The pathophysiological role of estrogens in the initial stages of pregnancy: molecular mechanisms and clinical implications for pregnancy outcome from the periconceptional period to end of the first trimester

Association between ovarian hyperstimulation syndrome and adverse obstetric and neonatal outcomes in Korea: a nationwide health insurance database study

PURPOSE

To investigate the association of ovarian hyperstimulation syndrome (OHSS) and adverse maternal and neonatal outcomes.

METHODS

This retrospective study used combined Korea National Health Insurance (KNHI) claims and National Health Screening Program for Infants and Children data. Women who gave birth through in vitro fertilization using fresh embryo transfer during 2017-2022 were enrolled. Z-scores were calculated. Student's t-test, analysis of variance, Pearson's chi-squared (χ2) test, and multivariate logistic regression analyses were performed.

RESULTS

The non-OHSS group included 27,337 women, while the OHSS group included 1,570 women (mild to moderate, 1,308; severe, 262). The OHSS group was significantly younger (34.86 ± 3.54 vs. 36.21 ± 3.58 years, p < 0.0001) and had significantly higher rates of primiparity, cesarean section, and polycystic ovary syndrome (88.98% vs. 82.89%, p < 0.0001; 75.8% vs. 65.75%, p < 0.0001; and 29.24% vs. 14.37%, p < 0.0001, respectively). OHSS was associated with a decreased incidence of low birth weight and with an increased incidence of macrosomia (adjusted odds ratio [95% confidence interval], 0.53 [0.38-0.72], p < 0.0001; and 1.83 [1.42-2.35], p < 0.0001). OHSS was associated with an increased incidence of transient tachypnea of the newborn (TTN) and respiratory distress syndrome (RDS) (1.32 [1.02-1.71], p = 0.03; and 1.57 [1.30-1.91], p < 0.0001).

CONCLUSION

OHSS is associated with a decreased incidence of low birth weight and an increased incidence of macrosomia, TTN, and RDS.

Oocyte and zygote development potential in minimal stimulation, natural cycle and conventionally stimulated IVF: an international multi-centre retrospective cohort study

PURPOSE

The aim of this research is to assess the development potential of oocytes and zygotes obtained from Natural cycle IVF (NC-IVF), different minimal stimulation IVF (Min stim-IVF) and conventionally stimulated IVF (cIVF) treatment protocols.

METHODS

International multi-centre retrospective cohort study including 1483 NC-IVF, 1208 Min stim-IVF, and 1892 cIVF cycles performed in 8 IVF centres between 01.2022 and 03.2023. The five Min stim-IVF protocols analysed included low dose clomiphene citrate, aromatase inhibitors, low dose (≤ 100 IU) gonadotropins, each alone or in combination. For each IVF protocol, we assessed and modelled the transition probabilities of (i) each observed oocyte developing into a zygote, (ii) each observed zygote developing into a gestational sac and (iii) each observed zygote developing into a live birth.

RESULTS

All modelled transition probabilities were found to be maximal in NC-IVF, minimal in cIVF with Min stim-IVF in between. The probability of transition from oocyte to zygote was 0.72 for NC-IVF, 0.56 to 0.65 for Min stim-IVF protocols and 0.54 for cIVF. The probability of transition from zygote to gestational sac was 0.21 for NC-IVF, 0.14 to 0.19 for Min stim-IVF and 0.09 for cIVF protocols and from zygote to live birth 0.16 for NC-IVF, 0.09 to 0.16 for Min stim-IVF and 0.06 for cIVF protocols.

CONCLUSIONS

The transition probabilities of oocytes and zygotes appears to be higher in NC-IVF, followed by Min stim-IVF and then cIVF, suggesting that increasing dosages of gonadotropins might have a negative effect on oocyte/zygote development potential.

TRIAL REGISTRATION

Clinicaltrial.gov: NCT05125497. Registration date 03.11.2021.

An isotope dilution-liquid chromatography-tandem mass spectrometry-based candidate reference measurement procedure for the quantification of 17β-estradiol in human serum and plasma

OBJECTIVES

A new candidate isotope dilution-liquid chromatography-tandem mass spectrometry (ID-LC-MS/MS)-based reference measurement procedure (RMP) has been developed for the accurate and precise quantification of 17β-estradiol (E2) in human serum and plasma covering a measurement range from 0.400 to 5,000 pg/mL (1.47-18,357 pmol/L). To address this broad range, two separate methods were created: a high sensitivity (HS) method for concentrations between 0.400 and 5.00 pg/mL (1.47-18.4 pmol/L) and a standard range (SR) method for concentrations between 5.00 and 5,000 pg/mL (18.4-18,357 pmol/L).

METHODS

As the primary reference material, E2 (CRM 6004-a) from the National Metrology Institute of Japan was used to ensure traceability to the international system (SI). A two-dimensional heart-cut LC approach was utilized for LC-MS/MS analysis, employing a supported liquid extraction sample preparation protocol for the SR method and a liquid-liquid extraction protocol followed by derivatization for the HS method. Assay validation was conducted following current guidelines. Selectivity and specificity were assessed using spiked serum samples, while potential matrix effects were evaluated through a post-column infusion experiment and comparison of standard line slopes. Precision, accuracy, and trueness were determined using an extensive 5-day protocol. Standard measurement uncertainty was evaluated according to the Guide to the Expression of Uncertainty in Measurement (GUM), with three individual sample preparations performed on at least two different days. Equivalence with higher-order RMPs was demonstrated through participation in the CDC Steroid Hormones Standardization (HoSt) program.

RESULTS

The RMP enabled the quantification of E2 within the range of 0.400-5,000 pg/mL (1.47-18,357 pmol/L), demonstrating no interference from structurally related compounds and no evidence of matrix effects. The relative mean bias of the SR method ranged from -2.4 to 1.9 % across all levels, including secondary reference materials and spiked samples, whereas the HS method exhibited a mean bias ranging from -3.0 to 2.9 %. Expanded measurement uncertainties (k=2) for target value assignment ranged from 1.7 to 4.4 % for the SR method and were found to be ≤6.1 % for the HS method. The method's transferability was demonstrated in a comparison study at a second laboratory. Additionally, the candidate RMP exhibited excellent correlation and equivalence to JCTLM-listed RMPs through the CDC HoSt program.

CONCLUSIONS

In summary, the ID-LC-MS/MS-based RMP accurately quantifies E2. Its robust performance makes it suitable for standardizing routine assays and measuring individual patient samples, ensuring traceability.

Estradiol and progesterone levels in early pregnancy after modified natural, programmed, and gonadotrophin-stimulated frozen embryo transfer cycles: a randomized controlled trial

STUDY QUESTION

Are serum estradiol and progesterone levels higher in women treated with programmed cycle (PC) FET compared to women treated with a gonadotrophin-stimulated (gSC) FET or a modified natural cycle (mNC) FET during early pregnancy?

SUMMARY ANSWER

Estradiol and progesterone levels are higher on the day of embryo transfer in women treated with PC compared to those treated with a mNC or gSC.

WHAT IS KNOWN ALREADY

Various FET treatment regimens may affect the maternal hormone balance very differently in early pregnancy. Recent studies show that a PC is associated with increased risk of hypertensive pregnancy disorders, high birth weight, and postpartum hemorrhages. The underlying mechanism is not known but differences in hormone levels could play a role.

STUDY DESIGN, SIZE, DURATION

This was a parallel open-label randomized controlled drug trial conducted from April 2021 until December 2024. The target sample size was 100 cycles in each treatment arm for a power of 80%. A total of 305 cycles were included and 257 were included in the per-protocol analysis. Ovulatory women were randomized to either a PC or a mNC. Anovulatory women were randomized to a PC or a gSC. Blood samples were obtained at seven consecutive time points from the start of the cycle until gestational age (GA) 9 + 6 weeks. Obstetric and neonatal follow-up was completed through the patients' digital medical records. Primary outcomes were differences in serum estradiol and progesterone between patient groups and treatment regimens. Secondary outcomes were to compare the type of cycle with reproductive, obstetric, and neonatal outcomes between groups.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The trial was conducted in the Fertility Clinic at Herlev University Hospital, Denmark. Participants were women aged 18-40 years with BMI ≤35 kg/m2. Only women using autologous frozen blastocysts were eligible and all women had a normal wet cervical wet smear within the last 3 years.

MAIN RESULTS AND THE ROLE OF CHANCE

For ovulatory women, estradiol and progesterone levels were higher in PCs on the day of embryo transfer day compared to mNCs (estradiol: 0.86 nmol/l vs 0.54 nmol/l, adjusted P < 0.001, progesterone: 68.5 nmol/l vs 40.3 nmol/l, adjusted P < 0.001), and progesterone levels were also higher in PCs at GA 8 + 0 (87.5 nmol/l vs 61.2 nmol/l, adjusted P = 0.02). For anovulatory women, the same trend was observed when comparing PCs to gSCs. Serum estradiol was significantly higher on the day of embryo transfer day (0.96 nmol/l vs 0.54 nmol/l, adjusted P < 0.01), though no significant differences in progesterone were found. We found no differences in pregnancy rates, live birth rates, pregnancy loss rates, or cancelation rates. Ovulatory women treated with PCs had significantly larger children with an estimated treatment difference of 292 grams (P < 0.01) compared to those treated with mNCs. Furthermore, we observed a higher risk of postpartum hemorrhages in PCs compared to mNCs (22/40 (55%) vs 10/40 (25%), P = 0.01).

