Idiopathic recurrent pregnancy loss recurs at similar gestational ages

Immunopharmacological properties of VitD3: 1,25VitD3 modulates regulatory T cells and Th17 cells and the cytokine balance in PBMCs from women with unexplained recurrent spontaneous abortion [URSA]

BACKGROUND

VitD3 may contribute to a successful pregnancy through modulation of immune responses, so VitD3 deficiency may have a role in the immunopathogenesis of unexplained recurrent spontaneous abortion [URSA]. However, the mechanisms of immunomodulatory actions of VitD3 in decreasing the risk of recurrent spontaneous abortion have not been understood well.

OBJECTIVE

The purpose of this research was to investigate the influence of 1,25VitD3 on regulatory T cells /Th17 axis, the gene expressions and concentrations of related cytokines including, TGF-β, IL-10, IL-6, IL-23, and IL-17A in peripheral blood mononuclear cells [PBMCs] of healthy women as a control group and women with URSA.

METHOD

Isolation of PBMCs was performed from peripheral blood of the subjects of the studied groups [20 women with URSA as a case group, and 20 control women]. The effects of 1,25VitD3 [50 nM, for 24 hours] on the studied parameters were evaluated and were compared to the positive and negative controls in vitro. Flow cytometry analysis was used to determine the percentages of regulatory T cells and Th17 cells. For gene expression measurement and cytokines assay, Real-time PCR and ELISA were carried out.

RESULTS

The proportion of regulatory T cells was markedly lower, while the proportion of Th17 cells in women with URSA was considerably higher than in the control group [P=0.01, P=0.01]. The ratio of the frequency of Tregs to the baseline [1,25VitD3/Untreated] increased, while the ratio of the frequency of Th17 cells to the baseline decreased in women with URSA relative to the controls [P= 0.01, P=0.04]. 1,25VitD3 increased IL-10 expressions at both the protein and mRNA levels in PBMCs in women with URSA relative to the control group [P=0.0001, P=0.04]. TGF-β levels in the cultured supernatants decreased significantly in the case group in the presence of 1,25VitD3 relative to the controls [P=0.03]. 1,25VitD3 treatment also significantly decreased gene expressions of IL-6, IL-17A, and IL-23 in PBMCs of women with URSA [P=0.01, P=0.001, P=0.0005], as well as the levels of those cytokines in cell culture supernatants [P=0.03, P=0.02, P=0.01, respectively] in women with URSA relative to the controls.

CONCLUSION

According to the findings of this research, modulation of immune responses by 1,25VitD3 is accomplished by strengthening Tregs function and inhibiting inflammatory responses of Th17 cells which may have a positive impact on pregnancy outcome. Thus, as an immunomodulating agent, VitD3 may be effective in reducing the risk of URSA.

Evaluation of the Effects of 1,25 Vitamin D3 on Regulatory T Cells and T Helper 17 Cells in Vitamin D-deficient Women with Unexplained Recurrent Pregnancy Loss

BACKGROUND

Vitamin D insufficiency and deficiency can be associated with adverse effects on pregnancy outcomes, which may include recurrent pregnancy loss through the mechanisms that are yet unknown. The aim of this study was to evaluate the effect of 1,25VitD3 on regulatory T cells (Tregs) and T helper17 (Th17) cell populations In vitro in unexplained recurrent pregnancy loss (URPL) patients and healthy women.

METHODS

Samples from 20 non-pregnant women with a history of URPL were compared to 20 normal non-pregnant women. Peripheral blood mononuclear cells (PBMC) were divided into 3 wells for each subject: in the presence of 1, 25 VitD3 (50 nM, for 16 hours), PHA (positive control) (10μM), and without any treatment (as a baseline or negative control). The percentage of regulatory T cells and Th17 cells was measured by flow cytometry at baseline and then after cell culture experiments.

RESULTS

Our study indicated that the percentage of Tregs in patients with URPL was significantly lower than the control group (2.42 ± 0.27 vs. 3.41 ± 0.29, P= 0.01). The percentage of Th17 cells was significantly greater in URPL patients compared to the control group (2.91 ± 0.33 vs. 1.18± 0.15, P=0.001). 1, 25VitD3 treatment significantly increased the percentage of Tregs from the baseline in the URPL group compared to that in the control group (1.23 ± 0.03 vs. 1.00 ± 0.03, P= 0.01).

CONCLUSION

Vitamin D deficiency may be a contributor to recurrent pregnancy loss and suggests supplementation of women with Vit D pre-pregnancy may be protective against URPL.

