Low-molecular-weight heparin in the treatment of recurrent IVF-ET failure and thrombophilia: a prospective randomized placebo-controlled trial

Prophylactic low-molecular-weight heparin in women with thrombophilia undergoing in vitro fertilization

OBJECTIVE

To verify whether low-molecular-weight heparin (LMWH) could increase pregnancy rates and/or decrease abortion rates in women with thrombophilia undergoing assisted reproduction cycles.

METHODS

Cross-sectional study with patients undergoing in vitro fertilization (IVF) (N = 104). Women without thrombophilia (control group, n = 20), women with thrombophilia who did not receive LMWH (untreated group, n = 30), and women with thrombophilia, treated with daily enoxaparin from the day of embryo transfer until week 36 of gestation (treated group, n = 54). All women underwent controlled ovarian hyperstimulation. IVF was performed by intracytoplasmic sperm injection, and embryos were transferred on day 3. Pregnancy was detected by β-human chorionic gonadotropin (biochemical pregnancy) and fetal heartbeat at week 5 to 6. Ongoing pregnancy was determined by ultrasound on week 12.

RESULTS

Patients in the untreated thrombophilia group presented with significantly lower ongoing pregnancy rates and live birth rates and significantly higher early pregnancy loss and abortion rates when compared with the control and the treated thrombophilia groups.

CONCLUSIONS

In women with diagnosed coagulation disorders, use of LMWH is important to avoid miscarriages.

Low-molecular-weight heparin in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection: A meta-analysis

INTRODUCTION

This meta-analysis aimed to evaluate the efficacy and safety of low-molecular-weight heparin (LMWH) on pregnancy outcomes in thrombophilic women receiving in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI).

MATERIAL AND METHODS

A systematic literature search of PubMed, EMBASE, the Cochrane Library, and China National Knowledge Infrastructure was performed to identify randomized controlled trials (RCTs) comparing LMWH with no treatment or placebo published from database inception until February 19, 2023. Primary outcomes were the clinical pregnancy rate and implantation rate, and secondary outcomes were the live birth rate, miscarriage rate, and the risk of bleeding events. The certainty of the evidence was rated using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) system. Meta-analysis was conducted using STATA 14.0.

RESULTS

Five RCTs involving 1094 thrombophilic women receiving IVF/ICSI were finally included. Administration of LMWH was associated with statistically higher clinical pregnancy rate (4 RCTs, risk ratio [RR] 1.50, 95% confidence interval [CI] 1.23-1.82, p < 0.001, low certainty evidence), implantation rate (5 RCTs, RR 1.49, 95% CI 1.25-1.78, p < 0.001, very low certainty evidence), and live birth rate (2 RCTs, RR 2.15, 95% CI 1.60-2.89, p < 0.001, very low certainty evidence), but with statistically lower miscarriage rate (2 RCTs, RR 0.36, 95% CI 0.15-0.86, p = 0.021, very low certainty evidence). However, using LMWH was linked to a higher risk of bleeding events (2 RCTs, RR 2.36, 95% CI 1.49-3.74, p < 0.001, very low certainty evidence).

CONCLUSIONS

Very low certainty evidence suggests that administration of LMWH may benefit pregnancy outcomes in thrombophilic women receiving IVF/ICSI treatment, although it may also increase the risk of bleeding events. However, before putting our findings into practice, healthcare professionals should conduct an in-depth evaluation of the available evidence and specific patient situations. Furthermore, due to the low methodological quality of the included studies, more high-quality studies are needed to validate our findings in the future.

Cuyun Recipe ameliorates pregnancy loss by regulating macrophage polarization and hypercoagulable state during the peri-implantation period in an ovarian hyperstimulation mouse model

BACKGROUND

The Chinese herbal prescription Cuyun Recipe (CYR) has been widely used to treat clinical infertility and has shown good efficacy. Animal experiments have shown that CYR can promote implantation in mice, however, the exact mechanism underlying the implantation has not been elucidated.

PURPOSE

To investigate the effect and mechanism of CYR on regulating macrophage polarization and hypercoagulability during the peri-implantation period in mice with ovarian hyperstimulation.

METHODS

An ovarian hyperstimulation mouse model was developed, followed by treatment with CYR. Mice were sacrificed on day (D)4.5, D6, or D8 of gestation. The number of implantation sites, the pathological changes of the uterus and ovaries were assessed. The polarization of monocytes/macrophages in the spleen and endometrium, the expression and localization of cytokines were further detected. Furthermore, analyses of hypercoagulable state of the blood were also performed.

RESULTS

Treatment with CYR increased the average number of implantation sites, promoted angiogenesis in endometrial, and regulated monocytes/macrophages and the cytokine levels. Moreover, CYR downregulated the overexpression of D-dimer and fgl2 after ovarian hyperstimulation.

CONCLUSION

CYR facilitates embryo implantation by alleviating ovarian hyperstimulation, promoting endometrial decidualization and angiogenesis, regulating macrophage polarization, and reversing the hypercoagulable state of the blood.

Immunomodulation for unexplained recurrent implantation failure: where are we now?

In brief

Immune dysfunction may contribute to or cause recurrent implantation failure. This article summarizes normal and pathologic immune responses at implantation and critically appraises currently used immunomodulatory therapies.

Abstract

Recurrent implantation failure (RIF) may be defined as the absence of pregnancy despite the transfer of ≥3 good-quality blastocysts and is unexplained in up to 50% of cases. There are currently no effective treatments for patients with unexplained RIF. Since the maternal immune system is intricately involved in mediating endometrial receptivity and embryo implantation, both insufficient and excessive endometrial inflammatory responses during the window of implantation are proposed to lead to implantation failure. Recent strategies to improve conception rates in RIF patients have focused on modulating maternal immune responses at implantation, through either promoting or suppressing inflammation. Unfortunately, there are no validated, readily available diagnostic tests to confirm immune-mediated RIF. As such, immune therapies are often started empirically without robust evidence as to their efficacy. Like other chronic diseases, patient selection for immunomodulatory therapy is crucial, and personalized medicine for RIF patients is emerging. As the literature on the subject is heterogenous and rapidly evolving, we aim to summarize the potential efficacy, mechanisms of actions and side effects of select therapies for the practicing clinician.

Recurrent implantation failure: A comprehensive summary from etiology to treatment

Implantation is the first step in human reproduction. Successful implantation depends on the crosstalk between embryo and endometrium. Recurrent implantation failure (RIF) is a clinical phenomenon characterized by a lack of implantation after the transfer of several embryos and disturbs approximately 10% couples undergoing in vitro fertilization and embryo transfer. Despite increasing literature on RIF, there is still no widely accepted definition or standard protocol for the diagnosis and treatment of RIF. Progress in predicting and preventing RIF has been hampered by a lack of widely accepted definitions. Most couples with RIF can become pregnant after clinical intervention. The prognosis for couples with RIF is related to maternal age. RIF can be caused by immunology, thrombophilias, endometrial receptivity, microbiome, anatomical abnormalities, male factors, and embryo aneuploidy. It is important to determine the most possible etiologies, and individualized treatment aimed at the primary cause seems to be an effective method for increasing the implantation rate. Couples with RIF require psychological support and appropriate clinical intervention. Further studies are required to evaluate diagnostic method and he effectiveness of each therapy, and guide clinical treatment.

