The myometrial junctional zone spiral arteries in normal and abnormal pregnancies: a review of the literature

Association between endometrial thickness and birthweight of singletons from vitrified-warmed cycles: a retrospective cohort study

RESEARCH QUESTION

What is the association between endometrial thickness (EMT) and the birthweight of singleton infants born from frozen-thawed embryo transfer cycles?

DESIGN

This retrospective cohort study was conducted from January 2016 to December 2019. Participants were categorized into a natural cycle (NC, n = 8132) group and hormone replacement therapy (HRT, n = 4975) group. Only singleton deliveries were included. The primary outcomes were measures of birthweight and relevant indexes. Multivariable logistic regression and multivariable-adjusted linear regression models that incorporated restricted cubic splines were used.

RESULTS

In the HRT group, the risk of delivering a small for gestational age (SGA) infant was increased in women with an EMT <8.0 mm (adjusted odds ratio [aOR] 1.85, 95% confidence interval [CI] 1.17-2.91) compared with women with an EMT of 8.0 to <12.0 mm, and increased with an EMT ≥12.0 mm (aOR 1.85, 95% CI 1.03-3.33). An inverted U-shaped relationship was found between EMT and birthweight in women with HRT. No significant differences were shown in birthweight z-score, or being SGA or large for gestational age, in singletons among the three EMT groups in the natural cycles.

CONCLUSIONS

A thinner endometrium seen in women undergoing HRT cycles was associated with a lower birthweight z-score, as well as a higher risk of SGA. However, no significant association was observed between EMT and birthweight z-score or SGA in the NC group. It is noteworthy that a thicker endometrium was not associated with a higher birthweight in frozen-thawed embryo transfer (FET) cycles. Women with a thin endometrium who achieve pregnancy require specialized attention, particularly if they are undergoing FET with HRT cycles.

JPT2 in subclinical hypothyroidism-related miscarriage as a transcription co-factor: involvement of LEPR/STAT3 activation

BACKGROUND AND PURPOSE

Subclinical hypothyroidism (SCH) has been identified to be associated with implantation failure, in which the dysfunction of trophoblast cells is involved. In this study, the transcriptomics of aborted placenta from SCH rats were analyzed. Jupiter microtubule-associated homolog 2 (JPT2) was downregulated in the aborted placenta. This study aims to investigate its role in SCH-associated miscarriage.

METHODS

Spontaneous abortion was observed in SCH rats generated by thyroidectomy combined with levothyroxine administration. The transcriptomics analysis was performed using aborted placenta. Afterward, the effects of JPT2 on trophoblast cells were explored using gain-and loss-of-function experiments.

RESULTS

Transcriptomics analysis showed 1286 downregulated genes and 2300 upregulated genes in the aborted placenta, and JPT2 was significantly downregulated in the aborted placenta from SCH rats. Afterward, gain-and loss-of-function experiments exhibited that overexpression of JPT2 promoted the proliferation, migration, invasion, spheroid formation of HTR-8/SVneo trophoblast cells and their attachment to endometrial stromal cells, while these biological behaviors were suppressed by JPT2 knockdown. Furthermore, JPT2 accelerated the transcription of leptin receptor (LEPR), and activated signal transducer and activator of transcription 3 (STAT3) signal in a transcription factor AP-2γ-dependent manner. In addition, silencing of LEPR abolished the role of JPT2.

CONCLUSION

Our results revealed that JPT2, which was downregulated in the aborted placenta from SCH rats, promoted proliferation, migration, invasion, spheroid formation, and attachment of trophoblast cells via regulating LEPR/STAT3 axis as a transcription co-factor. It is indicated that low expression of JPT2 may contribute to the abortion in individuals with SCH.

Possible contributions of fibrogenesis to recurrent miscarriages - A transcriptome analysis

Recurrent miscarriages (RM) generally refer to two or more consecutive pregnancy losses. The risk of miscarriages grows with its frequency of occurrences, so as the future obstetric complications or longer-term health problems for patients. Most previous researches sought to discover the etiology of RM by making comparisons between patients with RM and fertile women. Our study collected decidua tissues from patients with RM and single miscarriage (SM) for transcriptome sequencing analysis and aimed at identifying vital factors contributing to additional miscarriages after previous miscarriage. Between the RM and SM group, a total of 122 differentially expressed genes (DEGs) were detected and pathways associated with cell adhesion and ECM remodeling were particularly enriched in the RM group, which indicated abnormally activated fibrogenesis process. Particularly, the enhancement of ITGB6, EGFLAM and COL3A1 in the RM group were validated by RT-qPCR. Our study discovered that fibrogenesis, which might be caused by intrauterine manipulation, could lead to recurrent miscarriages after a previous miscarriage. Therefore, we encourage higher attention to thorough prevention and prompt remedies towards fibrotic disorders related diseases.

Diagnostic and management dilemmas of pregnancies at the utero-tubal junction: A case series and management algorithm

OBJECTIVE

A pregnancy at the utero-tubal junction is a rare type of ectopic pregnancy and is associated with high maternal morbidity if it remains undetected. In the present study we discuss four cases of ectopic pregnancies at the utero-tubal junction which caused diagnostic and management dilemmas.

METHODS

Four cases of early pregnancies with the gestational sac (G-sac) implanted near the utero-tubal junction are described. In case 1 this was suspected after a failed attempt at dilatation and curettage at our hospital, cases 2 and 3 presented with amenorrhea and pain abdomen and case 4 was diagnosed on first pregnancy documentation scan after frozen embryo transfer.

RESULTS

As initial two-dimensional (2D) transvaginal scan (TVS) failed to diagnose the exact location of the G-sac, three-dimensional (3D) TVS helped to localize the exact location of pregnancy and subsequent individualized management. Case 1 had a partial intramural ectopic pregnancy managed by laparotomy and removal of the ectopic sac. The second and third cases were eccentric uterine pregnancies. The fourth was an interstitial ectopic pregnancy managed by a laparoscopic loop and stitch technique.

CONCLUSION

This case series describes the role of 3D TVS for the evaluation of pregnancies implanted at the utero-tubal junction and individual management of eccentric intrauterine, interstitial ectopic and intramural ectopic pregnancies. A diagnostic algorithm for such types of cases and management options is discussed.

Immune dysfunction mediated by the competitive endogenous RNA network in fetal side placental tissue of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS), a common endocrine and metabolic disorder affecting women in their reproductive years. Emerging evidence suggests that the maternal-fetal immune system is crucial for proper pregnancy. However, whether immune function is altered at the end of pregnancy in PCOS women and the underlying molecular mechanisms is currently unexplored. Herein, the basic maternal immune system was investigated (n = 136 in the control group; n = 103 in the PCOS group), and whole-transcriptome sequencing was carried out to quantify the mRNAs, miRNAs, and lncRNAs expression levels in fetal side placental tissue of women with PCOS. GO, KEGG, and GSEA analysis were employed for functional enrichment analysis. The process of identifying hub genes was conducted utilizing the protein-protein interaction network. CIBERSORT and Connectivity Map were deployed to determine immune cell infiltration and predict potential drugs, respectively. A network of mRNA-miRNA-lncRNA was constructed and then validated by qRT-PCR. First, red blood cell count, neutrophil count, lymphocyte count, hypersensitive C-reactive protein, and procalcitonin were significantly elevated, while placental growth factor was hindered in PCOS women. We identified 308 DEmRNAs, 77 DEmiRNAs, and 332 DElncRNAs in PCOS samples. Functional enrichment analysis revealed that there were significant changes observed in terms of the immune system, especially the chemokine pathway. Eight genes, including FOS, JUN, EGR1, CXCL10, CXCR1, CXCR2, CXCL11, and CXCL8, were considered as hub genes. Furthermore, the degree of infiltration of neutrophils was dramatically decreased in PCOS tissues. In total, 57 ceRNA events were finally obtained, and immune-related ceRNA networks were validated. Some potential drug candidates, such as enalapril and RS-100329, could have a function in PCOS therapy. This study represents the inaugural attempt to evaluate the immune system at the end of pregnancy and placental ceRNA networks in PCOS, indicating alterations in the chemokine pathway, which may impact fetal and placental growth, and provides new therapy targets.

The Role of Ultrasonography and Magnetic Resonance Imaging in the Diagnosis of the Adherent Placenta: An Observational Study

Introduction Placenta accreta is an important factor responsible for maternal morbidity and mortality and is commonly associated with emergent postpartum hysterectomy. The precise prenatal diagnosis of affected pregnancies allows optimal obstetric management. Ultrasonography (USG) and magnetic resonance imaging (MRI) are the only diagnostic modalities available for the prenatal diagnosis of placenta accreta. Objective This study aims to evaluate the accuracy of USG and MRI in diagnosing adherent placenta. Methods Thirty females with placenta previa or a history of previous cesarean sections were evaluated with USG at 28-30 weeks, followed by MRI. The findings of USG and MRI were compared with the intra-operative findings (gold standard) as determined at surgery and by pathological examination. Results Abnormal bridging vessel (n = 24; 80%) was the most common finding seen on USG, whereas abnormal bulge (n = 22; 73.3%) and heterogenous placenta (n = 21; 70%) were the most common findings seen on MRI. The sensitivity of USG and MRI was in the range of 86.7%-92.9% and 92.9%-100%, respectively, in diagnosing three types of adherent placenta. The positive predictive values (PPV) of USG and MRI were in the range of 86.7%-86.7% and 93.8%-100%, respectively, in diagnosing three types of adherent placenta. The accuracy of USG and MRI was in the range of 86.7%-96.7% and 96.7%-100%, respectively, in diagnosing three types of adherent placenta. Conclusion MRI helps to accurately classify placental invasion according to depth, as can be seen from the results of the present study, where the MRI technique was more accurate in diagnosing three types of adherent placenta.