LIMITATIONS, REASONS FOR CAUTION

The target sample size of 100 cycles was not achieved in either of the anovulatory arms.

WIDER IMPLICATIONS OF THE FINDINGS

This is the first randomized trial to investigate differences in maternal sex hormones between FET regimens. Although higher levels of estradiol and progesterone were demonstrated in PCs compared to mNCs and gSCs on the day of embryo transfer day, the significance of these findings is currently unclear. Further research is needed to verify these results and to examine possible effects on pregnancy and fetal development.

STUDY FUNDING/COMPETING INTEREST(S)

The study has received grants from Gedeon Richter Nordics AB (DK-2019-04, DK-2022-03, DK-2023-08, DK-2023-06, DK-2024-08) and a grant from the Gangsted-Rasmussen Foundation (ref. A39784). The study has also received a grant from the local research board at Herlev University Hospital. The funders of the trial had no role in the design and planning phase, data analysis, or interpretation of the results. Ongoing analyses of biobank samples have been funded by Merck A/S. M.S.S., H.U., and M.L.B. have no conflicts of interest. N.F.M. has, outside this work, received funding for congress registration from Gedeon Richter Nordics AB. P.F.S. has, outside this work, received grants from Merck A/S, Gedeon Richter Nordics AB, and Ferring Pharmaceuticals A/S. Outside this work, B.N. has received grants from Merck A/S, Gedeon Richter Nordics AB, and Ferring Pharmaceuticals A/S, personal fees from Ferring Pharmaceuticals A/S, travel support from Gedeon Richter Nordics AB, and participated in a data safety monitoring or advisory board for Ferring Pharmaceuticals A/S.

TRIAL REGISTRATION NUMBER

2020-001218-39 in EudraCT.

TRIAL REGISTRATION DATE

17 November 2020.

DATE OF FIRST PATIENT’S ENROLMENT

20 April 2021.

Antiviral resistance and barrier integrity at the maternal-fetal interface restrict hepatitis E virus from crossing the placental barrier

Hepatitis E virus (HEV) genotype 1 (HEV-1) infection in pregnant women is associated with adverse outcomes of pregnancy including fulminant hepatic failure, fetal loss, premature birth, and neonatal mortality, although the underlying mechanisms remain largely unclear. In this study, we first demonstrated that HEV-1 robustly infects pregnant gerbils and causes pregnancy-associated adverse outcomes, which were recorded in 4/6 HEV-1-infected but only 1/5 in PBS-inoculated pregnant gerbils. However, vertical transmission of HEV-1 from mothers to newborns is not evident, as HEV-1 RNA was not detected in uterus tissues or in newborn pups. To further determine whether HEV-1 can cross the placental barrier, we established an in vitro blood-placental barrier by coculturing human placental trophoblast cells (BeWo) and umbilical vein endothelial cells (HUVEC) in Transwell inserts. By using the placental barrier under the conditions in this study, we showed that quasi-enveloped or nonenveloped HEV-1, HEV-3, or HEV-4 virions do not readily cross the barrier prior to 4 d postinoculation when it has high barrier integrity. Importantly, we demonstrated that the placental barrier induces local antiviral resistance at the maternal-fetal interface, that interactions between maternal- and fetal-derived cocultured cells are important for induction of antiviral resistance, and that anti-HEV resistance can be transferred to nonplacental HepG2 liver cells. We also revealed that the main effectors of antiviral resistance at the placental barrier are type III interferons (IFN-λ1, λ2/3) and the chemokine CXCL10. The findings have important implications in understanding the mechanisms leading to HEV-1-associated maternal and fetal adverse outcomes in pregnant women.

Impact of relative estradiol changes during ovarian stimulation on blastocyst formation and live birth in assisted reproductive technology

This study aimed to evaluate the predictive value of relative change in E2 levels during controlled ovarian stimulation (COS) on embryo development and pregnancy outcomes in assisted reproductive technology (ART). We retrospectively analyzed 9,376 patients who underwent their first fresh ART cycle from January 1, 2020, to December 31, 2022. Patients were classified into four groups based on relative change in E2 levels: low response group, moderate response group, moderate-high response group, and high response group. The primary outcomes were blastocyst formation rate, clinical pregnancy rate, and live birth rate, while secondary outcomes included miscarriage rate and ectopic pregnancy rate. Most cycles (96.5%) demonstrated an increase in E2 levels during COS. The blastocyst formation rate significantly increased across the groups (low response group: 0.13, moderate response group: 0.21, moderate-high response group: 0.28, high response group: 0.34; P < 0.001). Multivariable logistic regression showed significantly higher blastocyst formation rates in the moderate response group (adjusted OR = 2.012, 95% CI: 1.687-2.399), moderate-high response group (adjusted OR = 4.613, 95% CI: 3.853-5.523), and high response group (adjusted OR = 11.295, 95% CI: 9.192-13.880) compared to the low response group. Both clinical pregnancy rate and live birth rate were significantly higher in the moderate-high response group and high response group compared to the low response group (clinical pregnancy rate: 54.5% and 61.5% vs. 35.5%, adjusted RR = 1.21 [95% CI: 1.03-1.42] and 1.27 [95% CI: 1.08-1.51]; live birth rate: 44.9% and 52.0% vs. 25.7%, adjusted RR = 1.27 [95% CI: 1.06-1.52] and 1.35 [95% CI: 1.11-1.64]). However, no significant differences were observed in either clinical pregnancy rate or live birth rate between the moderate response group and low response group (clinical pregnancy rate: adjusted RR = 1.07 [95% CI: 0.91-1.25]; live birth rate: adjusted RR = 1.11 [95% CI: 0.92-1.33]). No significant differences in miscarriage rate or ectopic pregnancy rate were observed across the groups. Higher E2 responses were associated with improved embryo development and better pregnancy outcomes.

High serum estradiol levels on the day of frozen blastocyst transfer are associated with increased early miscarriage rates in artificial cycles using transdermal estrogens

STUDY QUESTION

Do serum estradiol (E2) levels on the day of frozen blastocyst transfer (FBT) affect pregnancy outcomes in hormonal replacement therapy (HRT) cycles using transdermal estrogens?

SUMMARY ANSWER

E2 levels ≥313 pg/ml on the day of FBT are associated with increased early miscarriage rates (EMRs), but do not significantly impact the live birth rate (LBR).

WHAT IS KNOWN ALREADY

E2 plays a crucial role in endometrial receptivity and placentation. The effect of serum E2 levels measured around the time of FBT in HRT cycles remains debated, with some studies indicating a negative impact of high E2 levels and others finding no significant difference. Currently, no studies focus exclusively on HRT cycles using transdermal estrogens, which are considered safer regarding thromboembolic complications.

STUDY DESIGN, SIZE, DURATION

This retrospective cohort study analyzed 2364 patients undergoing HRT-FBT cycles at a university hospital between January 2019 and December 2022. Each patient was included only once during the study period.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The study involved patients undergoing single autologous FBT under HRT with transdermal estrogens and vaginal micronized progesterone. Serum E2 levels were measured in the morning of the FBT at a single laboratory. Primary outcomes included the LBR, with secondary outcomes encompassing clinical pregnancy rates, EMRs, and neonatal outcomes (birth weight and term of delivery). Patients were categorized into three groups based on E2 levels: <25th centile (<122 pg/ml), between 25th and 75th centile (122-312 pg/ml), and >75th centile (≥313 pg/ml), and analyzed using univariate and multivariate logistic regression models.

MAIN RESULTS AND THE ROLE OF CHANCE

Of the 2364 patients, 590 were in the '<122 pg/ml' group, 1184 in the '122-312 pg/ml' group, and 590 in the '≥313 pg/ml' group. The median (interquartile range) E2 level in the entire study population was 195.3 pg/ml (122.1-312.8). The LBRs across the E2 level groups were 33.7%, 31.6%, and 31.0%. Crude and adjusted odds ratios (ORs) showed no significant differences in LBR between the '<122 pg/ml' and '≥313 pg/ml' groups compared to the '122-312 pg/ml' reference group (adjusted OR 0.9, 95% CI 0.72-1.14 and 0.9, 95% CI 0.69-1.09, respectively). The EMRs for the groups were 25.5%, 24.6%, and 30.3%, respectively. While crude analysis showed no differences between the groups, the multivariable analysis indicated that the '≥313 pg/ml' group had a significantly higher risk of early miscarriage compared to the reference group (adjusted OR 1.5, 95% CI 1.06-2.18). No significant differences were observed in clinical pregnancy rates or neonatal outcomes.

LIMITATIONS, REASONS FOR CAUTION

The primary limitation is the study's retrospective design, which introduces risks of selection and confusion bias, although multivariable analysis was employed to mitigate these issues.

WIDER IMPLICATIONS OF THE FINDINGS

Managing high serum E2 levels on the day of the FBT may enhance ART outcomes. Future research should aim to define optimal E2 thresholds for HRT-FBT cycles and develop personalized treatment protocols that account for individual patient variability.

STUDY FUNDING/COMPETING INTEREST(S)

No funding was received. The authors have no conflicts of interest.

TRIAL REGISTRATION NUMBER

N/A.