The role of thrombophilias in reproduction: A swot analysis

Thrombophilia is a group of inherited or acquired coagulation disorders that have been associated with reproductive failure. However, there are still no clear recommendations on whether its inclusion in the initial study of the infertile couple or patients with recurrent implantation failure is necessary. In this discussion paper, based on a SWOT (strengths, weaknesses, opportunities, threats) analysis, the different aspects of the repercussions of thrombophilia screening and treatment in reproduction are evaluated. To avoid possible subjectivity in the analysis and results of this study, researchers followed Oxford criteria for the evaluation of evidence. The results from the evaluation of the reviewed bibliography seem to indicate that, pending new evidence, it would be advisable not to include thrombophilia screening in the initial baseline study of the infertile couple. There is no evidence to support a clear association between thrombophilia and implantation failure or infertility. Thrombophilia testing in this setting may increase cost, with minimal potential benefit and lead to inappropriate use of anticoagulants with possible deleterious adverse effects. Future well-designed studies are needed to assess the possible benefit of anticoagulant therapy in infertile thrombophilic patients with implantation failure.

Activated protein C resistance impact on Syrian candidates for in vitro fertilisation and the benefit of anticoagulation therapy: a retrospective cohort study

Activated protein C resistance (APCR) is a common thrombophilia, caused mainly by a mutation. The impact of APCR on the efficacy of In Vitro Fertilization (IVF) are still unclear, and no solid recommendations for its management were published. To investigate the effect of APCR on IVF outcomes and assess the efficacy of our management protocol, we retrospectively scanned the medical records of women who were tested with APCR assay in 2019 at our fertility centre. The 66 women (12%) positive for APCR had lower odds of reaching clinical pregnancies after IVF 0.18 [95% CI: 0.07-0.47] and fewer live births. The administration of low-molecular-weight heparin and aspirin associated with more implantation in treated compared to untreated APCR-positive women with an odds ratio of 43.2 [7.51-248.6]. In conclusion, APCR negatively affects the number of clinical pregnancies after IVF, but anticoagulation therapy can mitigate this effect and significantly increase clinical pregnancies.Impact StatementWhat is already known on this subject? The evidence about the impact of APCR on IVF outcomes is still inconclusive. According to the Canadian guideline, routine screening for thrombophilia in patients with recurrent pregnancy loss is not recommended. No clear recommendations regarding the management of APCR in the planning for IVF are yet available.What do the results of this study add? APCR significantly increases implantation failure among infertile women who conduct IVF. Management of APCR using LMWH and aspirin was effective in mitigating this effect and increasing successful implantation.What are the implications of these findings for clinical practice and/or further research? Our findings can support the recommendation to include APCR assay in the routine tests for infertile women conducting IVF, and suggest the combination between LMWH and aspirin as an effective therapy to increase successful implantation in APCR positive candidates. However, more controlled clinical trials are still needed to confirm our results.

Evidence for the effectiveness of immunologic therapies in women with subfertility and/or undergoing assisted reproduction

Implantation is a critical step in the establishment of a successful pregnancy, depending on a complex immune-endocrine dialogue between the developing embryo and maternal endometrium. Research suggests that altered immunity in the maternal decidua results in implantation impairment and failure. Immunomodulatory drugs have, thus, been widely used in assisted conception to aid embryo implantation, despite an absence of consensus on their effectiveness and safety. We conducted a systematic review and meta-analysis of interventional studies investigating the use of immunomodulators in women undergoing assisted reproduction. Evidence was uncertain of an effect for most of the included interventions, owing to heterogeneous findings and a paucity of high-quality studies. For certain patient subgroups, however, the use of specific immunomodulatory therapies may offer some benefit. There is a need for further large randomized controlled trials to corroborate these findings.

Uterine cytokine profiles after low-molecular-weight heparin administration are associated with pregnancy outcomes of patients with repeated implantation failure

INTRODUCTION

Low molecular-weight heparin (LMWH) plays a role in repeated implantation failure (RIF), but outcomes are controversial. LMWH can potentially modulate local immune responses associated with the establishment and maintenance of pregnancy. The study aimed to explore the effects of LWMH in uterine inflammatory cytokine profiles and pregnancy outcomes of patients with repeated implantation failure (RIF) but without thrombophilia.

METHODS

We compared clinical characteristics and reproductive outcomes among 326 patients with RIF, but not thrombophilia, undergoing frozen embryo transfer (FET) cycle with or without LMWH treatment. Endometrium secretions were aspirated from both groups after 3 days of progesterone administration before and after LMWH treatment. Cytokine mRNA expression was analyzed in primary endometrial cells in vitro.

RESULTS

The clinical and ongoing pregnancy rates did not significantly differ between the groups (31.5% vs. 24.4%, p = 0.15; 29.6% vs. 20.7%, p = 0.06). Concentrations of IL-6 and granulocyte-colony stimulating factor (G-CSF) in uterine secretions were significantly increased in the LWMH group, regardless of pregnancy outcomes (P < 0.05). And, in all patients treated with LWMH, those of secreted IL-6, IL-15 and G-CSF were significantly increased in pregnant group (P < 0.05). The expression of mRNA for G-CSF and IL-6 was significantly increased in human endometrial stromal cells in vitro (P < 0.05) after stimulation with LWMH (10 IU/mL).

CONCLUSIONS

Uterine cytokine profiles after LMWH administration are associated with pregnancy outcomes and LMWH may be beneficial for patients with three implantation failures who do not have coagulation disorders.

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.

Thrombophilia, Inflammation, and Recurrent Pregnancy Loss: A Case-Based Review

Recurrent pregnancy loss (RPL) is defined as the loss of two or more pregnancies and is often multifactorial with the majority of miscarriages being due to aneuploidy and anatomic or physiological abnormalities. However, inherited or acquired thrombophilias have also been associated with RPL, albeit inconsistently. While inherited thrombophilias, such as factor V Leiden and prothrombin gene mutation, are relatively prevalent in women with RPL compared with the general population, a causal link has yet to be definitively established. Recently, systemic inflammation, as measured by high-sensitivity C-reactive protein, has also been hypothesized to play a role in infertility. Based on limited prospective trial data, antithrombotic therapy and antiplatelet agents have been proposed as possible tools for the prevention of RPL. Because of the multifactorial nature of RPL and infertility, various clinicians, as obstetricians and gynecologists, endocrinologists, hematologists, or vascular medicine specialists, may be requested to counsel these women. This, together with evidence gaps, frequently leads to distinctly different diagnostic and therapeutic recommendations, especially regarding thrombophilia testing and treatment. Using four case vignettes in this review, we critically appraise the literature and highlight how two clinicians from different subspecialties approach the relationship between RPL, inflammation, and thrombophilia.