Evaluation of maternal serum SERPINC1, E-selectin, P-selectin, RBP4 and PP13 levels in pregnancies complicated with preeclampsia

OBJECTIVE

The aim of this study is to investigate whether Serpin clade C (SERPINC1), E-selectin, P-selectin, Placental protein 13 (PP13), and Retinol-binding protein-4 (RBP4) levels in maternal serum were associated with the presence of preeclampsia and to compare them with uncomplicated pregnancies.

METHODS

This prospective study included 40 women with preeclampsia and 40 healthy pregnant women. An enzyme-linked immunosorbent assay kit was used to measure serum SERPINC1, E-selectin, P-selectin, PP13, and RBP4 levels.

RESULTS

The preeclampsia group had significantly higher E-selectin and P-selectin levels than the control group. PP13 and SERPINC1 levels were also significantly lower than the control group. There was no significant difference in RBP4 levels. The receiver operating characteristic curve revealed the best cutoff values for the following: E-selectin >19.2 ng/mL, with 87.5% sensitivity and 95% specificity; P-selectin >5.1 ng/mL, with 97.5% sensitivity and 100% specificity; PP13 ≤ 107.03 pg/mL, with 72.5% sensitivity and 77.5% specificity; and SERPINC1 ≤ 87.76 ng/mL, with 100% sensitivity and 97.5% specificity.

CONCLUSION

In this study, the endothelial dysfunction parameters SERPINC1, PP13, E-selectin, and P-selectin were found to be associated with preeclampsia. Endothelial dysfunction biomarkers in maternal non-serum body fluids may differ. More research is needed, especially to determine the relationship between SERPINC1 and preeclampsia.

Longitudinal assessment of placental perfusion in normal and hypertensive pregnancies using pseudo-continuous arterial spin-labeled MRI: preliminary experience

OBJECTIVES

To evaluate longitudinal placental perfusion using pseudo-continuous arterial spin-labeled (pCASL) MRI in normal pregnancies and in pregnancies affected by chronic hypertension (cHTN), who are at the greatest risk for placental-mediated disease conditions.

METHODS

Eighteen normal and 23 pregnant subjects with cHTN requiring antihypertensive therapy were scanned at 3 T using free-breathing pCASL-MRI at 16-20 and 24-28 weeks of gestational age.

RESULTS

Mean placental perfusion was 103.1 ± 48.0 and 71.4 ± 18.3 mL/100 g/min at 16-20 and 24-28 weeks respectively in normal pregnancies and 79.4 ± 27.4 and 74.9 ± 26.6 mL/100 g/min in cHTN pregnancies. There was a significant decrease in perfusion between the first and second scans in normal pregnancies (p = 0.004), which was not observed in cHTN pregnancies (p = 0.36). The mean perfusion was not statistically different between normal and cHTN pregnancies at both scans, but the absolute change in perfusion per week was statistically different between these groups (p = 0.044). Furthermore, placental perfusion was significantly lower at both time points (p = 0.027 and 0.044 respectively) in the four pregnant subjects with cHTN who went on to have infants that were small for gestational age (52.7 ± 20.4 and 50.4 ± 20.9 mL/100 g/min) versus those who did not (85 ± 25.6 and 80.0 ± 25.1 mL/100 g/min).

CONCLUSION

pCASL-MRI enables longitudinal assessment of placental perfusion in pregnant subjects. Placental perfusion in the second trimester declined in normal pregnancies whereas it remained unchanged in cHTN pregnancies, consistent with alterations due to vascular disease pathology. Perfusion was significantly lower in those with small for gestational age infants, indicating that pCASL-MRI-measured perfusion may be an effective imaging biomarker for placental insufficiency.

CLINICAL RELEVANCE STATEMENT

pCASL-MRI enables longitudinal assessment of placental perfusion without administering exogenous contrast agent and can identify placental insufficiency in pregnant subjects with chronic hypertension that can lead to earlier interventions.

KEY POINTS

• Arterial spin-labeled (ASL) magnetic resonance imaging (MRI) enables longitudinal assessment of placental perfusion without administering exogenous contrast agent. • ASL-MRI-measured placental perfusion decreased significantly between 16-20 week and 24-28 week gestational age in normal pregnancies, while it remained relatively constant in hypertensive pregnancies, attributed to vascular disease pathology. • ASL-MRI-measured placental perfusion was significantly lower in subjects with hypertension who had a small for gestational age infant at 16-20-week gestation, indicating perfusion as an effective biomarker of placental insufficiency.

Unraveling the mysteries of spiral artery remodeling

Spiral artery remodeling is the process by which the uterine vessels become large bore low resistance conduits, allowing delivery of high volumes of maternal blood to the placenta to nourish the developing fetus. Failure of this process is associated with the pathophysiology of most of the major obstetric complications, including late miscarriage, fetal growth restriction and pre-eclampsia. However, the point at which remodeling 'fails' in these pathological pregnancies is not yet clear. Spiral artery remodeling has predominantly been described in terms of its morphological features, however we are starting to understand more about the cellular and molecular triggers of the different aspects of this process. This review will discuss the current state of knowledge of spiral artery remodeling, in particular the processes involved in loss of the vascular smooth muscle cells, and consider where in the process defects would lead to a pathological pregnancy.

Evaluating circulating soluble markers of endothelial dysfunction and risk factors associated with PE: A multicentre longitudinal case control study in northern Ghana

Serpin E1/PAI-1, N-terminal pro-brain natriuretic peptide (NTpro-BNP) and neuropilin-1 are markers which have been associated with endothelial dysfunction. However, data on the levels of these markers in PE is limited. The limited data on the pathophysiology of PE in relation to these markers necessitated the study. This was a multicentre case-control study conducted at the Obstetrics and Gynaecology Department of the Tamale Teaching Hospital, the Bawku Presbyterian Hospital and the Bolgatanga Regional Hospital. Out of 520 consenting pregnant women, 127 pregnant women met the inclusion criteria (53 with PE and 74 controls) and were included in this study. Venous, placental, cord and peripheral blood were collected for biomarker assay, haematological parameters and placental parasite determination. Placental tissue sections were obtained for placental malaria and histopathological lesions associated with hypoperfusion. Maternal heart rate and foetal umbilical artery Doppler impedance indices; resistance index (RI) and systolic diastolic (SD) ratio were determined to confirm utero-placental hypoperfusion. Significantly higher proportions of foeto-maternal complications; eclampsia, low birth weight (LBW), neonatal intensive care unit admissions (NICU), intrauterine growth restriction (IUGR), caesarian deliveries and early gestational age at delivery were associated with PE. Women with PE had lower concentrations of platelet (p = 0.02) whereas red cell distribution width (RDW) was markedly elevated (p = 0.01). NTPro-BNP concentration was markedly elevated (p = 0.01) in women with PE whereas neuropilin-1 concentration was lower (p = 0.03) compared to the non-PE group. Maternal heart rate was elevated in women with PE and Doppler resistance indices (RI and SD) were significantly elevated in foetuses of PE women than foetuses of the controls. Placental mal-perfusion lesions were higher in women with PE compared to the non-PE group. Women with PE had increased risk of adverse foeto-maternal complications, significantly associated with placental mal-perfusion lesions, had reduced platelet concentration and elevated RDW-CV levels. NTPro-BNP, RI and SD are elevated in women with PE whereas neuropilin-1 concentration is reduced. Significant changes in these pathological variables in PE women is indicative of significant derangement in endothelial function culminating in adverse maternal and perinatal outcomes of pregnancy.

The thicker the endometrium, the better the neonatal outcomes?

STUDY QUESTION

Is endometrial thickness (EMT) on the hCG trigger day related to the neonatal outcome of a single birth after fresh embryo transfer (ET)?

SUMMARY ANSWER

An EMT ≤7.8 mm was an independent predictor for greater odds of preterm delivery (PTD) of singletons born after fresh ET.

WHAT IS KNOWN ALREADY

There may be a positive association between live birth rates and EMT after fresh ET. It is still unknown whether a similar association is seen for the neonatal outcomes of singletons in fresh cycles.

STUDY DESIGN SIZE DURATION

This retrospective study involved singleton live births in women undergoing autologous IVF cycles during the period from 1 October 2016 to 31 July 2021.