T3-THR Signaling Governed by DIO2 Contributes to Endometrial Receptivity by Regulating Epithelial Cell Membrane Fluidity

Maintaining normal thyroid function is crucial in pregnancy, and the thyroid hormone signaling pathway is involved in embryo implantation. However, the regulation of iodothyronine deiodinase 2 (DIO2), which is the central hub controlling thyroid hormone signaling, and the intracellular pathway activated by triiodothyronine (T3) binding to the thyroid hormone receptor (THR) in endometrial cells, remains unclear. Here, we demonstrate that DIO2 expression increases in endometrium during the establishment of endometrial receptivity and is involved in this process. Iopanoic acid inhibition of DIO2 in vivo can cause a delayed receptive state. In vitro adhesion models have consistently confirmed that knocking down DIO2 in epithelial cells inhibited receptivity establishment. Membrane lipidomics was performed to explore how DIO2 regulates the morphological transformation of endometrial epithelial cells. We found that the deletion of Dio2 inhibited the increase in the degree of lipid unsaturation, which subsequently decreased membrane fluidity. Transcriptomics analysis was employed to explore the downstream target gene of T3-THR signaling mediated by Dio2-mediated T3-THR signaling, and Scd1 is confirmed as the direct target gene of THR in endometrial epithelial cells. These data reveal that DIO2 could regulate lipid metabolism by targeting Scd1 through the T3-THR signaling pathway, thereby modifying membrane fluidity of endometrial epithelial cells and promoting cell morphological transformation to establish endometrial receptivity. These findings contribute to filling the gap in downstream pathways activated by T3-THR signaling in endometrial cells and provide insights into the new therapeutics, prediagnosis, and preventive strategies for the derailment of endometrial receptivity and subsequently adverse "ripple effect" including infertility.

Spatial Analysis of Placentae During Congenital Cytomegalovirus Infection Reveals Distinct Cellular Profiles in Immune Cells and Trophoblasts

Cytomegalovirus (CMV) is the most common cause of birth defects by an infectious agent. Approximately 10% of infants with congenital CMV (cCMV) infection are symptomatic. Infected infants can exhibit long-term effects such as sensorineural hearing and vision loss and neurodevelopmental delay. To date, the mechanisms by which cCMV infection results in symptomatic disease are incompletely understood. The placenta has been implicated as a main thoroughfare for vertical transmission, as both placental immune cells and trophoblasts can be infected by CMV. The goal of this study was to spatially investigate changes in genes and proteins from immune cells and trophoblasts during cCMV infection. Utilizing the NanoString GeoMx Digital Spatial Profiler, we noted that both immune cells and trophoblasts in CMV + placentae exhibited increased expression and upregulation of immune activation receptors and pathways. Pro-apoptotic proteins were decreased in CMV + placentae, as were transcripts associated with cell death pathways. Spatially, immune cells infiltrating into CMV + placental villi had more CD4 + T cells expressing cell death markers than those T cells in the decidua (p = 0.002). In contrast, the decidua exhibited a CD8+ T cell abundance with far less upregulation of immune activation receptors than in the villi (p=0.03). These data can inform and direct future research into the immune mechanisms CMV uses to infect, evade, and vertically transmit the virus to the fetus.

Expression of Estrogen Receptors in Main Immune Organs in Sheep During Early Pregnancy

Estrogen exerts its action via estrogen receptors (ERs), including ERα and ERβ, and has effects on immunomodulation during pregnancy. It is known that there are changes in the function of the maternal immune organs during pregnancy. However, it is not clear if early pregnancy has effects on the expression of ERα and ERβ in the ovine maternal thymus, lymph nodes, spleen, and liver. In this study, these maternal immune organs were harvested at day 16 of the estrous cycle and at days 13, 16, and 25 of pregnancy (n = 6 for each group) after the ewes were euthanized. The mRNA and protein expression of ERα and ERβ were analyzed using real-time PCR and Western blot and immunohistochemical analyses. The results reveal that the mRNA and protein expression of both ERα and ERβ were upregulated in the maternal spleen and the expression of ERα and ERβ in the thymus, lymph nodes, and liver was modulated during early pregnancy. In conclusion, early pregnancy modulates the expression of ERα and ERβ in the maternal thymus, lymph nodes, spleen, and liver in a tissue-specific manner, which is related to the regulation of maternal immune function during early pregnancy in ewes.

A nomogram prediction model for embryo implantation outcomes based on the cervical microbiota of the infertile patients during IVF-FET

The microbiota of the female genital tract is crucial for reproductive health. This study aims to investigate the impact of the lower genital tract microbiota on in vitro fertilization and frozen embryo transfer (IVF-FET) outcomes. This study included 131 women aged 20-35 years who underwent their first or second IVF-FET cycle with no obvious unfavorable factors for implantation. Cervical microbiota samples were collected on the embryo transfer day and analyzed using 16S rDNA full-length sequencing. Clinical outcomes were followed up for analysis. Clinical pregnancy (CP) was achieved in 84 patients, and 47 patients experienced non-pregnancy (NP). The cervical microbiota diversity between NP and CP groups showed no significant differences, but some genera such as Halomonas (P = 0.018), Klebsiella (P = 0.039), Atopobium (P = 0.016), and Ligilactobacillus (P = 0.021) were obviously different between the two groups. Notably, there was no significant difference in the abundance of Lactobacillus between the two groups. A nomogram prediction model was developed using the random forest algorithm and logistic regression, including the classification of Halomonas, Atopobium, and Veillonella, as well as the relative abundance of Lactobacillus, to identify high-risk patients with embryo implantation failure. Both internal (area under the curve [AUC] = 0.718, 95% confidence interval [CI]: 0.628-0.807, P < 0.001) and external validation (AUC = 0.654, 95% CI: 0.553-0.755, P = 0.037) of the model performed well. In conclusion, this study established a correlation between cervical microbiota and embryo implantation failure in infertile women undergoing IVF-FET and developed a prediction model that could help in early identification of patients at high risk of implantation failure.IMPORTANCEThis study investigated the potential role of abnormal cervical microbiota in the pathology of implantation failure after in vitro fertilization and frozen embryo transfer (IVF-FET) treatment. Despite nearly half a century of advancements in assisted reproductive technology (ART), the implantation rate of high-quality embryos still hovered around 50%. Moreover, unexplained recurrent implantation failure (RIF) remains a significant challenge in ART. To our knowledge, we first discovered a prediction model for embryo implantation failure, identifying Halomonas and Veillonella as significantly adverse factors for embryo implantation. Despite some limitations, the internal and external validation of the model could bode well for its clinical application prospect. The insights gained from this study pave the way for intervention in the genital tract microbiota prior to IVF-FET, particularly in patients with RIF and RSA.

MicroRNA-155 targets p65 to regulate PD-L1 expression in the early pregnancy endometrium

Reproductive disorders in dairy cows represent a significant challenge to the advancement of the dairy industry. Pregnancy success is closely related to the mechanism of immune tolerance, with the PD-1/PD-L1 signaling pathway playing a role in immune regulation, which is associated with immune tolerance and pregnancy maintenance. MicroRNAs can regulate pivotal molecules within the signaling pathway, physiological activities, and disease processes. p65 and PD-L1 expression was significantly increased in the early pregnant uterine epithelium. In contrast, the expression of p65 and PD-L1 was homogeneous in the endometrial epithelium of E2 and P4 co-stimulated bEECs and changed with the stimulation time and concentration. MiR-155 expression was significantly reduced in the early pregnant uterine epithelium. p65 was identified as a molecular target of miR-155 using a dual luciferase assay and mimics/inhibitor transfection, and miR-155 inhibited p65 expression by binding to the 3'-UTR of p65 mRNA. The regulation of PD-L1 expression by p65 was confirmed through the knockdown of p65 by si-p65 and the overexpression of p65 by pcDNA3.1-p65. In the context of pregnancy, miR-155 was observed to target p65, thereby regulating PD-L1 expression at the endometrial epithelium.

Microbiome and Pregnancy Dysbiosis: A Narrative Review on Offspring Health

Background: Emerging evidence suggests that the maternal microbiome plays a crucial role in shaping fetal neurodevelopment, immune programming, and metabolic health. Dysbiosis during pregnancy-whether gastrointestinal, oral, or vaginal-can significantly influence pregnancy outcomes and long-term child health. Materials and Methods: The search was performed using databases such as PubMed, Scopus, and Google Scholar including research published from January 2000 to January 2025. The keywords used were "Fetal Programming", " Maternal Immune Activation", "Maternal microbiome", "Microbiota-Gut-Brain Axis", and "Pregnancy Dysbiosis". Results: The maternal microbiome undergoes substantial changes during pregnancy, with alterations in microbial diversity and function linked to conditions such as gestational diabetes, obesity, and preeclampsia. Pregnancy-related dysbiosis has been associated with adverse neurodevelopmental outcomes, including an increased risk of autism spectrum disorder (ASD), attention-deficit/hyperactivity disorder (ADHD), and cognitive impairments in offspring. Conclusions: Understanding the intricate relationship between maternal microbiota and fetal health is essential for developing targeted interventions. Personalized microbiome-based strategies, including dietary modifications and probiotic supplementation, hold promise in optimizing pregnancy outcomes and promoting health in offspring.