The Pathophysiology of Hypercoagulability and Infertility

Alongside an interplay of a multitude of factors, attainment of a favorable pregnancy outcome is predicated on successful implantation, which in itself is a complex process anchored by balanced interchange with the hemostatic system. Among other etiologies, failure of implantation can result in infertility, and lead affected couples to consider assisted reproductive technology (ART) in an effort to fulfill their desire for procreation. Given the critical role of the hemostatic system in the process of implantation, documentation of a hypercoagulable state during controlled ovarian stimulation in the context of in vitro fertilization, as well as the potential association of its derangement in the setting of thrombophilia, with infertility, ART, ovarian hyperstimulation syndrome, and failure of implantation are explored. Additionally, current evidence addressing the relationship between ART and thromboembolism is examined, as is the role of therapy with heparin and aspirin to decrease thrombotic risk and improve ART-related pregnancy outcomes. Evidence-based recommendations from relevant professional societies are summarized.

The role of low molecular weight heparin on recurrent pregnancy loss: A systematic review and meta-analysis

To assess the roles of the low molecular weight heparin (LMWH) on recurrent pregnancy loss (RPL). The relevant studies of all randomized controlled trials (RCTs) were retrieved, and the systematic evaluation was conducted. PubMed, Embase, and Cochrane library databases were searched by using keywords, including low-molecular-weight heparin or LMWH, and recurrent miscarriage or recurrent pregnancy loss in pregnant women from their earliest data to February 2020. Two investigators independently evaluated eligibility. Risk ratios (RRs) and their corresponding 95% confidence interval (CI) were determined. To pool the results, this meta-analysis was performed using random-effect model due to the high heterogeneity among these eight studies. A total of eight RCTs involving 1854 participants were included in the meta-analysis involving 963 patients with RPL who were prescribed LMWH (enoxaparin, tinzaparin, or dalteparin) alone and 891 patients who were treated with no LMWH interventions (placebo, folic acid or non-treatment) were compared. Pooled data from the remaining eight RCTs showed the differences between intervention groups and control groups. Compared with control groups, LMWH had significantly improved live births (RR,1.19; 95%CI, 1.03 to 1.38; P = 0.02), and reduced miscarriage rates (RR, 0.62; 95%CI, 0.43 to 0.91; P = 0.01). The study suggested that LMWH could improve the live births and reduce the miscarriage rates of RPL. Therefore, LMWH might be a good treatment choice for women with unexplained PRL.

Efficacy of therapies and interventions for repeated embryo implantation failure: a systematic review and meta-analysis

The aim of the present systematic review and meta-analysis was to assess the effect of the different therapeutic options for repeated embryo implantation failure (RIF) on a subsequent IVF cycle outcome. Twenty-two RCTs and nineteen observational studies were included. Pooling of results showed a beneficial effect of intrauterine PBMC infusion on both CPR (RR 2.18; 95% CI 1.58-3.00; p < 0.00001; OR 2.03; 95% CI 1.22-3.36; p = 0.006) and LBR (RR 2.41; 95% CI 1.40-4.16; p = 0.002; OR 3.73; 95% CI 1.13-12.29; p = 0.03), of subcutaneous G-CSF administration on CPR (RR 2.29; 95% CI 1.58-3.31; p < 0.0001) and of intrauterine PRP infusion on CPR (RR 2.45; 95% CI 1.55-3.86; p = 0.0001). Observational studies also demonstrated a positive effect of IVIG and intrauterine hCG infusion on both CPR and LBR and of atosiban on CPR. Studies investigating intrauterine G-CSF infusion, LMWH, intravenous intralipid, hysteroscopy, blastocyst-stage ET, ZIFT, PGT-A and AH failed to observe an impact on IVF outcome. The quality of the evidence that emerged from RCTs focused on intrauterine PBMC infusion and subcutaneous G-CSF administration was moderate. For all other therapies/interventions it varied from low to very low. In conclusion, intrauterine PBMC infusion and subcutaneous G-CSF administration are the most promising therapeutic options for RIF. However, further well conducted RCTs are necessary before their introduction into clinical practice.

Recurrent implantation failure in IVF: A Canadian Fertility and Andrology Society Clinical Practice Guideline

Recurrent implantation failure (RIF) after IVF is a challenging topic for clinicians and can be a devastating reality for some patients with infertility. The purpose of this guideline from the Canadian Fertility and Andrology Society (CFAS) is to provide the most relevant evidence to date for the assessment and management of RIF. This guideline was developed using the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. This guideline recognizes the presence of heterogeneity in the definition of RIF. Recommendations are offered here on the investigation of RIF and management options that may increase the chance of a live birth.

Safety and Efficacy of Enoxaparin in Pregnancy: A Systematic Review and Meta-Analysis

Introduction

International guidelines support the use of low molecular weight heparins for the treatment of thromboembolism and thromboprophylaxis during pregnancy. However, evidence of the benefit and harm associated with specific low molecular weight heparins such as enoxaparin is dated. No current systematic review and meta-analysis describing the safety and efficacy of enoxaparin for thromboembolism and thromboprophylaxis during pregnancy exists.

Methods

PubMed, Embase, and Cochrane databases were searched on August 17, 2018 for clinical trials or observational studies in pregnant women receiving enoxaparin; patients with a prosthetic heart valve were excluded. Risk ratios (RR) with 95% confidence intervals (CI) were calculated using a random effects model, and heterogeneity was measured using the I² statistic.

Results

Of the 485 records identified in the search, 24 studies published clinical trials, and observational studies were found dating back to 2000. Only one observational cohort and one randomized control trial focused on the use of enoxaparin for thromboprophylaxis and therefore efficacy was not assessed; the other studies included women with recurrent pregnancy loss (15 studies), history of placental vascular complications (five studies), and recurrent in vitro fertilization failure (two studies) and were therefore analyzed in terms of safety only. Bleeding events were non-significantly more often reported for enoxaparin compared to untreated controls (RR 1.35 [0.88–2.07]) but less often reported for enoxaparin versus aspirin (RR 0.93 [0.62–1.39]); thromboembolic events, thrombocytopenia, and teratogenicity were rarely reported events; in patients with a history of recurrent pregnancy loss, encouragingly the rates of pregnancy loss were significantly lower for enoxaparin compared to untreated controls (RR 0.58 [0.34–0.96]) and enoxaparin + aspirin versus aspirin alone (RR 0.42 [0.32–0.56]) as well as observably lower for enoxaparin versus aspirin alone (RR 0.39 [0.15–1.01]), though significant heterogeneity was observed (I² > 60).

Conclusion

Literature on the efficacy and safety of enoxaparin for thromboembolism and thromboprophylaxis remains scanty, and therefore efficacy was not assessed; in terms of safety, when including other indications for enoxaparin in pregnancy, we found that enoxaparin was associated with significantly lower complications than aspirin. Given differences in study design and study heterogeneity, pregnancy loss results should be interpreted with caution. Moreover, reports of thromboembolic events, thrombocytopenia, and congenital malformations were rare.

