Epigenetic dysregulation in recurrent pregnancy loss: the pivotal roles of DNMT and TET enzymes

Investigation of perturbation of DNMT and TET enzymes in endometrial cancer (308)

Do high endothelial venules (HEVs) appear in the uterus of healthy and pathological pregnancies? Our study reveals that HEVs are present in the non-pregnant endometrium and decidua parietalis (decP) but decline upon placentation in decidua basalis (decB) and are less abundant in decidual tissues from idiopathic, recurrent pregnancy losses (RPLs). RPL is associated with a compromised decidual vascular phenotype. Endometrial (n = 29) and first trimester decidual (n = 86, 6-12th week of gestation) tissue samples obtained from endometrial biopsies or elective pregnancy terminations were used to determine the number of HEVs and T cells. In addition, quantification of HEVs and immune cells was performed in a cohort of decidual tissues from RPL (n = 25). Position and frequency of HEVs were determined in non-pregnant endometrial as well as decidual tissue sections using immunofluorescence (IF) staining with antibodies against E-selectin, intercellular adhesion molecule, von Willebrand factor, ephrin receptor B4, CD34 and a carbohydrate epitope specific to HEVs (MECA-79). Immune cell distribution and characterization was determined by antibodies recognizing CD45 and CD3 by IF staining- and flow cytometry-based analyses. Antibodies against c-c motif chemokine ligand 21 (CCL21) and lymphotoxin-beta were used in IF staining and Western blot analyses of decidual tissues. Functional HEVs are found in high numbers in the secretory endometrium and decP but decline in numbers upon placentation in decB (P ≤ 0.001). Decidua parietalis tissues contain higher levels of the HEV-maintaining factor lymphotoxin beta and decP-associated HEVs also express CCL21 (P ≤ 0.05), a potent T-cell chemoattractant. Moreover, there is a positive correlation between the numbers of decidual HEVs and the abundance of CD3+ cells in decidual tissue sections (P ≤ 0.001). In-depth analysis of a RPL tissue collection revealed a decreased decB (P ≤ 0.01) and decP (P ≤ 0.01) HEV density as well as reduced numbers of T cells in decB (P ≤ 0.05) and decP (P ≤ .001) sections when compared with age-matched healthy control samples. Using receiver-operating characteristics analyses, we found significant predictive values for the ratios of CD3/CD45 (P < 0.001) and HEVs/total vessels (P < 0.001) for the occurrence of RPL. Analyses were performed in first trimester decidual tissues from elective terminations of pregnancy or non-pregnant endometrium samples from patients diagnosed with non-endometrial pathologies including cervical polyps, ovarian cysts and myomas. First trimester decidual tissues may include pregnancies which potentially would have developed placental disorders later in gestation. In addition, our cohort of non-pregnant endometrium may not reflect the endometrial vascular phenotype of healthy women. Finally, determination of immune cell distributions in the patient cohorts studied may be influenced by the different modes of tissue derivation. Pregnancy terminations were performed by surgical aspiration, endometrial tissues were obtained by biopsies and RPL tissues were collected after spontaneous loss of pregnancy. In this study, we propose an inherent mechanism by which the endometrium and in particular the decidua control T-cell recruitment. By demonstrating reduced HEV densities and numbers of T cells in decB and decP tissues of RPL samples we further support previous findings reporting an altered vascular phenotype in early pregnancy loss. Altogether, the findings provide important information to further decipher the etiologies of unexplained RPL. This study was supported by the Austrian Science Fund (P31470 B30 to M.K.) and by the Austrian National Bank (17613ONB to J.P.). There are no competing interests to declare. N/A.

