposity by altering programming of fat cell development, increasing energy storage in fat tissue, and interfering with neuroendocrine control of appetite and satiety. Obesity adds more than $200 billion to US healthcare costs and the number of obese individuals continues to increase. Hence, there is an urgent, unmet need to understand the mechanisms underlying how exposures to certain EDCs may predispose our population to be obese. In this review, we discuss the history of obesogen discovery from its origins in reproductive biology to its latest role in the transgenerational inheritance of obesity in mice. We discuss the development of adipose tissue in an embryo, maintenance of adipocyte number in adults, how EDC disruption programs stem cells to preferentially make more adipocytes, the mechanisms by which chemicals can permanently alter the germline epigenome, and whether there are barriers to EDCs in the gametes.

Obesogens: an emerging threat to public health

Endocrine disrupting chemicals (EDCs) are defined as exogenous chemicals, or mixtures of chemicals, that can interfere with any aspect of hormone action. The field of endocrine disruption is historically rooted in wildlife biology and reproductive endocrinology where EDCs are demonstrated contributors to infertility, premature puberty, endometriosis, and other disorders. Recently, EDCs have been implicated in metabolic syndrome and obesity. Adipose tissue is a true endocrine organ and, therefore, an organ that is highly susceptible to disturbance by EDCs. A subset of EDCs, called "obesogens," promote adiposity by altering programming of fat cell development, increasing energy storage in fat tissue, and interfering with neuroendocrine control of appetite and satiety. Obesity adds more than $200 billion to US healthcare costs and the number of obese individuals continues to increase. Hence, there is an urgent, unmet need to understand the mechanisms underlying how exposures to certain EDCs may predispose our population to be obese. In this review, we discuss the history of obesogen discovery from its origins in reproductive biology to its latest role in the transgenerational inheritance of obesity in mice. We discuss the development of adipose tissue in an embryo, maintenance of adipocyte number in adults, how EDC disruption programs stem cells to preferentially make more adipocytes, the mechanisms by which chemicals can permanently alter the germline epigenome, and whether there are barriers to EDCs in the gametes.

Adult air pollution exposure and risk of infertility in the Nurses' Health Study II

STUDY QUESTION

Is there an association between air pollution exposures and incident infertility?

SUMMARY ANSWER

Increased exposure to air pollution is associated with an increased incidence of infertility.

WHAT IS KNOWN ALREADY

Exposures to air pollution have been associated with lower conception and fertility rates. However, the impact of pollution on infertility incidence is unknown.

STUDY DESIGN, SIZE, DURATION

Prospective cohort study using data collected from 116 430 female nurses from September 1989 to December 2003 as part of the Nurses' Health Study II cohort.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Infertility was defined by report of attempted conception for ≥12 months without success. Participants were able to report if evaluation was sought and if so, offer multiple clinical indications for infertility. After exclusion, 36 294 members were included in the analysis. Proximity to major roadways and ambient exposures to particulate matter less than 10 microns (PM10), between 2.5 and 10 microns (PM2.5-10), and less than 2.5 microns (PM2.5) were determined for residential addresses for the 36 294 members between the years of 1993 and 2003. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using multivariable adjusted Cox proportional hazard models with time-varying covariates.

MAIN RESULTS AND THE ROLE OF CHANCE

Over 213 416 person-years, there were 2508 incident reports of infertility. Results for overall infertility were inconsistent across exposure types. We observed a small increased risk for those living closer to compared to farther from a major road, multivariable adjusted HR = 1.11 (CI: 1.02-1.20). This was consistent for those reporting primary or secondary infertility. For women living closer to compared to farther from a major road, for primary infertility HR = 1.05 (CI: 0.94-1.17), while for secondary infertility HR = 1.21 (CI: 1.07-1.36). In addition, the HR for every 10 µg/m(3) increase in cumulative PM2.5-10 among women with primary infertility was 1.10 (CI: 0.96-1.27), and similarly was 1.10 (CI: 0.94-1.28) for those with secondary infertility.

LIMITATIONS, REASONS FOR CAUTION

Within the 2 year window of infertility diagnosis, we do not have the exact date of diagnosis or the exact timing of the start of attempting conception. As infertility status and subtypes of infertility were prospectively collected biennially, we were unable to tightly examine the timing of exposures on incidence of infertility. In terms of exposure quantification, we used ambient air pollution exposures as a proxy for personal exposures, potentially leading to exposure misclassification. However, several studies suggest that ambient measurements are an acceptable surrogate for individual level exposures in most populations.

WIDER IMPLICATIONS OF THE FINDINGS

We observed an association between all size fractions of PM exposure, as well as traffic-related air pollution, and incidence of infertility. Of note, the strongest association was observed between cumulative average exposures over the course of follow-up and the risk of infertility, suggesting that chronic exposures may be of greater importance than short-term exposures.