PARTICIPANTS/MATERIALS SETTING METHODS

A total of 2010 women who fulfilled the inclusion criteria were included. A multivariable regression analysis was performed to detect the relationship between EMT and neonatal outcomes after controlling for potential confounders. Smooth curve fitting and threshold effect analysis were used to evaluate the accurate cutoff value of EMT.

MAIN RESULTS AND THE ROLE OF CHANCE

The results of the multivariate regression analyses showed that the odds of PTD were reduced by 45% with an EMT of 9.00-9.90 mm (adjusted odds ratio (OR): 0.55, 95% CI: 0.13 to 0.98; P = 0.0451), reduced by 58% with an EMT of 10.00-10.90 mm (adjusted OR: 0.42, 95% CI: 0.06 to 0.87; P = 0.0211) and reduced by 75% with an EMT >11 mm (adjusted OR: 0.25, 95% CI: 0.04 to 0.66; P = 0.0034), compared to the group with an EMT of 6.00-8.90 mm. It could also be seen from the adjusted smooth curves that the odds of PTD decreased and gestational age (GA) increased with increasing EMT. Combined with the analysis of threshold effects, the results indicated that when the EMT was ≤7.6 mm, the incidence of PTD decreased as the EMT gradually increased (adjusted OR: 0.47, 95% CI: 0.03 to 0.99; P = 0.0107), and when the EMT was ≤7.8 mm, the GA increased (adjusted β: 1.94, 95% CI: 1.26 to 2.63; P < 0.0001) as the EMT gradually increased.

LIMITATIONS REASONS FOR CAUTION

The main limitation of our study is its retrospective design. Although we found a significant decrease in PTD as the EMT increased, in terms of GA, the magnitude of the differences was modest, which may limit the clinical relevance of the findings.

WIDER IMPLICATIONS OF THE FINDINGS

Our data provide new insight into the relationship between EMT and neonatal outcomes by indicating that a thin endometrium of ≤7.8 mm is associated with an increased odds of PTD of singletons after fresh ET.

STUDY FUNDING/COMPETING INTERESTS

This study was supported by the National Natural Science Foundation of China (grant no. 82071717). There are no conflicts of interest.

Exploring the potential of microRNA as a diagnostic tool for gestational diabetes

MicroRNAs (miRNAs) are small non-coding RNAs that play critical roles in regulating host gene expression. Recent studies have indicated a role of miRNAs in the pathogenesis of gestational diabetes mellitus (GDM), a common pregnancy-related disorder characterized by impaired glucose metabolism. Aberrant expression of miRNAs has been observed in the placenta and/or maternal blood of GDM patients, suggesting their potential use as biomarkers for early diagnosis and prognosis. Additionally, several miRNAs have been shown to modulate key signaling pathways involved in glucose homeostasis, insulin sensitivity, and inflammation, providing insights into the pathophysiology of GDM. This review summarizes the current knowledge on the dynamics of miRNA in pregnancy, their role in GDM as well as their potential as diagnostic and therapeutic targets.

Establishment of the fetal-maternal interface: developmental events in human implantation and placentation

Early pregnancy is a complex and well-orchestrated differentiation process that involves all the cellular elements of the fetal-maternal interface. Aberrant trophoblast-decidual interactions can lead to miscarriage and disorders that occur later in pregnancy, including preeclampsia, intrauterine fetal growth restriction, and preterm labor. A great deal of research on the regulation of implantation and placentation has been performed in a wide range of species. However, there is significant species variation regarding trophoblast differentiation as well as decidual-specific gene expression and regulation. Most of the relevant information has been obtained from studies using mouse models. A comprehensive understanding of the physiology and pathology of human implantation and placentation has only recently been obtained because of emerging advanced technologies. With the derivation of human trophoblast stem cells, 3D-organoid cultures, and single-cell analyses of differentiated cells, cell type-specific transcript profiles and functions were generated, and each exhibited a unique signature. Additionally, through integrative transcriptomic information, researchers can uncover the cellular dysfunction of embryonic and placental cells in peri-implantation embryos and the early pathological placenta. In fact, the clinical utility of fetal-maternal cellular trafficking has been applied for the noninvasive prenatal diagnosis of aneuploidies and the prediction of pregnancy complications. Furthermore, recent studies have proposed a viable path toward the development of therapeutic strategies targeting placenta-enriched molecules for placental dysfunction and diseases.

Endometrial Receptivity During the Preimplantation Period: A Narrative Review

Endometrial receptivity is a complex and critical process fundamental to achieving a successful pregnancy. While researchers have made significant strides in understanding the underlying mechanisms governing endometrial receptivity, effective diagnostic and therapeutic strategies remain scarce. This review article aims to elucidate the various factors that contribute to endometrial receptivity, including the hormonal regulation and molecular mechanisms that govern this process, as well as potential biomarkers for assessing endometrial receptivity. One of the major challenges in identifying reliable biomarkers for endometrial receptivity is the intricate nature of the process itself. Nonetheless, recent advances in transcriptomic and proteomic technologies have identified several candidate biomarkers that could potentially enhance our ability to predict endometrial receptivity. Furthermore, emerging technologies such as single-cell RNA sequencing and mass spectrometry-based proteomics hold great promise for providing novel insights into the molecular mechanisms underlying endometrial receptivity. Despite the lack of reliable biomarkers, various therapeutic strategies have been proposed to improve endometrial receptivity. One promising approach involves the transplantation of mesenchymal stem cells (MSCs), which have been shown to increase endometrial thickness and receptivity in both animal models and clinical trials. Growth factors, cytokines, and exosomes derived from MSCs and other cell types may also have therapeutic potential for addressing endometrial dysfunction.

MiR-95-3p/EPM2A/MMP2 contributes to the pathogenesis of severe preeclampsia through the regulation of trophoblast biological behaviour

OBJECTIVE

Preeclampsia (PE) is a maternal multisystem disease with an unclear mechanism. Data showed that MiR-95-3p promoted cell migration, invasion and proliferation, leading to the occurrence and development of many cancers, and placental trophoblasts and tumor cells had similar migration, invasion and proliferation abilities. Meanwhile we found that MiR-95-3p was differentially expressed in PE and normal placenta. Therefore, this article aimed to explore the biological function and mechanism of miR-95-3p in PE.

METHODS

The expression of miR-95-3p in PE and normal placental tissue was explored by high-throughput sequencing and qRT-PCR. The effects of miR-95-3p on trophoblast migration, invasion, proliferation, angiogenesis and apoptosis were investigated by Transwell migration and invasion assays, cell viability assay, tube formation assay and flow cytometry in two trophoblast cell lines (HTR-8/SVneo and JAR). The miR-95-3p target gene EPM2A was identified and verified by unique identifier mRNA next-generation sequencing and dual-luciferase reporter gene experiments. Rescue experiments were conducted to investigate whether miR-95-3p regulated EPM2A to participate in trophoblast migration and invasion. Finally, the effects of miR-95-3p and EPM2A on the expression of angiogenic factors and inflammation-related factors were investigated by ELISA.

RESULTS

We found that miR-95-3p was expressed at low levels in the placental tissue of patients with PE and was negatively correlated with EPM2A expression. In vitro upregulation of miR-95-3p and downregulation of EPM2A promote trophoblast migration, invasion and proliferation. Furthermore, EPM2A was confirmed as a target mRNA of miR-95-3p. Upregulation of EPM2A mitigated miR-95-3p-mediated promotion of trophoblast migration and invasion and vice versa. Finally, both miR-95-3p and EPM2A regulate the expression of trophoblast angiogenesis-related factors and inflammation-related factors.

CONCLUSION

Our findings demonstrated that miR-95-3p promoted the migration and invasion of trophoblast cells by targeting EPM2A to inhibit the occurrence and development of PE.

Estrogen Actions in Placental Vascular Morphogenesis and Spiral Artery Remodeling: A Comparative View between Humans and Mice

Estrogens, mainly 17β-estradiol (E2), play a critical role in reproductive organogenesis, ovulation, and fertility via estrogen receptors. E2 is also a well-known regulator of utero-placental vascular development and blood-flow dynamics throughout gestation. Mouse and human placentas possess strikingly different morphological configurations that confer important reproductive advantages. However, the functional interplay between fetal and maternal vasculature remains similar in both species. In this review, we briefly describe the structural and functional characteristics, as well as the development, of mouse and human placentas. In addition, we summarize the current knowledge regarding estrogen actions during utero-placental vascular morphogenesis, which includes uterine angiogenesis, the control of trophoblast behavior, spiral artery remodeling, and hemodynamic adaptation throughout pregnancy, in both mice and humans. Finally, the estrogens that are present in abnormal placentation are also mentioned. Overall, this review highlights the importance of the actions of estrogens in the physiology and pathophysiology of placental vascular development.

