FSH dose is negatively correlated with number of oocytes retrieved: analysis of a data set with ~650,000 ART cycles that previously identified an inverse relationship between FSH dose and live birth rate

PURPOSE

To evaluate whether total FSH dose was negatively correlated with number of oocytes retrieved in a large data set where previously, a negative correlation between FSH dose and live birth rate was identified.

METHODS

Data from 650,637 fresh autologous in vitro fertilization (IVF) cycles reported to the Society for Assisted Reproductive Technology between 2004 and 2012 were included. Logistic regression analysis was performed to determine if the relationship between total FSH dose used during ART with number of oocytes retrieved was impacted by the patient's health prognosis, age, BMI, ovarian stimulation protocol, or infertility diagnosis.

RESULTS

The number of oocytes retrieved was negatively correlated with FSH dose (P < 0.0001). Regardless of patient prognosis, age, BMI, ovarian stimulation protocol, and infertility diagnosis, the highest number of oocytes retrieved was in the 1001-2000 IU FSH group, and was 36-51% lower in the > 5000 IU compared with the optimal, 1001-2000 IU, FSH groups. Overall, ~80% of patients received FSH doses outside of the optimal FSH dose. Moreover, 61% of good prognosis patients (excludes individuals likely prescribed higher FSH doses) received doses exceeding the optimal dose range.

CONCLUSION

The inverse relationship between FSH dose and the number of oocytes retrieved independent of patient age or health implies that excessive FSH doses during ART may be detrimental to oocyte retrieval.

ARID1A Mutations Promote P300-Dependent Endometrial Invasion through Super-Enhancer Hyperacetylation

Endometriosis affects 1 in 10 women and is characterized by the presence of abnormal endometrium at ectopic sites. ARID1A mutations are observed in deeply invasive forms of the disease, often correlating with malignancy. To identify epigenetic dependencies driving invasion, we use an unbiased approach to map chromatin state transitions accompanying ARID1A loss in the endometrium. We show that super-enhancers marked by high H3K27 acetylation are strongly associated with ARID1A binding. ARID1A loss leads to H3K27 hyperacetylation and increased chromatin accessibility and enhancer RNA transcription at super-enhancers, but not typical enhancers, indicating that ARID1A normally prevents super-enhancer hyperactivation. ARID1A co-localizes with P300 at super-enhancers, and genetic or pharmacological inhibition of P300 in ARID1A mutant endometrial epithelia suppresses invasion and induces anoikis through the rescue of super-enhancer hyperacetylation. Among hyperactivated super-enhancers, SERPINE1 (PAI-1) is identified as an essential target gene driving ARID1A mutant endometrial invasion. Broadly, our findings provide rationale for therapeutic strategies targeting super-enhancers in ARID1A mutant endometrium.

Loss of HDAC3 results in nonreceptive endometrium and female infertility

Endometriosis is a disease in which tissue that normally grows inside the uterus grows outside the uterus and causes chronic pelvic pain and infertility. However, the exact mechanisms of the pathogenesis of endometriosis-associated infertility are unknown. Epigenetic dysregulation has recently been implicated in infertility. Here, we report a reduction of histone deacetylase 3 (HDAC3) protein amounts in eutopic endometrium of infertile women with endometriosis compared to a control group. To investigate the effect of HDAC3 loss in the uterus, we generated mice with conditional ablation of Hdac3 in progesterone receptor (PGR)-positive cells (Pgr^cre/+Hdac3^f/f ; Hdac3^d/d ). Loss of Hdac3 in the uterus of mice results in infertility due to implantation failure and decidualization defect. Expression microarray and ChIP-seq analyses identified COL1A1 and COL1A2 as direct targets of HDAC3 in both mice and humans. Reduction of HDAC3 abrogated decidualization in a primary culture of human endometrial stromal cells (hESCs) similar to that observed in infertile patients with endometriosis. Whereas attenuation of HDAC3 resulted in p300 recruitment to Col1a1 and Col1a2 genes in the uterus of mice as well as hESCs, inhibition of p300 permitted hESCs to undergo decidualization. Collectively, we found attenuation of HDAC3 and overexpression of collagen type I in the eutopic endometrium of infertile patients with endometriosis. HDAC3 loss caused a defect of decidualization through the aberrant transcriptional activation of Col1a1 and Col1a2 genes in mice and COL1A1 and COL1A2 genes in humans. Our results suggest that HDAC3 is critical for endometrial receptivity and decidualization.

Intrauterine human chorionic gonadotropin infusion in oocyte donors promotes endometrial synchrony and induction of early decidual markers for stromal survival: a randomized clinical trial

STUDY QUESTION

Does a single intrauterine infusion of human chorionic gonadotropin (hCG) at the time corresponding to a Day 3 embryo transfer in oocyte donors induce favorable molecular changes in the endometrium for embryo implantation?

SUMMARY ANSWER

Intrauterine hCG was associated with endometrial synchronization between endometrial glands and stroma following ovarian stimulation and the induction of early decidual markers associated with stromal cell survival.

WHAT IS KNOWN ALREADY

The clinical potential for increasing IVF success rates using an intrauterine hCG infusion prior to embryo transfer remains unclear based on previously reported positive and non-significant findings. However, infusion of CG in the non-human primate increases the expression of pro-survival early decidual markers important for endometrial receptivity, including α-smooth muscle actin (α-SMA) and NOTCH1.

STUDY DESIGN, SIZE, DURATION

Oocyte donors (n=15) were randomly assigned to receive an intrauterine infusion of 500 IU hCG (n=7) or embryo culture media vehicle (n=8) 3 days following oocyte retrieval during their donor stimulation cycle. Endometrial biopsies were performed 2 days later, followed by either RNA isolation or tissue fixation in formalin and paraffin embedding.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Reverse transcription of total RNA from endometrial biopsies generated cDNA, which was used for analysis in the endometrial receptivity array (ERA; n = 5/group) or quantitative RT-PCR to determine relative expression of ESR1, PGR, C3 and NOTCH1. Tissue sections were stained with hematoxylin and eosin followed by blinded staging analysis for dating of endometrial glands and stroma. Immunostaining for ESR1, PGR, α-SMA, C3 and NOTCH1 was performed to determine their tissue localization.