Funding

Sanofi.

Electronic supplementary material

The online version of this article (10.1007/s12325-019-01124-z) contains supplementary material, which is available to authorized users.

A narrative review of adjuvants in in vitro fertilisation: evidence for good clinical practice

A review of studies published between January 1, 1984 and January 31, 2019 was performed with the aim of analysing the efficacy and adverse effects of commonly used adjuvants to in vitro fertilisation. The authors preferentially selected recent systematic reviews and randomised control trials (where available) from an electronic literature search. The review showed that low molecular weight heparin, corticosteroids and embryo glue may be of use in selected patient groups. Other adjuncts (such as growth hormone, assisted hatching, endometrial disruption and dehydroepiandrosterone) cannot currently be recommended as collated results showed no overall benefit to clinical pregnancy rates or live birth rates. There is a significant lack of robust evidence in this field, and areas in particular need of further research have been highlighted. In conclusion, caution should be exercised in prescribing adjuvants in in vitro fertilisation, either individually or in combination as further research is needed to ascertain their efficacy. Many adjuvants carry the risk of adverse effects which should also be considered. Patients should be clearly informed of the evidence, and where it is lacking, for these treatments. There is a need for further good quality trials to address the questions regarding best practice.

American Society of Hematology 2018 guidelines for management of venous thromboembolism: venous thromboembolism in the context of pregnancy

BACKGROUND

Venous thromboembolism (VTE) complicates ∼1.2 of every 1000 deliveries. Despite these low absolute risks, pregnancy-associated VTE is a leading cause of maternal morbidity and mortality.

OBJECTIVE

These evidence-based guidelines of the American Society of Hematology (ASH) are intended to support patients, clinicians and others in decisions about the prevention and management of pregnancy-associated VTE.

METHODS

ASH formed a multidisciplinary guideline panel balanced to minimize potential bias from conflicts of interest. The McMaster University GRADE Centre supported the guideline development process, including updating or performing systematic evidence reviews. The panel prioritized clinical questions and outcomes according to their importance for clinicians and patients. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess evidence and make recommendations.

RESULTS

The panel agreed on 31 recommendations related to the treatment of VTE and superficial vein thrombosis, diagnosis of VTE, and thrombosis prophylaxis.

CONCLUSIONS

There was a strong recommendation for low-molecular-weight heparin (LWMH) over unfractionated heparin for acute VTE. Most recommendations were conditional, including those for either twice-per-day or once-per-day LMWH dosing for the treatment of acute VTE and initial outpatient therapy over hospital admission with low-risk acute VTE, as well as against routine anti-factor Xa (FXa) monitoring to guide dosing with LMWH for VTE treatment. There was a strong recommendation (low certainty in evidence) for antepartum anticoagulant prophylaxis with a history of unprovoked or hormonally associated VTE and a conditional recommendation against antepartum anticoagulant prophylaxis with prior VTE associated with a resolved nonhormonal provoking risk factor.

Heparin prevents oxidative stress-induced apoptosis in human decidualized endometrial stromal cells

Clinical trials have shown that administering heparin during the luteal phase has beneficial effects on implantation and live birth rates. Heparin exerts direct effects on decidual human endometrial stromal cells (HESCs), which are independent of its anticoagulant effect. However, the accurate effects of heparin on the decidualization process remain unidentified. Here, we demonstrate that HESCs become dramatically resistant to oxidative stress upon decidualization, and we hypothesize a possible direct action of heparin on the decidualization of HESCs, which would lead to improved implantation. To test this hypothesis, we established primary HESC cultures and propagated them, and then we decidualized confluent cultures with 8-bromo-cAMP, with medroxyprogesterone acetate, and with or without heparin. We treated the cells with hydrogen peroxide (H₂O₂) as a source of reactive oxygen species (ROS). Adding heparin to decidualized HESCs induced prolactin secretion. Decidualized HESCs treated with heparin were prevented from undergoing apoptosis induced by oxidative stress. Heparin induced nuclear accumulation of the forkhead transcription factor FOXO1 and expression of its downstream target, the ROS scavenger superoxide dismutase 2. These results demonstrate that heparin-treated decidualized HESCs acquired further resistance to oxidative stress, suggesting that heparin may improve the implantation environment.

Efficacy of low-molecular-weight heparin on the outcomes of in vitro fertilization/intracytoplasmic sperm injection pregnancy in non-thrombophilic women: a meta-analysis

Introduction

The aim of our study was to evaluate the effect of low‐molecular‐weight heparin on pregnancy outcomes in women without thrombophilia during in vitro fertilization/intracytoplasmic sperm injection treatment.

Material and methods

We searched Pubmed, Web of Science, Embase, Cochrane and CNKI (from inception to 2 February 2018). Our study identified randomized controlled trials or quasi‐randomized controlled trials comparing low‐molecular‐weight heparin subcutaneous treatment with no treatment or only luteal support control. The outcomes included live birth rate, clinical pregnancy rate and miscarriage rate.

Results

Five trials, including 935 women receiving in vitro fertilization/intracytoplasmic sperm injection treatment, were included in meta‐analyses. There were 458 women receiving low‐molecular‐weight heparin and 477 in the control group. No significant differences for live birth rate, clinical pregnancy rate and miscarriage rate were found between the low‐molecular‐weight heparin and control groups. Of them, four trials reported live birth rate as an outcome and the risk ratio was 1.13 (95% confidence interval 0.88–1.43, p = 0.34). All five trials reported clinical pregnancy rate as an outcome, the risk ratio was 1.08 (95% confidence interval 0.87–1.32, p = 0.47). Three trials reported miscarriage rate and the risk ratio was 0.58 (95% confidence interval 0.30–1.10, p = 0.09). In women with two or more failed in vitro fertilization/intracytoplasmic sperm injection cycles, the risk ratio of live birth rate was 1.15 and the risk ratio of clinical pregnancy rate was 1.17. In women with three or more failed in vitro fertilization/intracytoplasmic sperm injection cycles, the risk ratios of live birth rate and clinical pregnancy rate were 1.36 and 1.35, respectively.

Conclusions

Our results suggested that low‐molecular‐weight heparin had no effect on pregnancy success rate in non‐thrombophilic women undergoing in vitro fertilization/intracytoplasmic sperm injection treatment. However, to justify the use of low‐molecular‐weight heparin in clinical practice, multicenter trials are still necessary.

Effects of multiple inherited and acquired thrombophilia on outcomes of in-vitro fertilization

INTRODUCTION

The effects of multiple inherited and acquired thrombophilic defects on the outcome of in-vitro fertilization (IVF) remain unexplored. The aim of this study was to evaluate the association between multiple thrombophilia and clinical outcomes in a large prospective cohort of women undergoing IVF.

