Low-molecular weight heparin induces in vitro trophoblast invasiveness: role of matrix metalloproteinases and tissue inhibitors

Low Molecular Weight Heparin-Aspirin-Prednisolone Combination Does Not Increase the Live Birth Rate in Recurrent Implantation Failure: A Retrospective Cohort Study

This study investigates the triple combination of adjuvants (low molecular weight heparin (LMWH)-aspirin-prednisolone) whether it improves the live birth rates of IVF&ICSI patients with previous implantation failure. This retrospective study included 1095 patients with >2 failed either fresh or frozen single embryo transfer cycles between 2014 Jan and 2021 Jan. Patients were divided into two subgroups. Group A consisted of patients with only vaginal progesterone for luteal phase support. Group B consisted of patients with triple (daily subcutaneous LMWH, daily 150 mg aspirin, and daily 16 mg prednisolone) luteal phase supplementation to vaginal progesterone. Demographic parameters, cycle characteristics, embryology, and pregnancy outcomes were compared, and the study's primary outcome was the live birth rate. Demographic parameters were similar between the groups. Positive b-hCG, miscarriage, and live birth rates were similar between groups as Group A vs. Group B, positive b-hCG 30.8% (190/617) vs. 35.4% (169/478), miscarriage rates 4.4% (27/617) vs. 6.7% (32/478), and live birth rates 20.4% (126/617) vs. 23.8% (114/478), respectively. When patients were stratified according to previous failures, live birth rates were still similar. Pregnancy outcomes were significantly improved in only patients with diminished ovarian reserve (Group A vs. Group B, positive b-hCG 24.2% vs. 34.3%, live birth rate 12.1% vs. 21.9%, p < 0.01). Whether the embryo transfer was fresh or frozen-thawed did not affect the results. A combined supplementation of LMWH, aspirin, and prednisolone in the luteal phase does not improve live birth rates of IVF&ICSI patients with previous implantation failure except potentially for patients with diminished ovarian reserve.

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.

Treating unexplained recurrent pregnancy loss based on lessons learned from obstetric antiphospholipid syndrome and inherited thrombophilia: A propensity-score adjusted retrospective study

The efficacy of low molecular weight heparin (LMWH) is well-established in patients with obstetric antiphospholipid syndrome (O-APS). Their role in women with unexplained recurrent pregnancy loss (U-RPL) and late obstetrical complications (intrauterine growth restriction, IUGR and preeclampsia) is controversial. Here we compared rates of miscarriage and late obstetrical complications in RPL patients diagnosed with O-APS (n = 57) or hereditary thrombophilia (n = 25) (both assuming LMWH from the beginning of pregnancy) and in patients with a history of U-RPL (n = 118), assuming or not LMWH, followed at the 'Pregnancy at risk' and 'Recurrent pregnancy loss' outpatient clinics at the San Raffaele Hospital from April 2010 to April 2020. Patients with systemic autoimmune diseases other than primary O-APS were excluded. We tested for bivariate or multivariate associations among adverse pregnancy outcomes, the presence of thrombophilia and LMWH use by using chi-square test, Anova, propensity score adjusted univariate logistic regression and multivariate analysis as appropriate. U-RPL patients assuming LMWH from the beginning of pregnancy (group A) had a significantly lower rate of miscarriage compared to U-RPL patients who were not treated with LMWH (group B) (13 % vs. 41 % respectively, p 0.001) and similar pregnancy rates compared to both O-APS patients with a history of RPL taking LMWH (group C, 18 %) and RPL patients with thrombophilia and treated with LMWH (group D, 16 %). Our data highlight a protective effect of LMWH on miscarriage in patients with a history of U-RPL. In these patients, LMWH seems as effective as in O-APS and hereditary thrombophilia in reducing RPL.