MAIN RESULTS AND THE ROLE OF CHANCE

Intrauterine hCG infusion was associated with endometrial synchrony and reprograming of stromal development following ovarian stimulation. ESR1 and PGR were significantly elevated in the endometrium of hCG-treated patients, consistent with earlier staging. The ERA did not predict an overall positive impact of intrauterine hCG on endometrial receptivity. However, ACTA2, encoding α-SMA was significantly increased in response to intrauterine hCG. Similar to the hCG-treated non-human primate, sub-epithelial and peri-vascular α-SMA expression was induced in women following hCG infusion. Other known targets of hCG in the baboon were also found to be increased, including C3 and NOTCH1, which have known roles in endometrial receptivity.

LIMITATIONS, REASONS FOR CAUTION

This study differs from our previous work in the hCG-treated non-human primate along with clinical studies in infertile patients. Specifically, we performed a single intrauterine infusion in oocyte donors instead of either continuous hCG via an osmotic mini-pump in the baboon or infusion followed by blastocyst-derived hCG in infertile women undergoing embryo transfer. Therefore, the full impact of intrauterine hCG in promoting endometrial receptivity may not have been evident.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest a potential clinical benefit for intrauterine hCG prior to embryo transfer on Day 3 in counteracting endometrial dyssynchrony from ovarian stimulation and promoting expression of markers important for stromal survival. Finally, there were no obvious negative effects of intrauterine hCG treatment.

STUDY FUNDING/COMPETING INTERESTS

Funding for this work was provided by NICHD R01 HD042280 (A.T.F.) and NICHD F30 HD082951 (M.R.S.). C.S. and P.D.-G are co-inventors of the patented ERA, which is owned by IGENOMIX SL and was used in this study, and C.S. is a shareholder in IGENOMIX SL. M.R.-A. is employed by IGENOMIX SL. No other authors have any conflicts of interest to report.

TRIAL REGISTRATION NUMBER

This study was registered with ClinicalTrials.gov (NCT01786252).

TRIAL REGISTRATION DATE

5 February 2013.

DATE OF FIRST PATIENT'S ENROLLMENT

10 May 2013.

Assisted reproductive technology use and outcomes among women with a history of cancer

STUDY QUESTION

How do the assisted reproductive technology (ART) outcomes of women presenting for ART after cancer diagnosis compare to women without cancer?

SUMMARY ANSWER

The likelihood of a live birth after ART among women with prior cancer using autologous oocytes is reduced and varies by cancer diagnosis but is similar to women without cancer when donor oocytes are used.

WHAT IS KNOWN ALREADY

Premenopausal patients faced with a cancer diagnosis frequently present for fertility preservation.

STUDY DESIGN, SIZE, DURATION

Population-based cohort study of women treated with ART in NY, TX and IL, USA.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Women with their first ART treatment between 2004 and 2009 were identified from the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database and linked to their respective State Cancer Registries based on name, date of birth and social security number. Years were rounded, i.e. year 1 = 6-18 months before treatment. This study used reports of cancer from 5 years, 6 months prior to treatment until 6 months after first ART treatment. Women who only presented for embryo banking were omitted from the analysis. The likelihood of pregnancy and of live birth with ART using autologous oocytes was modeled using logistic regression, with women without prior cancer as the reference group, adjusted for woman's age, parity, cumulative FSH dosage, infertility diagnosis, number of diagnoses, number of ART cycles, State of residency and year of ART treatment. Results of the modeling are reported as adjusted odds ratios (AORs) and (95% confidence intervals).

MAIN RESULTS AND THE ROLE OF CHANCE

The study population included 53 426 women; 441 women were diagnosed with cancer within 5 years prior to ART cycle start. Mean (±SD) age at cancer diagnosis was 33.4 ± 5.7 years; age at start of ART treatment was 34.9 ± 5.8 for women with cancer compared with 35.3 ± 5.3 years for women without cancer (P = 0.03). Live birth rates among women using autologous oocytes differed substantially by cancer status (47.7% without cancer versus 24.7% with cancer, P < 0.0001), and cancer diagnosis (ranging from 53.5% for melanoma to 14.3% for breast cancer, P < 0.0001. The live birth rates among women using donor oocytes did not vary significantly by cancer status (60.4% for women with any cancer versus 64.5% for women without cancer), or by cancer diagnosis (ranging from 57.9% for breast cancer to 63.6% for endocrine cancer). Women with breast cancer make up about one-third of all cancers in this cohort. Among women with breast cancer, 2.8% of the 106 women who underwent ART within 6 months of being diagnosed with cancer used donor oocytes compared with 34.8% of the 46 women who received ART treatment a longer time after being diagnosed with cancer (P < 0.0001). We conjecture that the former group were either unaware that they had cancer or decided to undergo ART therapy prior to cancer treatment. However, their live birth rate was only 11.7% compared with 28.8%, the overall live birth rate for all women with cancer using autologous oocytes (P < 0.0001). The live birth rate for women diagnosed with breast cancer more than 6 months before ART (23.3%) did not differ significantly from the overall live birth rate for cancer (P = 0.49). If this difference is substantiated by a larger study, it would indicate a negative effect of severe recent illness itself on ART success, rather than the poor outcome being only related to the destructive effects of chemotherapies on ovarian follicles. Alternatively, because of the short time difference between cancer diagnosis and ART treatment, these pre-existing cancers may have been detected due to the increased medical surveillance during ART therapy. In women who only used autologous oocytes, women with prior cancers were significantly less likely to become pregnant and to have a live birth than those without cancer (adjusted odds ratio (AOR): 0.34, [95% confidence interval (CI): 0.27, 0.42] and 0.36 [0.28, 0.46], respectively). This was also evident with specific cancer diagnoses: breast cancer (0.20 [0.13, 0.32] and 0.19 [0.11, 0.30], respectively), cervical cancer (0.36 [0.15, 0.87] and 0.33 [0.13, 0.84], respectively) and all female genital cancers (0.49 [0.27, 0.87] and 0.47 [0.25, 0.86], respectively). Of note, among women with cancer who became pregnant, their likelihood of having a live birth did not differ significantly from women without cancer (85.8 versus 86.7% for women using autologous oocytes, and 85.3 versus 86.9% for women using donor oocytes).