MATERIALS AND METHODS

Consecutive women scheduled for IVF were eligible. The primary study outcome was live birth. Secondary outcomes included spontaneous abortion, clinical pregnancy, and symptomatic venous thromboembolism.

RESULTS

687 women with a mean age of 34.6 (±3.2) years were included. Overall, 22 women (3.2%) had two or more thrombophilic defects. The probability of live birth was not statistically significantly different between women with ≥2 thrombophilia (odds ratio [OR] 0.62; 95% confidence interval [CI], 0.18 to 2.11) or ≥1 thrombophilia (OR 0.67;95% CI, 0.41 to 1.09) and women without any thrombophilia. None of the individual inherited thrombophilia nor positivity to antiphospholipid antibodies or lupus anticoagulant were associated with live birth. Single positivity for lupus anticoagulant carried a more than threefold higher risk of abortion (OR 3.74; 95% CI, 1.30 to 10.75). There were no statistically significant associations between individual or multiple thrombophilic defects and clinical pregnancy or pregnancy test results. No woman had a history of venous thromboembolism and none developed a thrombotic event during the study.

CONCLUSIONS

In women undergoing IVF, the presence of two or more thrombophilic defects was rare and showed no statistically significant associations with IVF outcomes.

Enhancement of trophoblast differentiation and survival by low molecular weight heparin requires heparin-binding EGF-like growth factor

STUDY QUESTION

Does low molecular weight heparin (LMWH) require heparin-binding epidermal growth factor (EGF)-like growth factor (HBEGF) signaling to induce extravillous trophoblast differentiation and decrease apoptosis during oxidative stress?

SUMMARY ANSWER

LMWH increased HBEGF expression and secretion, and HBEGF signaling was required to stimulate trophoblast extravillous differentiation, increase invasion in vitro and reduce trophoblast apoptosis during oxidative stress.

WHAT IS KNOWN ALREADY

Abnormal trophoblast differentiation and survival contribute to placental insufficiency syndromes, including preeclampsia and intrauterine growth restriction. Preeclampsia often manifests as a pro-thrombotic state, with unsuccessful transformation of the spiral arteries that reduces oxygen supply and can produce placental infarction. LMWH improves placental function by increasing blood flow. Recent data suggest that the actions of LMWH transcend its anti-coagulative properties, but the molecular mechanism is unknown. There is evidence that LMWH alters the expression of human HBEGF in trophoblast cells, which regulates human trophoblast pathophysiology. HBEGF, itself, is capable of increasing trophoblast survival and invasiveness.

STUDY DESIGN, SIZE, DURATION

First-trimester placental explants and the HTR-8/SVneo cell line, established using extravillous trophoblast outgrowths from first-trimester villous explants, were treated in vitro with LMWH to examine the effects on HBEGF signaling and trophoblast function under normal physiological and pathological conditions. A highly specific antagonist of HBEGF and other inhibitors of HBEGF downstream signaling were used to determine the relationship between LMWH treatment and HBEGF.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Placental tissues (n = 5) were obtained with IRB approval and patient consent from first-trimester terminations. Placental explants and HTR-8/SVneo cells were cultured on plastic or Matrigel™ and treated with a therapeutic dose of LMWH (Enoxaparin; 10 IU/ml), with or without CRM197, pan Erb-B2 Receptor Tyrosine Kinase (ERBB) inhibitor, anti-ERBB1 or ERBB4 blocking antibodies, or pretreatment of cells with heparitinase I. Extravillous differentiation was assessed by immunocytochemistry to determine the relative levels of integrins α6β4 and α1β1. Trophoblast invasiveness was assessed in villous explants by measuring outgrowth from villous tips cultured on Matrigel, and by invasion assays with HTR-8/SVneo cells cultured on Matrigel-coated transwell insert. Placental explants and HTR-8/SVneo cells were exposed to oxidative stress in a hypoxia-reoxygenation (H-R) model, measuring cell death by TUNEL assay, caspase 3 cleavage, and BCL-2α expression.

MAIN RESULTS AND THE ROLE OF CHANCE

LMWH induced extravillous differentiation, according to trophoblast invasion assays and integrin (α6β4-α1β1) switching. Treatment with LMWH rescued cytotrophoblasts and HTR-8/SVneo cells from apoptosis during exposure to reoxygenation injury, based on TUNEL, caspase 3 cleavage and BCL-2α expression. Experiments using CRM197, ERBB1 and ERBB4 blocking antibodies, pan-ERBB inhibitor and removal of cell surface heparin demonstrated that the effects of LMWH on trophoblast invasion and survival were dependent upon HBEGF signaling.

LARGE SCALE DATA

N/A.

LIMITATIONS, REASONS FOR CAUTION

The primary limitation of this study was the use of only in vitro experiments. Patient demographics from elective terminations were not available.

WIDER IMPLICATIONS OF THE FINDINGS

These data provide new insights into the non-coagulation-related aspects of perinatal LMWH treatment in the management of placental insufficiency disorders.

STUDY FUNDING/COMPETING INTEREST(S)

This research was supported by grants from the National Institutes of Health (HD071408 and HL128628), the March of Dimes, and the W. K. Kellogg Foundation. There were no conflicts or competing interests.

'To test or not to test', the arguments for and against thrombophilia testing in obstetrics

Clinicians increasingly investigate women for thrombophilias due to their associations with venous thromboembolism and placenta-mediated pregnancy complication. These associations, however, are modest and based largely on retrospective data from studies with heterogeneous classifications and populations, leading to discordance between evidence and guidelines. Current evidence suggests a contributory rather than causative role for thrombophilia in placenta-mediated pregnancy complication and venous thromboembolism. With little evidence of benefit from antithrombotic therapy in placenta-mediated pregnancy complication, thrombophilia screening remains controversial. Given the low absolute risk of placenta-mediated pregnancy complication and gestational venous thromboembolism with heritable thrombophilia, universal screening is inappropriate. Selective screening for antiphospholipid syndrome is supported by robust evidence of benefit. Conversely, selective screening for heritable thrombophilia has not been shown to effectively manage placenta-mediated pregnancy complication. Therefore, at present heritable thrombophilia screening is not warranted for placenta-mediated pregnancy complication. Until we have better evidence from better stratified patient groups, caution should remain if we wish to practice evidence-based medicine.

Does intrauterine injection of low-molecular-weight heparin improve the clinical pregnancy rate in intracytoplasmic sperm injection?

Objective

Heparin can modulate proteins, and influence processes involved in implantation and trophoblastic development. This study aimed to assess the improvement of clinical pregnancy and implantation rates after local intrauterine injection of low-molecular-weight heparin (LMWH) in patients undergoing intracytoplasmic sperm injection (ICSI).

Methods

A randomised case/control design was followed in women scheduled for ICSI. The study arm was injected with intrauterine LMWH during mock embryo transfer immediately following the ovum pickup procedure, while the control arm was given an intrauterine injection with a similar volume of tissue culture media. Side effects, the clinical pregnancy rate, and the implantation rate were recorded.