STUDY FUNDING/COMPETING INTERESTS

The work for this paper was supported by the following: S.M.: Reproductive Scientist Development Program HD000849, and the Building Interdisciplinary Research Careers in Women's Health HD043444, the Boston University CTSI 1UL1TR001430, and a research grant from the Boston University Department of Obstetrics and Gynecology, S.A.M.: R01HD57210 from the National Institute of Child Health and Human Development and the Massachusetts Institute of Technology Center for Environmental Health Sciences Translational Pilot Project Program, R01CA50385 from the National Cancer Institute, J.E.H. and F.L.: 5R01ES017017 from the National Institute for Environmental Health Sciences, 5 P42 ES007381 from the National Institute of Environmental Health at the National Institute of Health. L.V.F.: T32HD060454 in reproductive, perinatal, and pediatric epidemiology from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. The Nurses' Health Study II is additionally supported by infrastructure grant UM1CA176726 from the National Cancer Institute, NIH, U.S. Department of Health and Human Services. The authors have no actual or potential competing financial interests to disclose.

Prenatal diethylstilbestrol exposure and reproductive hormones in premenopausal women

Diethylstilbestrol (DES), a synthetic estrogen widely prescribed to pregnant women in the mid-1900s, is a potent endocrine disruptor. Prenatal DES exposure has been associated with reproductive disorders in women, but little is known about its effects on endogenous hormones. We assessed the association between prenatal DES exposure and reproductive hormones among participants from the Harvard Study of Moods and Cycles (HSMC), a longitudinal study of premenopausal women aged 36–45 years from Massachusetts (1995–1999). Prenatal DES exposure was reported at baseline (43 DES exposed and 782 unexposed). Early follicular-phase concentrations of follicle-stimulating hormone (FSH), luteinizing hormone (LH) and estradiol were measured at baseline and every 6 months during 36 months of follow-up. Inhibin B concentrations were measured through 18 months. We used multivariable logistic and repeated-measures linear regression to estimate odds ratios (OR) and percent differences in mean hormone values (β), respectively, comparing DES exposed with unexposed women, adjusted for potential confounders. DES-exposed women had lower mean concentrations of estradiol (pg/ml) (β=−15.6%, 95% confidence interval (CI): −26.5%, −3.2%) and inhibin B (pg/ml) (β=−20.3%, CI: −35.1%, −2.3%), and higher mean concentrations of FSH (IU/I) (β=12.2%, CI: −1.5%, 27.9%) and LH (IU/I) (β=10.4%, CI: −7.2%, 31.3%), than unexposed women. ORs for the association of DES with maximum FSH>10 IU/I and minimum inhibin B<45 pg/ml – indicators of low ovarian reserve – were 1.90 (CI: 0.86, 4.22) and 4.00 (CI: 0.88–18.1), respectively. Prenatal DES exposure was associated with variation in concentrations of FSH, estradiol and inhibin B among women of late reproductive age.

Diethylstilbestrol can effectively accelerate estradiol-17-O-glucuronidation, while potently inhibiting estradiol-3-O-glucuronidation

This in vitro study investigates the effects of diethylstilbestrol (DES), a widely used toxic synthetic estrogen, on estradiol-3- and 17-O- (E2-3/17-O) glucuronidation, via culturing human liver microsomes (HLMs) or recombinant UDP-glucuronosyltransferases (UGTs) with DES and E2. DES can potently inhibit E2-3-O-glucuronidation in HLM, a probe reaction for UGT1A1. Kinetic assays indicate that the inhibition follows a competitive inhibition mechanism, with the Ki value of 2.1±0.3μM, which is less than the possible in vivo level. In contrast to the inhibition on E2-3-O-glucuronidation, the acceleration is observed on E2-17-O-glucuronidation in HLM, in which cholestatic E2-17-O-glucuronide is generated. In the presence of DES (0-6.25μM), Km values for E2-17-O-glucuronidation are located in the range of 7.2-7.4μM, while Vmax values range from 0.38 to 1.54nmol/min/mg. The mechanism behind the activation in HLM is further demonstrated by the fact that DES can efficiently elevate the activity of UGT1A4 in catalyzing E2-17-O-glucuronidation. The presence of DES (2μM) can elevate Vmax from 0.016 to 0.81nmol/min/mg, while lifting Km in a much lesser extent from 4.4 to 11μM. Activation of E2-17-O-glucuronidation is well described by a two binding site model, with KA, α, and β values of 0.077±0.18μM, 3.3±1.1 and 104±56, respectively. However, diverse effects of DES towards E2-3/17-O-glucuronidation are not observed in liver microsomes from several common experimental animals. In summary, this study issues new potential toxic mechanisms for DES: potently inhibiting the activity of UGT1A1 and powerfully accelerating the formation of cholestatic E2-17-O-glucuronide by UGT1A4.

Mechanisms in endocrinology: thyroid and polycystic ovary syndrome

Thyroid disorders, especially Hashimoto's thyroiditis (HT), and polycystic ovary syndrome (PCOS) are closely associated, based on a number of studies showing a significantly higher prevalence of HT in women with PCOS than in controls. However, the mechanisms of this association are not as clear. Certainly, genetic susceptibility contributes an important part to the development of HT and PCOS. However, a common genetic background has not yet been established. Polymorphisms of the PCOS-related gene for fibrillin 3 (FBN3) could be involved in the pathogenesis of HT and PCOS. Fibrillins influence the activity of transforming growth factor beta (TGFβ). Multifunctional TGFβ is also a key regulator of immune tolerance by stimulating regulatory T cells (Tregs), which are known to inhibit excessive immune response. With lower TGFβ and Treg levels, the autoimmune processes, well known in HT and assumed in PCOS, might develop. In fact, lower levels of TGFβ1 were found in HT as well as in PCOS women carrying allele 8 of D19S884 in the FBN3 gene. Additionally, vitamin D deficiency was shown to decrease Tregs. Finally, high estrogen-to-progesterone ratio owing to anovulatory cycles in PCOS women could enhance the immune response. Harmful metabolic and reproductive effects were shown to be more pronounced in women with HT and PCOS when compared with women with HT alone or with controls. In conclusion, HT and PCOS are associated not only with respect to their prevalence, but also with regard to etiology and clinical consequences. However, a possible crosstalk of this association is yet to be elucidated.