LIMITATIONS, REASONS FOR CAUTION

Women may not have been residents of the individual States for the entire 5-year pre-ART period, and therefore some cancers may not have been identified through this linkage. As a result, the actual observed number of cancers may be an underestimate. In addition, the overall prevalence is low due to the age distributions. Also, because we restricted the pre-ART period to 5 years prior, we would not have identified women who were survivors of early childhood cancers (younger than age 13 years at cancer diagnosis), or who had ART more than 5 years after being diagnosed with cancer. Additional analyses are currently underway evaluating live birth outcomes after embryo banking among women with cancer prior to ART, cycles which were excluded from the analyses in this paper. Future studies are planned which will include more States, as well as linkages to vital records to obtain information on spontaneous conceptions and births, to further clarify some of the issues raised in this analysis.

WIDER IMPLICATIONS OF THE FINDINGS

Since the live birth rates using donor oocytes were not reduced in women with a prior cancer, but were reduced with autologous cycles, this suggests that factors acting in the pre- or peri-conceptional periods may be responsible for the decline.

STUDY FUNDING/COMPETING INTERESTS

The study was funded by grant R01 CA151973 from the National Cancer Institute, National Institutes of Health, USA. B.L. is a research consultant for the Society for Assisted Reproductive Technology. All other authors report no conflict of interest.

Cancer in women after assisted reproductive technology

OBJECTIVE

To evaluate the risk of cancer after assisted reproductive technology (ART) therapy.

DESIGN

Longitudinal cohort study.

SETTING

Not applicable.

PATIENT(S)

New York, Texas, and Illinois residents between 2004 and 2009, treated with ART, comprising cycles of 113,226 women, including 53,859 women without prior ART treatment, who were linked to their respective state cancer registries and whose cycles were reported to the Society for Assisted Reproductive Technology Clinic Outcomes Reporting System (SART CORS).

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Diagnosis of cancer, as reported to the state cancer registry; standardized incidence ratios (SIR) and their 95% confidence intervals, comparing the observed to expected cancer cases based on age-specific cancer rates in the general population of each state.

RESULT(S)

Among the cohort of women without prior ART therapy, hazard ratios (HR) and 95% confidence intervals (CI) were calculated for treatment parameters and reproductive history factors. The mean follow-up period was 4.87 years; among women without prior ART, 450 women developed 460 cancers. Women treated with ART had a statistically significantly lower risk for all cancers (for all women: SIR 0.78; CI, 0.73-0.83; women without prior ART: SIR 0.75; CI, 0.68-0.82), breast cancer, and all female genital cancers; a non-statistically-significant lower risk for endocrine and uterine cancer; and a non-statistically-significant higher risk for melanoma and ovarian cancer. Among women without prior ART, we found no statistically significant increased HR by parity, number of cycles, cumulative follicle-stimulating hormone dosage, or cycle outcome.

CONCLUSION(S)

Women initiating ART treatment have no greater risk for developing cancer after nearly 5 years of follow-up compared with the general population and with other women treated with ART.

ARID1A Is Essential for Endometrial Function during Early Pregnancy

AT-rich interactive domain 1A gene (ARID1A) loss is a frequent event in endometriosis-associated ovarian carcinomas. Endometriosis is a disease in which tissue that normally grows inside the uterus grows outside the uterus, and 50% of women with endometriosis are infertile. ARID1A protein levels were significantly lower in the eutopic endometrium of women with endometriosis compared to women without endometriosis. However, an understanding of the physiological effects of ARID1A loss remains quite poor, and the function of Arid1a in the female reproductive tract has remained elusive. In order to understand the role of Arid1a in the uterus, we have generated mice with conditional ablation of Arid1a in the PGR positive cells (Pgrcre/+Arid1af/f; Arid1ad/d). Ovarian function and uterine development of Arid1ad/d mice were normal. However, Arid1ad/d mice were sterile due to defective embryo implantation and decidualization. The epithelial proliferation was significantly increased in Arid1ad/d mice compared to control mice. Enhanced epithelial estrogen activity and reduced epithelial PGR expression, which impedes maturation of the receptive uterus, was observed in Arid1ad/d mice at the peri-implantation period. The microarray analysis revealed that ARID1A represses the genes related to cell cycle and DNA replication. We showed that ARID1A positively regulates Klf15 expression with PGR to inhibit epithelial proliferation at peri-implantation. Our results suggest that Arid1a has a critical role in modulating epithelial proliferation which is a critical requisite for fertility. This finding provides a new signaling pathway for steroid hormone regulation in female reproductive biology and furthers our understanding of the molecular mechanisms that underlie dysregulation of hormonal signaling in human reproductive disorders such as endometriosis.

Statewide Medicaid Enhanced Prenatal Care Programs and Infant Mortality

OBJECTIVE

To evaluate whether participation in a statewide enhanced prenatal and postnatal care program, the Maternal Infant Health Program (MIHP), reduced infant mortality risk.

METHODS

Data included birth and death records, Medicaid claims, and program participation. The study population consisted of Medicaid-insured singleton infants born between January 1, 2009, and December 31, 2012, in Michigan (n = 248 059). The MIHP participants were propensity score-matched with nonparticipants based on demographics, previous pregnancies, socioeconomic status, and chronic disease. Infant mortality, neonatal mortality, and postneonatal mortality analyses were presented by race.

RESULTS

Infants with any MIHP participation had reduced odds of death in the first year of life compared with matched nonparticipants (odds ratio [OR] 0.73, 95% confidence interval [CI] 0.63-0.84). Infant death odds were reduced both among black infants (OR 0.71, 95% CI 0.58-0.87) and infants of other races (OR 0.74, 95% CI 0.61-0.91). Neonatal death (OR 0.70, 95% CI 0.57-0.86) and postneonatal death odds (OR 0.78, 95% CI 0.63-0.96) were also reduced. Enrollment and screening in MIHP by the end of the second pregnancy trimester and at least 3 additional prenatal MIHP contacts reduced infant mortality odds further (OR 0.70, 95% CI 0.58-0.85; neonatal: OR 0.67, 95% CI 0.51-0.89; postneonatal: OR 0.74, 95% CI 0.56-0.98).

CONCLUSIONS

A state Medicaid-sponsored population-based home-visitation program can be a successful approach to reduce mortality risk in a diverse, disadvantaged population. A likely mechanism is the reduction in the risk of adverse birth outcomes, consistent with previous findings on the effects of the program.

Reduced expression of the epidermal growth factor signaling system in preeclampsia

INTRODUCTION

The epidermal growth factor (EGF) signaling system regulates trophoblast differentiation, and its disruption could contribute to perinatal disease. We hypothesized that this pathway is altered in preeclampsia, a disorder associated with trophoblast apoptosis and failure to invade and remodel the uterine spiral arteries.