Results

The pregnancy rate was acceptable (33.9%) in the LMWH arm with no significant reported side effects, confirming the safety of the intervention. No statistically significant differences were found in the clinical pregnancy and implantation rates between both groups (p=0.182 and p=0.096, respectively). The odds ratio of being pregnant after intrauterine injection with LMWH compared to the control group was 0.572 (95% confidence interval [CI], 0.27−1.22), while the risk ratio was 0.717 (95% CI, 0.46−1.13; p=0.146). No statistical significance was found between the two groups in other factors affecting implantation, such as day of transfer (p=0.726), number of embryos transferred (p=0.362), or embryo quality.

Conclusion

Intrauterine injection of LMWH is a safe intervention, but the dose used in this study failed to improve the outcome of ICSI. Based on its safety, further research involving modification of the dosage and/or the timing of administration could result in improved ICSI success rates.

Low-molecular-weight-heparin can benefit women with recurrent pregnancy loss and sole protein S deficiency: a historical control cohort study from Taiwan

BACKGROUND

Heritable thrombophilias are assumed important etiologies for recurrent pregnancy loss. Unlike in the Caucasian populations, protein S and protein C deficiencies, instead of Factor V Lieden and Prothrombin mutations, are relatively common in the Han Chinese population. In this study we aimed to investigate the therapeutic effect of low molecular weight heparin upon women with recurrent pregnancy loss and documented protein S deficiency.

METHODS

During 2011-2016, 68 women with recurrent pregnancy loss (RPL) and protein S deficiency (both the free antigen and function of protein S were reduced) were initially enrolled. All the women must have experienced at least three recurrent miscarriages. After excluding those carrying balanced translocation, medical condition such as diabetes mellitus, chronic hypertension, and autoimmune disorders (including systemic lupus erythematosus and anti-phospholipid syndrome), coexisting thrombophilias other than persistent protein S deficiency (including transient low protein S level, protein C deficiency, and antithrombin III), only 51 women with RPL and sole protein S deficiency were enrolled. Initially they were prescribed low dose Aspirin (ASA: 100 mg/day) and unfortunately there were still 39 women ended up again with early pregnancy loss (12 livebirths were achieved though). Low-molecular-weight-heparin (LMWH) was given for the 39 women in a dose of 1 mg/Kg every 12 h from the day when the next clinical pregnancy was confirmed to the timing at least 24 h before delivery. The perinatal outcomes were assessed.

RESULTS

Of 50 treatment subjects performed for the 39 women (i.e. 11 women enrolled twice for two pregnancies), 46 singletons and one twin achieved livebirths. The successful live-birth rate in the whole series was 94 % (47/50). Nineteen livebirths delivered vaginally whereas 28 delivered by cesarean section. The cesarean delivery rate is thus 59.57 %. Emergent deliveries occurred in 3 but no postpartum hemorrhage had been noted.

CONCLUSIONS

Our pilot study in Taiwan, an East Asian population, indicated anti-coagulation therapy is of benefit to women with recurrent pregnancy loss who had documented sole protein S deficiency.

TRIAL REGISTRATION

ISRCTN64574169. Retrospectively registered 29 Jun 2016.

Thrombophilia and assisted reproduction technology-any detrimental impact or unnecessary overuse?

PURPOSE

The aim of this study is to provide an overview of the studies investigating a possible association between thrombophilia and assisted reproductive technology (ART) outcome.

METHODS

This is a literature review.

RESULTS

Congenital thrombophilias (CoT) are reported to be associated with pregnancy loss. However, the association between CoT and early pregnancy loss is weak and does not necessarily support causation. CoT are more likely to be associated with late fetal loss. Even though data pooled from case-control and cohort studies suggest an increased risk of ART failure in women with CoTs, there seems no association when the analysis is confined to better quality cohort studies. The evidence supporting anticoagulation to improve ART outcome in CoT carriers is weak. Likewise, studies on antiphospholipid antibodies (APAs) and ART outcome suffer from multiple methodological limitations and a detrimental impact of APA positivity is controversial. Empirical administration of heparin or low molecular weight heparin to women with recurrent ART failures is supported by weak evidence. Importantly, thrombophilias are likely to increase thrombotic complications after ovarian stimulation for ART.

CONCLUSIONS

Current evidence does not support routinely testing for or treatment of thrombophilia in the setting of ART nor in couples with implantation failure. A careful personal and family history should be obtained and a risk assessment for thrombotic complications should be made in every woman undergoing ovarian stimulation. If positive, testing for thrombophilia is warranted.

Increased circulating cell-derived microparticle count is associated with recurrent implantation failure after IVF and embryo transfer

Cell-derived microparticles (cMPs) are small membrane vesicles that are released from many different cell types in response to cellular activation or apoptosis. Elevated cMP counts have been found in almost all thrombotic diseases and pregnancy wastage, such as recurrent spontaneous abortion and in a number of conditions associated with inflammation, cellular activation and angiogenesis. cMP count was investigated in patients experiencing unexplained recurrent implantation failure (RIF). The study group was composed of 30 women diagnosed with RIF (RIF group). The first control group (IVF group) (n = 30) comprised patients undergoing a first successful IVF cycle. The second control group (FER group) included 30 healthy women who had at least one child born at term and no history of infertility or obstetric complications. cMP count was significantly higher in the RIF group compared with the IVF and FER groups (P < 0.05 and P < 0.01, respectively) (RIF group: 15.8 ± 6.2 nM phosphatidylserine equivalent [PS eq]; IVF group: 10.9 ± 5.3 nM PS eq; FER group: 9.6 ± 4.0 nM PS eq). No statistical difference was found in cMP count between the IVF and FER groups. Increased cMP count is, therefore, associated with RIF after IVF and embryo transfer.

Thrombophilia and Pregnancy Complications

There is a paucity of strong evidence associated with adverse pregnancy outcomes and thrombophilia in pregnancy. These problems include both early (recurrent miscarriage) and late placental vascular-mediated problems (fetal loss, pre-eclampsia, placental abruption and intra-uterine growth restriction). Due to poor quality case-control and cohort study designs, there is often an increase in the relative risk of these complications associated with thrombophilia, particularly recurrent early pregnancy loss, late fetal loss and pre-eclampsia, but the absolute risk remains very small. It appears that low-molecular weight heparin has other benefits on the placental vascular system besides its anticoagulant properties. Its use is in the context of antiphospholipid syndrome and recurrent pregnancy loss and also in women with implantation failure to improve live birth rates. There is currently no role for low-molecular weight heparin to prevent late placental-mediated complications in patients with inherited thrombophilia and this may be due to small patient numbers in the studies involved in summarising the evidence. There is potential for low-molecular weight heparin to improve pregnancy outcomes in women with prior severe vascular complications of pregnancy such as early-onset intra-uterine growth restriction and pre-eclampsia but further high quality randomised controlled trials are required to answer this question.