Transgenerational developmental programming

BACKGROUND

The concept of developmental programming suggests that the early life environment influences offspring characteristics in later life, including the propensity to develop diseases such as the metabolic syndrome. There is now growing evidence that the effects of developmental programming may also manifest in further generations without further suboptimal exposure. This review considers the evidence, primarily from rodent models, for effects persisting to subsequent generations, and evaluates the mechanisms by which developmental programming may be transmitted to further generations. In particular, we focus on the potential role of the intrauterine environment in contributing to a developmentally programmed phenotype in subsequent generations.

METHODS

The literature was systematically searched at http://pubmed.org and http://scholar.google.com to identify published findings regarding transgenerational (F2 and beyond) developmental programming effects in human populations and animal models.

RESULTS

Transmission of programming effects is often viewed as a form of epigenetic inheritance, either via the maternal or paternal line. Evidence exists for both germline and somatic inheritance of epigenetic modifications which may be responsible for phenotypic changes in further generations. However, there is increasing evidence for the role of both extra-genomic components of the zygote and the interaction of the developing conceptus with the intrauterine environment in propagating programming effects.

CONCLUSIONS

The contribution of a suboptimal reproductive tract environment or maternal adaptations to pregnancy may be critical to inheritance of programming effects via the maternal line. As the effects of age exacerbate the programmed metabolic phenotype, advancing maternal age may increase the likelihood of developmental programming effects being transmitted to further generations. We suggest that developmental programming effects could be propagated through the maternal line de novo in generations beyond F2 as a consequence of development in a suboptimally developed intrauterine tract and not necessarily though directly transmitted epigenetic mechanisms.

The improvement of in vivo model (Balb/c mice) for cervical carcinogenesis using diethylstilbestrol (DES)

Cervical cancer is the most common gynecological cancer and one of the major causes of female cancer-related death worldwide particularly in developing countries. Thus far, there are a few in vivo models have been developed in investigating this type of cancer. In this study, we induced cervical cancer in Balb/c mice by exploiting the carcinogenic property of diestylstilbestrol (DES). The Balb/c pregnant mice were given subcutaneous (SC) injection of 67μg/kg body weight of DES on GD 13, and the mice gave birth approximately at gestation day 19-22. Female offspring were reared and the body weight was recorded once weekly. The female offspring were sacrificed at age of 5 months. Upon termination, blood was collected in a plain tube via cardiac puncture and the reproductive tracts were collected and weighed. The reproductive tract sections were stained using H&E for observation of pathological changes. The progression of disease state was monitored by measuring the level of serum interleukin (IL-6) using the Mouse IL-6 ELISA Assay Kit (BD OptEIA™, USA). All parameters were compared with Not-induced group. The outcome of this study demonstrated a significant difference in body weight gain, reproductive organ weight, diameter of cervix and the level of serum IL-6 in the Induced group as compared to the Not-induced group (P<0.05). Histopathological findings revealed the presence of adenosis only in the Induced group. It shows that DES could be employed as an agent to induce cervical carcinogenesis in animal model. In addition to that, new potential anti-cancer agents from various sources could be further evaluated using this technique.

[Iatrogenic endometriosis during reproductive age: main issues?]

Among endometriotic lesions a small proportion is secondary to various medical activities, and may be considered as iatrogenic. Any medical or surgical procedure increasing the menstrual flow or the retrograde flow bears a potential risk: conization, hydrotubation or copper intra-uterine device. Surgical procedures, by laparotomy or laparoscopic approach, are able to favor transport and cutaneous seeding of endometrial tissue, especially when a hysterotomy has been performed. Diagnosis and treatment of these lesions are today standardized. Few preventive measures are available, besides adequate surgical procedure, but none has been properly evaluated, mainly because these lesions are not frequent.

Clear Cell Adenocarcinoma of the Female Genital Tract: Long-Term Outcome and Fertility Aspects After Brachytherapy Aimed at a Conservative Treatment

Objectives

To assess the outcome and the fertility aspects in the particular population of cervical and/or vaginal clear cell adenocarcinoma (CCA) associated or not to previous in utero diethylstilbestrol exposure.

Methods

From January 1970 to December 2003, data from 61 consecutive patients with cervical and/or vaginal histologically proven CCA treated with brachytherapy (BT) aimed at a conservative treatment at the Institut Gustave Roussy as a part of treatment were retrospectively analyzed.