Analysis of blocking antibodies and lymphocyte subsets in patients with recurrent reproductive failure

This study aimed to explore the relationship between recurrent reproductive failure (RRF) and blocking antibody (BA) and lymphocytes, to explore the difference of immune status between recurrent spontaneous abortion (RSA) and recurrent implantation failure (RIF) patients. We undertook a retrospective analysis of BA and lymphocyte subsets detected by flow cytometry in 720 RRF patients (411 RSA and 309 RIF patients) who were treated at Shanxi Maternal and Child Health Hospital from April 2015 to October 2019. The BA negative rate of RRF patients was 81.80%, which was significantly higher than that of normal women (23.46%) (p < 0.05). There was no significant difference in BA negative rates between RSA and RIF patients. Compared with the normal value, the percentage of CD3⁺ T lymphocytes and CD3⁺CD4⁺ T lymphocytes in RRF patients were 71.1% (65.9-76.0) and 36.8% (32.5-41.9) respectively, which were significantly lower than the normal value (p < 0.05). The percentage of B cells in RSA patients [11.0 (8.8-13.9)] was significantly lower than that in RIF patients [11.9 (9.4-14.8)]. The occurrence of RRF is related to the lack of BA and the change of lymphoid subsets. There are some differences in immune status between RSA and RIF patients.

Genetics of recurrent pregnancy loss: a review

PURPOSE OF REVIEW

Human reproduction is remarkably inefficient; with pregnancy loss occurring in 10-30% of clinically recognized pregnancies. Of those, 3-5% of couples experience recurrent pregnancy loss (RPL), more than 50% of who never receive an underlying diagnosis. Herein, we review evidence that genetic changes, including pathogenic variant(s) in highly penetrant genes, may provide an explanation for a proportion of couples with pregnancy loss.

RECENT FINDINGS

Genetic abnormalities that may predispose to pregnancy loss include chromosomal aneuploidy, copy number variants, single-gene changes and others. Although previously limited by the need for hypothesis-driven assessment, advancement of various molecular technologies have sheparded in the opportunity to identify molecular cause of highly heterogeneous conditions, including RPL. The identification of causative genetic aberrations associated with RPL demonstrates a promising area of further research.

SUMMARY

The journey of human development from a single-cell zygote to a term infant is complex process. Early research into copy number variants and highly penetrant single-gene changes may provide diagnosis for a proportion of couples with RPL as well as inform genes critical for early human development.

Serum and placental periostin levels in women with early pregnancy loss

OBJECTIVES

Periostin is secreted from the placenta in the embryonic period and it is emphasized that it may be involved in endometrial implantation. In this study, we aimed to investigate periostin serum levels and placental tissue expression in first trimester pregnancy losses.

STUDY DESIGN

In this prospective case-control study, 30 patients who underwent dilatation and curettage with first trimester spontaneous abortion (<10 weeks of gestation) were included in the study group and 30 patients who had voluntary pregnancy termination (<10 gestational weeks) were included in the control group. Serum samples collected from the study and control groups were analyzed usingenzyme-linkedimmunosorbent assay (ELISA), and trophoblastic and decidual tissues were examined using immunohistochemical staining with streptavidin-biotin-peroxidase techniques.

RESULTS

There were no significant differences between the groups in terms of age, gravida status, parity number, gestational week, and number of previous abortions. In the spontaneous abortion group, the serum level of periostin was significantly lower than in the voluntary termination group (6.56 ± 4.16 pg/mLvs. 9.51 ± 4.52 pg/mL, p = 0.03). There was no significant difference between the two groups in terms of periostin expression in decidual and trophoblastic tissue (p = 0.617, p = 0.274, p = 0.497).

CONCLUSION

Periostin serum levels were significantly reduced in patients with spontaneous pregnancy loss. Periostin can be used as a predictive marker for the success of endometrial implantation.

Evaluation of 1,25(OH)2D3 Effects on FOXP3, ROR-γt, GITR, and CTLA-4 Gene Expression in the PBMCs of Vitamin D-Deficient Women with Unexplained Recurrent Pregnancy Loss (URPL)

Background:

Vitamin D insufficiency and deficiency can be associated with adverse effects on fetus and pregnancy outcomes. This study aimed at evaluating the effect of 1,25VitD3 on specific transcription factor and markers of Tregs and Th17 cells in PBMCs of women with URPL as a case group and PBMCs of healthy women as a control group.

Methods:

Samples from 20 non-pregnant patients with a history of URPL were compared to 20 normal non-pregnant women. PBMCs were divided into three wells for each subject in the presence of 1,25VitD3 (50 nM, for 16 hours), PHA (10 µM; positive control), and without any treatment (negative control). By Real-time PCR (Taqman assay), specific transcription factors of Tregs and Th17 cells, FOXP3, ROR-γt, GITR, and CTLA-4 mRNA expressions in two groups were measured.