Study question What are the subsequent pregnancy outcomes (livebirths, miscarriages or other adverse pregnancy outcomes) in a cohort of women with recurrent miscarriage (RM)? Summary answer The overall live birth rate in women with RM was 62% (466/748), falling to 44% in women aged &amp;gt;40 and 54% in women with infertility. What is known already RM affects approximately 1% of women of reproductive age. RM is recognized as a prognostic indicator for subsequent pregnancies and adverse pregnancy outcomes including ante-partum hemorrhage, diabetes, preterm birth, small for gestational age and perinatal death. While RM has known associations with advanced maternal age, obesity, diabetes, thyroid dysfunction and endometriosis, approximately 50% of women/couples will be left without an explanation for their pregnancy loss, even after completing investigations. Study design, size, duration A retrospective cohort study was undertaken to identify subsequent pregnancy outcomes in women with RM, where RM referral criteria are 3 consecutive first-trimester miscarriages. Women attending the pregnancy loss clinic at a tertiary university hospital in the Republic of Ireland over a 12-year period (2008 - 2020) with a confirmed diagnosis of primary or secondary first-trimester RM were eligible for inclusion. In total, 923 charts were identified for review against the eligibility criteria. Participants/materials, setting, methods Women with non-consecutive first trimester miscarriages or ectopic pregnancy were excluded. Epidemiological and clinical information was gathered from paper and electronic medical records. Data were analysed descriptively using SPSS (Version 27). Main results and the role of chance Of 748 women identified, 332(44%) had primary RM, 416(56%) had secondary RM. The median age was 36(range 19-47) years with 12% aged under 29 and 64% of women aged ≥35. 142(19%) had a history of infertility with 43(5.7%) attending for ART. 12% of women had anti-nuclear antibodies(89/742), 8% had abnormal thyroid function tests(60/742), 4.7% were heterozygous carriers of the Factor V Leiden gene mutation(35/737), 1.5% had positive anti-cardiolipin antibodies(11/733), 2% were carriers of a Prothrombin gene mutation(7/343) and 1% had elevated HbA1c levels(7/742). Fetal karyotype was recorded in 141 pregnancies, with 111 abnormal results(78%;111/141). Trisomy(T) 16 was most common(17/111; 15%) followed by T21 and T22(n = 14; 13%). Parental karyotyping of 697 sets of parents identified 28 balanced translocations(4%; 28/697). Prescribed pharmacological treatments included high dose folic acid(75%; n = 548/728), aspirin(96%; 696/726), progesterone (52%; 389/728), tinzaparin(24%; 175/727), prednisolone(4%; 28/726), metformin(2%; 12/727) and hydroxychloroquine(1%; 7/727). 573 women had a subsequent pregnancy (76.6%); 359(62%; 359/573) had a live birth, 190 had a miscarriage(33%) and 18(3%) had an adverse pregnancy outcome such as ectopic pregnancy, stillbirth or second-trimester miscarriage. Including successive pregnancies over the study period, the overall live birth rate was 62%(466/748), falling to 44% in women aged &amp;gt;40 and 54% in women with infertility. Limitations, reasons for caution This work covers a 12-year period, and while the RM clinic staffing is largely unchanged, some changes in management of RM patients has occurred in this time, reflecting up-to-date evidence and greater public awareness. Furthermore, the adoption of an electronic health chart in 2017 may have affected data availability. Wider implications of the findings Our findings confirm RM occurs more frequently in women aged &amp;gt;35. Aneuploidy remains a leading cause of miscarriage. Age is a prognostic indicator for livebirth after RM. These findings will facilitate counselling in this cohort. The substantial rates of prescribed medications and infertility in women with RM merit further exploration. Trial registration number N/A