Results

The median follow-up was 9.4 years, ranging from 0.3 to 27.4 years. The 5-year specific overall survival rate was 79%. The median time of disease-free survival was 5.8 years. In the subgroup of 42 patients with a cervical CCA, 12 patients tried to be pregnant, 2 patients became pregnant and had miscarriages (P2M2 and P1M1). No pregnancy has been observed in 10 patients exclusively owing to anomalies of the reproductive tract: 6 patients had partial or total diaphragm, 2 patients had an anatomical alteration of the uterus, 1 patient had atrophic endometrium, and 1 patient had primary infertility. In the subgroup of 19 patients with a vaginal CCA, 7 patients tried to be pregnant. All of them had no morphological and/or functional anomalies of the genital tract. Three of 7 patients had delivered healthy babies (P1D1, P2D2, and P3M2D1), and another one had a miscarriage (P1M1). Moreover, all babies were delivered by cesarean section. The pregnancy rate was 10% (6 of 61 patients) with 3 healthy babies.

Conclusion

Conservative approach in patients with female genital tract CCA including BT gives good results with good survival rates and an interesting global pregnancy rate.

Anti-Müllerian hormone: a potential new tool in epidemiologic studies of female fecundability

The objective of the present commentary is to suggest that epidemiologists explore the use of anti-Müllerian hormone (AMH) as a new measurement tool in fecundability studies. The authors briefly summarize the advantages and limitations of the 3 current approaches to studies of fecundability. All 3 approaches involve the collection of time-to-pregnancy or attempt-time data, and most are limited to participants who plan their pregnancies. AMH is produced by ovarian follicles during their early growth stages and is measured clinically to assess ovarian reserve (the number of remaining oocytes). Unlike time to pregnancy, serum AMH level can be assessed regardless of pregnancy-attempt status. Measurements are not significantly affected by phase of the menstrual cycle, oral contraceptive use, or early pregnancy. The authors suggest that AMH measurement can be a valuable addition to traditionally designed fecundability studies. In addition, this hormone should be investigated as an independent measure of fecundability in studies that focus on exposures hypothesized to target the ovary.

Adverse health outcomes in women exposed in utero to diethylstilbestrol

BACKGROUND

Before 1971, several million women were exposed in utero to diethylstilbestrol (DES) given to their mothers to prevent pregnancy complications. Several adverse outcomes have been linked to such exposure, but their cumulative effects are not well understood.

METHODS

We combined data from three studies initiated in the 1970s with continued long-term follow-up of 4653 women exposed in utero to DES and 1927 unexposed controls. We assessed the risks of 12 adverse outcomes linked to DES exposure, including cumulative risks to 45 years of age for reproductive outcomes and to 55 years of age for other outcomes, and their relationships to the baseline presence or absence of vaginal epithelial changes, which are correlated with a higher dose of, and earlier exposure to, DES in utero.

RESULTS

Cumulative risks in women exposed to DES, as compared with those not exposed, were as follows: for infertility, 33.3% vs. 15.5% (hazard ratio, 2.37; 95% confidence interval [CI], 2.05 to 2.75); spontaneous abortion, 50.3% vs. 38.6% (hazard ratio, 1.64; 95% CI, 1.42 to 1.88); preterm delivery, 53.3% vs. 17.8% (hazard ratio, 4.68; 95% CI, 3.74 to 5.86); loss of second-trimester pregnancy, 16.4% vs. 1.7% (hazard ratio, 3.77; 95% CI, 2.56 to 5.54); ectopic pregnancy, 14.6% vs. 2.9% (hazard ratio, 3.72; 95% CI, 2.58 to 5.38); preeclampsia, 26.4% vs. 13.7% (hazard ratio 1.42; 95% CI, 1.07 to 1.89); stillbirth, 8.9% vs. 2.6% (hazard ratio, 2.45; 95% CI, 1.33 to 4.54); early menopause, 5.1% vs. 1.7% (hazard ratio, 2.35; 95% CI, 1.67 to 3.31); grade 2 or higher cervical intraepithelial neoplasia, 6.9% vs. 3.4% (hazard ratio, 2.28; 95% CI, 1.59 to 3.27); and breast cancer at 40 years of age or older, 3.9% vs. 2.2% (hazard ratio, 1.82; 95% CI, 1.04 to 3.18). For most outcomes, the risks among exposed women were higher for those with vaginal epithelial changes than for those without such changes.

CONCLUSIONS

In utero exposure of women to DES is associated with a high lifetime risk of a broad spectrum of adverse health outcomes. (Funded by the National Cancer Institute.).

Human type 2 17beta-hydroxysteroid dehydrogenase in umbilical vein and artery endothelial cells: differential inactivation of sex steroids according to the vessel type

The human placenta produces high amounts of estradiol. 17β-hydroxysteroid dehydrogenase type 2 (17βHSD2) is expressed by placental endothelial cells and was proposed to regulate sex hormone levels. Previous results obtained in term placenta suggested that 17βHSD2 expression and activity differ among umbilical cord vessels. In this study, 17βHSD2 expression level and enzymatic activity, and estrogen receptor α and β expression levels, were measured in endothelial cell cultures from umbilical arteries (HUAEC) and vein (HUVEC) using real-time quantitative PCR, western blot, and radiolabeled steroids. 17βHSD2-specific activities were also measured in proximal and distal segments of freshly isolated umbilical cord arteries and vein. 17βHSD2 mRNA level and activity were higher in HUAEC than in HUVEC. Activity was higher in umbilical arteries than in the umbilical vein. In arteries, enzymatic activity was higher near the placenta, suggesting a gradient of expression. No difference was found in ERα expression, whereas ERβ was expressed at a higher level in HUAEC than in HUVEC. Expression profiles of estrogen receptors and 17βHSD2 suggest a vessel type-specific response to estrogens. Our data support a differential modulation of biologically active sex steroid levels according to the vessel type in the foeto-placental unit, with apparent higher inactivation in the arterial system.