Results:

FOXP3/ROR-γt mRNA expression in PBMCs decreased significantly in women experiencing URPL compared to the control group (p = 0.0001). Although 1,25VitD3 (50 nM) increased FOXP3 gene expression (p = 0.0001), it did not significantly affect ROR-γt gene expression. Besides, 1,25VitD3 treatment significantly increased FOXP3/ROR-γt mRNA expression from baseline in PBMCs of the fetal loss group compared to that of the control group (p = 0.01). The 1,25VitD3 also increased GITR gene expression (p = 0.017) in PBMCs of URPL women compared to the controls.

Conclusion:

Vitamin D deficiency may be a contributor to recurrent pregnancy loss and suggests that the supplementation of women with Vitamin D pre-pregnancy may be protective against URPL via affecting Tregs signature genes, FOXP3 and GITR.

Insights of efferocytosis in normal and pathological pregnancy

Efferocytosis, which is known as the phagocytic clearance of dying cells by professional as well as non-professional phagocytes, including a great number of intracellular/extracellular factors and signals, is interrelated with the immune system, contributing to local and systemic homeostasis, especially in tissues with high constitutive rates of apoptosis. Accumulating studies have indicated that immune dysregulation is associated with the pathogenesis of the female reproductive system, which causes preeclampsia (PE), recurrent spontaneous abortion (RSA), ruptured ectopic pregnancy, and so on. And some studies have revealed the pleiotropic and essential role of efferocytosis in these obstetrical disorders. More specifically, the occurrence and development of these diseases were in connection with some efferocytosis-related factors and signals, such as C1q, MBL, and IL-33/ST2. In this review, we systematically review the diverse impacts of efferocytosis in immune system and discuss its relevance to normal and pathological pregnancy. These findings may instruct future basic researches as well as clinical applications of efferocytosis-related factors and signals as latent predictors or therapeutic targets on the obstetrical disorders.

Maternal carriers of the ANXA5 M2 haplotype are exposed to a greater risk for placenta-mediated pregnancy complications

PURPOSE

Annexin A5 (ANXA5) is a protein abundantly expressed in normal placenta where it contributes to the healthy outcome of a pregnancy. Lower ANXA5 levels have been observed in M2/ANXA5 haplotype carrying chorion. Consequently, this study aimed to assess the potential association of M2 maternal carrier status with the risk of recurrent pregnancy loss (RPL), the timing of miscarriages, and other obstetric complications, for the first time in a population from Latin America.

METHODS

This study was designed as a prospective recruitment of RPL patients with post hoc analysis. The distribution of the M2/ANXA5 haplotype was compared between a group of 229 Argentine women with RPL and 100 parous controls, and was further analyzed in subgroups of patients stratified according to the timing of miscarriages and in relation to other obstetric complications.

RESULTS

No significant differences were found in the distribution of M2 haplotype among either RPL patients or the subgroups with embryonic, early fetal, or late fetal losses compared to parous controls. Notwithstanding, maternal M2/ANXA5 was found to be independently associated with a higher risk of suffering intrauterine growth restriction (IUGR) and/or preeclampsia (PE). Simultaneously, the presence of inherited and/or acquired thrombophilia also proved to be an independent risk factor for these.

CONCLUSIONS

The association found between the maternal carriage of the M2/ANXA5 haplotype and an elevated risk of IUGR and/or PE supports the hypothesis that carrier status of this haplotype and the consequently reduced placental ANXA5 expression might be responsible, at least partially, for the onset of these gestational vascular complications.

The Importance of an Evidence-based Workup for Recurrent Pregnancy Loss

Choosing an evidence-based workup and treatment for recurrent pregnancy loss is imperative to provide best patient care and create a culture that permits rigorous research into potential (not yet evidence-based) tests and therapeutics. As health sciences technologies become more sophisticated, more precise, and less expensive, new tools may be developed that allow better evaluation and treatment of couples with recurrent pregnancy loss. The goal must remain optimizing value and adhering to evidence-based care.

Functional single nucleotide polymorphisms of matrix metalloproteinase 7 and 12 genes in idiopathic recurrent spontaneous abortion

PURPOSE

The aim of this study was to investigate the potential association of matrix metalloproteinase 7 (MMP7) -181 A/G and MMP12 -82 A/G functional single nucleotide polymorphisms (SNP) with idiopathic recurrent spontaneous abortion (IRSA) in Slovenian reproductive couples.