Successful Pregnancy Following Assisted Reproduction in Woman With Systemic Lupus Erythematosus and Hypertension: A Case Report

Patients with systemic lupus erythematosus have a poor prognosis of pregnancy, since it is associated with significant maternal and fetal morbidity, including spontaneous miscarriage, pre-eclampsia, intrauterine growth restriction, fetal death and pre-term delivery. We report a case with successful pregnancy in a patient with systemic lupus erythematosus and hypertension. A 39-year-old nulliparous woman presented with systemic lupus erythematosus with antinuclear and antiphospholipid antibodies, hypertension and recurrent pregnancy loss presented for assisted reproduction. The patient responded well to enoxaparin and prednisone during both assisted reproduction and prenatal treatment. This case report indicates that prescription of immunosuppressant and blood thinners can be safely recommended throughout the whole prenatal period in patients with systemic lupus erythematosus. Enoxaparin and prednisone may be prescribed concurrently during pregnancy.

Frequency of hereditary thrombophilia in women with recurrent pregnancy loss in Northern Pakistan

AIM

Hereditary thrombophilia (HT) screening is performed as routine work-up of recurrent pregnancy loss (RPL) in Pakistan. In Northern Pakistan the prevalence of HT is not known. HT is not detected in the majority of RPL cases, especially in patients with ≤ 3 pregnancy losses (PL). The aim of this study was to determine the frequency of HT in women with RPL, and to find the prevalence of HT in patients with ≤ 3 PL and > 3 PL.

MATERIAL AND METHODS

Lupus-anticoagulant-negative patients with unexplained RPL were screened for protein C, protein S, antithrombin, and factor V Leiden.

RESULTS

A total of 315 patients with RPL were screened and 13 (4%) had evidence of HT. Protein C and protein S deficiency were detected in 6/140 (4.3%) women with > 3 PL and in 2/175 (1.1%) women with ≤ 3 PL. Antithrombin deficiency was detected in 2/140 (0.75%) women with > 3 PL and in no patients with ≤ 3 PL. Factor V Leiden was detected in 3/26 (12%) women with > 3 PL and in no patients with ≤ 3 PL. The prevalence of HT in patients with >3 PL was significantly higher than in patients with ≤ 3 PL (P = 0.002). We detected a strong association between HT and >3 PL (odds ratio 7.3; 95% confidence interval: 1.60-33.85) as compared to ≤ 3 PL.

CONCLUSION

HT was detected in 4% of patients with RPL. The prevalence of HT in patients with > 3 PL is significantly higher than in patients with ≤ 3 PL.

The physiologic and therapeutic role of heparin in implantation and placentation

Implantation, trophoblast development and placentation are crucial processes in the establishment and development of normal pregnancy. Abnormalities of these processes can lead to pregnancy complications known as the great obstetrical syndromes: preeclampsia, intrauterine growth restriction, fetal demise, premature prelabor rupture of membranes, preterm labor, and recurrent pregnancy loss. There is mounting evidence regarding the physiological and therapeutic role of heparins in the establishment of normal gestation and as a modality for treatment and prevention of pregnancy complications. In this review, we will summarize the properties and the physiological contributions of heparins to the success of implantation, placentation and normal pregnancy.

Treatment of high risk pregnancies

Introduction: The efficacy of a therapy with certoparin; also in combination with aspirin and prednisolone; in high-risk pregnancies has been examined prospectively.

Method: Data of 616 pregnancies have been analyzed. 238 patients injected Mono Embolex 3000; 239 patients Mono Embolex 8000 only. 62 patients injected Mono Embolex 8000 and took aspirin 50–100 mg daily; 60 Mono Embolex 3000 and aspirin 50–100 mg daily. 30 patients took aspirin 50–100 mg; prednisolone 2.5–5 mg and 17 injected mono Embolex 8000; 13 Mono Embolex 3000 daily from the start of their pregnancy. The target variable was the life birth rate.

When given aspirin the HPA-status of the partner is measured if the pregnant woman is negative for HPA 1a or 5b. In HPA-negative mothers and HPA-positive fathers a test for HPA-antibodies is performed posterior week 16.

Result: Applied early; a mean life birth rate of 95 % has been achieved in the monotherapy with Mono Embolex. Where heparin and aspirin were applied before pregnancy week 17 a life birth rate of 100 % was achieved. In patientswith a combination of aspirin and prednisolone a life birth rate of 87 % was achieved. Considering the life birth rate the status of thrombophilia gene-polymorphisms is irrelevant. The HPA-status was examined in 139 patients. In one of the HPA 5a-negative and 3 of the HPA 5b-negative women an immunization occurred but the platelet count of the fetus was not decreased. 3.3 % showed local allergic reaction and 0.5 % slight bleeding.

Conclusion: Certoparin, aspirin and prednisolone are safe drugs to increase life birth rate.

Low molecular weight heparin modulates maternal immune response in pregnant women and mice with thrombophilia

PROBLEM

Thrombophilia is associated with pregnancy complications. Treatment with low molecular weight heparin (LMWH) improves pregnancy outcome, but the underlying mechanisms are not clear.

METHODS OF STUDY

We analyzed Treg frequency in blood from thrombophilic pregnancies treated with LMWH (n = 32) or untreated (n = 33) and from healthy pregnancies (n = 39) at all trimesters. Additionally, we treated pregnant wild-type, heterozygous and homozygous factor-V-Leiden (FVL) mice with LMWH or PBS and determined Treg frequency, pro-/anti-inflammatory cytokine levels and Caspase-3-activity in placenta and decidua.

RESULTS

Treg frequencies were increased in second and third trimester in LMWH-treated thrombophilic pregnancies compared to controls. Treg levels were comparable to those of normal pregnancies. Homozygous FVL mice had decreased decidual Tregs compared to wild-type mice. LMWH treatment normalized Tregs and was associated with increased decidual IL-10 mRNA. LMWH diminished Caspase-3-activity in mice of all genotypes.

CONCLUSION

We demonstrated anti-apoptotic and anti-inflammatory effects of LMWH in pregnant FVL mice. LMWH increased Treg levels in mice and humans, which suggests benefits of LMWH treatment for thrombophilic women during pregnancy.

Anticoagulation and in vitro fertilization and ovarian stimulation

Assisted reproductive technology is widely used to treat couples affected by infertility. Complications associated with assisted reproduction include venous thromboembolism, ovarian hyperstimulation syndrome, and recurrent implantation failure. It has also been proposed that thrombophilia may be associated with an increased likelihood of these events. Although data are limited, antithrombotic therapy is frequently used to enhance the likelihood of successful assisted reproduction. This chapter reviews the risks of venous and arterial thromboembolism associated with assisted reproduction, as well as available data regarding the impact of thrombophilia on the risks of thromboembolism and failure of implantation. The role of antithrombotic therapy in reducing the likelihood of these events, along with recommendations from various guidelines, are also discussed.

Antithrombotic treatment for pregnancy complications: which path for the journey to precision medicine?