Determination of diethylstilbestrol based on biotin-streptavidin-amplified time-resolved fluoro-immunoassay

A rapid and sensitive time-resolved fluoroimmunoassay (TR-FIA) based on the biotin-streptavidin amplification system was developed for the determination of diethylstilbestrol (DES). Europium-labelled streptavidin derivatives combined with europium and anhydride of diethylene triamine penta-acetic acid were used to label streptavidin; biotin was coupled with goat anti-rabbit IgG to form a biotin-goat anti-rabbit IgG bridge between streptavidin-europium and the anti-DES antibody in the immunoassay. The DES assay was carried out by measuring the fluorescence of Eu(3+) -SA at 615 nm. The presented method produced a wide linear range, 0.001-1000.0 ng/mL, and a detection limit up to 0.81 pg/mL for DES. The method was applied to determine DES in serum samples, with recoveries of 97.4-107.8% and RSD 1.32-4.04%. The assay results by the present method showed that biotin-streptavidin amplified TR-FIA for DES detection; it may offer high sensitivity and promising alternative special methods in biological samples.

Preterm birth, fetal growth, and age at menarche among women exposed prenatally to diethylstilbestrol (DES)

Diethylstilbestrol (DES), a synthetic estrogen used in pregnancy during the 1950s and 1960s, provides a model for potential health effects of endocrine disrupting compounds in the environment. We evaluated prenatal exposure to DES, based on medical record review, in relation to gestational length, fetal growth, and age at menarche in 4429 exposed and 1427 unexposed daughters. DES exposure was associated with an increase in preterm birth (odds ratio (OR)=2.97; 95% CI=2.27, 3.87), and a higher risk of small for gestational age (SGA) (OR=1.61; 95% CI=1.31, 1.98). The association between DES exposure and early menarche was borderline, with stronger effects when early menarche was defined as ≤ 10 years (OR=1.41 95% CI=0.97, 2.03) than defined as ≤ 11 years (OR=1.16; 95% CI=0.97, 1.39). This study provides evidence that prenatal DES exposure was associated with fetal growth and gestational length, which may mediate associations between DES and health outcomes in later life.

Autoimmune disease incidence among women prenatally exposed to diethylstilbestrol

OBJECTIVE

Animal studies have suggested that prenatal diethylstilbestrol (DES) exposure may alter immune system development and function including antigen self-recognition. A cohort study was conducted to investigate whether prenatal DES exposure might influence the incidence of at least some specific autoimmune diseases in women.

METHODS

A group of women who were and were not prenatally exposed to DES have been followed for more than 25 years for numerous health outcomes including autoimmune disease. To verify diagnoses, medical records or physician abstracts were requested for all women who reported a diagnosis of rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), optic neuritis (ON), and idiopathic thrombocytopenic purpura (ITP). Incidence rates of these autoimmune diseases were compared between women who were and who were not prenatally DES-exposed.

RESULTS

Overall, there was no increase in verified autoimmune disease among DES-exposed women relative to those who were not exposed (RR 1.2; 95% CI 0.7, 2.1). There was, however, a positive association between prenatal DES exposure and RA among women younger than 45 years (RR 4.9; 95% CI 1.1, 21.6) and an inverse association among women who were 45 years and older (RR 0.1; 95% CI 0.01, 0.7).

CONCLUSION

Overall, these data provide little support for an association between prenatal DES exposure and development of autoimmune disease. The implication that such exposure may be related to RA in an unusual age-related manner is based on small numbers of cases and warrants further study.

Diethylstilbestrol exposure in utero and depression in women

Diethylstilbestrol (DES) is an estrogenic endocrine disruptor with long-term health effects, possibly including depression, following exposure in utero. Understanding the relation between in utero DES exposure and depression will provide insight to the potential adverse effects of bisphenol A, a functionally similar and ubiquitous endocrine disruptor. The association between in utero DES exposure and depression was assessed among participants in the Nurses' Health Study II who first reported their history of antidepressant use in 1993 and lifetime history of depressive symptoms in 2001. DES exposure was reported by 1,612 (2.2%) women. A history of depression at baseline was higher among women exposed to DES in utero compared with those not exposed (age-adjusted odds ratio (OR) = 1.47, 95% confidence interval (CI): 1.26, 1.72) (P < 0.001). Incident depression (first use of antidepressants among women who also reported depressive symptoms) during follow-up (1995-2005) was reported by 19.7% of women exposed to DES and 15.9% unexposed (age-adjusted OR = 1.41, 95% CI: 1.22, 1.63) (P < 0.001). Adjustment for risk factors of depression and correlates of DES exposure moderately attenuated the association (multivariable-adjusted OR = 1.30, 95% CI: 1.13, 1.51) (P = 0.0004). These results suggest that the neurophysiologic effects of in utero exposure to DES could lead to an increased risk of depression in adult life. Further research should assess whether in utero exposure to bisphenol A has similar adverse effects.