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 antithrombin binding regions of heparin mediate fetal growth and reduced placental damage in the RUPP model of preeclampsia†

Preeclampsia is a serious hypertensive disorder of pregnancy, which is only cured with delivery of the placenta, thereby commonly necessitating preterm birth of the fetus. Low-molecular-weight heparin (LMWH) has demonstrated potential to reduce the incidence of preeclampsia in high-risk pregnant women, although the underlying mechanism by which LMWH protects against preeclampsia is unknown. Given the complex structure and biologic actions of heparin, we tested the hypothesis that heparin can mediate preeclampsia prevention via nonanticoagulant pathways. We compared the effects of a nonanticoagulant, glycol-split LMWH (gsHep)—rendered nonanticoagulant through disruption of the antithrombin binding regions—with the LMWH dalteparin in the rat reduced uterine perfusion pressure (RUPP) surgical model of preeclampsia. Although RUPP animals exhibit significantly elevated blood pressure and reduced plasma levels of placental growth factor (PGF) compared to sham, neither dalteparin nor gsHep treatment significantly impacted these parameters. However, the observed positive correlation between PGF levels and number of viable fetuses in RUPP-induced animals suggests that reduced PGF levels were predominately due to placental loss. Daily subcutaneous injections of low-dose dalteparin but not gsHep significantly restored fetal growth that was impaired by RUPP surgery. Placentas from RUPP animals exhibited an abnormal labyrinth structure, characterized by expanded sinusoidal blood spaces, relative to sham-operated animals. Morphometric analysis demonstrated that dalteparin but not gsHep treatment normalized development of the labyrinth in RUPP-exposed conceptuses. These data suggest that the antithrombin-binding regions of LMWH are required to confer its protective effects on fetal growth and placental development.

Low Molecular Weight Heparins (LMWH) and Implications along Pregnancy: a Focus on the Placenta

Low molecular weight heparins (LMWH) have been largely studied for their use during pregnancy. The biology and the pharmacology of these molecules are well known and may be summarized in three main mechanisms of action: anti-coagulant, anti-inflammatory, and immunomodulant. The clinical implications of these drugs during pregnancy are mainly related to their action on the placenta, because of the presence of specific molecular and cellular targets, particularly at the trophoblast-endometrial interface. As well as for the prevention and treatment of thromboembolism, LMWH have been largely investigated for the improvement of embryo implantation and for the prevention of placenta-related complications such as preeclampsia, fetal growth restriction, and intrauterine fetal death. However, data on this topic are still unclear. The present review discusses the biological features, the mechanisms of action, and the possible contribution of LMWH to the success of placentation along pregnancy, pointing out the need for future basic science and clinical researches in this important field with the final aim to improve clinical practice in high-risk pregnancies.

The role of maternal-foetal interface inflammation mediated by NLRP3 inflammasome in the pathogenesis of recurrent spontaneous abortion

INTRODUCTION

Approximately half of the recurrent spontaneous abortions (RSAs) that remain unidentified to date may be closely related to inflammation. Our previous study found excessive NLRP3 inflammasomes in RSA patients. Here, we investigated further the role of inflammasomes in the maternal-foetal interface of RSA patients.

METHODS

Villous and decidual tissues were collected during uterine curettage. The trophoblast cell line TEV-1 was cultured with lipopolysaccharide (LPS) or low molecular weight heparin (LMWH), and then the macrophage cell line RAW264.7 was treated with trophoblast media. The expression and localisation of inflammasomes in tissues and cells were detected, and the migration and proliferation of cells were analysed.

RESULTS

A significantly increased expression of inflammasomes was observed in RSA tissues compared with those in the normal group, and it was more obvious in villous tissues than in decidual tissues. In TEV-1 cells, after LPS stimulation, the expression of inflammasomes was increased, but the cell activity was decreased, whereas in RAW264.7, both expression of inflammasomes and cell activity were increased in the LPS group. In addition, LMWH could inhibit the action of LPS in above cells.

DISCUSSION

In patients experiencing RSA, abnormal inflammatory response might be mediated by NLRP3 inflammasomes on the maternal-foetal interface, which may reduce trophoblast activity and promote macrophage activity, leading to early embryo implantation failure. LMWH is expected to treat RSA patients by blocking this process.