Haemostatic and vascular biology mechanisms appear to play an important role in the pathogenesis of placenta-mediated pregnancy complications. Although low-dose aspirin (LDA) has a modest effect in preventing preeclampsia, antithrombotic interventions, LDA and low molecular weight heparin (LMWH) have not definitively proven their effectiveness in women with placenta-mediated pregnancy complications selected by previous pregnancy outcome alone. Given the heterogeneous aetiology of placenta-mediated pregnancy complications, it is critical to stratify patients according to maternal and fetal characteristics and disease mechanisms rather than simply by pregnancy outcome, such as miscarriage. Such stratification could identify those who could benefit from antithrombotic interventions in pregnancy. We lack data on genome-wide association studies, biomarkers and trials of interventions applied to specific homogeneous populations. Future studies should focus on elaborating different disease mechanisms and examining antithrombotic interventions in specific and more homogeneous groups, such as thrombophilic women with well-characterized placenta-mediated pregnancy complications, stratified by disease severity and pathological findings. Because of fetal safety concerns with new anticoagulants, the intervention should focus on heparins alone or in combination with LDA. Thus, placenta-mediated pregnancy complications deserve precision medicine, defining disease by mechanism rather than outcome with interventions focused on a more personalized approach.

Heparin for assisted reproduction

BACKGROUND

Heparin as an adjunct in assisted reproduction (peri-implantation heparin) is given at or after egg collection or at embryo transfer during assisted reproduction. Heparin has been advocated to improve embryo implantation and clinical outcomes.  It has been proposed that heparin enhances the intra-uterine environment by improving decidualisation with an associated activation of growth factors and a cytokine expression profile in the endometrium that is favourable to pregnancy.

OBJECTIVES

To investigate whether the administration of heparin around the time of implantation (peri-implantation heparin) improves clinical outcomes in subfertile women undergoing assisted reproduction.

SEARCH METHODS

A comprehensive and exhaustive search strategy was developed in consultation with the Trials Search Co-ordinator of the Cochrane Menstrual Disorders and Subfertility Group (MDSG). The strategy was used in an attempt to identify all relevant studies regardless of language or publication status (published, unpublished, in press, and in progress). Relevant trials were identified from both electronic databases and other resources (last search 6 May 2013).

SELECTION CRITERIA

All randomised controlled trials (RCTs) were included where peri-implantation heparin was given during assisted reproduction. Peri-implantation low molecular weight heparin (LMWH) during IVF/ICSI was given at or after egg collection or at embryo transfer in the included studies. Live birth rate was the primary outcome.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility and quality of trials and extracted relevant data. The quality of the evidence was evaluated using GRADE methods.

MAIN RESULTS

Three RCTs (involving 386 women) were included in the review.Peri-implantation LMWH administration during assisted reproduction was associated with a significant improvement in live birth rate compared with placebo or no LMWH (odds ratio (OR) 1.77, 95% confidence interval (CI) 1.07 to 2.90, three studies, 386 women, I(2) = 51%, very low quality evidence with high heterogeneity). There was also a significant improvement in the clinical pregnancy rate with use of LMWH (OR 1.61, 95% CI 1.03 to 2.53, three studies, 386 women, I(2) = 29%, very low quality evidence with low heterogeneity).However these findings should be interpreted with extreme caution as they were dependent upon the choice of statistical method: they were no longer statistically significant when a random-effects model was used.Adverse events were poorly reported in all included studies, with no comparative data available. However, LMWH did cause adverse effects including bruising, ecchymosis, bleeding, thrombocytopenia and allergic reactions. It appeared that these adverse effects were increased if heparin therapy was used over a longer duration.

AUTHORS' CONCLUSIONS

The results of this Cochrane review of three randomised controlled trials with a total of 386 women suggested that peri-implantation LMWH in assisted reproduction treatment (ART) cycles may improve the live birth rate in women undergoing assisted reproduction. However, these results were dependent on small low quality studies with substantial heterogeneity, and were sensitive to the choice of statistical model. There were side effects reported with use of heparin, including bruising and bleeding, and no reliable data on long-term effects. The results do not justify this use of heparin outside well-conducted research trials.These findings need to be further investigated with well-designed, adequately powered, double-blind, randomised, placebo-controlled, multicentre trials. Further investigations could also focus on the effects of the local (uterine) and not systemic application of heparin during ART.

Implantation in assisted reproduction: a look at endometrial receptivity

Implantation failure in assisted reproduction is thought to be mainly due to impaired uterine receptivity. With normal uterine anatomy, changes in endocrine profile during ovarian stimulation and medical conditions of the mother (i.e. thrombophilia and abnormal immunological response) could result in a non-receptive endometrium. High oestradiol concentrations during ovarian stimulation lead to premature progesterone elevation, causing endometrial advancement and hampering implantation, which can be overcome by a freeze-all approach and embryo transfer in natural cycles or by milder stimulation protocols. Patients with recurrent implantation failure (RIF) should be tested for inherited and acquired thrombophilias. Each patient should be individually assessed and counselled regarding therapy with low-molecular-weight heparin (LMWH). Empirical treatment with LMWH, aspirin or corticosteroids is not effective for women with RIF who have negative thrombophilic tests. If thrombophilic tests are normal, patients should be tested for immunological causes. If human leukocyte antigen dissimilarity is proven, treatment with intravenous immunoglobulin might be beneficial. Preliminary observational studies using intralipid infusion in the presence of increased natural killer cytotoxic activity are interesting but the proposed rationale is controversial and randomized controlled trials are needed. Hysteroscopy and/or endometrial scratching in the cycle preceding ovarian stimulation should become standard for patients with RIF.

Association of common thrombophilias and antiphospholipid antibodies with success rate of in vitro fertilisation

Assisted reproductive technology (ART) is extensively used as a tool for pregnancy achievement in subfertile couples. Congenital and acquired thrombophilias have been suggested by some investigators to play a role in abnormal embryo implantation and placentation. The objective of this study was to assess the role of common thrombophilias in women with unexplained infertility undergoing in vitro fertilisation (IVF). We retrospectively analysed 594 women from a large healthcare maintenance organisation going through IVF and who had a thrombophilia workup, and compared them for prevalence of thrombophilia to two reference groups consisting of 637 fertile women from previous work and 17,337 women members of the same healthcare organisation with no history of venous thromboembolism. The mean age of the women at the first cycle of IVF was 30.9 years (SD: 4.1).The mean number of IVF cycles was 7.3 (SD: 5.0), and the mean fertility success rate per woman was 14.6% (SD: 19.0%). None of the common thrombophilias tested was found to be significantly associated with the number of IVF cycles or with lower fertility success rate. Rather, women who had APCR and /or factor V Leiden and lupus anticoagulant had significantly higher live birth rates (12.3% and 12.6%, respectively) in comparison to women who were tested negative (9.0% and 9.7%, respectively). Thus, hypercoagulability is not associated with failure to achieve pregnancy. These data suggest that neither screening for thrombophilia nor anticoagulant treatment is indicated in cases with unexplained reproductive failure.