Gut Micro- and Mycobiota in Preeclampsia: Bacterial Composition Differences Suggest Role in Pathophysiology

Preeclampsia is a severe pregnancy-related inflammatory disease without an effective treatment. The pathophysiology remains partly unknown. However, an increased inflammatory response and oxidative stress are part of the maternal systemic reaction. Recent data have suggested that dysbiosis of the gut microbiome plays a role in preeclampsia as well as other inflammatory diseases. However, dysbiosis in preeclampsia has not been studied in a Scandinavian population. Furthermore, although the fungal flora may also have anti-inflammatory properties, it has never been studied in preeclampsia. We included 25 preeclamptic and 29 healthy third-trimester women for the ITS and 16S sequencing of fungal and bacterial microbiota, respectively. Calprotectin was measured to assess systemic and intestinal inflammatory responses. The fungal diversity differed with BMI and gestational length, suggesting a link between fungi and the immune changes seen in pregnancy. An LEfSe analysis showed 18 significantly differentially abundant bacterial taxa in PE, including enriched Bacteroidetes and depleted Verrucomicrobia and Syntergistota at the phylum level and depleted Akkermansia at the genus level, suggesting a role in the pathophysiology of PE.

Immune Tolerance of Embryo Implantation and Pregnancy: The Role of Human Decidual Stromal Cell- and Embryonic-Derived Extracellular Vesicles

Embryo–endometrial communication plays a critical role in embryo implantation and the establishment of a successful pregnancy. Successful pregnancy outcomes involve maternal immune modulation during embryo implantation. The endometrium is usually primed and immunomodulated by steroid hormones and embryo signals for subsequent embryo implantation and the maintenance of pregnancy. The roles of extracellular vesicles (EVs) and microRNAs for the embryo–maternal interactions have been elucidated recently. New evidence shows that endometrial EVs and trophectoderm-originated EV cargo, including microRNAs, proteins, and lipids in the physiological microenvironment, regulate maternal immunomodulation for embryo implantation and subsequent pregnancy. On the other hand, trophoblast-derived EVs also control the cross-communication between the trophoblasts and immune cells. The exploration of EV functions and mechanisms in the processes of embryo implantation and pregnancy will shed light on a practical tool for the diagnostic or therapeutic approaches to reproductive medicine and infertility.

Maternal selection of human embryos in early gestation: Insights from recurrent miscarriage

Compared to most mammals, human pregnancy is unusual in that it involves chromosomally diverse embryos, cyclical breakdown and regeneration of the uterine mucosa, and intimate integration of fetal and maternal cells at the uteroplacental interface. Not surprisingly, pregnancy often falters in early gestation. Whether these losses result in clinical miscarriages depends on the origins and impacts of chromosomal errors on fetal development and the ability of the decidualizing endometrium to engage in embryo biosensing and selection. Aneuploidy originating in oocytes during meiosis drives the age-related risk of miscarriage. By contrast, the frequency of endometrial cycles with an impaired decidual response may account for the stepwise increase in miscarriage rates with each pregnancy loss independently of maternal age. Additional physiological mechanisms operate in early gestation to ensure that most failing pregnancies are lost before vascular maternal-fetal connections are established by the end of the first trimester. Here, we summarise how investigations into the mechanisms that cause miscarriage led to new insights into the processes that govern maternal selection of human embryos in early gestation.

Functional prominence of natural killer cells and natural killer T cells in pregnancy and infertility: A comprehensive review and update

During pregnancy, complicated connections are formed between a mother and a fetus. In a successful pregnancy, the maternal-fetal interface is affected by dynamic changes, and the fetus is protected against the mother's immune system. Natural killer (NK) cells are one of the immune system cells in the female reproductive system that play an essential role in the physiology of pregnancy. NK cells not only exist in peripheral blood (PB) but also can exist in the decidua. Studies have suggested multiple roles for these cells, including decidualization, control of trophoblast growth and invasion, embryo acceptance and maintenance by the mother, and facilitation of placental development during pregnancy. Natural killer T (NKT) cells are another group of NK cells that play a crucial role in the maintenance of pregnancy and regulation of the immune system during pregnancy. Studies show that NK and NKT cells are not only effective in maintaining pregnancy but also can be involved in infertility-related diseases. This review focuses on NK and NKT cells biology and provides a detailed description of the functions of these cells in implantation, placentation, and immune tolerance during pregnancy and their role in pregnancy complications.

Blood vessel assessment using computed tomography : Effects of ephedrine on uterine artery

Background: Ephedrine increased blood pressure due to the contractile properties of resistance vessels. Excessive contraction of the uterine arteries might cause fetal distress. This study was to determine the diameter of the uterine artery of female New Zealand rabbits after the administration of different doses of ephedrine using CT.

Methods: Thirty-two rabbits were randomly divided into a control group (Group C), low dosage group (Group L), medium dosage group (Group M) and high dosage group (Group H). Normal saline and doses corresponding to the human dose of 7.5, 15 and 30 mg of ephedrine were injected respectively. The marginal ear and uterine artery diameters were measured 5, 10, 15, 30, and 45 min after injection using CT, and the hemodynamic changes were recorded.

Results: The increase in mean arterial pressure in group M (p = 0.009), and H (p = 0.013) was higher than that in group C. Compared with group C, substantial contraction of the marginal ear artery was observed at the three doses of ephedrine. There were no differences in the uterine artery diameter among groups L, M and C, However, in Group H, a significant contraction of the uterine artery compared with the other groups (p < 0.001) was observed.

Discussion: CT can be used to evaluate the effects of drugs on organs and blood vessels. Ephedrine can not only constrict the peripheral blood vessels but also do not affect the uterine artery at a dose of 15 mg or less. However, the dose should not exceed 30 mg, which may cause severe uterine artery depression.

Maternal anxiety affects embryo implantation via impairing adrenergic receptor signaling in decidual cells

Recurrent implantation failure (RIF) is defined as the failed pregnancy after good embryo transfer over 3 cycles during in vitro fertilization (IVF).The human endometrium plays a vital role in providing the site for embryo implantation, with several factors implicated in unsatisfactory endometrial receptivity in RIF. Our present results revealed that women with pregnancy loss or infertility have a higher serum epinephrine level, indicating a potential correlation between psychological stress and pregnancy failure. RNA-sequencing of the tissues collected at the endometrial receptive phase in normal and RIF women showed that stress hormones could affect the functional status of endometrial receptivity. Subsequent analysis revealed that the epinephrine signaling acts as an important regulator of endometrial receptivity through the PI3K-AKT and FOXO1 signaling pathways. We also found that patients with RIF show attenuated expression of the alpha-2C-adrenergic receptor (ADRA2C) and that its down regulation induced by high level epinephrine could inhibit the decidualization. Early pregnant mice treated with stress showed high serum epinephrine levels, defective uterine adrenergic receptor expression, and low pregnancy rates. Altogether, our findings indicate that mental stress during early pregnancy can alter the functional status of endometrial receptivity.

Human Leukocyte Antigen HLA-C, HLA-G, HLA-F and HLA-E placental profiles are altered in Early Severe Preeclampsia and Preterm Birth with Chorioamnionitis

BACKGROUND

The extravillous trophoblast expresses each of the non-classical MHC class I antigens - HLA-E, F, and G and a single classical class I antigen HLA-C. We recently demonstrated dynamic expression patterns of HLA-C, G and F during early EVT invasion and placentation.

OBJECTIVE

In this study we investigate the hypothesis that the immune inflammatory mediated complications of pregnancy such as early preeclampsia and preterm labor, may show altered expression profiles of non-classical HLA.

STUDY DESIGN

Real time q-PCR, western blot and immunohistochemistry were performed on placental villous tissues and basal plate sections from term non-laboring deliveries, preterm deliveries and severe early onset preeclampsia both with and without small for gestational age neonates.

RESULTS

HLA-G is strongly and exclusively expressed by the EVT within the placental basal plate and its levels increase in pregnancies complicated by severe early onset PE with SGA neonates as compared to healthy term controls. HLA-C shows a similar profile in the EVT of PE pregnancies, but significantly decreases in the villous placenta. HLA-F protein levels are decreased in both EVT and villous placenta of severe early onset PE pregnancies both with and without SGA babies as compared to Term and PTB deliveries. HLA-E decreases in blood vessels in placentas from PE pregnancies as compared to Term and PTB deliveries. HLA-F and HLA-C are increased in the placenta of PTBs with chorioamnionitis as compared to idiopathic PTB.

CONCLUSION

Dysregulation of placental HLA expression at the maternal fetal interface may contribute to the compromised maternal tolerance in PTB with chorioamnionitis and excessive maternal systemic inflammation associated with severe early onset PE.

Placental protein 13 dilation of pregnant rat uterine vein is endothelium dependent and involves nitric oxide/calcium activated potassium channels signals

INTRODUCTION

Accumulating evidence demonstrates the importance of the galectin protein Placental Protein 13 (PP13) in predicting Preeclampsia (PE), a gestational disorder that has no cure and is associated with a compromised uterine vascular adaptation to pregnancy. Uterine vasculature undergoes significant remodeling (growth in length and in circumference) during normal pregnancy to accommodate the increased blood volume to the feto-placental unit. The aim of this study was to demonstrate the role of PP13 on the uterine veins (UVs).