METHODS

Six EGF family peptides and a truncated EGF receptor splice variant (p110/EGFR) were examined using immunohistochemistry in the trophoblast of placentas (N = 76) from women with preeclampsia, and compared to placentas from women of similar gestational age (GA) with preterm labor (PTL) or small for gestational age (SGA) fetuses, as well as normal term placentas. EGF, transforming growth factor-α (TGFA), and heparin-binding EGF-like growth factor (HBEGF) were evaluated using ELISA in maternal plasma from another 20 pregnancies with or without preeclampsia. Cell death was evaluated in the HTR-8/SVneo human cytotrophoblast cell line using TUNEL to evaluate the protective effects of EGF peptides.

RESULTS

Trophoblast HBEGF, TGFA, and EGF were significantly reduced in preeclampsia compared to PTL and SGA, while p110/EGFR accumulated significantly on the surface of the chorionic villi (p < 0.05). Plasma EGF levels were significantly decreased in preeclamptic patients, compared to non-preeclamptic patients (p < 0.05). HBEGF, EGF, TGFA, epiregulin, and betacellulin each blocked cytotrophoblast cell death in vitro (p < 0.05).

DISCUSSION

Three members of the EGF family are dysregulated in placentas with preeclampsia, whereas p110/EGFR, a potential EGF receptor antagonist, is overexpressed. These findings are consistent with the concept that disruption of the EGF signaling system contributes to aberrant trophoblast development associated with preeclampsia.

MTA1 and MTA3 Regulate HIF1a Expression in Hypoxia-Treated Human Trophoblast Cell Line HTR8/Svneo

Hypoxia plays an important role in placental trophoblast differentiation and function during early pregnancy. Hypoxia-inducible factor 1 alpha (HIF1a) is known to regulate cellular adaption to hypoxic conditions. However, our current understanding of the role of HIF1a in trophoblast physiology is far from complete. Metastasis Associated Protein 1 and 3 (MTA1 and MTA3) are components of the Nucleosome Remodeling and Deacetylase (NuRD) complex, a chromatin remodeling complex, and are highly expressed in term placental trophoblasts. However, the role of MTA1 and MTA3 in the hypoxic placental environment of early pregnancy is unknown. In the present study, we examined the association among MTA1, MTA3 and HIF1a expression under hypoxic conditions in trophoblasts both in vivo and in vitro. We first investigated the localization of MTA1 and MTA3 with HIF1a expression in the placental trophoblast of 1st trimester placenta via immunohistochemistry. Our data reveals that under physiologically hypoxic environment, MTA1 and MTA3 along with HIF1a are highly expressed by villous trophoblasts. Next, we investigated the effect of hypoxia on these genes in vitro using the first trimester-derived HTR8/SVneo cell line and observed up-regulation of MTA1 and MTA3 as well as HIF1a protein following hypoxia treatment. To investigate the direct effect of MTA1 and MTA3 upon HIF1a, we over-expressed MTA1 and MTA3 genes in HTR8/SVneo cells respectively and examined protein levels of HIF1a via Western blot as well as HIF1a target gene expression using a luciferase assay driven by a hypoxia-response element promoter (HRE-luciferase). We found that over-expressions of MTA1 and MTA3 up-regulate both HIF1a protein level and HRE-luciferase activity under hypoxic condition. In summary, both MTA1 and MTA3 are induced by hypoxia and up-regulate HIF1a expression and HIF1a target gene expression in trophoblasts. These data suggest that MTA1 and MTA3 play critical roles in trophoblast function and differentiation during early pregnancy.

β-Catenin activation contributes to the pathogenesis of adenomyosis through epithelial-mesenchymal transition

Adenomyosis is defined by the presence of endometrial glands and stroma within the myometrium. Despite its frequent occurrence, the precise aetiology and physiopathology of adenomyosis is still unknown. WNT/β-catenin signalling molecules are important and should be tightly regulated for uterine function. To investigate the role of β-catenin signalling in adenomyosis, the expression of β-catenin was examined. Nuclear and cytoplasmic β-catenin expression was significantly higher in epithelial cells of human adenomyosis compared to control endometrium. To determine whether constitutive activation of β-catenin in the murine uterus leads to development of adenomyosis, mice that expressed a dominant stabilized β-catenin in the uterus were used by crossing PR-Cre mice with Ctnnb1(f(ex3)/+) mice. Uteri of PR(cre) (/+) Ctnnb1(f(ex3)/+) mice displayed an abnormal irregular structure and highly active proliferation in the myometrium, and subsequently developed adenomyosis. Interestingly, the expression of E-cadherin was repressed in epithelial cells of PR(cre) (/+) Ctnnb1(f(ex3)/+) mice compared to control mice. Repression of E-cadherin is one of the hallmarks of epithelial-mesenchymal transition (EMT). The expression of SNAIL and ZEB1 was observed in some epithelial cells of the uterus in PR(cre) (/+) Ctnnb1(f(ex3)/+) mice but not in control mice. Vimentin and COUP-TFII, mesenchymal cell markers, were expressed in some epithelial cells of PR(cre) (/+) Ctnnb1(f(ex3)/+) mice. In human adenomyosis, the expression of E-cadherin was decreased in epithelial cells compared to control endometrium, while CD10, an endometrial stromal marker, was expressed in some epithelial cells of human adenomyosis. These results suggest that abnormal activation of β-catenin contributes to adenomyosis development through the induction of EMT.

Cumulative birth rates with linked assisted reproductive technology cycles

BACKGROUND

Live-birth rates after treatment with assisted reproductive technology have traditionally been reported on a per-cycle basis. For women receiving continued treatment, cumulative success rates are a more important measure.

METHODS

We linked data from cycles of assisted reproductive technology in the Society for Assisted Reproductive Technology Clinic Outcome Reporting System database for the period from 2004 through 2009 to individual women in order to estimate cumulative live-birth rates. Conservative estimates assumed that women who did not return for treatment would not have a live birth; optimal estimates assumed that these women would have live-birth rates similar to those for women continuing treatment.

