Effect of dalteparin sodium administration on IVF outcome in non-thrombophilic young women: a pilot study

Effect of low-molecular-weight heparin in women undergoing frozen-thawed embryo transfer cycles: a retrospective cohort study

BACKGROUND

Recurrent pregnancy loss (RPL) and recurrent implantation failure (RIF) during in vitro fertilization (IVF) treatment are still tough problems without effective treatments; thus, they are important research topics. There is controversy on whether low molecular weight heparin (LMWH) improves pregnancy outcomes in women with unexplained RPL and RIF. Moreover, currently, there is a paucity of reports on the role of LMWH in the entire population undergoing frozen-thawed embryo transfer (FET) cycles. This study aimed to estimate the effects of LMWH on pregnancy outcomes in women undergoing FET cycles.

METHODS

There were 1881 female patients included in the study. Of the 1881 patients, 107 underwent preimplantation genetic diagnosis cycles, which were analyzed individually. The patients were divided into two groups: the LMWH group received injections of 4100 IU/d LMWH from the day of transfer until 14 ± 2 days posttransplant, the control group was the comparison group (without LMWH use). The baseline characteristics and reproductive outcomes of the patients were reviewed.

RESULTS

Of the 1774 women with normal FET cycles, no significant differences were found in the number of embryos implanted (1.31 ± 0.02 vs. 1.28 ± 0.02), embryo implantation rate, biochemical pregnancy rate, clinical pregnancy rate, live birth rate, late abortion rate, and ectopic pregnancy rate between the two groups. The LMWH group had a higher early abortion (17.8% [76/427] vs. 12.5% [55/439], p = 0.030). In the sub-group analysis, among the patients who underwent more than four transfers, the LMWH group had a lower late abortion rate (1.7% [1/60] vs. 13.2% [7/53], p = 0.043). Similarly, of the 107 women who underwent preimplantation genetic diagnosis cycles, the reproductive outcomes were comparable between the two groups.

CONCLUSION

In the general population and PGD patients, LMWH did not improve pregnancy outcomes. Therefore, the routine use of LMWH is not recommended for early treatment.

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.

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.

Fibrin clot properties among women with endometriosis and the impact of ovarian stimulation

RESEARCH QUESTION

Is there a difference in fibrin clot phenotype in women with endometriosis before and after ovarian stimulation?

DESIGN

Prospective study including 73 infertile women in two age-matched groups: (i) with confirmed endometriosis (n = 29); (ii) without endometriosis (n = 44). Assessments of plasma fibrin clot permeability (K_s), efficiency of fibrinolysis using clot lysis time (CLT), along with thrombin generation (prothrombin fragments 1+2 [F1+2] and endogenous thrombin potential [ETP]) and fibrinolysis inhibitors were performed together with clinical pregnancy rate.

RESULTS

Endometriosis was associated with increased thrombin generation, reflected by both higher F1+2 (+96.1%, P = 0.005) and ETP (+14.2%, P = 0.014) along with unfavourably altered fibrin clot properties represented by lower K_s (-31%, P < 0.001) and prolonged CLT (+13.5%, P = 0.02), compared with the non-endometriosis group. Moreover, women with endometriosis had higher plasminogen activator inhibitor-1 (PAI-1; +272%, P = 0.004) concentrations and alpha-2-antiplasmin activity (+39.9%, P < 0.001) in contrast to the other group. Ovarian stimulation led to reduction in F1+2 (-48.1%, P < 0.001), improvement of fibrin clot phenotype reflected by higher K_s (+25.9%, P < 0.001) and shortened CLT (-11.9%, P < 0.001), along with lower PAI-1 (-54%, P = 0.016) compared with the baseline in women with endometriosis.

CONCLUSIONS

Endometriosis is associated with the prothrombotic fibrin clot phenotype and increased thrombin generation. Ovarian stimulation favourably alters fibrin clot properties and leads to comparable pregnancy outcomes to those in women without endometriosis.

Effectiveness of the use of Low Molecular Heparin in patients with repetition abortion history: Systematic review and meta-analysis

Objective:

To evaluate the efficacy and safety of using low molecular weight heparin (LMWH) in women with a history of recurrent abortion without an identified cause.

Methods:

To develop a systematic review to select the studies. Total found 437 papers. Seven studies were completed or requested. The following variables were analyzed: clinical pregnancy, implantation rate, live births, abortion, premature birth, pregnancy, continuous pregnancy, beyond the 20^th gestational week, congenital abnormality, hemorrhage, preeclampsia, placental premature detachment.

Results:

The LMWH group had a higher incidence of continuous pregnancy after the 20^th week of gestation and there was no significant difference between the LMWH group and the expectant management group in the analysis of other variables.

Conclusions:

There was no data showing risk and/or less use of LMWH compared to expectant management; on the contrary, LMWH use increased the incidence of evolutionary pregnancy after the 20^th gestational week. LMWH has some influence on prophylactic treatment of repeat abortion for unknown cause.

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.

Heparin modulates chemokines in human endometrial stromal cells by interaction with tumor necrosis factor α and thrombin

OBJECTIVE

To study the impact of heparins on chemokines in decidualized human endometrial stromal cells (ESCs) in vitro.

DESIGN

In vitro experiment.

SETTING

Research laboratory.

PATIENT(S)

Premenopausal women undergoing hysterectomy for benign reasons.

INTERVENTION(S)

ESCs were isolated from hysterectomy specimens, decidualized in vitro and incubated with unfractionated heparin and low-molecular-weight heparins (LMWHs) as well as tumor necrosis factor (TNF) α or thrombin with or without heparins.

MAIN OUTCOME MEASURE(S)

Chemokines CXCL1, CXCL5, CXCL8, CCL2, and CCL5 were measured with the use of ELISA, and CXCL5, CXCL8, CCL2, and CCL5 were detected with the use of real-time reverse-transcription polymerase chain reaction. Cell viability was determined with the use of a fluorometric assay.

RESULT(S)

TNF-α and thrombin stimulated distinct patterns of chemokines in ESCs. Unfractionated heparin and LMWHs attenuated the TNF-α-mediated induction of CXCL8 and enhanced CXCL5, CCL2, and CCL5. The stimulating effect of thrombin on CXCL8 could be inhibited by heparin, whereas heparin had no impact on thrombin-induced CXCL1 and CCL2. Nuclear factor of transcription κB signaling mediated the effects of TNF-α. The effects of thrombin were mediated via extracellular signal-regulated protein kinases 1/2.

CONCLUSION(S)

Heparins have modulating effects on TNF-α- and thrombin-induced endometrial chemokines, which might have implications in the regulation of endometrial receptivity and early implantation.

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.

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.