Dynamic change of estrogen and progesterone metabolites in human urine during pregnancy

Endogenous estrogen and progesterone and their metabolites play a key role in regulating and maintaining the normal pregnancy process. However, the dynamic change of these estrogen and progesterone metabolites' level across the entire gestational period is not fully revealed. This study systematically measures the temporal changes of estrogen, progesterone, and their metabolites in human urine during normal pregnancy using ultrahigh performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). We find that the levels of estrone, estradiol, estriol, 16-epiestriol, 17-epiestriol, 2-methoxyestradiol, and 4-hydroxyestrone gradually increase during pregnancy. The levels of 2-hydroxyestrone, 2-hydroxyestradiol, and 4-hydroxyestradiol rapidly decrease in the early pregnancy and then maintain at lower levels. The levels of 4-methoxyestradiol, 4-methoxyestrone and 2-methoxyestrone peak in the mid-pregnancy and then gradually decrease. The levels of pregnenolone, 17α-hydroxy pregnenolone, 17α-hydroxy progesterone, pregnanolone, epipregnanolone gradually increase during pregnancy. The levels of progesterone, 20α-hydroxy progesterone, 5α-dihydroprogesterone and 5β-dihydroprogesterone first increase in the mid pregnancy and then decrease in the late pregnancy. In sum, this study comprehensively depicts the dynamic change of estrogen, progesterone, and their metabolites in human urine during pregnancy, which lays the foundation for hormone monitoring and early diagnosis of pregnancy complications, and further mechanistic study of the roles of these metabolites in pregnancy.

Decreasing serum estradiol level on day of progesterone start in programmed frozen embryo transfer cycles and the pregnancy outcomes

High serum estradiol levels may reduce the success of conception and live birth in both in vitro fertilization and frozen embryo transfer (FET). This retrospective study sought to determine whether an association exists between decreasing the serum estradiol level and the clinical outcome following programmed FET cycles. The analysis retrieved the data of patients who underwent programmed FET cycles at the Center of Reproductive Medicine of Weifang People's Hospital from January 2022 to March 2023. The pregnancy outcomes were compared between patient groups with different estradiol levels but otherwise identical profiles. Of all 769 included patients, 188 received 3 mg/d estradiol valerate (group A) and 581 received 4 mg/d 17β-estradiol (group B). Of group B patients, 186 (group BP) with identical baseline clinical data as patients in group A were selected by using propensity score matching. While the serum estradiol level was much lower in those receiving 3 mg/d estradiol valerate (group A) than those receiving 4 mg/d 17β-estradiol (group BP), the endometrial thickness was not affected by the medication regimen. Both groups had comparable pregnancy outcomes, including clinical pregnancy, implantation, early miscarriage, ectopic pregnancy, and live birth rate. In programmed FET cycles, decreasing the serum level of estradiol does not significantly impact the pregnancy outcome.

The study on the clinical efficacy of endometrial receptivity analysis and influence factors of displaced window of implantation

The endometrial receptive status is critical for a successful embryo implantation, but it only last for a short period of time, and the window of implantation (WOI) of each woman changes individually, which will lead to poor outcomes of assisted reproduction. This so-called WOI can be detected by molecular diagnostic method, endometrial receptivity analysis (ERA), which was gradually applied to clinical practice. This study aimed to evaluate the clinical efficacy of personalized embryo transfer (pET) guided by ERA in patients with and without RIF. A total of 3605 patients with previous failed embryo transfer (ET) cycle in the reproductive medicine center of Renmin Hospital Hubei University of Medicine from January 2016 to October 2022 were retrospectively analyzed. The 3605 patients were divided into non-RIF group and RIF group, among which 782 patients who received ERA test underwent personalized embryo transfer (pET). The decision whether to accept ERA test or not was based on the patient's voluntary choice. We divided the 782 patients into normal WOI group and displaced WOI group according to the result of ERA test. The pregnancy outcomes were compared between the different groups. The age, number of previous ET cycle and serum E2/P ratio were mainly analyzed to investigate its relationship with displaced WOI. The clinical pregnancy rate and live birth rate in non-RIF with pET group were higher than that of non-RIF with non-personalized embryo transfer (npET) group (64.5% vs 58.3%, P = 0.025; 57.1% vs 48.3%, P = 0.003). The clinical pregnancy rate and the live birth rate in RIF with pET group were significantly higher than that of RIF with npET group (62.7% vs 49.3%, P < 0.001; 52.5% vs 40.4%, P < 0.001) after propensity score matching (PSM). The early abortion rate in the non-RIF with pET group was lower than that in the non-RIF with npET group (8.2% vs 13.0%, P = 0.038). There was a significant difference in age and the number of previous failed ET cycle between the normal WOI group and displaced WOI group (age: 32.26 vs 33.53 years, P < 0.001; the number of previous failed ET cycle: 1.68 vs 2.04, P < 0.001). Logistic regression analysis also showed that the age and number of previous failed ET cycles were positively correlated with displaced WOI. The displaced WOI rate increased gradually with the increase of age and number of previous failed ET cycle; the displaced WOI rate in the median group (4.46 < E2/P ≤ 10.39 pg/ng) was significantly lower than that in the other two groups (54.8% vs 40.6% vs 58.5%, P < 0.001). The clinical pregnancy rate and live birth rate of patients with previous failed ET cycle was improved after pET guided by ERA, especially in RIF patients; the early abortion rate of the non-RIF patient was reduced after pET guided by ERA. An appropriate E2/P ratio was beneficial for maintaining endometrial receptivity state, and the age and number of previous failed ET cycle was correlated with increased displaced WOI.

Sensitive months for green spaces' impact on macrosomia and interaction with air pollutants: A birth cohort study

Macrosomia poses significant health risks to mother and fetuses, yet the protective sensitive window for the effects of green space resources on the risk of macrosomia remains unexplored. This study identified sensitive windows of green space exposure and examined the interactions with air pollutants. In a study of 221,380 full-term newborns delivered at the Hospital, from 2017 to 2021, Normalized Difference Vegetation Index (NDVI) and atmospheric pollutant concentrations were matched to participants based on their residences in the Ningxia region. A Cox proportional hazards model was utilized to estimate the association between green space exposure and macrosomia and analyze the differences between the macrosomia (<4500 g) and macrosomia (≥4500 g) groups. Green space exposure for each month of pregnancy was employed to identify possible sensitive windows. Possible interactions between green spaces and air pollutants were tested on additive and multiplicative scales. Across 250, 500, 1000, and 2000-m buffers, increased NDVI exposure and range throughout the pregnancy were linked to a lower macrosomia risk, with the strongest association in the macrosomia (≥4500 g) group. The key window for the protective effect of green spaces was in late pregnancy, with the most pronounced protective effect noted in the 9th month of pregnancy. We also found a consistent combined effect between low green space and the air pollutants (NO2 and SO2). The research highlights the beneficial impact of increased green space during late pregnancy and the combined effect of low green space and elevated air pollutant levels on macrosomia risk, which can support government initiatives in urban green space development and public health protection.

Indicators of Endogenous Intoxication in Uncomplicated Pregnancy. Medium-Weight Molecules and Lipid Peroxidation Products

The endogenous intoxication level was assessed based on the content of medium-weight molecules (MWM) and LPO products in the blood serum of women with uncomplicated pregnancy depending on the gestational age: 6-12, 18-22, 28-32, and 38-40 weeks. A significant increase in the MWM level at λ = 280 nm was found at weeks 28-32 compared to the second trimester (p = 0.05), as well as before delivery compared to the first trimester (p = 0.013). In the third trimester of pregnancy and before delivery, the substrates with double bonds and diene conjugates content increased (p < 0.05), but the levels of highly toxic TBA-active products before delivery did not differ from that at the beginning of the gestation process. These phase changes in LPO processes correspond to changes in the hormonal status of the body during uncomplicated pregnancy, and MWM measured at λ = 280 nm is a sensitive marker for monitoring of the endogenous intoxication level.

The Relationship Between the Average Decreased Times of Estradiol and Early Miscarriage: An Observational Study

Decreased estradiol (E2) levels are associated with early miscarriage (EM), but the relationship between decreased times of E2 and EM has not been reported. We aimed to investigate the relationship between the average decreased times of E2 (ADTE) and EM. Women with a history of miscarriage were retrospectively recruited from the Reproductive Center of Lanzhou University Second Hospital (Lanzhou, China) between September 2019 and February 2022. Based on pregnancy outcome, they were divided into ongoing pregnancy group (n = 359) and EM group (n = 104). In addition, subgroup analyses were performed for the number of previous miscarriages and whether E2 levels decreased continuously. The exposure and outcome variables were ADTE and miscarriage before 12 weeks of gestation, respectively. Totally, 1171 patients were recruited and 463 patients were finally analyzed. ADTE was associated with EM (odds ratio [OR] = 1.346, 95% confidence interval [CI]1.154-1.571, P < 0.001). When ADTE ≥ 2.5, the EM risk increased 1.17-fold compared to patients with 0-1.249 times (OR = 2.170, 95% CI 1.144-4.117, P = 0.018). Moreover, a threshold effect existed in the ADTE and the risk of EM with a value of 4.9 times. When exceeding 4.9 times, the EM risk increased 4.713-fold for each increased unit (OR = 5.713, 95% CI 1.255-23.170, P = 0.024). Subgroup analysis showed that ADTE had a greater effect on the occurrence of EM in women with a history of 1-2 miscarriages than in women with 3 miscarriages. Decreased E2 was a risk factor for EM regardless of whether it dropped continuously or not. In conclusion, our study identifies a potential link between ADTE and early miscarriage risk in women with prior miscarriages, yet cautious interpretation is necessary due to inherent design limitations. Further research with prospective designs and large population samples is essential to validate ADTE's utility as a predictive indicator for early miscarriage in clinical settings.