STUDY QUESTIONWhat are the subsequent reproductive outcomes (livebirths, miscarriages or other adverse pregnancy outcomes or no further pregnancy) of women with recurrent miscarriage (RM) attending a dedicated clinic?SUMMARY ANSWEROf women with RM, 77% had a subsequent pregnancy, and among these pregnancies, the livebirth rate was 63%.WHAT IS KNOWN ALREADYRM affects ∼1–3% of women of reproductive age. RM has known associations with advanced maternal age, obesity, diabetes, inherited thrombophilias, thyroid dysfunction, endometriosis and parental balanced translocations. However, ∼ 50% of women or couples will be left without an explanation for their pregnancy loss, even after completing investigations. RM is also associated with secondary infertility and adverse pregnancy outcomes including preterm birth and perinatal death.STUDY DESIGN, SIZE, DURATIONWe undertook a retrospective cohort study to identify subsequent pregnancy outcomes in women with RM, defined as three consecutive first-trimester miscarriages. Women attending the RM clinic at a tertiary university hospital in the Republic of Ireland over 12 years (2008–2020) with a confirmed diagnosis of primary or secondary first-trimester RM were eligible for inclusion. In total, 923 charts were identified for review against the eligibility criteria.PARTICIPANTS/MATERIALS, SETTING, METHODSWomen with non-consecutive first-trimester miscarriages or ectopic pregnancy were excluded. Epidemiological and clinical information regarding medical history, investigation and management was gathered from paper and electronic medical records. Data were analysed using SPSS (Version 27). Associations between maternal characteristics and outcomes were explored using the χ2 test, with significance set at P < 0.05. Multinomial regression analysis was performed using a stepwise approach.MAIN RESULTS AND THE ROLE OF CHANCEThere were 748 women who were included; 332 (44%) had primary RM and 416 (56%) had secondary RM. The median age was 36 years (range 19–47). Foetal aneuploidy was the most common investigative finding (15%; n = 111/748); 60% had unexplained RM. In addition to supportive care, most women were prescribed aspirin (96%) and folic acid (75%). Of the 748 women, 573 had a subsequent pregnancy (77%) and 359 (48% of all women; 63% of pregnancies) had a livebirth, while 208 had a further pregnancy loss (28% of all women; 36% of pregnancies) and 6 were still pregnant at the end of the study. Women aged 35–39 years were more likely to have a livebirth than no further pregnancy (relative risk ratio (RRR): 2.29 (95% CI: 1.51–5.30)). Women aged 30–34 years were more likely to have a livebirth (RRR: 3.74 (95% CI: 1.80–7.79)) or a miscarriage (RRR: 2.32 (95% CI: 1.07–4.96)) than no further pregnancy. Smokers were less likely to have a livebirth (RRR: 0.37 (95% CI: 0.20–0.69)) or a miscarriage (RRR: 0.45 (95% CI: 0.22–0.90)) than no further pregnancy. Couples with an abnormal parental karyotype were less likely to have a miscarriage than no further pregnancy (RRR: 0.09 (95% CI: 0.01–0.79)). Including successive pregnancies conceived over the study period, the overall livebirth rate was 63% (n = 466/742), but this was reduced to 44% in women aged ≥40 years and 54% in women with infertility.LIMITATIONS, REASONS FOR CAUTIONThis work covers 13 years; however, those included in the later years have a shorter follow-up time. Although electronic health records have improved data availability, data collection in this cohort remains hampered by the absence of a formal booking visit for women presenting with miscarriage and a national miscarriage database or register.WIDER IMPLICATIONS OF THE FINDINGSOur findings are largely reassuring as most women with RM and hoping to conceive achieved a livebirth. In addition to older age, smoking and parental balanced translocations were associated with a reduced likelihood of further pregnancy. No investigation or treatment was associated with pregnancy outcome, reiterating the importance of the supportive aspects of care for women and their partners after RM and counselling regarding individual risk factors. This contributes to the limited international data on the investigative findings and treatment of women with RM. The high rate of prescribed medications merits greater scrutiny, in conjunction with other pregnancy outcomes, and reiterates the need for a national guideline on RM.STUDY FUNDING/COMPETING INTEREST(S)L.A.L. is a PhD scholar funded through the Pregnancy Loss Research Group, Department of Obstetrics and Gynaecology, University College Cork. M.H. and C.F. are Postdoctoral Researchers on a project funded by the Health Research Board Ireland [ILP-HSR-2019-011] and led by K.O.D., titled: ‘Study of the impact of dedicated recurrent miscarriage clinics in the Republic of Ireland’. The funders had no role in study design, data collection and analysis, decision to publish or preparation of the manuscript. The authors have no conflicts of interests to declare.TRIAL REGISTRATION NUMBERN/A.

Advances of intravenous immunoglobulin G in modulation of anti-fetal immunity in selected at-risk populations: science and therapeutics.

Pregnancy Zone Protein (PZP) is significantly upregulated in the decidua of recurrent and spontaneous miscarriage and negatively correlated to Glycodelin A (GdA)