RESULTS

The data were from 246,740 women, with 471,208 cycles and 140,859 live births. Live-birth rates declined with increasing maternal age and increasing cycle number with autologous, but not donor, oocytes. By the third cycle, the conservative and optimal estimates of live-birth rates with autologous oocytes had declined from 63.3% and 74.6%, respectively, for women younger than 31 years of age to 18.6% and 27.8% for those 41 or 42 years of age and to 6.6% and 11.3% for those 43 years of age or older. When donor oocytes were used, the rates were higher than 60% and 80%, respectively, for all ages. Rates were higher with blastocyst embryos (day of transfer, 5 or 6) than with cleavage embryos (day of transfer, 2 or 3). At the third cycle, the conservative and optimal estimates of cumulative live-birth rates were, respectively, 42.7% and 65.3% for transfer of cleavage embryos and 52.4% and 80.7% for transfer of blastocyst embryos when fresh autologous oocytes were used.

CONCLUSIONS

Our results indicate that live-birth rates approaching natural fecundity can be achieved by means of assisted reproductive technology when there are favorable patient and embryo characteristics. Live-birth rates among older women are lower than those among younger women when autologous oocytes are used but are similar to the rates among young women when donor oocytes are used. (Funded by the National Institutes of Health and the Society for Assisted Reproductive Technology.).

High throughput, cell type-specific analysis of key proteins in human endometrial biopsies of women from fertile and infertile couples

BACKGROUND

Although histological dating of endometrial biopsies provides little help for prediction or diagnosis of infertility, analysis of individual endometrial proteins, proteomic profiling and transcriptome analysis have suggested several biomarkers with altered expression arising from intrinsic abnormalities, inadequate stimulation by or in response to gonadal steroids or altered function due to systemic disorders. The objective of this study was to delineate the developmental dynamics of potentially important proteins in the secretory phase of the menstrual cycle, utilizing a collection of endometrial biopsies from women of fertile (n = 89) and infertile (n = 89) couples.

METHODS AND RESULTS

Progesterone receptor-B (PGR-B), leukemia inhibitory factor, glycodelin/progestagen-associated endometrial protein (PAEP), homeobox A10, heparin-binding EGF-like growth factor, calcitonin and chemokine ligand 14 (CXCL14) were measured using a high-throughput, quantitative immunohistochemical method. Significant cyclic and tissue-specific regulation was documented for each protein, as well as their dysregulation in women of infertile couples. Infertile patients demonstrated a delay early in the secretory phase in the decline of PGR-B (P < 0.05) and premature mid-secretory increases in PAEP (P < 0.05) and CXCL14 (P < 0.05), suggesting that the implantation interval could be closing early. Correlation analysis identified potential interactions among certain proteins that were disrupted by infertility.

CONCLUSIONS

This approach overcomes the limitations of a small sample number. Protein expression and localization provided important insights into the potential roles of these proteins in normal and pathological development of the endometrium that is not attainable from transcriptome analysis, establishing a basis for biomarker, diagnostic and targeted drug development for women with infertility.

Function-specific intracellular signaling pathways downstream of heparin-binding EGF-like growth factor utilized by human trophoblasts

Heparin-binding EGF-like growth factor (HBEGF) is expressed by trophoblast cells throughout gestation. First-trimester cytotrophoblast cells are protected from hypoxia-induced apoptosis because of the accumulation of HBEGF through a posttranscriptional autocrine mechanism. Exogenous application of HBEGF is cytoprotective in a hypoxia/reoxygenation (H/R) injury model and initiates trophoblast extravillous differentiation to an invasive phenotype. The downstream signaling pathways induced by HBEGF that mediate these various cellular activities were identified using two human first-trimester cytotrophoblast cell lines, HTR-8/SVneo and SW.71, with similar results. Recombinant HBEGF (1 nM) induced transient phosphorylation of MAPK3/1 (ERK), MAPK14 (p38), and AKT within 15 min and JNK after 1-2 h. To determine which downstream pathways regulate the various functions of HBEGF, cells were treated with specific inhibitors of the ERK upstream regulator MEK (U0126), the AKT upstream regulator phosphoinositide-3 (PI3)-kinase (LY294002), MAPK14 (SB203580), and JNK (SP600125), as well as with inactive structural analogues. Only SB203580 specifically prevented HBEGF-mediated rescue during H/R, while each inhibitor attenuated HBEGF-stimulated cell migration. Accumulation of HBEGF at reduced oxygen was blocked only by a combination of U0126, SB203580, and SP600125. We conclude that HBEGF advances trophoblast extravillous differentiation through coordinate activation of PI3 kinase, ERK, MAPK14, and JNK, while only MAPK14 is required for its antiapoptotic activity. Additionally, hypoxia induces an autocrine increase in HBEGF protein levels through MAPK14, JNK or ERK. These experiments reveal a complexity of the intracellular signaling circuitry that regulates trophoblast functions critical for implantation and placentation.

Diverse functions of HBEGF during pregnancy

The establishment of pregnancy requires an intimate physical interaction and a molecular dialogue between the conceptus and the maternal reproductive tract that commences at implantation and continues until the placenta is formed and fully functional. Failure of the regulatory processes that ensure the fidelity of this relationship can precipitate a catastrophic pregnancy loss. One of the earliest identified molecular mediators of blastocyst implantation is heparin-binding epidermal growth factor (EGF)-like growth factor (HBEGF), which signals between the endometrium and implanting trophoblast cells to synchronize their corresponding developmental programs. HBEGF expression by trophoblast cells of the developing placenta appears to regulate extravillous differentiation and provide cytoprotection in a sometimes-hostile environment. This versatile member of the EGF signaling system will be examined in light of its associations with key events during early pregnancy.

Diminished survival of human cytotrophoblast cells exposed to hypoxia/reoxygenation injury and associated reduction of heparin-binding epidermal growth factor-like growth factor

OBJECTIVE

The antiapoptotic action of heparin-binding epidermal growth factor (HBEGF)-like growth factor and its regulation by O(2) constitutes a key factor for trophoblast survival. The hypothesis that cytotrophoblast survival is compromised by exposure to hypoxia-reoxygenation (H/R) injury, which may contribute to preeclampsia and some missed abortions, prompted us to investigate HBEGF regulation and its role as a survival factor during H/R in cytotrophoblast cells.

STUDY DESIGN

A transformed human first-trimester cytotrophoblast cell line HTR-8/SVneo was exposed to H/R (2% O(2) followed by 20% O(2)) and assessed for HBEGF expression and cell death.

RESULTS

Cellular HBEGF declined significantly within 30 minutes of reoxygenation after culture at 2% O(2). H/R significantly reduced proliferation and increased cell death when compared with trophoblast cells cultured continuously at 2% or 20% O(2). Restoration of cell survival also was achieved by adding recombinant HBEGF during reoxygenation. HBEGF inhibited apoptosis through its binding to either human epidermal receptor (HER)-1 or HER4, its cognate receptors.