Vascular health and exercise in females throughout the lifespan: Exploring puberty, pregnancy and menopause

This narrative review highlights the impact of exercise on vascular health in females over the lifespan with an emphasis on puberty, pregnancy and menopause. These events encompass substantial changes in sex hormone levels, particularly oestrogens and progesterone. They are also accompanied by distinct adaptations of the central, peripheral and cerebral vasculature. Regular exercise is an effective mechanism to reduce vascular risk in females of all ages, especially for those at higher risk for vascular disorders. However, there are large variabilities in the vascular adaptations to exercise in females that may be related to circulating sex hormone levels. In addition, exogenous hormones, such as oral contraceptives taken after puberty or hormonal replacement therapy taken to mitigate symptoms of menopause, may interact with exercise-induced changes in vascular function. We highlight how more research is needed to understand the optimal exercise interventions to promote vascular health in females across the lifespan, especially during times of hormonal transition.

Lipidomic Signature of Pregnant and Postpartum Females by Longitudinal and Transversal Evaluation: Putative Biomarkers Determined by UHPLC-QTOF-ESI+-MS

BACKGROUND

Pregnancy induces significant physiological and metabolic changes in the mother to support fetal growth and prepare for childbirth. These adaptations impact various systems, including immune tolerance, metabolism, and endocrine function. While metabolomics has been utilized to study pregnancy-related metabolic changes, comprehensive comparisons between pregnant and non-pregnant states, particularly using ultra-high-performance liquid chromatography coupled with mass spectrometry (UHPLC-MS), remain limited.

METHODS

This study aimed to explore the dynamic, longitudinal metabolic shifts during pregnancy by profiling plasma samples from 65 pregnant women across three time points (6-14 weeks, 14-22 weeks, and >24 weeks) and 42 postpartum women. Lipidomics was prioritized, and a solvent mixture was employed to enhance lipid extraction, using UHPLC-QTOF-ESI+-MS.

RESULTS

A total of 290 metabolites were identified and analyzed. Our results revealed significant metabolic differences between pregnant and postpartum women, with lipid molecules such as estrogen derivatives, fatty acids, and ceramides showing strong potential as biomarkers. Further biomarker analysis highlighted distinct metabolic signatures between early and late pregnancy stages, particularly in lipid metabolism (with AUC values > 0.8).

CONCLUSIONS

These findings contribute to a deeper understanding of pregnancy-related metabolic changes and may offer insights into maternal and neonatal health outcomes.

Relationship between relaxin-2 levels in serum and mode of conception in twin gestations: A prospective cohort study

AIM

Relaxin is a peptide hormone commonly associated with pregnancy when it is thought to play a role in modulating various physiological processes to optimize maternal-fetal adaptation. In twin pregnancies these adaptive requirements are higher than in singleton pregnancies, therefore it is important to understand how circulating relaxin behaves in such conditions. This prospective cohort study aims to determine the serum relaxin-2 levels throughout gestation in twin pregnancies and to investigate its association with the mode of conception.

METHODS

Blood samples were collected during each trimester of gestation from 26 women with twin pregnancies obtained through spontaneous conception (SC, n = 18) or assisted reproductive technologies, specifically through intracytoplasmic sperm injection (ART, n = 8). Serum relaxin-2 levels were measured by a highly sensitive ELISA method.

RESULTS

The results indicated that serum relaxin-2 level peaks in the first trimester (491.05 ± 207.41 pg/mL), then decreases in the second trimester (446.27 ± 180.4 pg/mL; p < 0.057) and in the third trimester (422.19 ± 194.30 pg/mL; p < 0.025). Interestingly, the serum relaxin-2 level was higher in the spontaneous conception group with respect to the assisted reproductive technologies group (p < 0.001), when measured at each trimester of gestation. In addition, the multivariate regression analysis showed that only the assisted reproductive technologies had a significant impact on serum levels of relaxin-2 (p < 0.001), and no significant association was found with other women's clinical and demographic characteristics.

CONCLUSIONS

These findings extend the current knowledge about the pattern of circulating relaxin-2 throughout gestation in twin pregnancies, providing a sensitive measurement of serum relaxin-2 levels and a description of its putative physiological roles in humans.

The Association of Female and Male Preconception Dyslipidemia With Live Birth in Couples Seeking Fertility Treatment

CONTEXT

Dyslipidemia is common, and resultant endothelial dysfunction may impact reproductive outcomes. No prospective study has examined the effect of preconception lipid parameters in both female and male partners or their interaction on live birth.

OBJECTIVE

To determine whether live birth is associated with preconception lipids in both partners by planned fertility treatment.

DESIGN

Secondary analysis of the Folic Acid and Zinc Supplementation Trial, conducted between June 2013 and December 2017. Couples were followed for 9 months after randomization and until delivery.

SETTING

Multicenter study.

PARTICIPANTS

Couples seeking fertility treatment (n = 2370; females 18-45 years, males ≥18 years).

EXPOSURES

Female, male, and couple abnormal vs normal preconception lipid concentrations [total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein, triglycerides].

MAIN OUTCOME MEASURES

Live birth.

RESULTS

Among 2370 couples, most males (84%) and females (76%) had at least 1 abnormal lipid parameter. Males planning in vitro fertilization (IVF, n = 373) with elevated LDL had lower probability of live birth than those with normal levels [47.4% vs 59.7%, adjusted relative risk (aRR) 0.79, 95% confidence interval (CI) 0.65-0.98]. In couples planning IVF where both partners had elevated TC or LDL, live birth was lower than those with normal levels (TC: 32.4% vs 58.0%, aRR 0.53, 95% CI 0.36-0.79; and LDL: 41.9% vs 63.8%, aRR 0.69, 95% CI 0.55-0.85). Lipid parameters were not associated with live birth for couples planning non-IVF treatments.

CONCLUSION

Couples planning IVF where both partners had elevated TC or LDL and males planning IVF with elevated LDL had decreased probability of live birth. These findings may support lipid screening in patients seeking fertility treatment for prognostic information for reproductive outcomes.

Estrogen receptors in mitochondrial metabolism: age-related changes and implications for pregnancy complications

Estrogen hormones are primarily associated with their role as female sex hormones responsible for primary and secondary sexual development. Estrogen receptors are known to undergo age-dependent decreases due to age-related changes in hormone production. In the mitochondria, estrogen functions by reducing the production of reactive oxygen species in the electron transport chain, inhibiting apoptosis, and regulating mitochondrial DNA content. Moreover, estrogen receptors may be the key components in maintaining mitochondrial membrane potential and structure. Although estrogen plays a crucial role in the development of pregnancy, our understanding of how estrogen receptors change with aging during pregnancy remains limited. During pregnancy, estrogen levels are significantly elevated, with a corresponding upregulation of estrogen receptors, which play various roles in pregnancy. However, the exact role of estrogen receptors in pregnancy complications remains to be further investigated. The paper reviews the role of estrogen receptors in the regulation of mitochondrial metabolism and in pregnancy complications, with a special focus on the effect of age-related changes on estrogen levels and estrogen receptors function. We also address how estrogen maintains mitochondrial function, including reducing the production of reactive oxygen species in the electron transport chain, inhibiting apoptosis, regulating mitochondrial DNA content, and maintaining mitochondrial membrane potential and structure. However, the effects of estrogen on mitochondria-endoplasmic reticulum contacts have not been well studied. Based on these emergent roles in mitochondria, the differential roles of estrogen receptors in pregnancy complications are of great relevance. The paper emphasizes the association between maternal health and estrogen receptors and indicates the need for future research to elucidate the interdependence of estrogen receptor-regulated maternal health with mitochondrial function and their relationship with the gut microbiome. Overall, we summarize the important role of estrogen receptors during pregnancy and highlight the need for further research to better understand the role of estrogen receptors in aging and pregnancy complications. This not only helps to reveal the mechanism underlying the role of estrogen in maternal health but also has potential clinical implications for the development of new therapies targeting age-related diseases and pregnancy complications.

Associations between adverse pregnancy outcomes and cognitive impairment and dementia: a systematic review and meta-analysis

BACKGROUND

Individuals with adverse pregnancy outcomes have an increased risk of cerebrovascular disease, but the association between adverse pregnancy outcomes and cognitive impairment and dementia is less well established. We aimed to synthesise, combine, and assess the growing body of data examining the associations between adverse pregnancy outcomes and mild cognitive impairment and dementia in parous women.

METHODS

In this systematic review and meta-analysis, we searched PubMed (MEDLINE), Web of Science, and Embase from database inception up to July 18, 2024, with no language restrictions, for observational studies or clinical trials that reported mild cognitive impairment or dementia as outcomes and included female individuals or women who had an adverse pregnancy outcome, including hypertensive disorders of pregnancy, gestational diabetes, stillbirth, fetal growth restriction, preterm birth, or placental abruption. We excluded studies of men, nulliparous women, women with pre-pregnancy conditions associated with impaired cognition, and studies examining cognitive impairment within 6 months of pregnancy. Database searches were supplemented by manual review of the reference lists of included studies. If studies met eligibility criteria but did not have sufficient data for meta-analysis (ie, did not report a summary statistic or a hazard ratio [HR] for outcome estimation), they were included in the systematic review and excluded from the meta-analysis. After removing duplicates, two investigators independently screened titles and abstracts using Covidence software, with potentially eligible studies undergoing full-text review by the same reviewers, with further review by a third reviewer and disagreements resolved by discussion and group consensus. Study quality was assessed and summary statistics extracted by two reviewers independently. The primary outcomes of our study were mild cognitive impairment, all-cause dementia, Alzheimer's disease, and vascular dementia. Heterogeneity was measured using the Q test and I2 statistic, and we used random-effects models with inverse-variance weighting to assess the association between adverse pregnancy outcome and primary outcomes with sufficient meta-analysable data via pooled adjusted HRs and 95% CIs. The study protocol was registered with PROSPERO, CRD42023453511.