Low-dose low-molecular-weight heparin prophylaxis against obstetrical complications in pregnancies with metabolic and immunological disorder-associated placental inflammation

Objective: We investigated the importance of prophylactic administration of low-dose low-molecular-weight heparin (LMWH) in women with risk factors associated with placental inflammation.Materials and methods: This retrospective cohort study included 300 pregnant women with a singleton pregnancy (30 primigravidas and 270 multigravidas) who received prophylactic low-dose LMWH to prevent placental inflammation. Based on maternal risk factors, patients were categorized into 3 groups as follows: Group 1: Patients with metabolic risk factors for placental inflammation (n = 205), Group 2: Patients with immunological risk factors for placental inflammation (n = 42), Group 3: Patients with metabolic and immunological risk factors for placental inflammation (n = 53). Obstetric histories, demographic features, clinical characteristics, and present pregnancy outcomes were compared between groups. Live birth rates, composite adverse obstetric outcomes, and the Beksac obstetric index were compared between present and previous pregnancies in multigravidas.Results: Pregnancy outcomes were significantly better in the present pregnancy than in previous pregnancies. A significant increase was observed in live birth rates (33.4% vs. 69.9%, 27.5% vs. 60.5%, and 30.1% vs. 69.4% in groups 1, 2, and 3, respectively) and in the Beksac obstetric index (0.32 vs. 0.43, 0.33 vs. 0.47, and 0.38 vs. 0.57 in groups 1, 2, and 3 respectively) (p < .001 for all). A significant decrease in composite adverse pregnancy outcome rates was observed during the present pregnancy (23.5% vs. 100%, 28.9% vs. 100%, and 24.5% vs. 100% in groups 1, 2, and 3, respectively) (p < .001 for all). Live birth and composite adverse obstetric outcome rates were 70% and 33.3%, respectively in primigravidas.Conclusion: Low-dose low-molecular-weight heparin prophylaxis is useful to prevent metabolic and immunological disorders causing placental inflammation, which is the most likely pathophysiological mechanism contributing to various obstetrical complications.

Evaluation of T cell cytokines and their role in recurrent miscarriage

Recurrent miscarriage (RM) is defined as two or more consecutive pregnancy losses that affect approximately 5% of conceived women worldwide. RM is a multi-factorial reproductive problem and has been associated with parental chromosomal abnormalities, embryonic chromosomal rearrangements, uterine anomalies, autoimmune disorders, endocrine dysfunction, thrombophilia, life style factors, and maternal infections. However, the exact cause is still undecided in remaining 50% of cases. Immunological rejection of the embryo due to exacerbated maternal immune reaction against paternal embryonic antigens has been set forth as one of the significant reason for RM. The accurate means that shield the embryo during normal pregnancy from the attack of maternal immune network and dismissal are inadequately implicit. However, it is suggested that the genetically irreconcilable embryo escapes maternal immune rejection due to communication among many vital cytokines exuded at maternal-embryonic interface both by maternal and embryonic cells. Previous investigations suggested the Th1/Th2 dominance in altered immunity of RM patients, according to which the allogenic embryo flees maternal T cell reaction by inclining the Th0 differentiation toward Th2 pathway resulting into diminished pro-inflammatory Th1 immunity. However, recently pro-inflammatory Th17 cells and immunoregulatory Treg cells have been discovered as essential immune players in RM besides Th1/Th2 components. Cytokines are believed to develop a complicated regulatory network so as to establish a state of homeostasis between the semi-allogenic embryo and the maternal immune system. However, an adverse imbalance among cytokines at maternal-embryonic interface perhaps due to their gene polymorphisms may render immunoregulatory means not enough to re-establish homeostasis and thus may collapse pregnancy.

Spontaneous pregnancies in patients with at least one failed IVF cycle after the management of autoimmune disorders, hereditary thrombophilia, and methylation disorders

Objective:

This study aimed to describe the impact on achieving spontaneous pregnancy of treating patients with at least one failed in-vitro fertilization (IVF) cycle for autoimmune disorders, hereditary thrombophilia, and methylation disorders.

Methods:

Fifty-three patients who met the enrollment criteria seen between January 2007 and October 2017 were included in this retrospective cohort study. The patients were retrospectively assessed for the presence of hereditary thrombophilia, methylenetetrahydrofolate reductase (MTHFR) polymorphisms, serum vitamin B12/folate/homocysteine levels, and autoimmune antibody positivity. The required data were extracted from the institutional patient database. Statistical analyses were performed on Statistical Package for the Social Sciences (SPSS.22^®). The Kolmogorov-Smirnov test was used to evaluate the distribution of the data, and since the data did not following a normal distribution, proportions and median (minimum-maximum) values were used.

