Maternal and paternal carriage of the annexin A5 M2 haplotype: a possible risk factor for recurrent implantation failure (RIF)

Paternal thrombophilia and recurrent implantation failure: an exploratory case-control study

OBJECTIVE

Many pieces of literature have reported that inherited and acquired thrombophilia might be a risk factor for recurrent implantation failure (RIF), however, most studies have only focused on RIF patients and not their male partners. We studied the possible association of paternal thrombophilia with RIF risk.

METHODS

Forty-two male partners aged 20-45 suffered from RIF compared with 42 males from couples with at least one successful pregnancy. All participants were investigated for thrombophilia markers.

RESULTS

The prevalence of coagulation Factor V activity was significantly higher in the case group (42.9%) than in the control group (16.7%) (p=0.008) (OR=3.75; 95% CI, 1.38, 10.12). The prevalence of protein C and protein S deficiencies in RIF patients were 4.8% and 2.4%, respectively, and 0% in the controls. The prevalence of antithrombin III (ATIII) deficiency was significantly higher in the case group (19%) than in the control group (2.4%) (p=0.01). None of MTHFR C677T and MTHFR A1298C were statistically significant between the two groups. Combined thrombophilia was 45.2% in the men of the RIF group when compared with the control, 14.2% (p=0.001) (OR = 4.95; 95% CI, 1.75-13.86).

CONCLUSIONS

Paternal thrombophilia may be related to recurrent implantation failure, so evaluation of this factor in RIF patients could be used to identify relevant risk groups and may help in the proper management of these cases to enhance the chance of implantation.

Use of anticoagulants to improve pregnancy outcomes in couples positive for M2 haplotype: A systematic review

BACKGROUND

Placental mediated pregnancy complications (PMPC) are common, often recurring, and pose a significant health risk to mother and fetus. Evidence suggests that the hypercoagulable state associated with many PMPC, could reflect reduced expression of Annexin 5 (ANXA5), a naturally occurring anticoagulant protein in placental tissue. The ANXA5 M2 haplotype is a genetic variant, which results in reduced expression of ANXA5 protein. M2 haplotype carrier couples may therefore be at increased risk of PMPC. Evidence regarding the effectiveness of anticoagulation to prevent PMPC is inconsistent. Furthermore, studies have not selected or stratified for M2 haplotype carriers, in whom there is a predisposition to hypercoagulability, to assess the effectiveness of anticoagulation, which may vary from those without the M2 haplotype.

OBJECTIVES AND RATIONALE

The aim of this study was to systematically review the current evidence to assess whether anticoagulant treatment improves pregnancy outcomes in couples positive for M2 haplotype.

SEARCH METHODS

The review was registered on PROSPERO (CRD42022343943). A comprehensive literature search was performed using MEDLINE, Embase and Cochrane collaboration databases from inception to January 2023. Two reviewers assessed the articles for eligibility and extracted the data simultaneously. Primary outcome was successful pregnancy and live birth. Secondary outcomes included PMPC (implantation failure, miscarriage, pre-eclampsia, preterm birth and fetal growth restriction).

OUTCOMES

From a pool of 410 references, 10 were selected for full text review, of which three studies (a post hoc analysis of a randomised controlled trial, cohort study and a case report) were included in this review. Included studies comprised of 223 individuals, 129 of whom who received anticoagulation treatment after testing positive for M2 haplotype. The studies collectively showed an improvement in pregnancy outcomes in M2 haplotype positive individuals however, given the heterogeneity of studies, it was not possible to conduct a meta-analysis and draw firm conclusions.

WIDER IMPLICATIONS

Current evidence is limited, such that the value of screening couples for the M2 haplotype to select or stratify for treatment with prophylactic anticoagulation remains unknown. Thus, further studies including well designed, large, multi-centre randomised controlled trials are required to assess whether anticoagulation treatment will be effective in improving pregnancy outcomes in M2 haplotype couples.

The role of the annexin A protein family at the maternal-fetal interface

Successful pregnancy requires the tolerance of the maternal immune system for the semi-allogeneic embryo, as well as a synchrony between the receptive endometrium and the competent embryo. The annexin family belongs to calcium-regulated phospholipid-binding protein, which functions as a membrane skeleton to stabilize the lipid bilayer and participate in various biological processes in humans. There is an abundance of the annexin family at the maternal-fetal interface, and it exerts a crucial role in embryo implantation and the subsequent development of the placenta. Altered expression of the annexin family and dysfunction of annexin proteins or polymorphisms of the ANXA gene are involved in a range of pregnancy complications. In this review, we summarize the current knowledge of the annexin A protein family at the maternal-fetal interface and its association with female reproductive disorders, suggesting the use of ANXA as the potential therapeutic target in the clinical diagnosis and treatment of pregnancy complications.

Association of male factors with recurrent pregnancy loss

The role of male factors in recurrent pregnancy loss (RPL) is receiving increased attention since sperm quantity and quality, male genetic mutations, as well as epigenetic modifications, have all been associated with RPL. A growing number of studies have been published on the relationship between male factors and RPL; however, these reports are limited due to small sample sizes, inconsistent inclusion criteria, and detection methods. Herein, we investigate the effects of several male factors on RPL from a genetic and non-genetic perspective to aid clinicians in determining the etiology and optimal treatment strategy for patients with RPL.