FINDINGS

Of 11 251 publications identified, 15 studies (including 7 347 202 participants) met inclusion criteria for the systematic review, and 11 studies (6 263 431 participants) had sufficient data for meta-analysis. A history of any adverse pregnancy outcome was associated with higher risk of all-cause dementia (adjusted HR 1·32 [95% CI 1·17-1·49]; I2= 80%), Alzheimer's disease (1·26 [1·04-1·53]; I2=63%), and vascular dementia (1·94 [1·70-2·21]; I2=0%). A history of any hypertensive disorder of pregnancy was significantly associated with all-cause dementia (1·32 [1·11-1·57]; I2=74%) and vascular dementia (1·78 [1·46-2·17]; I2=0%), but not Alzheimer's disease (1·24 [0·98-1·57]; I2=66%). Stillbirth was not significantly associated with higher risk of all-cause dementia (1·26 [95% CI 0·93-1·71]; I2=62%). In individual studies, similar effect directions were observed for preterm birth and fetal growth restriction, but data were insufficient for meta-analysis.

INTERPRETATION

Given their increased risk of dementia, women with a history of adverse pregnancy outcomes should be evaluated for additional dementia risk factors and monitored closely for any signs of cognitive decline. Furthermore, to obtain more reliable findings, future studies should measure both exposures and outcomes prospectively and objectively.

FUNDING

National Institutes of Health, National Institute of Neurological Disorders and Stroke, National Institute on Aging, and National Heart, Lung and Blood Institute.

Dietary supplementation with thyme oil improves the reproductive characteristics of Barki adult and prepubertal ewes

The reproductive technology has a significant impact on the development of livestock production. The thyme oil, rich in phytoestrogen chemicals like apigenin, has been found to enhance reproductive performance by mimicking estrogen's action. This study aimed to investigate the effects of oral supplementation with thyme essential oil on the reproductive organ biometry, and reproductive performance in adult and prepubertal Barki ewes. Seventy ewes were treated with intravaginal sponges impregnated with 40 mg. medroxyprogesterone acetate for 14 days and simultaneously assigned randomly to two groups (20 adult and 15 prepubertal ewes per group), i.e., a control and a thyme oil treated (2.25 mg/kg body weight) group. The number of follicles, follicle diameter, corpora lutea diameter, and estrogen concentration were higher in the thyme oil-treated group than in the control group without comparing between adult ewes and prepubertal ewes. Additionally, the number and diameter of the large follicles were higher (P < 0.05) in the right-side ovary of adult ewes compared with that in prepubertal ewes at day 15. Moreover, thyme oil treatment resulted in higher conception (P < 0.01), lambing rates (P < 0.05), and fecundity (P < 0.01), with values 95.12, 136.73, and 130.25 compared with those in the control group, with values 63.51, 105.24, and 66.97, respectively, without comparing between adult ewes and prepubertal ewes. The adult ewes had a stronger estrus response and better fertility measurement values than prepubertal ewes. Additionally, the estrogen serum levels were positively correlated with the number (P < 0.05) and diameter (P < 0.01) of follicles, and the progesterone serum concentration was positively correlated with the corpora lutea diameter (P < 0.01), without treated group. In conclusion, dietary supplementation with thyme oil improved the follicular population and reproductive performance, which has a good effect on the adult and prepubertal ewes in the Barki ewes.

Interaction between young fecal transplantation and perfluorobutanesulfonate endocrine disrupting toxicity in aged recipients: An estrobolome perspective

Transplanting young feces into the aged was found to effectively counteract the endocrine disrupting effects of perfluorobutanesulfonate (PFBS) pollutant, showing promise in the maintenance of healthy aging. However, the interactive mechanisms between young fecal transplantation and PFBS endocrine disruption during aging remain unclear. In this follow-up study, aged zebrafish were administered young donor feces and then exposed to environmentally relevant concentrations of PFBS (0 and 100 μg/L). Alterations in the holistic estrobolome along gut-liver axis were investigated. The results showed that PFBS singular exposure significantly increased blood estradiol concentration in the aged, inducing an estrogenic activity. Concentrations of other estrogen forms, including estrone and estriol, were also disrupted by PFBS. Interestingly, young fecal transplant effectively mitigated the estrogenic toxicity of PFBS and largely restored estrogen equilibrium. After PFBS exposure, the transcriptions of estrogen metabolic genes were consistently upregulated in aged livers, causing the accumulation of 2-methoxyestradiol-3-methylether metabolite. In contrast, aged livers coexposed to young fecal transplant and PFBS enhanced the glucuronidation process, successfully facilitating the elimination and detoxification of estrogen metabolites. In aged gut, PFBS exposure inhibited β-glucuronidase enzyme activity, implying the suppression of estrogen deconjugation and recycle. However, in the combined group, β-glucuronidase activity was significantly stimulated, thus reestablishing estrobolome dynamics. Overall, current findings provide mechanistic insights into the antagonistic interaction between young fecal transplant and PFBS on reproductive endocrinology. Gut microbiota manipulation appears appealing to maintain healthy aging progression albeit the interruption of environmental xenobiotics.

Air pollutants as modulators of mitochondrial quality control in cardiovascular disease

It is important to understand the effects of environmental factors such as air pollution on mitochondrial structure and function, especially when these changes increase cardiovascular disease risk. Although lifestyle choices directly determine many mitochondrial diseases, increasingly, it is becoming clear that the structure and function of mitochondria may be affected by pollutants found in the atmosphere (e.g., gases, pesticides herbicide aerosols, or microparticles). To date, the role of such agents on mitochondria and the potential impact on cardiovascular fitness is neglected. Here we offer a review of airborne stressors and pollutants, that may contribute to impairments in mitochondrial function and structure to cause heart disease.

Differences in perinatal complications and serum hormone levels due to uterine endometrial preparation methods in frozen-thawed embryo transfer

AIM

In frozen-thawed embryo transfer (FET), differences in endometrial preparation methods affect the incidence of perinatal complications. However, the underlying causes are unclear. We aimed to investigate whether serum E2, P4 levels are associated with perinatal complications.

METHODS

This is a retrospective cohort study, involving 306 successful FET pregnancies from 2017 to 2022. Participants were divided into Natural Cycle (NC) and Hormone Replacement Cycle (HRC) group. We compared serum hormone levels, maternal backgrounds, and perinatal outcomes and complications. Furthermore, within the HRC group, serum hormone levels were compared for perinatal complications previously reported to show differences in incidence rates depending on the method of endometrial preparation.

RESULTS

HRC exhibited significantly higher serum E2 levels during the implantation period, but lower P4 levels during ovulation, implantation, and pregnancy test period compared with NC. HRC also had significantly higher rates of postpartum hemorrhage (PPH) and placenta accreta spectrum (PAS). There was no association found between perinatal complications more likely to occur in HRC and serum E2, P4 levels.

CONCLUSIONS

In HRC, there were more occurrences of PPH and PAS. Although serum E2, P4 levels during FET did not correlate with perinatal complications.

Supraphysiological Dose of Testosterone Impairs the Expression and Distribution of Sex Steroid Receptors during Endometrial Receptivity Development in Female Sprague-Dawley Rats

This study aims to investigate the effect of a supraphysiological dose of testosterone on the levels of sex steroid hormones and the expression and distribution of sex steroid receptors in the uterus during the endometrial receptivity development period. In this study, adult female Sprague-Dawley rats (n = 24) were subcutaneously administered 1 mg/kg/day of testosterone alone or in combination with the inhibitors (finasteride or anastrozole or both) from day 1 to day 3 post-coitus, while a group of six untreated rats served as a control group. The rats were sacrificed on the evening of post-coital day 4 of to measure sex steroid hormone levels by ELISA. Meanwhile, gene expression and protein distribution of sex steroid receptors were analysed by quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC), respectively. In this study, treatment with a supraphysiological dose of testosterone led to a significant reduction in oestrogen and progesterone levels compared to the control. The mRNA expression of the androgen receptor increased significantly in all treatment groups, while the mRNA expression of both the progesterone receptor and the oestrogen receptor-α decreased significantly in all treatment groups. The IHC findings of all sex steroid receptors were coherent with all mRNAs involved. This study shows that a supraphysiological dose of testosterone was able to interrupt the short period of the implantation window. This finding could serve as a basis for understanding the role of testosterone in endometrial receptivity in order to develop further therapeutic approaches targeting androgen-mediated disorders of endometrial receptivity.

Effect of estradiol supplementation on luteal support following a significant reduction in serum estradiol levels after hCG triggering: a prospective randomized controlled trial

OBJECTIVE

This study aimed to evaluate the impact of adding 4 mg estradiol valerate to progesterone for luteal support on pregnancy rates in IVF cycles following a long protocol with reduced luteal serum estradiol levels post-hCG triggering.

DESIGN, SETTING, AND PARTICIPANTS

The prospective randomized controlled trial was conducted at a public tertiary hospital reproductive center with 241 patients who experienced a significant decrease in serum estrogen levels post-oocyte retrieval.