METHODS

PP13 was tested on UVs isolated from rat by using a pressurized myograph. The PP13 investigation was carried out in the presence of: a) nitric oxide synthases inhibitors (l-NAME + L-NNA, 2 x 10^-4 M); b) small conductance Ca²⁺-activated K⁺ channels (SK_ca) inhibitor (Apamin, 10^-7 M); c) intermediate conductance Ca²⁺-activated K⁺ channels (IK_ca) inhibitor (TRAM-34, 10^-5 M); d) big conductance Ca²⁺-activated K⁺ channels (BK_ca) inhibitor (Paxilline, 10^-5 M) and in the absence of endothelium.

RESULTS

Our results showed that in late pregnancy, PP13 induced a significant dilation of UVs that is endothelium dependent. Further, PP13-dilation is mediated by the SKca - NO - BKca pathway.

DISCUSSION

For the first time, this study provides evidence that in pregnancy, the UVs are dilated by PP13 and suggests SK_Ca as a potential target for treatments aimed at restoring pregnancy complication associated with deficiency in uterine adaptation.

SIRT1 suppresses in vitro decidualization of human endometrial stromal cells through the downregulation of forkhead box O1 expression

SIRT1 regulates survival, DNA repair, and metabolism in human cells and has pleiotropic effects on age-related diseases through either deacetylating target proteins or inhibiting gene transcription. Forkhead box O1 (FOXO1) is one of the most important transcription factors during decidualization. Prolactin (PRL) and insulin-like growth factor-binding protein 1 (IGFBP1) are well-known FOXO1-dependent genes in decidualizing cells. To determine whether SIRT1 plays a role in decidualization, we investigated morphological changes in cells following artificially stimulated decidualization and expression levels of PRL, IGFBP1, and FOXO1 in the immortalized non-neoplastic human endometrial stromal cell line T HESCs. SIRT1 expression decreased in the decidualization condition and SIRT1 inhibited morphological changes caused by decidualization of T HESCs. SIRT1 suppressed PRL, IGFBP1, and FOXO1 expression; inhibited FOXO1, PRL, and IGFBP1 promoter activity; and decreased histone protein acetylation of the FOXO1 promoter. We found that FOXO1 expression increased in the secretory phase compared with the proliferative phase, whereas SIRT1 expression decreased in the secretory phase in the human endometrium. We also revealed that SIRT1 may inhibit embryo implantation according to the blastocyst-like spheroid implantation assay. Collectively, these results indicate that SIRT1 suppresses decidualization of human endometrial stromal cells by inhibiting FOXO1 expression.

Miscarriage syndrome: Linking early pregnancy loss to obstetric and age-related disorders

Upon embryo implantation, the uterine mucosa - the endometrium - transforms into a robust decidual matrix that accommodates the fetal placenta throughout pregnancy. This transition is driven by the differentiation of endometrial fibroblasts into specialised decidual cells. A synchronised influx of circulating natural killer (NK) cells and bone marrow-derived mesenchymal stem/progenitor cells (BM-MSC) is pivotal for decidual homeostasis and expansion in early pregnancy. We hypothesise that pathological signals interfering with the recruitment or activity of extrauterine cells at the maternal-fetal interface link miscarriage to subsequent adverse pregnancy outcomes, including further pregnancy losses and preterm labour. NK cells and BM-MSC are key homeostatic regulators in multiple tissues, pointing towards a shared aetiology between recurrent miscarriage and age-related disorders, including cardiometabolic disease. We propose the term ‘miscarriage syndrome’ to capture the health risks associated with miscarriage and discuss how this paradigm can inform clinical practice and accelerate the development of preventative strategies.

Using the Isolated Rat Placenta to Assess Fetoplacental Hemodynamics

Placental health is critical to fetal growth and maternal health during gestation. However, investigating placental flow in an ex-vivo isolated system where inflow is independently controlled has yet to be developed in the rat. Here, we describe a novel technique, isolated perfused placenta technique that allows for analysis of placental pressure outflow pressure, placental flow in rats at gestational day 20. Using this method, we successfully perfused placentas from dams and were able to observe increases in outflow pressure and flow as the inflow pressure to the placenta was increased in a step wise fashion. This method will help to advance the functional analysis of placental flow and therefore placental resistance and efficiency.

A mathematical model of maternal vascular growth and remodeling and changes in maternal hemodynamics in uncomplicated pregnancy

The maternal vasculature undergoes tremendous growth and remodeling (G&R) that enables a > 15-fold increase in blood flow through the uterine vasculature from conception to term. Hemodynamic metrics (e.g., uterine artery pulsatility index, UA-PI) are useful for the prognosis of pregnancy complications; however, improved characterization of the maternal hemodynamics is necessary to improve prognosis. The goal of this paper is to develop a mathematical framework to characterize maternal vascular G&R and hemodynamics in uncomplicated human pregnancies. A validated 1D model of the human vascular tree from the literature was adapted and inlet blood flow waveforms at the ascending aorta at 4 week increments from 0 to 40 weeks of gestation were prescribed. Peripheral resistances of each terminal vessel were adjusted to achieve target flow rates and mean arterial pressure at each gestational age. Vessel growth was governed by wall shear stress (and axial lengthening in uterine vessels), and changes in vessel distensibility were related to vessel growth. Uterine artery velocity waveforms generated from this model closely resembled ultrasound results from the literature. The literature UA-PI values changed significantly across gestation, increasing in the first month of gestation, then dramatically decreasing from 4 to 20 weeks. Our results captured well the time-course of vessel geometry, material properties, and UA-PI. This 1D fluid-G&R model captured the salient hemodynamic features across a broad range of clinical reports and across gestation for uncomplicated human pregnancy. While results capture available data well, this study highlights significant gaps in available data required to better understand vascular remodeling in pregnancy.

Protease inhibitor-based antiretroviral therapy in pregnancy: effects on hormones, placenta, and decidua

The use of antiretroviral therapy (ART) in pregnancy is important for maternal health, and has been successful in reducing vertical transmission rates to almost zero in those taking effective ART regimens with good adherence. However, there are reports of higher rates of low birthweight and preterm births in women with HIV, which can be further exacerbated by ART usage in pregnancy. Protease inhibitors, and ritonavir-boosted lopinavir in particular, might directly contribute to placental and uteroplacental pathology in part by altering plasma concentrations of the essential steroid hormones of pregnancy, progesterone and oestradiol. In this Review, we collate the increasing evidence of dysregulated maternal endocrinology, reproductive physiology, and placental compromise associated with protease inhibitors. Based on findings of placental and decidual effects, we recommend that ritonavir-boosted lopinavir should be avoided in pregnancy, in line with US and European guidelines. Long-term follow-up of children exposed to protease inhibitors in utero is also recommended.

Decidualization resistance in the origin of preeclampsia

Preeclampsia is a major obstetrical complication with short- and long-term life-threatening consequences for both mother and child. Shallow cytotrophoblast invasion through the uterine decidua into the spiral arteries is implicated in the pathogenesis of preeclampsia, although the cause of deficient arterial invasion remains unknown. Research that is focused on the "soil"-the maternal decidua-highlights the importance of this poorly understood but influential uterine layer. Decidualization of endometrial cells regulates embryo invasion, which is essential for spiral artery remodeling and establishing the maternal-fetal interface. Exploration of the association between impaired decidualization and preeclampsia revealed suboptimal endometrial maturation and uterine natural killer cells present in the decidua before preeclampsia development. Furthermore, decidualization defects in the endometrium of women with severe preeclampsia, characterized by impaired cytotrophoblast invasion, were detected at the time of delivery and persisted 5 years after the affected pregnancy. Recently, a maternal deficiency of annexin A2 expression was found to influence aberrant decidualization and shallow cytotrophoblast invasion, suggesting that decidualization resistance, which is a defective endometrial cell differentiation during the menstrual cycle, could underlie shallow trophoblast invasion and the poor establishment of the maternal-fetal interface. Based on these findings, the transcriptional signature in the endometrium that promotes decidualization deficiency could be detected before (or after) conception. This would serve to identify women at risk of developing severe preeclampsia and aid the development of therapies focused on improving decidualization, perhaps also preventing severe preeclampsia. Here, we discuss decidualization deficiency as a contributor to the pathogenesis of pregnancy disorders with particular attention to severe preeclampsia. We also review current diagnostic strategies and discuss future directions in diagnostic methods based on decidualization.

Increased risk of obstetric complications in patients with adenomyosis: A narrative literature review

Background

Reproductive‐age women occasionally face the pathological condition of adenomyosis, which is often concurrent with endometriosis. It is believed that endometriosis and adenomyosis increases the risk of obstetric complications. Although new insights into the mechanism of obstetric complications due to endometriosis are emerging, there is little information on the etiology of adverse pregnancy outcomes in pregnant women with adenomyosis.

Methods

We performed a literature review focusing on the pathophysiological pathways of obstetric complications in women with adenomyosis using currently available basic and clinical studies. We used the internet search engines PubMed and Google Scholar to search for studies published between January 2000 and June 2021. We carefully read pertinent sections within each document to ensure relevancy.