Research progress on ANXA5 in recurrent pregnancy loss

The incidence of recurrent pregnancy loss (RPL) in fertile women ranges from 1% to 5%, of which about 50% of them are due to unknown causes. The possible pathogenesis of RPL is an urgent problem to be solved in the clinical. Mutations or polymorphisms of certain genes in the coagulation mechanism are associated with susceptibility to thrombotic diseases and are one of the main reasons for the occurrence of RPL. Among them, the ANXA5 gene was newly studied and some single nucleotide polymorphisms (SNPs) in the promoter region of ANXA5 have been reported to be associated with RPL in multiple races. In this review, we summarized the research progress on the correlation between the SNPs in ANXA5 and RPL, hoping to provide some valuable guidance for the future studies.

Association between ANXA5 haplotypes and the risk of recurrent pregnancy loss

BACKGROUND

Annexin A5 (ANXA5) haplotypes can increase the risk of recurrent pregnancy loss (RPL). This study aimed to investigate the effect of ANXA5 haplotypes on ANXA5 expression in patients with RPL.

METHODS

Female subjects with RPL, parous controls (those who intentionally aborted without medical conditions or complications), and population controls (normal delivery) were studied. Real-time polymerase chain reaction was carried out to evaluate ANXA5 expression in the placenta and peripheral blood. Western blotting and immunohistochemistry were used to assess ANXA5 protein expression. The luciferase assay was performed to detect the effect of M1 and M2 haplotypes on transcription efficiency of the ANXA5 promoter.

RESULTS

We found that the percentage of the M2 carrier was highest in the RPL group. ANXA5 expression in the placenta and peripheral blood in subjects with RPL was significantly inhibited. Furthermore, ANXA5 expression in subjects carrying the M2 haplotype was remarkably suppressed compared with that in carriers of other haplotypes. Finally, the M2 haplotype decreased the transcription efficiency of the ANXA5 promoter.

CONCLUSION

Our findings show that ANXA5 expression is decreased in carriers of the M2 haplotype and that M1/M2 haplotypes in the ANXA5 gene are associated with an increased risk of RPL.

A review of the pathophysiology of recurrent implantation failure

Implantation is a critical step in human reproduction. The success of this step is dependent on a competent blastocyst, receptive endometrium, and successful cross talk between the embryonic and maternal interfaces. Recurrent implantation failure is the lack of implantation after the transfer of several embryo transfers. As the success of in vitro fertilization has increased and failures have become more unacceptable for patients and providers, the literature on recurrent implantation failure has increased. While this clinical phenomenon is often encountered, there is not a universally agreed-on definition-something addressed in an earlier portion of this Views and Reviews. Implantation failure can result from several different factors. In this review, we discuss factors including the maternal immune system, genetics of the embryo and parents, anatomic factors, hematologic factors, reproductive tract microbiome, and endocrine milieu, which factors into embryo and endometrial synchrony. These potential causes are at various stages of research and not all have clear implications or immediately apparent treatment.

A novel test for annexin A5 M2 haplotyping in in vitro fertilization patients and preimplantation embryos

OBJECTIVE

To develop a test for evaluating the annexin A5 M2 haplotype in in vitro fertilization patients and preimplantation embryos.

DESIGN

Test performance was measured by comparing Sanger sequencing of parental blood DNA and quantitative real-time polymerase chain reaction (qPCR) of saliva DNA, 3 fibroblast cell line 7-cell aliquots and their corresponding purified DNA, 123 trophectoderm biopsy samples, and DNA isolated from 1 embryonic stem cell line along with the Mendelian inheritance expectations, embryo Sanger sequencing, and single-nucleotide polymorphism (SNP) microarray-based linkage analysis.

SETTING

Preimplantation genetic testing laboratory research on IVF patient and embryo DNA.

PATIENT(S)

An assay was developed for the detection of the M2 haplotype on saliva samples of 6 in vitro fertilization patients. In addition, 13 patients who underwent preimplantation genetic testing with data on parental and embryo biopsy DNA available for research use were evaluated.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

The concordance rates between Sanger sequencing, SNP array-based linkage analysis, and Mendelian inheritance expectations with qPCR.

RESULT(S)

The concordance rate between Sanger sequencing and qPCR was 100% on parental blood DNA and saliva DNA. The sample concordance rate between all replicates of 7-cell aliquots was 100%. The sample concordance rate between 3 cell lines used to prepare 7-cell aliquots and purified genomic DNA was 100%. The concordance rate between qPCR and Sanger sequencing results from a single trophectoderm biopsy and isolated embryonic stem cell line was 100%. The concordance rate of trophectoderm biopsy qPCR results and expectations from Mendelian inheritance rules was 97%; however, when SNP array-based linkage analysis was included, the concordance rate reached 100%.

CONCLUSION(S)

This study resulted in the development of a convenient saliva collection method and qPCR-based genotyping method to screen for the M2 haplotype. In addition, a novel method for testing preimplantation embryos has been established, providing an alternative to the use of low molecular weight heparin, through selection of embryos without the M2 haplotype.