Study question What is the impact of female lifestyle (BMI, smoking, caffeine, alcohol) on RPL in the general population and on further miscarriage in the RPL population? Summary answer Being underweight and BMI&amp;gt;25 contributes significantly to increased risk of RPL (general population). BMI&amp;gt;25 or BMI&amp;gt;30 increases the risk of further miscarriages (RPL population) What is known already Lifestyle factors are modifiable and in many instances lifestyle optimisation enhances the chances of a positive reproductive outcome. Whilst the specific mechanisms leading to early pregnancy loss is still relatively unknown, poor lifestyle is associated with a hostile reproductive environment whereby optimal embryo implantation and securement of a pregnancy is compromised. The peri-implantation intrauterine environment is a key determinant of pre-implantation embryo development and early programming. RPL is a complex disease where causation has been attributed to numerous factors and whilst it is known that lifestyle factors affect sporadic miscarriage, the extent of this on RPL is less well known. Study design, size, duration A systematic review and meta-analysis was performed to assess the associations between lifestyle factors and RPL. Studies that analysed RPL in the context of BMI, smoking, alcohol and caffeine intake were included. The primary and secondary outcomes were odds of having RPL in the general population and odds of further miscarriage, respectively. Participants/materials, setting, methods Studies were included if they explored women of reproductive age who had been exposed to an aspect of female lifestyle. We excluded studies which assessed the effectiveness of an intervention aimed at altering lifestyle and studies which assessed lifestyle factors in the context of IVF outcomes or associations with PCOS. We screened all studies, reviewing full papers where required and disregarding those that did not meet the eligibility criteria using a double-blind approach. Main results and the role of chance The systematic search identified a total of 24, 705 records and an additional 194 records through hand-searching of references. 16 studies were included in this systematic review and meta-analysis. None of these studies were RCTs; there were 8 case control studies, 6 cohort studies, 1 survey-based study and 1 cross-sectional study. Underweight and women with BMI &amp;gt; 25 are at higher odds of RPL in the general population (OR 1.2, 95% CI 1.12–1.28 and OR 1.21, 95% CI 1.06–1.38, respectively). In women with RPL, having BMI &amp;gt; 30 and BMI &amp;gt; 25 has increased odds of further miscarriages (OR 1.77, 95% CI 1.25–2.50 and OR 1.35, 95% CI 1.07–1.72, respectively). The odds of RPL in the general population is increased in women who were cigarette smokers compared to non-smokers but this is not statistically significant (OR 1.62, 95% CI 0.90–2.93). Alcohol intake compared with no alcohol intake increases the risk of RPL, however this is not statistically significant (OR 1.12, 95% CI 0.88–1.44). The odds of RPL in the higher caffeine intake group (&amp;gt;99mg/day) compared to the lower caffeine intake group (≤99mg/day) is higher but not significant (OR 1.35, 95% CI 0.83–2.19). Limitations, reasons for caution The quality of the evidence was low or very low, mainly due to heterogeneity in study populations. There were inconsistencies in the definition of RPL, some studies included women with ‘≥3 consecutive miscarriages’, others ‘≥2 miscarriages’. We did not explore the impact of male lifestyle on the risk of RPL. Wider implications of the findings Being underweight and BMI&amp;gt;25 contributes significantly to increased risk of RPL. BMI&amp;gt;25 or BMI&amp;gt;30 increases the risk of further miscarriages in the RPL population. Studies addressing the effects of alcohol, cigarette smoking and caffeine on the risk of RPL with optimisation of BMI in this cohort of women are warranted. Trial registration number Is the frequency of low plasma-mannose-binding lectin (p-MBL) levels increased in recurrent pregnancy loss (RPL) after spontaneous conception or IVF/ICSI and recurrent implantation failure (RIF)?

A comparison of endometrial and subendometrial vascularity assessed by three-dimensional ultrasonography and power Doppler angiography between healthy fertile women and women with unexplained primary recurrent miscarriage