Birth defects in the sons and daughters of women who were exposed in utero to diethylstilbestrol (DES)

Prenatal exposure to diethylstilbestrol (DES) is associated with adverse health outcomes, including anatomic anomalies of the reproductive tract in women and of the genitourinary tract in men. The mouse model, which replicates many DES-related effects seen in humans, suggests that prenatal DES exposure causes alterations that may affect the next generation of offspring. We asked women participating in a large, multi-centre study of prenatal DES exposure to report birth defects occurring among 4029 sons and 3808 daughters (i.e., the third generation). A subcohort of 793 third generation daughters was also queried for birth defects. We used logistic regression models to generate odds ratio and 95% confidence intervals for the association between prenatal DES exposure in the mother and birth defects in the offspring. Based on the mothers' reports, overall birth defects were elevated in the sons (OR = 1.53; 95% CI = 1.04, 2.23) and in the daughters (OR = 2.35; 95% CI = 1.44, 3.82). Most estimates of association were imprecise, but daughters appeared to have an excess of heart conditions (OR = 4.56; 95% CI = 1.27, 16.34). Our data suggest a possible association between the mother's prenatal DES exposure and birth defects in their offspring, particularly in daughters. We cannot, however, rule-out the possible influence of reporting bias. In particular, the exposed daughters' elevated risk of cardiac defects may be as a result of the underreporting of these conditions by unexposed mothers.

The estrogen-injected female mouse: new insight into the etiology of PCOS

BACKGROUND

Female mice and rats injected with estrogen perinatally become anovulatory and develop follicular cysts. The current consensus is that this adverse response to estrogen involves the hypothalamus and occurs because of an estrogen-induced alteration in the GnRH delivery system. Whether or not this is true has yet to be firmly established. The present study examined an alternate possibility in which anovulation and cyst development occurs through an estrogen-induced disruption in the immune system, achieved through the intermediation of the thymus gland.

METHODS, RESULTS AND CONCLUSION

A putative role for the thymus in estrogen-induced anovulation and follicular cyst formation (a model of PCOS) was examined in female mice by removing the gland prior to estrogen injection. Whereas all intact, female mice injected with 20 microg estrogen at 5-7 days of age had ovaries with follicular cysts, no cysts were observed in animals in which thymectomy at 3 days of age preceded estrogen injection. In fact, after restoring immune function by thymocyte replacement, the majority of thymectomized, estrogen-injected mice had ovaries with corpora lutea. Thus, when estrogen is unable to act on the thymus, ovulation occurs and follicular cysts do not develop. This implicates the thymus in the cysts' genesis and discounts the role of the hypothalamus. Subsequent research established that the disease is transferable by lymphocyte infusion. Transfer took place between 100-day-old estrogen-injected and 15-day-old naïve mice only when recipients were thymectomized at 3 days of age. Thus, a prerequisite for cyst formation is the absence of regulatory T cells. Their absence in donor mice was judged to be the result of an estrogen-induced increase in the thymus' vascular permeability, causing de facto circumvention of the final stages of regulatory T cell development. The human thymus has a similar vulnerability to steroid action during the fetal stage. We propose that in utero exposure to excessive levels of steroids such as estrogen has a long-term effect on the ability of the thymus to produce regulatory T cells. In female offspring this can lead to PCOS.

Antenatal exposure to DES: lessons learned...future concerns

The short- and long-term effects of the widespread use of diethylstilbestrol (DES) over 3 decades have become a distant memory for many clinicians. Others are too young to remember the flurry of activity in the early 1970s on the part of many medical centers to identify the offspring of women who were prescribed DES during their pregnancies. This medication was given in an attempt to prevent multiple pregnancy-related problems such as miscarriage, premature birth, and abnormal bleeding. The recognition of the association of DES with an increased incidence of cervical and vaginal cancers in very young women led the Food and Drug Administration to ban its use during pregnancy in 1971. Other pregnancy-related problems for the daughters and genitourinary tract changes in the sons did not become apparent until years later. Ongoing follow-up of these offspring has raised concerns for their future as well as their mothers' future. Clinicians need to be up-to-date with current knowledge regarding risks for cancer and other health-related issues.

Secondary sex ratio among women exposed to diethylstilbestrol in utero

BACKGROUND

Diethylstilbestrol (DES), a synthetic estrogen widely prescribed to pregnant women during the mid-1900s, is a potent endocrine disruptor. Previous studies have suggested an association between endocrine-disrupting compounds and secondary sex ratio.

METHODS

Data were provided by women participating in the National Cancer Institute (NCI) DES Combined Cohort Study. We used generalized estimating equations to estimate odds ratios (ORs) and 95% confidence intervals (CIs) for the relation of in utero DES exposure to sex ratio (proportion of male births). Models were adjusted for maternal age, child's birth year, parity, and cohort, and accounted for clustering among women with multiple pregnancies.