INTERVENTIONS

Participants received either a daily 4 mg dose of estradiol valerate in addition to standard progesterone or standard progesterone alone for luteal support.

RESULTS

The ongoing pregnancy rate did not show a significant difference between the E2 group and the control group (56.6% vs. 52.2%, with an absolute rate difference (RD) of 4.4%, 95% CI -0.087 to 0.179, P = 0.262). Similarly, the live birth rate, implantation rate, clinical pregnancy rate, early abortion rate, and severe OHSS rate were comparable between the two groups. Notably, the E2 group had no biochemical miscarriages, contrasting significantly with the control group (0.0% vs. 10.7%, RD -10.7%, 95% CI -0.178 to -0.041, P = 0.000). In the blastocyst stage category, the clinical pregnancy rate was notably higher in the E2 group compared to the control group (75.6% vs. 60.8%, RD 14.9%, 95% CI 0.012 to 0.294, P = 0.016).

CONCLUSION

Adding 4 mg estradiol valerate to progesterone for luteal support does not affect the ongoing pregnancy rate in embryo transfer cycles using a long protocol with a significant decrease in serum estradiol levels after hCG triggering. However, it may reduce biochemical miscarriages and positively impact clinical pregnancy rates in blastocyst embryo transfer cycles.

TRIAL REGISTRATION

ChiCTR1800020342.

Contributions of white adipose tissue to energy requirements for female reproduction

Body composition impacts female fertility and there are established relationships between adipose tissue and the reproductive system. Maintaining functional adipose tissue is vital for meeting the energetic demands during the reproductive process, from ovulation to delivery and lactation. White adipose tissue (WAT) shows plastic responses to daily physiology and secretes diverse adipokines that affect the hypothalamic-pituitary-ovarian axis, but many other interorgan interactions remain to be determined. This review summarizes the current state of research on the dialogue between WAT and the female reproductive system, focusing on the impact of this crosstalk on ovarian and endometrial factors essential for fecundity.

Allicin in pregnancy diets modulates steroid metabolism in pregnant sows and placental sulphate metabolism promoting placental angiogenesis and foetal development

The low-birth-weight of piglets is an important factor affecting pig enterprises. The placenta, as a key organ for material exchange between mother and foetus, directly influences the growth and development of the foetus. Allicin exhibits various biological activities, including anti-inflammatory and antioxidant properties. It may also play a crucial role in enhancing sow reproductive performance and placental angiogenesis. In this study, we used 70 lactating Landrace × Yorkshire binary heterozygous sows to explore the effect of allicin on the reproductive performance of sows and placental development. The sows were randomly assigned into the Allicin group (Allicin), which was fed with a diet containing 0.25% allicin, and the negative control group, which was fed with basal feed. The experimental period lasted for 114 d from the date of mating to the end of farrowing. The results showed that the addition of allicin to the gestation diets increased the number of total born piglets, born alive piglets, and high-birth-weight piglets, reduced peripartum oxidative stress, alleviated dysregulation of glucose-lipid metabolism in sows, and increased the levels of antioxidant markers in the placenta. Differential analysis of metabolites in maternal plasma and placenta samples by non-targeted metabolomics revealed that allicin improved cholesterol metabolism, steroid biosynthesis, and increased plasma progesterone levels in sows. Allicin promoted sulphur metabolism, cysteine and methionine metabolism in placental samples and increased the hydrogen sulphide (H2S) content in the placenta. In addition, Quantitative Real-time PCR, Western blot and immunofluorescence results showed that allicin upregulated the expression of angiogenesis-related genes, VEGF-A, FLK 1 and Ang 1, in the placenta, implying that it promoted placental angiogenesis. These results indicate that supplementing the diet of pregnant sows with allicin reduces oxidative stress, alleviates dysregulation of glucose-lipid metabolism during the periparturient period, and promotes placental angiogenesis and foetal development by increasing plasma progesterone level and placental H2S content.

Correlation of Maternal Vitamin D Status in Early Pregnancy and Vitamin D Supplementation during Pregnancy with Atopic Dermatitis in Infants: A Prospective Birth Cohort Study

OBJECTIVE

This study aimed to investigate the association of maternal first-trimester vitamin D levels and vitamin D supplementation during pregnancy with infant atopic dermatitis (AD) and to determine the effect of variables such as mode of conception on the association.

METHODS

This study was based on the Shanghai sub-cohort of the International Birth Cohort of China. A total of 4051 woman-infant pairs with singleton pregnancies were recruited. Vitamin D deficiency and insufficiency were defined as serum 25-hydroxyvitamin D concentrations of 25 and 50 nmol/L, respectively. AD in infants was assessed during the first six months using a standardized questionnaire based on the British Working Party criteria. Modified Poisson regression estimated the association between maternal vitamin D status and infant AD.

RESULTS

The risk of AD in infants was higher in women with deficient 25-hydroxyvitamin D levels in the first trimester (RR: 1.77, 95% CI: 1.41-2.23). This increased risk was seen in naturally conceived pregnancies, but not in those conceived using assisted reproductive technology (ART). The incidence of AD decreased in infants of mothers who took multi-vitamin (RR: 0.79, 95% CI: 0.67-1.98) and vitamin D supplements (RR: 0.51, 95% CI: 0.37-0.71) compared to those whose mothers did not take any supplements. Maternal vitamin D deficiency had varying effects on AD risk based on passive smoking exposure and breastfeeding patterns.

CONCLUSIONS

Our findings highlight the importance of monitoring and supplementing vitamin D during pregnancy, especially in specific maternal populations, to reduce the risk of AD in offspring.

Associations between mycoestrogen exposure and sex steroid hormone concentrations in maternal serum and cord blood in the UPSIDE pregnancy cohort

Zearalenone (ZEN) is a fungal-derived toxin found in global food supplies including cereal grains and processed foods, impacting populations worldwide through diet. Because the chemical structure of ZEN and metabolites closely resembles 17β-estradiol (E2), they interact with estrogen receptors α/β earning their designation as 'mycoestrogens'. In animal models, gestational exposure to mycoestrogens disrupts estrogen activity and impairs fetal growth. Here, our objective was to evaluate relationships between mycoestrogen exposure and sex steroid hormone concentrations in maternal circulation and cord blood for the first time in humans. In each trimester, pregnant participants in the UPSIDE study (n = 297) provided urine for mycoestrogen analysis and serum for hormone analysis. At birth, placental mycoestrogens and cord steroids were measured. We fitted longitudinal models examining log-transformed mycoestrogen concentrations in relation to log-transformed hormones, adjusting for covariates. Secondarily, multivariable linear models examined associations at each time point (1st, 2nd, 3rd trimesters, delivery). We additionally considered effect modification by fetal sex. ZEN and its metabolite, α-zearalenol (α-ZOL), were detected in >93% and >75% of urine samples; >80% of placentas had detectable mycoestrogens. Longitudinal models from the full cohort exhibited few significant associations. In sex-stratified analyses, in pregnancies with male fetuses, estrone (E1) and free testosterone (fT) were inversely associated with ZEN (E1 %Δ: -6.68 95%CI: -12.34, -0.65; fT %Δ: -3.22 95%CI: -5.68, -0.70); while α-ZOL was positively associated with E2 (%Δ: 5.61 95%CI: -1.54, 9.85) in pregnancies with female fetuses. In analysis with cord hormones, urinary mycoestrogens were inversely associated with androstenedione (%Δ: 9.15 95%CI: 14.64, -3.30) in both sexes, and placental mycoestrogens were positively associated with cord fT (%Δ: 37.13, 95%CI: 4.86, 79.34) amongst male offspring. Findings support the hypothesis that mycoestrogens act as endocrine disruptors in humans, as in animal models and livestock. Additional work is needed to understand impacts on maternal and child health.

Follow-Up Study of 17-β Estradiol, Prolactin and Progesterone with the Kinetics and Prevalence of T. gondii Infection in Pregnant Women

Toxoplasmosis is an infection caused by the parasite Toxoplasma gondii. One-third of the world's population has come into contact with this parasite. In Mexico, the prevalence is between 15% and 50% in the general population and 34.9% in women with high-risk pregnancies. In pregnancy, the highest incidence of infection occurs in the third trimester and fetal damage is inversely proportional to gestational age. Maternal hormones play a fundamental role in the immune response. There are very few studies, with controversial results, on the levels of increased hormones and their relationship to the kinetics of T. gondii infections during pregnancy. The aim was to determine the serum levels of 17-β estradiol, prolactin, and progesterone, and their association with anti-T. gondii antibodies' kinetics in pregnancy. Fifty-two pregnant patients were studied. A questionnaire with sociodemographic and clinical aspects was used. Afterward, 10 mL of venous blood was collected by venipuncture every trimester. The concentrations of 17-β estradiol, progesterone, and prolactin were measured, using the ELISA method. In addition, anti-Toxoplasma IgG and IgM antibodies were also determined in the first, second, and third trimester. The prevalence of anti-Toxoplasma IgG antibodies was 26.92% in the first and second trimester and 32.7% in the third trimester. In seropositive women, 17-β estradiol increased in the second and third trimesters of pregnancy. Progesterone increased significantly p < 0.039 in the third trimester in these women, while prolactin increased in the second trimester with a statistical significance of p < 0.021. In addition, 17-β estradiol, progesterone, and prolactin are associated with T. gondii infection during pregnancy. New studies are necessary to clarify the specific mechanisms of immune response related to these hormones during pregnancy.