METHODS

A case-control study was conducted on 149 couples with 3 or more consecutive idiopathic spontaneous pregnancy loses and 149 women and men with at least 2 live births and no history of pregnancy complications. Genotyping of MMP7 -181 A/G and MMP12 -82 A/G SNPs was performed using polymerase chain reaction and restriction fragment length polymorphism methods.

RESULTS

There were no statistically significant differences in the distribution of MMP7 -181 A/G and MMP12 -82 A/G genotype, allele, or haplotype frequencies between IRSA patients and controls, as well as patients' primary and secondary IRSA. We also found no association of MMP7 -181 A/G and MMP12 -82 A/G genotypes, alleles, and haplotypes with IRSA.

CONCLUSIONS

We found no evidence to support the association between IRSA and MMP7 -181 A/G and MMP12 -82 A/G SNPs in Slovenian reproductive couples.

Systematic review and meta-analysis of genetic association studies in idiopathic recurrent spontaneous abortion

OBJECTIVES

1) To perform the first comprehensive systematic review of genetic association studies (GASs) in idiopathic recurrent spontaneous abortion (IRSA); 2) to analyze studies according to recurrent spontaneous abortion (RSA) definition and selection criteria for patients and control subjects; and 3) to perform meta-analyses for the association of candidate genes with IRSA.

DESIGN

Systematic review and meta-analysis.

SETTING

Not applicable.

PATIENT(S)

Couples with IRSA and their spontaneously aborted embryos.

INTERVENTION(S)

Summary odds ratios (ORs) were calculated by means of fixed- or random-effects models.

MAIN OUTCOME MEASURE(S)

Association of genetic variants with IRSA.

RESULT(S)

The systematic review included 428 case-control studies (1990-2015), which differed substantially regarding RSA definition, clinical evaluation of patients, and selection of control subjects. In women, 472 variants in 187 genes were investigated. Meta-analyses were performed for 36 variants in 16 genes. Association with IRSA defined as three or more spontaneous abortions (SAs) was detected for 21 variants in genes involved in immune response (IFNG, IL10, KIR2DS2, KIR2DS3, KIR2DS4, MBL, TNF), coagulation (F2, F5, PAI-1, PROZ), metabolism (GSTT1, MTHFR), and angiogenesis (NOS3, VEGFA). However, ORs were modest (0.51-2.37), with moderate or weak epidemiologic credibility. Minor differences in summary ORs were detected between IRSA defined as two or more and as three or more SAs. Male partners were included in 12.1% of studies, and one study included spontaneously aborted embryos.

CONCLUSION(S)

Candidate gene studies show moderate associations with IRSA. Owing to large differences in RSA definition and selection criteria for participants, consensus is needed. Future GASs should include both partners and spontaneously aborted embryos. Genome-wide association studies and large-scale replications of identified associations are recommended.

Sildenafil (Viagra®) blocks inflammatory injury in LPS-induced mouse abortion: A potential prophylactic treatment against acute pregnancy loss?

INTRODUCTION

Recurrent pregnancy losses (RPL) are common women's health issues. Inflammatory and thrombotic events have been associated with RPL including excessive production of cytokines, in particular TNF-α. However, mechanisms behind gestational losses are not yet fully understood. Sildenafil inhibits phosphodiesterase Type-5 (PDE5). This drug increases intracellular cyclic guanosine monophosphate, having vasodilatory and, more recently described, anti-inflammatory properties. PDE5 is present in murine and human uterus and placenta. Sildenafil is already used clinically for treatment of human fetal growth restriction (FGR). Our objective was to determine if Sildenafil alone or in combination with Heparin had protective effects in pregnant Swiss albino challenged to abort by lipopolysaccharide (LPS).

METHODS

Treatments (Sildenafil (50 mg/kg/day), Heparin (500 IU/Kg/day) or Sildenafil + Heparin at the same doses) were initiated the morning of copulation plug detection (gestational day (gd0)). On the 15th day of pregnancy, an intra-peritoneal injection of LPS (100 μg/kg) was administered. Untreated, pregnant mice challenged by LPS served as controls.

RESULTS

Assessments at 48 h after LPS revealed that Sildenafil + Heparin prevented fetal loss. Early assessments at 2 h after LPS indicated that the pretreatments prevented induction of inflammatory cytokine production (TNF-α, IL-1β/NF-κβ) and preserved placental histopathology.

DISCUSSION

Combined Sildenafil + Heparin therapy was superior to either treatment alone in most analyses. The known safety of Sildenafil and Heparin in human pregnancy suggests that usage of these combined agents may be of value for treatment of patients with impending pregnancy loss or prophylactically in women with a history of recurrent miscarriages.