Main findings

The prevalence of adverse pregnancy outcomes in women with adenomyosis is increased after adjusting for conceiving by assisted reproductive technology. Thus, adenomyosis emerges as a relevant factor associated with several obstetric complications such as preterm birth, preterm premature rupture of membranes, placental abruption, small for gestational age/fetal growth restriction, and preeclampsia.

Conclusion

It is plausible that the impact of adenomyosis on pregnancy outcomes is not always the same; rather it is dependent on the degree of uterine involvement and subtypes.

The Impact of Oxidative Stress of Environmental Origin on the Onset of Placental Diseases

Oxidative stress (OS) plays a pivotal role in placental development; however, abnormal loads in oxidative stress molecules may overwhelm the placental defense mechanisms and cause pathological situations. The environment in which the mother evolves triggers an exposure of the placental tissue to chemical, physical, and biological agents of OS, with potential pathological consequences. Here we shortly review the physiological and developmental functions of OS in the placenta, and present a series of environmental pollutants inducing placental oxidative stress, for which some insights regarding the underlying mechanisms have been proposed, leading to a recapitulation of the noxious effects of OS of environmental origin upon the human placenta.

Obstetric Outcome After Surgical Treatment of Endometriosis: A Review of the Literature

A diagnosis of endometriosis is associated with increased risks of adverse pregnancy outcomes including placenta praevia and preterm birth. Some studies have also suggested associations with gestational hypertension, foetal growth restriction, gestational diabetes, perinatal death, and obstetric haemorrhage. This review aims to assess the impact of pre-pregnancy surgical treatment of endometriosis on future obstetric outcomes. A search of the Medline, Embase and PubMed electronic databases was performed to identify studies reporting pre-pregnancy surgery for endometriosis and subsequent pregnancy outcome compared to controls with unresected endometriosis. Three studies met the inclusion criteria. The studies were heterogenous in design, definition of study groups and outcome measures. All three studies were judged at critical risk of bias. Pre-pregnancy excision of endometriosis was associated with an increased risk of caesarean section in one of two studies, OR 1.72 (95% CI 1.59–1.86) and OR 1.79 (95% CI 0.69–4.64). Placenta praevia rates were also increased in one of two studies OR 2.83 (95% CI 0.56–12.31) and OR 2.04 (95% CI 1.66–2.52). One study found increased risks of preterm birth, small for gestational age, gestational hypertension, and antepartum and postpartum haemorrhage (all p &lt; 0.05) with pre-pregnancy excision of endometriosis. There is insufficient evidence examining the role of pre-pregnancy endometriosis surgery in ameliorating adverse pregnancy outcomes, and thus reliable conclusions cannot be drawn. Prospectively designed studies are needed to assess the relationship between surgical treatments for endometriosis and obstetric outcome and examine potential confounders such as comorbid adenomyosis and infertility.

The Role of Decidual Subpopulations in Implantation, Menstruation and Miscarriage

In each menstrual cycle, the endometrium becomes receptive to embryo implantation while preparing for tissue breakdown and repair. Both pregnancy and menstruation are dependent on spontaneous decidualization of endometrial stromal cells, a progesterone-dependent process that follows rapid, oestrogen-dependent proliferation. During the implantation window, stromal cells mount an acute stress response, which leads to the emergence of functionally distinct decidual subsets, reflecting the level of replication stress incurred during the preceding proliferative phase. Progesterone-dependent, anti-inflammatory decidual cells (DeC) form a robust matrix that accommodates the conceptus whereas pro-inflammatory, progesterone-resistant stressed and senescent decidual cells (senDeC) control tissue remodelling and breakdown. To execute these functions, each decidual subset engages innate immune cells: DeC partner with uterine natural killer (uNK) cells to eliminate senDeC, while senDeC co-opt neutrophils and macrophages to assist with tissue breakdown and repair. Thus, successful transformation of cycling endometrium into the decidua of pregnancy not only requires continuous progesterone signalling but dominance of DeC over senDeC, aided by recruitment and differentiation of circulating NK cells and bone marrow-derived decidual progenitors. We discuss how the frequency of cycles resulting in imbalanced decidual subpopulations may determine the recurrence risk of miscarriage and highlight emerging therapeutic strategies.

Investigation of the pregnancy-induced muscle bundle dispersal of the inner myometrium of adult mouse uterus and its relationship to the metrial gland/MLAp

In the adult uterus of mice, rats and humans, the initially closely packed muscle bundles of the inner myometrium (muscular tissue that encircles the endometrium where the conceptus implants) undergo a pregnancy-induced dispersal that is clinically significant and hypothesized to regulate important pregnancy events. However, where, when and how this dispersal occurs, what its functions are, as well as its spatial relationship to the mouse metrial gland/mesometrial lymphoid aggregate of pregnancy (MG/MLAp), are unknown. The MG/MLAp, is a pregnancy-induced uterine structure required for successful rodent pregnancy located mesometrial to (above) the decidua basalis (pregnancy-modified mesometrial endometrium) and defined by its accumulation of maternal lymphocytes known as uterine Natural Killer (uNK) cells. To begin to understand how mouse inner myometrium dispersal (IMD) occurs, we spatiotemporally described it by observing the distribution of its muscle bundles and measuring their volume fraction (VF), as well as the VF of uNKs and stromal cells of inner myometrium. We discovered that (a) IMD (defined as reduction in VF of inner myometrium muscle bundles) is restricted to the mesometrial half of the uterus, is first evident at Embryonic day (E) 5.5 (early postimplantation) but not at E3.5 (preimplantation), further increases between E6.5 and E7.5 and remains unchanged from E7.5 to E10.5, (b) IMD initiation (observed between E3.5 and E5.5) occurs in the absence of uNKs and is associated with VF increases of pre-existing inner myometrium stromal cells and (c) the IMD observed between E6.5 and E7.5 is not associated with VF increases of uNKs or stromal cells. To get functional clues about IMD, we examined whether stromal cells between the dispersed muscle bundles undergo decidualization (important for correct fetomaternal interactions) and provide evidence that they do by E10.5, based on their production of Desmin (decidualization marker). Lastly, we examined whether mouse MG/MLAp only comprises the dispersed inner myometrium or additionally includes the mesometrial triangle (a triangular-like area mesometrial to the inner myometrium at the mesometrium-uterus attachment site), as is the case in rats. Our data supports that the dispersed inner myometrium is the only tissue that makes up the mouse MG/MLAp. In conclusion, we provide novel cellular and spatiotemporal insights about IMD that will contribute to understanding its mechanism and function and allow more informed inter-species comparisons about this process.

The roles of free iron, heme, haemoglobin, and the scavenger proteins haemopexin and alpha-1-microglobulin in preeclampsia and fetal growth restriction

BACKGROUND

Preeclampsia (PE) is a complex pregnancy syndrome characterised by maternal hypertension and organ damage after 20 weeks of gestation and is associated with an increased risk of cardiovascular disease later in life. Extracellular haemoglobin (Hb) and its metabolites heme and iron are highly toxic molecules and several defence mechanisms have evolved to protect the tissue.

OBJECTIVES

We will discuss the roles of free iron, heme, Hb, and the scavenger proteins haemopexin and alpha-1-microglobulin in pregnancies complicated by PE and fetal growth restriction (FGR).

CONCLUSION

In PE, oxidative stress causes syncytiotrophoblast (STB) stress and increased shedding of placental STB-derived extracellular vesicles (STBEV). The level in maternal circulation correlates with the severity of hypertension and supports the involvement of STBEVs in causing maternal symptoms in PE. In PE and FGR, iron homeostasis is changed, and iron levels significantly correlate with the severity of the disease. The normal increase in plasma volume taking place during pregnancy is less for PE and FGR and therefore have a different impact on, for example, iron concentration, compared to normal pregnancy. Excess iron promotes ferroptosis is suggested to play a role in trophoblast stress and lipotoxicity. Non-erythroid α-globin regulates vasodilation through the endothelial nitric oxide synthase pathway, and hypoxia-induced α-globin expression in STBs in PE placentas is suggested to contribute to hypertension in PE. Underlying placental pathology in PE with and without FGR might be amplified by iron and heme overload causing oxidative stress and ferroptosis. As the placenta becomes stressed, the release of STBEVs increases and affects the maternal vasculature.

Atrial natriuretic peptide promotes uterine decidualization and a TRAIL-dependent mechanism in spiral artery remodeling

Atrial natriuretic peptide (ANP) is an important hormone in cardiovascular biology. It is activated by the protease corin. In pregnancy, ANP and corin promote uterine spiral artery remodeling, but the underlying mechanism remains unknown. Here we report an ANP function in uterine decidualization and TNF-related apoptosis-inducing ligand-dependent (TRAIL-dependent) death in spiral arterial smooth muscle cells (SMCs) and endothelial cells (ECs). In ANP- or corin-deficient mice, uterine decidualization markers and TRAIL expression were decreased, whereas in cultured human endometrial stromal cells (HESCs), ANP increased decidualization and TRAIL expression. In uterine spiral arteries from pregnant wild-type mice, SMC and EC loss occurred sequentially before trophoblast invasion. In culture, TRAIL from decidualized HESCs induced apoptosis in uterine SMCs, but not in ECs with low TRAIL receptor expression. Subsequently, cyclophilin B was identified from apoptotic SMCs that upregulated endothelial TRAIL receptor and caused apoptosis in ECs. These results indicate that ANP promotes decidualization and TRAIL expression in endometrial stromal cells, contributing to sequential events in remodeling of spiral arteries, including SMC death and cyclophilin B release, which in turn induces TRAIL receptor expression and apoptosis in ECs.