CONCLUSION

These results provide evidence that cytotrophoblast exposure to H/R induces apoptosis and decreased cell proliferation. HBEGF accumulation is diminished under these conditions, whereas restoration of HBEGF signaling improves trophoblast survival.

Human trophoblast survival at low oxygen concentrations requires metalloproteinase-mediated shedding of heparin-binding EGF-like growth factor

Heparin-binding EGF-like growth factor (HBEGF), which is expressed in the placenta during normal pregnancy, is down regulated in pre-eclampsia, a human pregnancy disorder associated with poor trophoblast differentiation and survival. This growth factor protects against apoptosis during stress, suggesting a role in trophoblast survival in the relatively low O(2) ( approximately 2%) environment of the first trimester conceptus. Using a well-characterized human first trimester cytotrophoblast cell line, we found that a 4-hour exposure to 2% O(2) upregulates HBEGF synthesis and secretion independently of an increase in its mRNA. Five other expressed members of the EGF family are largely unaffected. At 2% O(2), signaling via HER1 or HER4, known HBEGF receptors, is required for both HBEGF upregulation and protection against apoptosis. This positive-feedback loop is dependent on metalloproteinase-mediated cleavage and shedding of the HBEGF ectodomain. The restoration of trophoblast survival by the addition of soluble HBEGF in cultures exposed to low O(2) and metalloproteinase inhibitor suggests that the effects of HBEGF are mediated by autocrine/paracrine, rather than juxtacrine, signaling. Our results provide evidence that a post-transcriptional mechanism induced in trophoblasts by low O(2) rapidly amplifies HBEGF signaling to inhibit apoptosis. These findings have a high clinical significance, as the downregulation of HBEGF in pre-eclampsia is likely to be a contributing factor leading to the demise of trophoblasts.

Histamine enhances cytotrophoblast invasion by inducing intracellular calcium transients through the histamine type-1 receptor

Blastocyst implantation and placentation require molecular and cellular interactions between the uterine endometrium and blastocyst trophectoderm. Previous studies showed that histamine produced in the mouse uterine luminal epithelium interacts with trophoblast histamine type-2 receptors (H2) to initiate blastocyst implantation. However, it is unknown whether similar histamine activity is operative in humans. Using a human cell line (HTR-8/SVneo) derived from first-trimester cytotrophoblasts that expresses both histamine type-1 receptor (H1) and H2, we found that histamine promotes cytotrophoblast invasiveness specifically through activation of H1. Stimulation of H1 in human cytotrophoblasts by histamine induced intracellular Ca2+ (Ca(2+)i) transients by activating phospholipase C and the inositol trisphosphate pathway. The enhanced invasion induced by histamine was blocked by pretreatment with H1 antagonist or by chelation of Ca(2+)i. These findings suggest possible differences between rodents and humans in histamine signaling to the trophoblast.

Effects of cornual catheterization on uterotubal histology and function

OBJECTIVE

To assess histologic damage and functional impairment following coaxial tubal catheterization.

DESIGN

Prospective randomized controlled study.

SETTING

Research laboratory.

PATIENT(S)

Ninety-two female New Zealand rabbits.

INTERVENTION(S)

Tubal cannulation and mating.

MAIN OUTCOME MEASURE(S)

Rabbits randomized for placement of unilateral catheter and guide wire (group 1), unilateral catheter and guide wire plus falloposcope (group 2), and catheterization as in group 1 or 2 but using a cage catheter (groups 3 and 4, respectively). A fifth group consisted of rabbits with tubal perforations. Rabbits were killed at 2 or 4 weeks after catheterization or after mating. The sixth group consisted of only control rabbits.

RESULT(S)

Only one catheterized tube in groups 1 and 3 showed inflammation, fibrosis, or edema. None of the tubes manifested ciliary loss. Serosal tubal adhesions were identified in two tubes in group 1, in one in group 3, in three tubes in group 5, and one in the control group. The nidation index in control and nonperforated catheterized tubes ranged from 72%-95% (not significant). Nidation index in tubes unintentionally perforated was 81%.

CONCLUSION(S)

Catheterization of the uterotubal junction and fallopian tube in rabbits does not cause long-term tubal damage or impair tubal function.

Effects of chronic hyperandrogenism and/or administered central nervous system insulin on ovarian manifestation and gonadotropin and steroid secretion

OBJECTIVE

Polycystic ovarian syndrome is characterized by hyperandrogenism and insulin resistance. We studied the effects of central hyperinsulinemia and peripheral hyperandrogenism on gonadotropin secretion, steroid secretion, and ovarian histology in female rats.

DESIGN

Experimental in vivo animal study.

SETTING

University research center.

ANIMAL(S)

250-300 g female Wistar rats.

INTERVENTION(S)

Insertion of testosterone pellets and/or administration of intracerebroventricular (ICV) insulin.

MAIN OUTCOME MEASURE(S)

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels before and after GnRH administration; testosterone, insulin, and glucose levels; and ovarian histology.

RESULT(S)

Compared with control, rats with testosterone implant had a lower LH and higher FSH while rats with testosterone plus insulin had a higher FSH. Intracerebroventricular (ICV) insulin alone increased LH in response to GnRH. Ovarian histology indicated that testosterone-implanted rats had larger ovaries and an increased number of cystic follicles >50 microm as well as substantial theca enlargement. The administration of testosterone did not alter serum insulin, and ICV insulin did not increase testosterone levels.

CONCLUSION(S)

We suggest that ICV insulin acts either directly or indirectly to increase the LH responsiveness to GnRH. ICV insulin arrested the maturation of follicles leading to an increase in the number of small follicles. Peripheral androgens stimulated theca enlargement with cystic follicles. The combination of ICV insulin and peripheral androgens attenuated ovarian histologic changes and gonadotropin secretion. Thus, central hyperinsulinemia and peripheral hyperandrogenism may play a role in gonadotropin secretion as well as ovarian morphology.