Clustering of retrospectively reported and prospectively observed time-to-pregnancy

PURPOSE

Given reportedly high clustering but limited validity of retrospectively reported time-to-pregnancy (TTP), we assessed within-woman clustering for retrospectively reported TTPs alone and including gold-standard prospectively observed TTPs among women with 2 or more retrospectively reported and 1 or more prospectively observed TTPs. We further investigated whether past trying times inform future trying time among women with 1 or more retrospectively reported and 1 or more prospectively observed TTPs.

METHODS

Five hundred one couples attempting pregnancy were prospectively observed until human chorionic gonadotropin pregnancy or 12 months of trying. Women reported TTP for past planned pregnancies. Clustering as measured by the frailty variance was estimated using discrete Cox frailty models, adjusted for age, body mass index, smoking at each attempt. Utility of past attempts to inform future attempts was assessed with discrete Cox models and relative risk regression, adjusted for enrollment age, body mass index, smoking.

RESULTS

Seventy-five women with 2 or more prior pregnancies contributed 180 retrospective and 91 prospective TTPs for frailty modeling. Retrospectively reported TTP clustering was high (frailty variance = 0.89) but substantially lower when including prospectively observed TTPs (frailty variance = 0.42). Among 202 women with 1 or more prior pregnancies, past trying times did not inform future trying time.

CONCLUSIONS

TTP recall rather than TTP may account for clustering. Past trying times may not inform future trying times.

Statistical Correlations of the Spontaneous Abortion with Trombophilia and Other Associated Pathologies

15-20% of all known pregnancies progress with a miscarriage or an ectopic pregnancy. The recurrent miscarriage is a delicate clinical situation because with all the advances in genetic and immunologic research the incriminating factors haven't been discovered yet. The treatment is also subject to controversies, being perceived as either ineffective or aggressive. A number of 376 pregnant women with a gestational age smaller than 12 weeks have been selected, 226 of them with spontaneous abortion. In the study group of patients with previous spontaneous abortions we have found a series of associated pathology. From the cases with secondary non idiopathic recurrent miscarriage we have identified 4 cases of thrombophilia with antiphospholipid syndrome, 2 cases of thrombocytosis, one case of autoimmune thyroiditis, one case of uterine tumor, one case of MTHFR C homozygous thrombophilia and one case of FVL heterozygous thrombophilia. Knowing the correlations between the recurrent miscarriage and the hereditary thrombophilia as well as the options of treatment for increasing the chances of having a pregnancy with a normal evolution direct the doctors in testing the patients with recurrent miscarriage for hereditary thrombophilia.

Etiology of spontaneous abortion before and after the demonstration of embryonic cardiac activity in women with recurrent spontaneous abortion

OBJECTIVE

To analyze the etiologic factors of spontaneous abortion in the first trimester among women with recurrent spontaneous abortion, specifically before and after the demonstration of embryonic cardiac activity.

METHODS

A retrospective analysis included women with recurrent spontaneous abortion admitted to a center in Guangzhou, China, for dilation and curettage after a spontaneous abortion in the first trimester between January 2008 and December 2012. The etiologic factors of spontaneous abortion occurring before versus after the demonstration of cardiac activity were compared.

RESULTS

A total of 232 women were included. Among 146 women with demonstrated cardiac activity before spontaneous abortion, 78 (53.4%) had an embryonic karyotype abnormality, 55 (37.7%) had traditional etiologic factors, and 34 (23.3%) had an unidentified cause. Among 86 women without cardiac activity, 41 (47.7%) had an embryonic karyotype abnormality, 28 (32.6%) had traditional etiologic factors, and 26 (30.2%) had an unidentified cause. After exclusion of abortions involving embryonic karyotype abnormalities, there was a higher incidence of APA positivity in the group with embryonic cardiac activity than in the other group (13/68 [19.1%] vs 1/45 [2.2%]; P=0.008) and a lower incidence of subclinical hypothyroidism (8/68 [11.8%] vs 12/45 [26.7%]; P=0.042).

CONCLUSION

The distribution of etiologic factors in spontaneous abortion differs according to whether embryonic cardiac activity is recorded.

M2/ANXA5 haplotype as a predisposition factor in Malay women and couples experiencing recurrent spontaneous abortion: a pilot study

Recurrent spontaneous abortion (RSA) is a prevalent condition among the Malay population of Malaysia, where carriage risk of conventional hereditary thrombophilia factors has been generally ruled out. The contribution of M2/ANXA5, a common haplotype in the annexin A5 gene promoter, was evalauted for RSA in Malay. Seventy-seven women who had experienced two or more unexplained RSA and 41 available male partners were selected for study, with 360 population controls recruited from healthy Malay individuals. Incidence of M2 carriage and odds ratios were calculated between control and patient groups, and clinically defined subgroups and RSA risk was evaluated. M2/ANXA5, found in 42.2% of the general Malay population, was associated with greater risks for women with primary and secondary RSA with early (gestational week 5-15) losses. The risk was somewhat higher in Malay couples when both partners were carriers and a trend of higher prevalence was seen for the male partners patients who had experienced RSA. M2 carriage seems to be a risk factor with unusually high incidence in Malay women and couples with primary and secondary RSA with 'early' spontaneous abortions. The associated male partner risk confirms the proposed role of M2/ANXA5 as a genetic trait impeding embryonic anticoagulation.