Accumulating evidence suggests the association between abnormal angiogenesis at the maternal-fetal interface and recurrent pregnancy loss (RPL); nonetheless, the mechanism remains largely unknown. Previous studies have reported the clinical effect of the traditional Chinese medicine Danshen in the treatment of RPL. This study aimed to investigate whether salvianolic acid B (SalB), the primary water-soluble component of Danshen, could reduce the embryonic absorption rate (EAR) by increasing placental and decidual angiogenesis in RPL mice and to explore the possible mechanism. The decidual and chorionic tissues were collected from normal pregnancies and unknown recurrent pregnancy loss (URPL) patients. Western blotting was used to determine the expression of vascular endothelial growth factor (VEGF) and hypoxia-inducible factor-1α (HIF-1α) in the tissues. Different doses of SalB and/or the VEGF inhibitor PTC299 were intragastrically administered to normal and RPL pregnant mice daily at 0.5 day of pregnancy for 10 days. The EAR, mean placental weight (MPW), and micro vessel density (MVD) were determined in placental and decidual tissues, and the number of live pups per litter was counted. The expression of VEGF and HIF-1α in the tissues was evaluated using western blotting and immunohistochemistry. The VEGF protein levels in decidual and chorionic tissues were significantly lower, and HIF-1α levels were significantly higher than that of normal pregnancies. The EAR was significantly higher, MVD, MPW, and protein levels of VEGF in the placental and decidual tissues of RPL mice were significantly lower than those in normal mice. In contrast, the protein levels of HIF-1α were significantly higher in RPL mice than in normal mice. SalB restored the morphological changes in the uterus of RPL mice, as well as the number of blood vessels in the placenta and decidua, and ameliorated adverse embryonic development in mice (such as neural tube defects and reduced crown-rump length), thereby increasing the pups per. Additionally, SalB increased the VEGF/VEGFR2/p-VEGFR2 levels, placental and decidual MVD, and MPW and decreased the HIF-1α levels and EAR in a dose-dependent manner. A positive association of daily SalB dose (0-100mg/kg) with the VEGF levels, placental and decidual MVD and MPW, and a negative association of daily SalB dose with the HIF-1α levels and EAR were observed.PTC299 reversed the aforementioned increases and decreases in the daily SalB intake of RPL mice. Among these, the daily dose of 100mg/kg of SalB was deemed optimal, and a daily dose of SalB exceeding 100mg/kg did not entirely induce these changes. No correlation between HIF-1α and VEGF was observed in decidual and placental/ chorionic tissues from normal pregnancies and URPL patients, and from normal and RPL mice, but a negative correlation between the two factors was observed in the tissues from RPL mice in the presence of SalB with or without PTC299. SalB ameliorates RPL by restoring physiological HIF-1α/VEGF balance and placental angiogenesis. Optimal daily dose was 100mg/kg, which demonstrated the absence of embryotoxicity or mitigated the embryotoxicity of RPL mice, while higher doses (400mg/kg) showed lesser improvement and increased hepatotoxicity. The promotion of placental and decidual angiogenesis may be an effective strategy for treating unexplained RPL.

ObjectiveThis study aimed to determine the express level of tumour necrosis factor α (TNF-α) in the decidual tissue and peripheral blood of patients with recurrent spontaneous abortion (RSA).Material and methodsEighty RSA patients and 100 control women were recruited in this study. Enzyme-linked immunosorbent assay (ELISA) was applied to determine the expression level of TNF-α in peripheral blood and decidual tissues from both groups. Additionally, the expression level of TNF-α was compared between RSA patients with different numbers of abortions, as well as primary and secondary RSA patients.ResultsThe expression level of TNF-α in peripheral blood and decidual tissues of RSA patients was significantly higher compared to the controls (p < 0.001). Patients who had undergone RSA twice expressed TNF-α in peripheral blood and decidual tissues at a similar level to patients who had experienced RSA three times (p > 0.05), but significantly lower than patients who had experienced RSA more than three times (p < 0.001). The expression level of TNF-α in peripheral blood and decidual tissues was significantly higher in the secondary RSA patients, when compared with primary RSA patients (p < 0.001).ConclusionsTaken together, the relatively high expression level of TNF-α in decidual tissue and peripheral blood may be one of the causes of RSA and therefore could be used as a clinical indicator.