Low Estradiol Level and Endometrial Thickness on the Day of Endometrial Transformation Influence Clinical Pregnancy After Intrauterine Insemination

Background

The causes of pregnancy failure after intrauterine insemination (IUI) are controversial. The purpose of this study was to investigate the influencing factors on clinical pregnancy after IUI.

Methods

This study retrospectively analyzed 1464 cycles of IUI performed at the Meizhou People's Hospital between March 2014 and June 2023. The χ2 test and logistic regression analysis was applied to assess the associations between the some factors (maternal age, paternal age, cycle type (natural cycle or ovulation induction cycle), hormone level on the day of endometrial transformation (estradiol (E2), luteinizing hormone (LH), and progesterone (P)), endometrial thickness on the day of endometrial transformation, and forward motile sperm concentration after treatment) and pregnancy failure.

Results

Among the 1464 IUI cycles in this study, 268 cycles of assisted reproduction resulted in clinical pregnancy, with a clinical pregnancy rate of 18.3%. During the cycles with clinical pregnancy, there were 25 (12.9%) preterm births and 169 (87.1%) full-term births. The E2 level on the day of endometrial transformation in clinical pregnancy group was higher than that in the pregnancy failure group (658.79±656.02 vs 561.21±558.83 pg/mL)(P=0.025). The clinical pregnancy group had a higher percentage of endometrial thickness between 8 and 13mm on the day of endometrial transformation than the pregnancy failure group (83.2% vs 75.0%)(P=0.002). The results of regressions analysis showed that low E2 level on the day of endometrial transformation (<238.3 pg/mL vs ≥238.3 pg/mL: OR 1.493, 95% CI: 1.086-2.052, P=0.014), and endometrial thickness <8mm on the day of endometrial transformation (<8mm vs 8-13mm: OR 1.886, 95% CI: 1.284-2.771, P=0.001) may increase risk of pregnancy failure performed IUI.

Conclusion

Low estradiol level, and endometrial thickness on the day of endometrial transformation may increase risk of pregnancy failure performed intrauterine insemination.

Reference data on estrogen metabolome in healthy pregnancy

INTRODUCTION

Estrogen hormones and their metabolites are implicated in the maintenance of healthy pregnancy and adequate fetal development. Abnormal levels were related to increased risk of pregnancy complications, particularly preeclampsia. Our aims were (1) to develop a methodological platform for the comprehensive assessment of estrogen metabolome in pregnancy; (2) to collect healthy reference data for relevant elements of estrogen metabolome in each trimester; (3) to assess unconjugated fractions of the estrogen metabolome, (4) to assess the dominant metabolic pathways of estrogen compounds.

METHODS

We enrolled healthy pregnant mothers between gestational week 5-15 (on the confirmation of pregnancy; 79 samples), gestational weeks 19-27 (70 samples), and gestational week 34-39 (54 samples). A method employing liquid chromatography-tandem mass spectrometry (LC-MS/MS) was developed to assess estrone, 17-beta-estradiol, estriol levels, and their metabolites as conjugated and unconjugated forms. Descriptive statistics were used to characterize the level of compounds in each trimester.

RESULTS

Estrone, 17-beta-estradiol and estriol levels are dramatically increasing with the advancement of pregnancy. Measured levels were in a very wide range. 17-beta-estradiol is neither glucuronated nor sulphated. To the contrary, estriol and estrone are significantly conjugated; unconjugated fraction is <15% of total hormone levels in any trimester. Regarding metabolism, 4-methoxy-estradiol and 17-epiestriol were not detected.

CONCLUSION

We concluded that (1) the levels of estrogen compounds and metabolites increase with advancing gestational age; (2) the wide ranges of levels challenge the establishment of a healthy reference range for clinical purposes; (3) 17-beta-estradiol is not conjugated significantly; (4) 4-methylation and 17-epimerization pathways of estrogens are negligible with our LC-MS/MS method.

Estrogen and Progesterone Receptors Are Dysregulated at the BPH/5 Mouse Preeclamptic-Like Maternal-Fetal Interface

The etiopathogenesis of preeclampsia, a leading hypertensive disorder of pregnancy, has been proposed to involve an abnormal circulating sex hormone profile and misexpression of placental estrogen and progesterone receptors (ER and PR, respectively). However, existing research is vastly confined to third trimester preeclamptic placentas. Consequently, the placental-uterine molecular crosstalk and the dynamic ER and PR expression pattern in the peri-conception period remain overlooked. Herein, our goal was to use the BPH/5 mouse to elucidate pre-pregnancy and early gestation Er and Pr dynamics in a preeclamptic-like uterus. BPH/5 females display low circulating estrogen concentration during proestrus, followed by early gestation hypoestrogenemia, hyperprogesteronemia, and a spontaneous preeclamptic-like phenotype. Preceding pregnancy, the gene encoding Er alpha (Erα, Esr1) is upregulated in the diestrual BPH/5 uterus. At the peak of decidualization, Esr1, Er beta (Erβ, Esr2), and Pr isoform B (Pr-B) were upregulated in the BPH/5 maternal-fetal interface. At the protein level, BPH/5 females display higher percentage of decidual cells with nuclear Erα expression, as well as Pr downregulation in the decidua, luminal and glandular epithelium. In conclusion, we provide evidence of disrupted sex hormone signaling in the peri-conception period of preeclamptic-like pregnancies, potentially shedding some light onto the intricate role of sex hormone signaling at unexplored timepoints of human preeclampsia.

Successful pregnancy using oral DHEA treatment for hypoandrogenemia in a 30-year-old female with 5 recurrent miscarriages, including fetal demise at 24 weeks: a case report

Hypoandrogenemia is not usually considered as a potential cause of recurrent miscarriage. We present the case of a 30-year-old female with 6 previous pregnancies resulting in one live birth and 5 pregnancy losses, including fetal demise at 24 weeks gestation. She had standard investigations after her 4th loss, at a specialized miscarriage clinic. Lupus anticoagulant, anticardiolipin antibodies, thyroid function, parental karyotypes were all normal. Fetal products confirmed triploidy for her 4th miscarriage at 16 weeks gestation. She was reassured and advised to conceive again but had fetal demise after 24 weeks gestation. This was her 5th pregnancy loss with no explanation. She attended our Restorative Reproductive Medicine (RRM) clinic in January 2022. In addition to poor follicle function, we found hypoandrogenemia for the first time. Treatment included follicle stimulation with clomiphene and DHEA 25 mg twice daily pre-conception with DHEA 20 mg once daily maintained throughout pregnancy. She delivered a healthy baby boy by cesarean section at 36 weeks gestation in November 2023. Hypoandrogenemia should be considered as a contributory factor for women with recurrent miscarriage or late pregnancy loss. Restoration of androgens to normal levels with oral DHEA is safe and can improve pregnancy outcome.

Molecular Determinants of Uterine Receptivity: Comparison of Successful Implantation, Recurrent Miscarriage, and Recurrent Implantation Failure

Embryo implantation is one of the most remarkable phenomena in human reproduction and is not yet fully understood. Proper endometrial function as well as a dynamic interaction between the endometrium itself and the blastocyst-the so-called embryo-maternal dialog-are necessary for successful implantation. Several physiological and molecular processes are involved in the success of implantation. This review describes estrogen, progesterone and their receptors, as well as the role of the cytokines interleukin (IL)-6, IL-8, leukemia inhibitory factor (LIF), IL-11, IL-1, and the glycoprotein glycodelin in successful implantation, in cases of recurrent implantation failure (RIF) and in cases of recurrent pregnancy loss (RPL). Are there differences at the molecular level underlying RIF or RPL? Since implantation has already taken place in the case of RPL, it is conceivable that different molecular biological baseline situations underlie the respective problems.

ICI 182,780 Attenuates Selective Upregulation of Uterine Artery Cystathionine β-Synthase Expression in Rat Pregnancy

Endogenous hydrogen sulfide (H2S) produced by cystathionine β-synthase (CBS) and cystathionine-γ lyase (CSE) has emerged as a novel uterine vasodilator contributing to pregnancy-associated increases in uterine blood flow, which safeguard pregnancy health. Uterine artery (UA) H2S production is stimulated via exogenous estrogen replacement and is associated with elevated endogenous estrogens during pregnancy through the selective upregulation of CBS without altering CSE. However, how endogenous estrogens regulate uterine artery CBS expression in pregnancy is unknown. This study was conducted to test a hypothesis that endogenous estrogens selectively stimulate UA CBS expression via specific estrogen receptors (ER). Treatment with E2β (0.01 to 100 nM) stimulated CBS but not CSE mRNA in organ cultures of fresh UA rings from both NP and P (gestational day 20, GD20) rats, with greater responses to all doses of E2β tested in P vs. NP UA. ER antagonist ICI 182,780 (ICI, 1 µM) completely attenuated E2β-stimulated CBS mRNA in both NP and P rat UA. Subcutaneous injection with ICI 182,780 (0.3 mg/rat) of GD19 P rats for 24 h significantly inhibited UA CBS but not mRNA expression, consistent with reduced endothelial and smooth muscle cell CBS (but not CSE) protein. ICI did not alter mesenteric and renal artery CBS and CSE mRNA. In addition, ICI decreased endothelial nitric oxide synthase mRNA in UA but not in mesenteric or renal arteries. Thus, pregnancy-augmented UA CBS/H2S production is mediated by the actions of endogenous estrogens via specific ER in pregnant rats.