RESULTS

The OR for having a male birth comparing DES-exposed to unexposed women was 1.05 (95% CI, 0.95-1.17). For exposed women with complete data on cumulative DES dose and timing (33%), those first exposed to DES earlier in gestation and to higher doses had the highest odds of having a male birth. The ORs were 0.91 (95% C, 0.65-1.27) for first exposure at > or = 13 weeks gestation to < 5 g DES; 0.95 (95% CI, 0.71-1.27) for first exposure at > or = 13 weeks to > or = 5 g; 1.16 (95% CI, 0.96-1.41) for first exposure at < 13 weeks to < 5 g; and 1.24 (95% CI, 1.04-1.48) for first exposure at < 13 weeks to > or = 5 g compared with no exposure. Results did not vary appreciably by maternal age, parity, cohort, or infertility history.

CONCLUSIONS

Overall, no association was observed between in utero DES exposure and secondary sex ratio, but a significant increase in the proportion of male births was found among women first exposed to DES earlier in gestation and to a higher cumulative dose.

[Uterine malformations and reproduction]

The frequency of uterine malformations impacting on reproduction seems not easy to determine. Their diagnosis needs specific explorations (hysterosalpingography, hysteroscopy and laparoscopy). Spontaneous fertility may be impaired in relation with uterine abnormalities. All these abnormalities could have repercussions on the conceptus' evolution like abortion, preterm delivery, vascular pathologies and intrauterine growth restriction. Ovarian function does not seem to be altered even though implantation rate could be reduced. Surgery, especially endoscopy, allows a precise diagnosis, a prognostic evaluation and an adequate treatment improving conception rates and pregnancy outcome. Mainly hysteroscopic septum section and expansion metroplasty were regularly described.

Human type 2 17 beta-hydroxysteroid dehydrogenase mRNA and protein distribution in placental villi at mid and term pregnancy

BACKGROUND

During human pregnancy, the placental villi produces high amounts of estradiol. This steroid is secreted by the syncytium, which is directly in contact with maternal blood. Estradiol has to cross placental foetal vessels to reach foetal circulation. The enzyme 17beta-hydroxysteroid dehydrogenase type 2 (17beta-HSD2) was detected in placental endothelial cells of foetal vessels inside the villi. This enzyme catalyzes the conversion of estradiol to estrone, and of testosterone to androstenedione. It was proposed that estradiol level into foetal circulation could be regulated by 17beta-HSD2.

METHODS

We obtained placentas from 10 to 26 6/7 weeks of pregnancy from women undergoing voluntary termination of pregnancy, term placentas were collected after normal spontaneous vaginal deliveries. We quantified 17beta-HSD2 mRNA levels in mid-gestation and term human placenta by RT-QPCR. We produced a new anti-17beta-HSD2 antibody to study its spatio-temporal expression by immunohistochemistry. We also compared steroid levels (testosterone, estrone and estradiol) and 17beta-HSD2 mRNA and protein levels between term placenta and endometrium.

RESULTS

High 17beta-HSD2 mRNA and protein levels were found in both mid-gestation and term placentas. However, we showed that 17beta-HSD2 mRNA levels increase by 2.27 fold between mid-gestation and term. This period coincides with a transitional phase in the development of the villous vasculature. In mid-gestation placenta, high levels of 17beta-HSD2 were found in mesenchymal villi and immature intermediate villi, more precisely in endothelial cells of the stromal channel. At term, high levels of 17beta-HSD2 were found in the numerous sinusoidal capillaries of terminal villi. 17beta-HSD2 mRNA and protein levels in term placentas were respectively 25.4 fold and 30 to 60 fold higher than in the endometrium. Steroid levels were also significantly higher in term placenta than in the endometrium.

CONCLUSION

The spatial and temporal expression of 17beta-HSD2 in the placenta during pregnancy and the comparison of 17beta-HSD2 expression and steroid levels between placental villi and endometrium are compatible with a role in the modulation of active and inactive forms of estrogens. Our observations strongly support the hypothesis that 17beta-HSD2 acts as a barrier decreasing estradiol secretion rates in the foetal circulation.

Preeclampsia Risk in Women Exposed in Utero to Diethylstilbestrol

OBJECTIVE

To assess whether preeclampsia risk is elevated in pregnancies of diethylstilbestrol (DES)-exposed daughters.

METHODS

This study used data from the National Cancer Institute DES Combined Cohorts Follow-up Study. A total of 285 preeclampsia cases (210 exposed and 75 unexposed) occurred in 7,313 live births (4,759 DES exposed and 2,554 unexposed). Poisson regression analysis estimated relative risks and 95% confidence intervals (CI) for preeclampsia adjusted for age at the index pregnancy, parity, education, smoking, body mass index, year of diagnosis, and cohort.

RESULTS

In utero DES exposure was associated with nearly a 50% elevation in preeclampsia risk. Adjustment for preeclampsia risk factors attenuated the relative risk slightly (1.42, 95% CI 1.04-1.94). The excess risk with DES was concentrated among women who developed preeclampsia in their first pregnancies (relative risk 1.81, 95% CI 1.17-2.79), who were exposed before 15 weeks of gestation (relative risk 1.57, 95% CI 1.11-2.23), and who were treated with magnesium sulfate (relative risk 2.10, 95% CI 0.82-5.42). Among DES-exposed women who had a prior hysterosalpingogram, preeclampsia prevalence was higher in those with uterine abnormalities (12.4%) than in those without (7.7%).