Transcriptomic Drivers of Differentiation, Maturation, and Polyploidy in Human Extravillous Trophoblast

During pregnancy, conceptus-derived extravillous trophoblast (EVT) invades the endomyometrium, anchors the placenta to the maternal uterus, and remodels the spiral arteries in order to establish maternal blood supply to the fetoplacental unit. Recent reports have described early gestation EVT as polyploid and senescent. Here, we extend these reports by performing comprehensive profiling of both the genomic organization and transcriptome of first trimester and term EVT. We define pathways and gene regulatory networks involved in both initial differentiation and maturation of this important trophoblast lineage at the maternal-fetal interface. Our results suggest that like first trimester EVT, term EVT undergoes senescence and endoreduplication, is primarily tetraploid, and lacks high rates of copy number variations. Additionally, we have highlighted senescence and polyploidy-related genes, pathways, networks, and transcription factors that appeared to be important in normal EVT differentiation and maturation and validated a key role for the unfolded protein response in this context.

Performance of plasma kisspeptin as a biomarker for miscarriage improves with gestational age during the first trimester

OBJECTIVE

To compare the performance of kisspeptin and beta human chorionic gonadotropin (βhCG), both alone and in combination, as biomarkers for miscarriage throughout the first trimester.

DESIGN

Prospective, nested case-control study.

SETTING

Tertiary Centre, Queen Charlotte Hospital, London, United Kingdom.

PATIENT(S)

Adult women who had miscarriages (n = 95, 173 samples) and women with healthy pregnancies (n = 265, 557 samples).

INTERVENTION(S)

The participants underwent serial ultrasound scans and blood sampling for measurement of plasma kisspeptin and βhCG levels during the first trimester.

MAIN OUTCOME MEASURE(S)

The ability of plasma kisspeptin and βhCG levels to distinguish pregnancies complicated by miscarriage from healthy pregnancies unaffected by miscarriage.

RESULT(S)

Gestation-adjusted levels of circulating kisspeptin and βhCG were lower in samples from women with miscarriages than in women with healthy pregnancies by 79% and 70%, respectively. The area under the receiver-operating characteristic curve for identifying miscarriage during the first trimester was 0.874 (95% confidence interval [CI] 0.844-0.904) for kisspeptin, 0.859 (95% CI 0.820-0.899) for βhCG, and 0.916 (95% CI 0.886-0.946) for the sum of the two markers. The performance of kisspeptin in identifying miscarriage improved with increasing length of gestation, whereas that of βhCG worsened. A decision matrix incorporating kisspeptin, βhCG, and gestational age had 83% to 87% accuracy for the prediction of miscarriage.

CONCLUSION(S)

Plasma kisspeptin is a promising biomarker for miscarriage and provides additional value to βhCG alone, especially during later gestational weeks of the first trimester.

Comparison of treatments for the prevention of fetal growth restriction in obstetric antiphospholipid syndrome: a systematic review and network meta-analysis

Women with criteria and non-criteria obstetric antiphospholipid syndrome (APS) carry an increased risk of pregnancy complications, including fetal growth restriction (FGR). The management of obstetric APS traditionally involves clinicians, obstetricians and gynaecologists; however, the most appropriate prophylactic treatment strategy for FGR prevention in APS is still debated. We performed a systematic review and network meta-analysis (NetMA) to summarize current evidence on pharmacological treatments for the prevention of FGR in APS. We searched PubMed and Embase from inception until July 2020, for randomized controlled trials and prospective studies on pregnant women with criteria or non-criteria obstetric APS. NetMA using a frequentist framework were conducted for the primary outcome (FGR) and for secondary outcomes (fetal or neonatal death and preterm birth). Adverse events were narratively summarised. Out of 1124 citations, we included eight studies on 395 pregnant patients with obstetric APS treated with low-dose aspirin (LDA) + unfractionated heparin (UFH) (n = 132 patients), LDA (n = 115), LDA + low molecular weight heparin (n = 100), LDA + corticosteroids (n = 29), LDA + UFH + intravenous immunoglobulin (n = 7), or untreated (n = 12). No difference among treatments emerged in terms of FGR prevention, but estimates were largely imprecise, and most studies were at high/unclear risk of bias. An increased risk of fetal or neonatal death was found for LDA monotherapy as compared to LDA + heparin, and for no treatment as compared to LDA + corticosteroids. The risk of preterm birth was higher for LDA + UFH + IVIg as compared to LDA or LDA + heparin, and for LDA + corticosteroids as compared to LDA or LDA + LMWH. No treatment was associated with an increased risk of bleeding, thrombocytopenia or osteopenia.

Role of ARID1A in the Regulation of Human Trophoblast Migration and Invasion

Migration and invasion of trophoblasts is critical for human placental development, trophoblastic differentiation, and pregnancy-associated diseases. AT-rich interactive domain-containing protein 1A (ARID1A), a subunit of the SWI-SNF complex, has been suggested to participate in the regulation of fertility via placental disruption in mice. However, whether ARID1A regulates human placental development and function remains unknown. Here, using human trophoblast-like JEG-3 cell line, we report that ARID1A controls trophoblast cell migration and invasion. Overexpression of ARID1A inhibits JEG-3 cell migration and invasion, whereas knockdown of ARID1A promotes migration and invasion in JEG-3 cells. Mechanistically, while ARID1A reduces JEG-3 cell migration by down-regulation of Snail transcription, it restrains JEG-3 cell invasion by binding to and destabilization of MMP-9 protein. Finally, ARID1A is apparently up-regulated in placental tissues of preeclampsia compared to that of normal pregnancies. Our results thereby imply that ARID1A acts as a critical gene in supporting the physiological function of human mature placenta.

Side-Population Trophoblasts Exhibit the Differentiation Potential of a Trophoblast Stem Cell Population, Persist to Term, and are Reduced in Fetal Growth Restriction

BACKGROUND

Fetal growth restriction often results from poor placental function and is a major cause of stillbirth. Clinically, fetal growth restriction is difficult to diagnose and currently has no effective treatment. Trophoblasts are unique placental cells that form the feto-maternal interface and facilitate nutrient and gas exchange. Fetal growth restriction is linked to inadequate trophoblast function. However, our understanding of the mechanisms underlying this dysfunction are poor, in part because of our inability to isolate and study the trophoblast stem cells from which mature trophoblasts arise in pathologic pregnancies.

METHODS

Cells isolated from first-trimester placentae using the Hoechst side-population technique were propagated or differentiated into mature trophoblasts. Side-population trophoblasts were isolated from normal third-trimester and growth restricted placentae using the same technique. First and third-trimester side-population trophoblasts were compared by microarray analysis.

RESULTS

First-trimester side-population trophoblasts could be propagated in an undifferentiated state or differentiated, via intermediate cytotrophoblasts, into syncytiotrophoblast or extravillous trophoblasts. Using the same technique, side-population trophoblasts could be isolated from term placentae for the first time, demonstrating that while they were present at consistent levels throughout gestation (~3·5%), side-population trophoblasts were significantly depleted in growth restricted pregnancies (0·32%).

CONCLUSIONS

Our novel method of isolating a population of human trophoblast stem cell-like cells directly from human placental tissue throughout gestation provides the first insights into trophoblast dysfunction in pregnancy pathologies. The depletion of side-population trophoblasts in growth restricted placentae may contribute to poor placental function.

First-trimester miscarriage rate decreases with hydralazine therapy in pregnancies with early uterine vascular insufficiency: a cohort study

BACKGROUND

Miscarriage is the most frequent cause of pregnancy loss, affecting 15-20% of clinically recognized pregnancies. Early uterine vascular insufficiency (EUVI), defined as abnormal uterine artery (UA) Doppler impedance indices in early pregnancy, is present in two-thirds of pregnancies ending in miscarriage after embryonic cardiac activity has been detected. There is currently no available therapy for reducing the risk of miscarriage in these cases.

OBJECTIVE

To determine whether vasodilator therapy with hydralazine can reduce abnormally high UA impedance indices and miscarriage rates in pregnancies with EUVI when administered from before 9 weeks' gestation until completing 13 weeks' gestation.

METHODS

A total of 253 consecutive singleton pregnancies with a live embryo and scanned before 9 weeks' gestation were included in the study. Ninety-two pregnancies (36.3%) were classified as having EUVI. Hydralazine was administered in daily doses of 50 mg, starting 24-36 h after the initial diagnosis of EUVI and continuing throughout the first trimester. The miscarriage rate in the hydralazine-treated EUVI group was compared with the one observed in our previously reported untreated cohort and the pregnancies with EUVI that declined treatment with hydralazine.