Differentiation of genetic abnormalities in early pregnancy loss

OBJECTIVE

To characterize the types of genetic abnormalities and their prevalence in early pregnancy loss at different developmental stages. We hypothesized that the prevalence of genetic abnormalities in pregnancy loss would differ across developmental stages.

METHODS

Women with a pregnancy loss at < 20 weeks' gestation (n = 86) were enrolled at the time of diagnosis. Maternal tissue without a fetal component was found in 13 samples. Chromosomal microarray analysis (CMA) was performed on 74 samples (including two samples from a twin pregnancy); 15 were pre-embryonic (no visible embryo on ultrasound examination), 31 were embryonic (embryo; 6 + 0 to 9 + 6 weeks' gestation) and 28 were fetal (fetus; 10 + 0 to 19 + 6 weeks' gestation) losses. The twin pregnancy was found to be monochorionic diamniotic and was subsequently treated as a single sample in our analysis. Nine samples that underwent CMA were excluded from analysis because of 100% maternal-cell contamination.

RESULTS

The overall prevalence of genetic abnormalities differed across developmental stages (9.1% pre-embryonic, 69.2% embryonic and 33.3% fetal; P < 0.01). This difference persisted when comparing pre-embryonic with embryonic samples (P < 0.01) and embryonic with fetal samples (P = 0.02) but not pre-embryonic with fetal samples (P = 0.12). Additionally, the prevalence of aneuploidy differed significantly across developmental stages (0.0% in pre-embryonic samples vs 65.4% in embryonic samples vs 25.9% in fetal samples, P < 0.001). Abnormalities were most common in embryonic cases, followed by fetal and then pre-embryonic. Maternal cell contamination (MCC) was noted in 47.4% of 46,XX cases assessed.

CONCLUSIONS

Genetic abnormalities detected by CMA are more likely to occur in the embryonic period than in pre-embryonic or fetal stages. MCC is common in early pregnancy loss and should be excluded when results demonstrate a 46,XX karyotype.

Recurrent pregnancy losses and gestational age are closely related: an observational cohort study on 759 pregnancy losses

To assess the accurate dating of the cessation of pregnancy in patients with recurrent pregnancy loss (RPL) and to evaluate the incidence and recurrence rate of pregnancy losses in similar gestational age. In a retrospective cohort study, couples with history of RPL and availability of precise documentation regarding previous pregnancy losses were included. The vast majority of losses occurred within the first trimester. In patients experiencing more than 2 miscarriages in the same gestational stage, a tendency for recurrent losses around the same period of gestation was observed. Overall, the probability of losses at different gestational stages goes down with increasing number of miscarriages at the same stage. The study supports the need to ascertain data regarding the timing of pregnancy loss as accurately as possible for prognosis of future pregnancies and management of couples. A classification for unexplained RPL based on gestational age of miscarriages could help researchers to better investigate RPL.

Successive time to pregnancy among women experiencing pregnancy loss

STUDY QUESTION

Is time to pregnancy (TTP) similar across successive pregnancy attempts among women experiencing pregnancy loss?

SUMMARY ANSWER

TTP after a loss may be longer compared with TTP before a loss.

WHAT IS KNOWN ALREADY

Two pregnancy cohort studies have reported that TTP is similar across pregnancy attempts in fertile women. However, this has not been investigated among women experiencing pregnancy losses.

STUDY DESIGN, SIZE, DURATION

Data for this analysis come from the Longitudinal Investigation of Fertility and the Environment Study, a population-based, preconception cohort of couples attempting pregnancy. During 2005-2009, recruitment was targeted to 16 counties in Michigan and Texas with reported exposures to persistent environmental chemicals. A total of 501 couples were recruited and followed for up to 12 months of pregnancy attempts allowing for continued participation of women with pregnancy losses until censoring.