Heparin-binding EGF-like growth factor regulates human extravillous cytotrophoblast development during conversion to the invasive phenotype

Cytotrophoblasts of the anchoring villi convert during human placentation from a transporting epithelium to an invasive, extravillous phenotype that expresses a distinct repertoire of adhesion molecules. Developing extravillous trophoblasts accumulate heparin-binding EGF-like growth factor (HB-EGF), a multifunctional cytokine, which binds HER1 and HER4 of the human EGF receptor (HER/ErbB) family. HB-EGF is downregulated in placentae of women with preeclampsia, a disorder associated with deficient trophoblast invasion, raising important questions about its physiological impact on cytotrophoblasts. Addition of HB-EGF during explant culture of first-trimester chorionic villi enhanced extravillous trophoblast differentiation and invasive activity. Using a first-trimester human cytotrophoblast line, the potential for autocrine and paracrine regulation of the developing trophoblast was established based on the expression of all four HER isoforms, as well as HB-EGF and related growth factors. HB-EGF did not alter proliferation, but initiated extravillous differentiation, with decreased alpha6 integrin expression, increased alpha1, and elevated cell migration. Function-blocking antibodies against EGF family members reduced basal cell motility and antibody inhibition of either HER1 or HER4 ligation prevented HB-EGF-induced integrin switching. We conclude that HER-mediated autocrine and paracrine signaling by HB-EGF or other EGF family members induces cytotrophoblast differentiation to an invasive phenotype.

Elevated early follicular gonadotropin levels in women with unexplained infertility do not provide evidence for disordered gonadotropin-releasing hormone secretion as assessed by luteinizing hormone pulse characteristics

OBJECTIVE

To determine whether women with rigorously defined unexplained infertility demonstrated altered GnRH secretion, as reflected by serum LH secretion patterns.

DESIGN

Prospective observational study.

SETTING

National Center for Infertility Research at Michigan.

PATIENT(S)

Nine women with rigorously defined unexplained infertility and 11 healthy, parous age-matched control women.Gonadotropin-releasing hormone (25 ng/kg) as a bolus injection.

MAIN OUTCOME MEASURE(S)

Daytime pulse patterns of LH secretion measured every 10 minutes; mean serum concentrations of LH, FSH, E(2), P, PRL, and cortisol; and response to a physiologic dose of GnRH in the early follicular, late follicular, mid-luteal, and late luteal phases of the same menstrual cycle.

RESULT(S)

Serum LH pulse frequency and pulse amplitude and LH secretion in response to a physiologic bolus of GnRH were not significantly different in unexplained infertility patients at any phase of the cycle. Luteinizing hormone pulse frequency and amplitude, as well as response to GnRH, varied significantly across the cycle. Mean early follicular serum LH and FSH concentrations were significantly higher in unexplained infertility patients than in fertile control subjects (LH: 5.31 +/-.51 vs. 4.03 +/-.33 [mIU/mL +/- SEM]; FSH: 5.81 +/-.63 vs. 3.80 +/-.45) but were not different at any other phase of the cycle.

CONCLUSION(S)

These data do not support the hypothesis that unexplained infertility is caused by an abnormality in pulsatile GnRH secretion or abnormal pituitary sensitivity to GnRH. However, the results are consistent with a difference in negative feedback from the ovary to the pituitary in unexplained infertility patients that is suggestive of diminished ovarian reserve.

Identification, molecular characterization, and tissue expression of OVCOV1

Key to the maternal-embryonic dialogue during early implantation are the extra embryonic trophoblast cells that play several critical roles including invasion of the maternal decidua. Cytotrophoblast proliferation and differentiation along an invasive pathway is regulated by a positive gradient of oxygen tension. We have employed transcript profiling to characterize the extra-embryonic tissues during early human implantation. We probed a cDNA library isolated from the ectoplacental cone region of stage 7.5 days post coitus mouse embryos with cDNA from hypoxic cultured human trophoblast cells. This identified the pattern of expression of a series of previously unknown genes that correlate to day 20 of human embryonic development. One EST was selected for further analysis since it is identical to the 1588-bp CGI-15 sequence assembled in silico. The human gene is organized into 10 exons 2063 bp in length. The open reading frame contains 1272 bp predicting protein composed of 365 amino acids. This gene is expressed in many tissues including those found in the reproductive tract. Its expression is regulated by oxygen tension and is unaffected by estradiol or progesterone treatment.

Pre-eclampsia and expression of heparin-binding EGF-like growth factor

BACKGROUND

Pre-eclampsia is a disorder of pregnancy associated with poor extravillous cytotrophoblast invasion and above-normal rates of apoptosis in the trophoblast. Heparin-binding epidermal-growth-factor-like growth factor (HB-EGF) has strong cytoprotective activity and is an important signalling protein that regulates trophoblast invasion during early placentation. We aimed to establish whether HB-EGF expression is altered in placentae of pre-eclamptic women.

METHODS

We assessed the expression of HB-EGF mRNA and protein by in-situ hybridisation and immunohistochemical techniques, respectively, in archived placental tissues from pregnancies terminated at around 20 weeks of gestation, and from women delivering between weeks 19 and 35 of gestation with preterm labour, small for gestational age infants, or pre-eclampsia.

FINDINGS

HB-EGF mRNA and protein were expressed in villous and extravillous cytotrophoblast cells up to week 35 of gestation in placentae from women who delivered preterm. Similar levels of HB-EGF protein were found in the placentae of women who were not in labour. HB-EGF expression was reduced about five-fold (p=0.0001) in pre-eclamptic pregnancies. Fetal growth retardation, which has been linked with shallow trophoblast invasion and moderate apoptosis, was associated with placentae expressing intermediate levels of HB-EGF.

INTERPRETATION

In pre-eclampsia, deficient HB-EGF signalling during placental development could impair trophoblast survival, differentiation, and invasion, leading to poor placental perfusion and hypertension.

Heparin-binding EGF-like growth factor modulation by antiprogestin and CG in the baboon (Papio anubis)

The objectives of this study were to determine whether antiprogestin therapy or the infusion of human CG to mimic blastocyst transit in the baboon alters heparin-binding EGF-like growth factor expression during the window of implantation. During the menstrual cycle, heparin-binding EGF-like growth factor protein accumulation in the glandular epithelium was low in the proliferative phase and increased to maximal expression on d 5 and 10 postovulation. Stromal cells accumulated high levels of heparin-binding EGF-like growth factor in the proliferative phase, which decreased by d 5 postovulation. These transitional changes in both cell types were delayed when cycling baboons were treated with the antiprogestin ZK 137.316 during the luteal phase. The treatment with human CG had no effect on expression of heparin-binding EGF-like growth factor when compared with cycling baboons on d 10 postovulation and was comparable with that observed on d 18 and 22 of pregnancy. However, the superimposition of the antiprogestin with the human CG treatment also decreased expression in the epithelial cells. In summary, heparin-binding EGF-like growth factor accumulation in the epithelial glands is under the influence of progesterone and does not seem to be influenced by the paracrine secretion of trophoblast CG.