RESULTS

The miscarriage rate among the hydralazine-treated EUVI group was significantly lower than the previously reported untreated cohort (7.8% versus 26.2%, p = .003; odds ratio (OR) = 4.3, 95% confidence interval (CI) = 1.6-11.9). In 15 untreated pregnancies with EUVI, the miscarriage rate was similar to that of the previously reported untreated cohort (26.7% versus 26.2%; p = .603) and higher than the hydralazine-treated group (26.7% versus 7.8%, p = .05; OR = 4.4, 95% CI = 1.1-18.2).

CONCLUSIONS

Hydralazine therapy in pregnancies with EUVI was associated with a significant decrease in the rate of miscarriage. We suggest a sequence of events leading to a higher risk of miscarriage in pregnancies with EUVI and propose a potential mechanism through which hydralazine may reduce this risk.

Pharmacological Interventions for the Prevention of Fetal Growth Restriction: A Systematic Review and Network Meta-Analysis

The prevention of fetal growth restriction (FGR) is challenging in clinical practice. To date, no meta-analysis summarized evidence on the relative benefits and harms of pharmacological interventions for FGR prevention. We performed a systematic review and network meta-analysis (NetMA), searching PubMed, Embase, Cochrane Library, and ClinicalTrials.gov from inception until November 2019. We included clinical trials and observational studies on singleton gestating women evaluating antiplatelet, anticoagulant, or other treatments, compared between each other or with controls (placebo or no treatment), and considering the pregnancy outcome FGR (primary outcome of the NetMA). Secondary efficacy outcomes included preterm birth, placental abruption, and fetal or neonatal death. Safety outcomes included bleeding and thrombocytopenia. Network meta-analyses using a frequentist framework were conducted to derive odds ratios (ORs) and 95% confidence intervals (CIs). Of 18,780 citations, we included 30 studies on 4,326 patients. Low molecular weight heparin (LMWH), alone or associated with low-dose aspirin (LDA), appeared more efficacious than controls in preventing FGR (OR 2.00, 95% CI 1.27-3.16 and OR 2.67, 95% CI 1.21-5.89 for controls vs. LMWH and LDA + LMWH, respectively). No difference between active treatments emerged in terms of FGR prevention, but estimates for treatments other than LMWH +/- LDA were imprecise. Only the confidence in the evidence regarding LMWH vs. controls was judged as moderate, according to the Confidence in Network Meta-Analysis framework. No treatment was associated with an increased risk of bleeding, although estimates were precise enough only for LMWH. These results should inform clinicians on the benefits of active pharmacological prophylaxis for FGR prevention.

Reduced angiovasculogenic and increased inflammatory profiles of cord blood cells in severe but not mild preeclampsia

Preeclampsia (PE) is a prevalent pregnancy disorder that leads to high maternal and fetal morbidity and mortality. While defective vascular development and angiogenesis in placenta are known as crucial pathological findings, its pathophysiological mechanism remains elusive. To better understand the effects of PE on angio-vasculogenesis and inflammatory networks in the fetus and to identify their biological signatures, we investigated the quantitative and functional characteristics of cord blood-derived mononuclear cells (CB-MNCs) and CD31-positive MNCs. Flow cytometry analysis demonstrated that the CB-MNCs from the severe PE group had significantly decreased number of cells expressing CD3, CD11b, CD14, CD19, KDR, and CD31 compared with the normal group. Quantitative real time PCR (qRT-PCR) shows down-regulation of the major angiogenic factor VEGFA in MNCs and CD31⁺ MNCs in severe PE. The major inflammatory cytokines IL1 was highly upregulated in CD31⁺ CB-MNCs in the severe PE patients. Mild PE patients, however, did not display any significant difference in expression of all measured angiogenic genes and most inflammatory genes. These findings show distinct angiogenic and inflammatory signatures from severe PE, and they may play a significant role in the pathogenesis of vascular defects in placenta of severe PE.

Attenuation of baroreflex sensitivity and heart rate variability is linked to reduced levels of nitric oxide in pregnant women having risks of developing gestational hypertension

Purpose: Decreased baroreflex sensitivity (BRS) and sympathovagal imbalance (SVI) have been reported as a cardiovascular (CV) risk in gestational hypertension (GH). Nitric oxide (NO) has been implicated in pathophysiology of GH. In the present study, we assessed the link of CV risks (decreased BRS and SVI) to the plasma levels of NO in women having risk of developing GH. Materials and Methods: A total of 96 pregnant women having risk factors for GH were recruited for the study. The blood pressure variability (BPV), heart rate variability (HRV), plasma NO, marker of insulin resistance (HOMA-IR), lipid risk factors, inflammatory markers (hsCRP, interleukin-6), and malondialdehyde (MDA), the marker of oxidative stress (OS) were measured at 16^th and 36^th week. Link of various parameters to NO was assessed by correlation and multiple regression analysis. Results: Of HRV indices, parasympathetic components were decreased and sympathetic components were increased, BRS was decreased, NO was decreased, HOMA-IR, lipid risk factors, hsCRP, interleukin-6, and MDA were increased significantly at 36^th week compared to 16^th week of pregnancy. Most of the markers of cardiometabolic risk were correlated with NO. However, only the markers of CV risk (SVI and reduced BRS) were independently associated with decreased level of NO, but not the metabolic markers except interleukin-6. The independent contribution of BRS (β = 0.334, P < .001) to NO was found to be most significant. Conclusion: It was concluded that decreased BRS, SVI, and increased interleukin-6 are associated with reduction in NO in GH, which may possibly be linked to the development of CV risks in GH.

Decreased Endometrial Thickness Is Associated With Higher Risk of Neonatal Complications in Women With Polycystic Ovary Syndrome

PURPOSE

To evaluate the association of endometrial thickness (EMT) with obstetric and neonatal outcomes in women with polycystic ovary syndrome (PCOS).

METHODS

A total of 1755 subfertile PCOS women with singleton livebirths after frozen-thawed embryo transfer were included between January 2009 and September 2019. Main obstetric outcomes were hypertensive disorders in pregnancy and abnormal placentation. Main neonatal outcomes were preterm birth (PTB), low birthweight (LBW) and small-for-gestational age (SGA). Crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were estimated by univariate and multivariate logistic regression analyses.

RESULTS

Each millimeter decrease in EMT was related to a 9% (adjusted OR 1.09, 95% CI 1.00-1.19; P = 0.053), 14% (adjusted OR 1.14, 95% CI 1.02-1.28; P = 0.002) and 22% (adjusted OR 1.22, 95% CI 1.07-1.38; P = 0.003) higher risk of PTB, LBW and SGA, respectively. Compared to women with EMT >13 mm, women with EMT ≤8 mm also had significantly higher risk of PTB (adjusted OR 3.79, 95% CI 1.53-9.39; P = 0.004), LBW (adjusted OR 4.33, 95% CI 1.39-13.50; P = 0.012) and SGA (adjusted OR 6.38, 95% CI 1.78-22.83; P = 0.004). These associations remained consistent in further subgroup analysis by endometrial preparation regimen and in sensitivity analyses among nulligravida women or women without adverse obstetric outcomes. No significant differences were found in the incidence of several pregnancy complications across EMT categories.

CONCLUSION

Decreased EMT was independently associated with increased risk of PTB, LBW and SGA in women with PCOS.

A Narrative Review of the Renin-Angiotensin-Aldosterone System in the Placenta and Placental Bed of HIV Infected Women of African Ancestry with Preeclampsia

PURPOSE OF REVIEW

Both HIV infection and preeclampsia (PE), a pregnancy-specific disorder of hypertension and multi-system organ involvement, have high prevalence rates especially in low-to-middle-income countries. The immunoexpression of specific renin-angiotensin-aldosterone system (RAAS) receptors in the placenta and placental bed interface may forecast the risk of PE.

RECENT FINDINGS

Preeclampsia is a leading risk factor for mortality worldwide and remains a challenge in HIV-infected individuals especially those on antiretroviral therapy (ART). Irregular RAAS stimulation may be linked to the pathophysiology of hypertension in HIV infection and in PE. The AT1 receptor is expressed across all trimesters of pregnancy, within placental tissue, eliciting vasoconstriction. This increased expression is associated with the severity of PE, implying that the increased expression may be involved in the pathogenesis of this pregnancy disorder. The AT2 receptor expression in normotensive pregnancies was shown to be lower as compared to non-pregnant individuals. Furthermore, in the PE placental bed, the AT2 receptor is the predominant receptor subtype and is found in extravillous trophoblast cells where they facilitate vasodilation. However, AT4R in placentae of PE pregnancies are found to be significantly reduced compared to normotensives pregnancies. The data on the role played by the RAAS pathway in pregnancy is conflicting. Investigation into a tissue-based RAAS with emphasis on immune-expression within the placenta and placental bed may help resolve this conundrum.