PARTICIPANTS, SETTING, METHODS

We assessed TTP among 70 couples recruited upon discontinuing contraception for purposes of becoming pregnant and experiencing ≥1 prospectively observed pregnancy losses during 12 months of trying. There were 61 couples who contributed two pregnancy attempts and 9 who contributed three. Women were instructed in the use of urine-based home fertility monitors to time intercourse relative to ovulation and recorded their bleeding patterns in daily journals. TTP was defined as the number of menstrual cycles taken to achieve pregnancy. Women were also instructed in the use of home digital pregnancy tests and asked to begin pregnancy testing on the day of expected menses. Women recorded the results of their pregnancy tests in a daily journal with a single positive pregnancy test result indicating an hCG-confirmed pregnancy. Pregnancy losses were ascertained from a subsequent recorded negative pregnancy test or clinically confirmed loss. We estimated fecundability odds ratios (FORs) comparing subsequent to first TTP using discrete Cox models with robust standard errors, accounting for cycles off contraception before study entry and adjusting for maternal age, body mass index, reproductive history and time-varying cigarette, alcohol and caffeine usage while trying.

MAIN RESULTS AND THE ROLE OF CHANCE

The mean female age was 30.3 ± 4.3 years; 21% had a prior pregnancy loss before study entry. Of the second and third attempts, 59 and 43%, respectively, were longer compared with the first attempt. FORs <1 suggest reduced fecundability or a longer TTP when comparing the second with the first attempt (0.42, 95% confidence interval (CI): 0.28, 0.65), and similarly for the third relative to the first attempt (0.64, 95% CI: 0.18, 2.36). TTP in the second attempt was a median of 1 cycle longer (interquartile range: 0, 3 cycles) compared with TTP in the first attempt.

LIMITATIONS, REASONS FOR CAUTION

As this is the first study to investigate successive TTP exclusively among women experiencing pregnancy loss, our findings await corroboration since most losses occurred early in gestation. As such, the generalizability of our findings for all pregnancy losses awaits further research. We also had limited power to detect a reduction in fecundability for the third compared with first pregnancy attempt.

WIDER IMPLICATIONS OF THE FINDINGS

Unlike fertile women, TTP in women experiencing early pregnancy losses may trend towards longer subsequent attempts. If the findings are corroborated, women experiencing losses may benefit from counselling regarding trying times.

STUDY FUNDING/COMPETING INTERESTS

This research was supported by the Intramural Research Program of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (contracts N01-HD-3-3355, N01-HD-3-3356 and NOH-HD-3-3358). K.J.S. was supported by an Intramural Research Training Award from the Eunice Kennedy Shriver National Institute of Child Health and Human Development, Division of Intramural Population Health Research. The authors have no conflicts of interest to declare.

What is the impact of SOCS3, IL-35 and IL17 in immune pathogenesis of recurrent pregnancy loss?

OBJECTIVE

To investigate the plasma levels of interleukin-4 (IL-4), IL-6, IL-10, tumor necrosis factor-alpha (TNF-alpha), interferon-gamma (IFN-gamma), transforming growth factor-beta (TGF-beta), IL-17, IL-35 and suppressor of cytokine signaling 3 (SOCS3) in the women with history of idiopathic recurrent pregnancy loss (RPL) and in the fertile controls.

METHODS

This study was conducted with 60 idiopathic RPL cases and 40 age-matched fertile controls. Mid-follicular plasma levels of IL-17, IFN-gamma, TNF-alpha, TGF-beta, IL-6, IL-4, IL-10, SOCS3 and IL-35 were assayed by an enzyme linked immunosorbent assay.

RESULTS

The mean age of RPL and control cases were 31.6 ± 0.6 and 32.1 ± 0.7 years, respectively. While plasma IL-35 and SOCS3 levels of RPL group were significantly lower than that of the control group; IFN-gamma, TNF-alpha, IL-4, IL-6, IL-10, IL-17 and TGF-beta levels of RPL group were significantly higher than that of the control group. The comparison of cytokine ratios between RPL and control groups indicated significantly high TNF-alpha/IL-10, TNF-alpha/IL-4, IFN-gamma/IL-10, IFN-gamma/IL-6 and IFN-gamma/IL-4 ratios in the RPL group. IL-35/IL-17 ratio was significantly low in the RPL group compared to that in the control group. Overstimulation of TNF-alpha presented moderate influence on recurrent miscarriage risk.

CONCLUSION

Decreased SOCS3 and IL-35 plasma levels and increased Th1/Th2 cytokine ratios in RPL cases pointed out the supression of anti-inflammatory process and this supression might play an important role in the pathogenesis of idiopathic RPL.

Leptin and leptin receptor polymorphisms and recurrent pregnancy loss

OBJECTIVE

Leptin signaling is important in the establishment of pregnancy. We sought to determine if single nucleotide polymorphisms (SNPs) in the leptin and leptin receptor genes are associated with idiopathic recurrent pregnancy loss (RPL).