Results:

The 53 patients included in the study had singleton pregnancies. The distribution of autoantibodies was as follows: thyroid peroxidase (n=17); antithyroglobulin (n=11); double-stranded DNA (n=4); antinuclear (n=8); anti-smooth muscle (n=1); and anticardiolipin IgG and IgM (n=1). Autoimmune diseases included Hashimoto's thyroiditis (n=23); SLE (n=7); Behcet's disease (n=1); Sjogren's syndrome (n=1); ulcerative colitis (n=1); and anti-phospholipid antibody syndrome (n=1). Ten patients had heterozygous Factor V Leiden thrombophilia; two had homozygous Factor 5 Leiden thrombophilia; and three had the prothrombin 20210A heterozygous mutation. Twenty-eight patients were positive for autoantibodies and hereditary thrombophilia and/or MTHFR polymorphisms.

Conclusions:

Evaluation and management of hereditary thrombophilia, MTHFR gene polymorphisms, and/or autoimmune conditions may be beneficial for patients with unexplained infertility.

Effects of glycol-split low molecular weight heparin on placental, endothelial, and anti-inflammatory pathways relevant to preeclampsia

Low molecular weight heparin (LMWH) is being investigated as a potential preventative therapy against preeclampsia. There is evidence suggesting that LMWH may prevent preeclampsia through anticoagulation-independent mechanisms. In this study, we compared the in vitro placental, endothelial, and anti-inflammatory effects of an LMWH (dalteparin) with a nonanticoagulant, glycol-split heparin derivative (gsHep). In contrast with dalteparin, gsHep did not interact with antithrombin III, possess significant anti-Factor Xa activity, or significantly prolong in vitro plasma clotting time. However, dalteparin and gsHep were otherwise mechanistically similar, both interacting with soluble fms-like tyrosine kinase-1 (sFlt1) and promoting release of the pro-angiogenic protein placental growth factor, but not the antiangiogenic sFlt1, from healthy placental villous explants. Placental explant media pretreated with dalteparin or gsHep significantly stimulated endothelial cell tube formation compared to untreated explants. Lastly, dalteparin and gsHep both significantly suppressed inflammation by inhibiting complement activation and leukocyte adhesion to endothelial cells that were activated using serum from preeclamptic women. Our data suggest that nonanticoagulant heparin derivatives may be utilized as a tool to distinguish the anticoagulation-independent mechanisms of LMWH, and provide insight into the role of anticoagulation in the prevention of preeclampsia.

Low-molecular-weight-heparin increases Th1- and Th17-associated chemokine levels during pregnancy in women with unexplained recurrent pregnancy loss: a randomised controlled trial

Low-molecular-weight heparin (LMWH) is widely used to treat recurrent pregnancy loss (RPL) because of its anti-coagulant effects. Although in vitro studies have suggested additional immunological effects, these are debated. We therefore investigated whether LMWH could modulate immune responses in vivo during pregnancy of women with unexplained RPL. A Swedish open multi-centre randomised controlled trial included 45 women treated with tinzaparin and 42 untreated women. Longitudinally collected plasma samples were obtained at gestational weeks (gw) 6, 18, 28 and 34 and analysed by multiplex bead technology for levels of 11 cytokines and chemokines, chosen to represent inflammation and T-helper subset-associated immunity. Mixed linear models test on LMWH-treated and untreated women showed differences during pregnancy of the Th1-associated chemokines CXCL10 (p = 0.01), CXCL11 (p < 0.001) and the Th17-associated chemokine CCL20 (p = 0.04), while CCL2, CCL17, CCL22, CXCL1, CXCL8, CXCL12, CXCL13 and IL-6 did not differ. Subsequent Student's t-test showed significantly higher plasma levels of CXCL10 and CXCL11 in treated than untreated women at gw 28 and 34. The consistent increase in the two Th1-associated chemokines suggests a potential proinflammatory and unfavourable effect of LMWH treatment during later stages of pregnancy, when Th1 immunity is known to disrupt immunological tolerance.