Do gene polymorphisms of two members of the human innate immune sensor nucleotide-binding oligomerization domain, leucine-rich repeat and pyrin domain-containing proteins (NLRP) family, NLRP2 and NLRP7, confer susceptibility to idiopathic recurrent miscarriage (RM)? We found a significant association of a tag single-nucleotide polymorphism (SNP) of NLRP7 (rs26949) with idiopathic RM, while a tag SNP of NLRP2 (rs127868) showed a marginally significant association. Human NLRP2 and NLRP7 have been suggested to be maternal effect genes, regulating early embryonic development and establishment of maternal imprints. Anecdotal evidence showed women who had experienced at least three consecutive miscarriages without hydatidiform mole carried non-synonymous NLRP7 variants. Whether these two genes are associated with idiopathic RM remains obscure. In this case-controlled study, 143 women who had experienced at least two consecutive spontaneous miscarriages (n = 91 women with two miscarriages, n = 52 with three or more) and 149 controls were included between 2004 and 2010. A total of five tag SNPs of NLRP2 and eight tag SNPs of NLRP7 were genotyped using the primer extension analysis. The deviation from the Hardy-Weinberg equilibrium was checked using χ(2) analysis. The logistic odds ratios (ORs) of RM were estimated with a 95% confidence interval (CI) in multivariate analysis after maternal age adjustment. The false discovery rate (FDR) was used to adjust for multiple testing. Tests for haplotype association with RM were performed. Gene-gene interactions among loci of the two genes were evaluated by using the multifactor dimensionality reduction (MDR) method. One tag SNP rs269949 of NLRP7 showed significant difference between patients and controls in a recessive model (FDR P = 0.0456, age-adjusted OR (AOR) = 16.49, 95% CI = 2.00-136.11 for the GG genotype). The difference was significant in patients with two consecutive miscarriages and also in those with three or more consecutive miscarriages. Meanwhile, one tag SNP of NLRP2 (rs12768) showed marginal significance between patients and controls in a co-dominant model (FDR P = 0.0505, AOR = 2.15, 95% CI = 1.29-3.58 for the AC genotype). In the haplotype analysis, NLRP2 and NLRP7 did not show any significant difference between the patients and controls. MDR test revealed that there is no significant gene-gene interaction among loci of NLRP2 and NLRP7. The results may be biased by heterogeneous ethnicities of the Taiwanese Han and a small sample size. The genetic loci responsible for the disease as well as their functional significance also await further investigation. Our study suggests the role of the NLRP family proteins in RM. This study was supported by grants from the National Science Council of the Republic of China (NSC-100-2314-B-006-011-MY3). None of the authors have any conflicts of interest.

ABSTRACTDNA methylation is dynamically modulated during postnatal brain development, and plays a key role in neuronal lineage commitment. This epigenetic mark has also recently been implicated in the development of neural sex differences, many of which are found in the hypothalamus. The level of DNA methylation depends on a balance between the placement of methyl marks by DNA methyltransferases (Dnmts) and their removal, which is catalyzed by ten-eleven translocation (Tet) methylcytosine dioxygenases. Here, we examined developmental changes and sex differences in the expression of Tet and Dnmt enzymes from birth to adulthood in two hypothalamic regions (the preoptic area and ventromedial nucleus) and the hippocampus of mice. We found highest expression of all Tet enzymes (Tet1, Tet2, Tet3) and Dnmts (Dnmt1, Dnmt3a, Dnmt3b) in newborns, despite the fact that global methylation and hydroxymethylation were at their lowest levels at birth. Expression of the Dnmt co-activator, Dnmt3l, followed a pattern opposite to that of the canonical Dnmts (i.e., was very low in newborns and increased with age). Tet enzyme activity was much higher at birth than at weaning in both the hypothalamus and hippocampus, mirroring developmental changes in gene expression. Sex differences in Tet enzyme expression were seen in all brain regions examined during the first week of life, whereas Dnmt expression was more balanced between the sexes. Neonatal testosterone treatment of females only partially masculinized enzyme expression. Thus, Tet expression and activity are elevated during neonatal brain development, and may play important roles in sexual differentiation of the brain.

BackgroundThis study aims to explore the effect of Sinomenine (SIN) on pregnancy outcomes of recurrent spontaneous abortion (RSA) in a mouse model.Material/MethodsThirty female CBA/J mice were allocated into 3 groups randomly, then mated with BALB/c mice (CBA/J×BALB/c) as normal-pregnancy group (n=10), or mated with DBA/2 mice (CBA/J×DBA/2) as RSA model (n=10), or CBA/J×DBA/2 mice treated with SIN as RSA+SIN group (n=10). The number of surviving and reabsorbed embryos in each group were counted on day 13.5 of gestation. The mouse serum was collected to determine the levels of interferon-γ (IFN)-γ and IL-4 by ELISA. Immunohistochemistry, qRT-PCR and immunoblotting were used to determine the location, mRNA and protein expressions of IFN-γ, IL-4, T-bet and GATA3 in the decidual and placental tissue.ResultsIn the RSA group, the amount of reabsorbed embryo was significantly higher than that in the normal-pregnancy group. However, SIN treatment showed a rescue effect on spontaneous abortion in RSA mice. IFN-γ, IL-4, T-bet, and GATA3 were all expressed in placental tissues and mainly located in the cytoplasm. The RSA group demonstrated higher expression levels of IFN-γ and T-bet than in the RSA+SIN and normal-pregnancy groups. Although RSA and RSA+SIN groups showed lower expression levels of IL-4 and GATA3 than in the normal-pregnancy group, there was no significant difference between RSA and RSA+SIN groups regarding IL-4 and GATA expression levels.ConclusionsSIN treatment demonstrates a therapeutic effect on spontaneous abortion in RSA mice, possibly through regulating the balance of Th1/Th2 in maternal circulation and decidual tissues.