STUDY DESIGN

We conducted a case-control study with cases defined as women with idiopathic RPL and controls as parous women without pregnancy losses. A total of 99 cases and 108 controls were genotyped for the leptin (-2548 G/A) SNP and the leptin receptor A223G SNP. Genotype and allele frequencies were compared between cases and controls using χ(2) test.

RESULT

In this population, there was no significant difference in the genotype or allele frequencies for the leptin (-2548 G/A) or leptin receptor A223G SNPs between women with idiopathic RPL and controls.

CONCLUSION

Although leptin signaling is critical to many aspects of reproduction, the maternal leptin and leptin receptor SNPs evaluated in this study are unlikely to have a clinically meaningful role in RPL.

Further insights into the role of the annexin A5 M2 haplotype as recurrent pregnancy loss factor, assessing timing of miscarriage and partner risk

OBJECTIVE

To study the influence of M2/ANXA5 for recurrent pregnancy loss (RPL), according to the timing of miscarriages and assess the male partner risk.

DESIGN

Genetic association study.

SETTING

Academic research center.

PATIENT(S)

Female patients from two academic centers in Germany and Bulgaria with two or more unexplained miscarriages were selected for this study. Male partners were available for a part of the German sample. Population controls were recruited from healthy individuals of respective populations.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Incidence of M2 carriage and odds ratios were calculated between patient and control groups, and RPL risk was evaluated.

RESULT(S)

The M2 haplotype in ANXA5 was associated with greater overall RPL risk in German and in Bulgarian women, and a trend of higher prevalence was seen for male partners of German RPL patients. The highest relative risk of M2 carriage was observed in women of both populations with "early" fetal losses between the 10th and 15th gestational weeks, which was significant in the meta-analysis.

CONCLUSION(S)

M2 carriage seems to have an RPL risk role mostly for early abortions, gestational weeks 10-15. In the first phase of pregnancy this correlates with vascular remodeling to accomplish the transition from high- to low-resistance blood vessels.

Determination of clinical cellular immune markers in women with recurrent pregnancy loss

PROBLEM

Dysregulated natural killer (NK) immunity and T-cell immunity are associated with recurrent pregnancy loss (RPL). We aim to define clinically relevant NK and T-cell parameters for RPL and determine their cutoff values.

METHODS OF STUDY

Ninety-five women with RPL (>3) including 42 idiopathic and 53 known-etiology RPL, and 29 age-matched fertile controls were enrolled. Peripheral blood immunophenotype, NK cell cytotoxicity (NKC), and T-helper (Th) 1 and Th2 cytokine producing cell ratios (Th1/Th2) were measured using flowcytometry. The cutoff values were determined using Youden's J with likelihood ratio (LR) >2.

RESULTS

Natural killer cell percentage and NKC, TNF-α(+) Th1 cells, and TNF-α/IL-10 producing Th1/Th2 cell ratio were significantly higher in idiopathic RPL than controls. By the area under the curve (AUC) analysis, NK cell percentage (AUC = 0.691), NKC (AUC = 0.649), TNF-α(+) Th1 cells (AUC = 0.681) and Th1/Th2 cell ratio (AUC = 0.660) were highly specific for RPL. The cutoff values for NK cell percentage, NKC (E:T cell ratio 25:1), and TNF-α/IL-10 producing Th1/Th2 cell ratio are 16.1, 23.8, and 36.2%, respectively. Seventy-six percent of idiopathic RPL showed at least one of more immune abnormalities by these criteria.

CONCLUSION

Differences in NK cell percentages, NKC and Th1/Th2 cell ratio differentiated RPL from fertile controls.

Sympathetic reactivity in late pregnancy is related to labour onset in women

Stress regulation during pregnancy is considered to be connected to the timing of labour initiation. Although increasing knowledge is emerging on the regulation of parturition, there is currently no way to predict the start of spontaneous labour in women. The main aim of this study was to assess pain threshold and the sympathetic nervous system response to cold pain in relation to the onset of labour in healthy pregnant women. Ninety-three pregnant women were recruited and assessed for skin conductance (SC) activity during a cold pressor test in gestational week 38. Pain threshold and cold endurance were also measured and the results were compared with data obtained from hospital records. Seventy-four women had a spontaneous labour onset and a valid SC measurement. SC activity during the cold pressor test decreased significantly with the number of days left to spontaneous parturition. This may indicate a gradual decrease in sympathetic autonomic nervous system reactivity even during the last weeks of pregnancy. Measuring SC activity during mild stress provocation is a rapid and non-invasive means to study variation in sympathetic reactivity during pregnancy, and may be useful in research on stress regulation in pregnancy and its relation to labour initiation.