Whole-body gene expression by data mining

To date, a comprehensive survey of the expression of lysyl oxidase (LOX), lysyl oxidase-like 1 (LOXL1), and lysyl oxidase-like 2 (LOXL2) has yet to be performed. The use of in vitro strategies to accomplish this task would prove daunting as it is both time-consuming and costly. We present a new in silico data mining strategy that directly addresses these limitations. Sequences corresponding to the 3' untranslated regions of LOX, LOXL1, and LOXL2 were individually queried against the human expressed sequence tag database (dbEST). In this manner, the entire tissue repertoire available in the dbEST was surveyed. This provided an estimate of the levels of mRNA transcripts in a variety of adult and fetal tissues. We have also employed this strategy to determine the pattern of expression and levels of a newly discovered gene, CGI-15. The veracity of this technique has been independently assessed by semiquantitative PCR analysis. The application of this technology is bounded only by the ever-growing information available in the GenBank, UniGene, and human EST databases. The utility of our data mining strategy to establish relative transcript levels in numerous tissues is presented.

[Aging and physical activity]

Advancing age is accompanied by changes in the cardiovascular system with a rapid reduction of, among other things, cardiac output, respiratory capacity, and maximum oxygen absorption capacity. Changes in articular cartilage, muscles, and intervertebral ligaments are the cause for many degenerative diseases of old age and considerably restrict physical performance capacity in later years. Nevertheless, there is increasing evidence that a high level of activity during old age and thus an influence on the aging process can be achieved by constant training begun as early as young adulthood. This type of training must concentrate on improving muscle strength, general flexibility, and endurance. Thus, it is our task to perceive physical activity as a medical prescription for the aging population.

Extracellular matrix composition and hypoxia regulate the expression of HLA-G and integrins in a human trophoblast cell line

During human placentation, extravillous cytotrophoblast cells emerge from chorionic villi contacting the decidua to invade the uterine wall. When isolated from first-trimester placentae, cytotrophoblast cells undergo step-wise differentiation in vitro that recapitulates the phenotypic heterogeneity observed in vivo. We examined a cell line, HTR-8/SVneo, that has been established from human first-trimester cytotrophoblast to determine whether these cells possess some of the unique cytotrophoblast characteristics that have been described previously. Exposure during serum-free culture to hypoxic conditions (2% oxygen concentration) increased HTR-8/SVneo cell proliferation and reduced invasion of a three-dimensional basement membrane (Matrigel). During culture on surfaces coated with individual extracellular matrix proteins, HTR-8/SVneo cells expressed cytokeratin but not the trophoblast-specific major histocompatibility protein, HLA-G. However, HLA-G expression was induced in HTR-8/SVneo cells that contacted Matrigel. Expression of the alpha5 integrin subunit was relatively unaffected by matrix composition, whereas alpha1 was up-regulated and alpha6 was down-regulated after transferring cells to Matrigel. Hypoxia increased alpha6 and decreased both alpha1 and HLA-G expression on Matrigel. HTR-8/SVneo cells retain several important characteristics associated with primary cultures of first-trimester human cytotrophoblast cells, including their altered behavior in response to a changing maternal environment.

Multiple roles for heparin-binding epidermal growth factor-like growth factor are suggested by its cell-specific expression during the human endometrial cycle and early placentation

Embryonic expression of the epidermal growth factor (EGF) receptor as well as embryonic and steroid-dependent uterine secretion of its ligand, heparin-binding EGF-like growth factor (HB-EGF), are temporally associated with the period of blastocyst implantation. We examined the temporal cell type-specific expression of HB-EGF in human endometrium during the menstrual cycle by immunohistochemistry and in situ hybridization. Early first trimester implantation sites were also examined to determine HB-EGF protein levels in decidual and fetal tissues. In the endometrial stroma, HB-EGF protein expression increased markedly during the late proliferative phase and then decreased in the early secretory phase. By contrast, luminal and glandular epithelial cells as well as blood vessel endothelium accumulated the protein between midcycle and cycle day 20, with peak expression observed during the period of uterine receptivity for implantation. HB-EGF expression decreased dramatically at the end of the cycle, before menses. Spatiotemporal expression of HB-EGF messenger ribonucleic acid demonstrated a similar pattern. During early pregnancy, HB-EGF immunostaining was noted in the decidua and in both villous and extravillous trophoblast populations. These findings suggest that HB-EGF promotes implantation and trophoblast invasion through paracrine and autocrine signaling as cells penetrate the stroma and displace the arteriole endothelium.

Ethanol elevates c-Myc levels in cultured mouse preimplantation embryos

A brief exposure to ethanol accelerates the rate of early mouse embryonic development in vitro, increasing blastocyst formation, trophoblast outgrowth, and implantation rates after embryo transfer. The physiological effects of ethanol during preimplantation development are associated with rapid changes in gene expression and apparently arise from the ability of ethanol to elevate cytoplasmic free Ca2+ and alter cellular signaling pathways. The purpose of this study was to examine whether the abundance of c-Myc, a transcription factor that promotes cell proliferation and is required for blastocyst development, is upregulated in mouse blastocysts challenged with ethanol. After exposure of mouse blastocysts to 0.1% (17.5 mM) ethanol, wc determined the levels of: 1) c-Myc mRNA, using reverse transcription and the polymerase chain reaction; and 2) c-Myc protein levels, using specific monoclonal antibodies. Within 10 min of exposure to ethanol, the relative abundance of c-Myc mRNA increased 6-fold, then rapidly returned to baseline levels within 1 hr. As expected, elevation of c-Myc mRNA by ethanol was attenuated in embryos that were first treated with the intracellular Ca2+ chelator, BAPTA-AM. Western blot analysis of solubilized embryos revealed that c-Myc mRNA was translated into a single 62-kD protein that increased in intensity 30 min after treatment with ethanol. Immunocytochemical staining demonstrated that c-Myc was localized exclusively in nuclei and that staining intensity increased significantly after 10 min. Peak levels of c-Myc protein were found 30 min after ethanol exposure and persisted for at least 2 hr. The c-myc proto-oncogene seems to be an immediate early response gene for ethanol that may regulate the transcription of other genes that influence early embryogenesis and growth.