Since hypercoagulability might result in recurrent miscarriage, anticoagulant agents could potentially increase the live-birth rate in subsequent pregnancies in women with either inherited thrombophilia or unexplained recurrent miscarriage. To evaluate the efficacy and safety of anticoagulant agents, such as aspirin and heparin, in women with a history of at least two miscarriages without apparent causes other than inherited thrombophilia. We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (April 2008), the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 1), MEDLINE (January 1966 to March 2007), and EMBASE (1980 to March 2007). We scanned bibliographies of all located articles for any unidentified articles. Randomised and quasi-randomised controlled trials that assessed the effect of anticoagulant treatment on the live-birth rate in women with a history of at least two miscarriages (up to 20 weeks of amenorrhoea) without apparent causes other than inherited thrombophilia were eligible. Interventions included aspirin, unfractionated heparin, and low molecular weight heparin for the prevention of miscarriage. One treatment could be compared with another or with placebo. Two authors assessed the trials for inclusion in the review and extracted the data. We double checked the data. Two studies (189 participants) were included in the review. In one study, 54 pregnant women with recurrent miscarriage (RM) but no detectable anticardiolipin antibodies were randomised to low-dose aspirin or placebo. RM was defined as three or more consecutive miscarriages (occurring before 22 weeks' gestational age (based on last menstrual period)). Similar live-birth rates were observed with aspirin and placebo, both 81% (risk ratio (RR) 1.00, 95% confidence interval (CI) 0.78 to 1.29). In the other study, 107 women with consecutive recurrent miscarriage without any apparent cause and no hereditary thrombophilia were randomised between enoxaparin and aspirin. Here RM was stated as three or more consecutive first trimester miscarriages or at least two consecutive second trimester miscarriages. Similar live birth rates were observed with enoxaparin and aspirin, respectively 82% and 84% (RR 0.97, 95% CI 0.81 to 1.16). There is a paucity in studies on the efficacy and safety of aspirin and heparin in women with a history of at least two miscarriages without apparent causes other than inherited thrombophilia. The two reviewed trials studied different treatments and only one study was placebo-controlled. Neither of the studies showed a benefit of one treatment over the other. Therefore, the use of anticoagulants in this setting is not recommended. However, large randomised placebo-controlled trials are still urgently needed.

HLA-C is the only polymorphic classical HLA I antigen expressed on trophoblast cells. It is known that higher incidence of C4d deposition on trophoblast cells is present in women with recurrent miscarriage. C4d is a footprint of antibody-mediated classical complement activation. Therefore, this study hypothesize that antibodies against HLA-C may play a role in the occurrence of unexplained consecutive recurrent miscarriage.Present case control study compared the incidence of HLA-C specific antibodies in 95 women with at least three consecutive miscarriages and 105 women with uneventful pregnancy. In the first trimester of the next pregnancy, presence and specificity of HLA antibodies were determined and their complement fixing ability. The incidence of HLA antibodies was compared with uni- and multivariate logistic regression models adjusting for possible confounders.Although in general a higher incidence of HLA antibodies was found in women with recurrent miscarriage 31.6% vs. in control subjects 9.5% (adjusted OR 4.3, 95% CI 2.0–9.5), the contribution of antibodies against HLA-C was significantly higher in women with recurrent miscarriage (9.5%) compared to women with uneventful pregnancy (1%) (adjusted OR 11.0, 95% CI 1.3–89.0). In contrast to the control group, HLA-C antibodies in the recurrent miscarriage group were more often able to bind complement.The higher incidence of antibodies specific for HLA-C in women with recurrent miscarriage suggests that HLA-C antibodies may be involved in the aetiology of unexplained consecutive recurrent miscarriage.