CONCLUSION

These data suggest that in utero exposure to DES is associated with a slightly elevated risk of preeclampsia, and that one possible biological mechanism involves uterine abnormalities.

Age at natural menopause in women exposed to diethylstilbestrol in utero

Age at natural menopause is related to several health outcomes, including cardiovascular disease and overall mortality. Age at menopause may be influenced by the number of follicles formed during gestation, suggesting that prenatal factors could influence menopausal age. Diethylstilbestrol (DES), a nonsteroidal estrogen widely prescribed during the 1950s and 1960s, is related to reproductive tract abnormalities, infertility, and vaginal cancer in prenatally exposed daughters but has not been studied in relation to age at menopause. The authors used survival analyses to estimate the risk of natural menopause in 4,210 DES-exposed versus 1,829 unexposed US women based on responses to questionnaires mailed in 1994, 1997, and 2001. DES-exposed women were 50% more likely to experience natural menopause at any given age (hazard ratio = 1.49, 95% confidence interval: 1.28, 1.74). Among women for whom dose information was complete, there were dose-response effects, with a greater than twofold risk for those exposed to >10,000 mg. The causal mechanism for earlier menopause may be related to a smaller follicle pool, more rapid follicle depletion, or changes in hormone synthesis and metabolism in DES-exposed daughters. Age at menopause has been related, albeit inconsistently, to several exposures, but, to the authors' knowledge, this is the first study to suggest that a prenatal exposure may influence reproductive lifespan.

Menstrual and reproductive characteristics of women whose mothers were exposed in utero to diethylstilbestrol (DES)

BACKGROUND

In women, prenatal exposure to diethylstilbestrol (DES) is associated with adult reproductive dysfunction. The mouse model, which replicates many DES outcomes, suggests DES causes epigenetic alterations, which are transmissable to daughters of prenatally exposed animals. We report menstrual and reproductive characteristics in a unique cohort comprising daughters of women exposed prenatally to DES.

METHODS

Menstrual and reproductive outcomes and baseline characteristics were assessed by mailed questionnaire in 793 women whose mothers had documented information regarding in utero DES exposure.

RESULTS

Mean age at menarche was 12.6 years in both groups, but daughters of the exposed women attained menstrual regularization later (mean age of 16.2 years vs. 15.8 years; P = 0.05), and were more likely to report irregular menstrual periods, odds ratio (OR) = 1.54 [95% confidence interval (95% CI 1.02-2.32)]. A possible association between mothers' DES exposure and daughters' infertility was compatible with chance, age, and cohort adjusted OR = 2.19 (95% CI 0.95-5.07). We found limited evidence that daughters of the exposed had more adverse reproductive outcomes, but daughters of exposed women had fewer live births (1.6) than the unexposed (1.9) (P = 0.005).

CONCLUSIONS

The high risk of reproductive dysfunction seen in women exposed to DES in utero was not observed in their daughters, but most women in our cohort have not yet attempted to start their families, and further follow-up is needed to assess their reproductive health. Our findings of menstrual irregularity and possible infertility in third-generation women are preliminary but compatible with speculation regarding transgenerational transmission of DES-related epigenetic alterations in humans.

Reproductive outcomes in men with prenatal exposure to diethylstilbestrol

OBJECTIVE

To examine prenatal diethylstilbestrol (DES) exposure in relation to male reproductive outcomes.

DESIGN

Prospective observational study.

SETTING

Participants were identified through record review, clinical trial participation, or an obstetrics clinic.

PATIENT(S)

A total of 1,085 DES-exposed and 1,047 unexposed men.

INTERVENTION(S)

Participants were exposed prenatally to DES through the mother's obstetrics care or clinical trial participation.

MAIN OUTCOME MEASURE(S)

Infertility; never fathering a pregnancy or live birth; number of pregnancies or live births fathered.

RESULT(S)

We found little evidence that prenatal DES exposure affects the likelihood of never fathering a pregnancy or live birth, or influences the mean number of fathered pregnancies or live births. Our data suggest that DES-exposed men are slightly more likely to experience infertility (relative risk [RR] = 1.3, 95% confidence interval [CI] = 1.0-1.6). The DES dose and gestational timing did not influence infertility or the number of pregnancies or live births fathered, but results were inconsistent for dose effects on the likelihood of never fathering a pregnancy or a live birth.

CONCLUSION(S)

Prenatal DES exposure may be associated with a slightly increased risk of having an infertility experience, but does not increase the likelihood of never fathering a pregnancy or a live birth, or the number of pregnancies or live births fathered.

The history of DES, lessons to be learned

Since the 1940s, diaethylstilbestrol (DES) has been used by millions of pregnant women to prevent miscarriages and many other disorders in pregnancy. In 1971, it became clear that this apparently innocent treatment proved to be a time bomb for the infants exposed to DES during the first trimester of pregnancy. DES is now associated with an increased risk of breast cancer, clear cell adenocarcinoma (CCAC) of the vagina and cervix, and reproductive anomalies. This article summarises the potential long-term health implications of DES on the mother, DES daughters and DES sons, and the possible side effects on the third generation. Health care professionals have to know the history of DES to prevent future disasters with drugs prescribed.