Post-Translational Modification-Dependent Activity of Matrix Metalloproteinases

Due to their capacity to process different proteins of the extracellular matrix (ECM), matrix metalloproteinases (MMPs) were initially described as a family of secreted proteases, functioning as main ECM regulators. However, through proteolytic processing of various biomolecules, MMPs also modulate intra- and extracellular pathways and networks. Thereby, they are functionally implicated in the regulation of multiple physiological and pathological processes. Consequently, MMP activity is tightly regulated through a combination of epigenetic, transcriptional, and post-transcriptional control of gene expression, proteolytic activation, post-translational modifications (PTMs), and extracellular inhibition. In addition, MMPs, their substrates and ECM binding partners are frequently modified by PTMs, which suggests an important role of PTMs in modulating the pleiotropic activities of these proteases. This review summarizes the recent progress towards understanding the role of PTMs (glycosylation, phosphorylation, glycosaminoglycans) on the activity of several members of the MMP family.

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.

Timing of initiation of low-molecular-weight heparin administration in pregnant women with antiphospholipid syndrome: a randomized clinical trial of efficacy and safety

Objective

We aimed to evaluate the effect of different timing of initiation of low-molecular-weight heparin (LMWH) administration on the pregnancy outcomes in women with antiphospholipid syndrome (APS).

Materials and methods

A randomized controlled study was conducted on women with obstetrical APS. All participants were randomly divided at documentation of positive pregnancy test into two groups; early initiation group in which LMWH therapy was started once positive pregnancy test was established (in the fifth week of gestation), and later initiation group in which LMWH therapy was started after sonographic confirmation of fetal cardiac pulsation (in the seventh week of gestation). In both groups, LMWH (enoxaparin) was given at a dose of 40 mg/day subcutaneously and the therapy continued until end of pregnancy. The primary outcome measure was ongoing pregnancy rate and the secondary outcome measures were fetal loss, live birth rate, preterm labor before 34 weeks of gestation, intrauterine growth restriction (IUGR), and congenital fetal malformations.

Results

Ninety-four women (48 in the early initiation group and 46 in the later initiation group) were subjected to final analysis. The ongoing pregnancy rate was significantly higher in the early initiation group than in the later initiation group (81.2% vs 60.9%; P=0.040). However, both groups were similar in the incidences of fetal loss, preterm labor before 34 weeks of gestation, and IUGR, and live birth rate. No recorded congenital fetal malformations in both groups.

Conclusion

Early administration of LMWH for pregnant women with obstetrical APS reduces early pregnancy loss, but does not affect the incidence of late obstetrical complications.

Minimally invasive spinal anesthesia for cesarean section in maternal anticoagulation therapy: a randomized controlled trial

BACKGROUND

Anticoagulant therapy during pregnancy is widely used due to the increasing awareness of maternal hypercoagulability. Few studies have reported the use of minimally invasive spinal anesthesia in these parturients. The objective of this study was to evaluate the safety and feasibility of minimally invasive spinal anesthesia in parturients with anticoagulation therapy undergoing cesarean section.

METHODS

This was a randomized, controlled study conducted in 239 parturients using anticoagulants and undergoing selective cesarean section. 37 parturients withdrew, and finally parturients received spinal anesthesia using 27gauge pen type fine spinal needles (experimental group, n = 110) and 22gauge traditional spinal needles (control group, n = 92). The primary efficacy outcomes included low back pain (LBP) and postdural puncture headache (PDPH) after delivery. Secondary efficacy outcomes included visual analogue scale during subarachnoid puncture (VASdural), difference between visual analogue scale (VAS) during peripheral venipuncture and VASdural (∆VAS), VAS of back puncture point 24, 48 and 72 h after operation (VASdural-24 h, VASdural-48 h and VASdural-72 h, respectively), maternal satisfaction and hospitalization stay.

RESULTS

No parturient had PDPH and was suspected with spinal or intracranial haematoma in two groups. There was no significant difference in VASlbp-24 h, VASlbp-48 h and VASlbp-72 h (P = 0.056; P = 0.813; P = 0.189, respectively) between two groups. In experimental group, VASdural (P = 0.017), ∆VAS (P = 0.001) and VASdural-24 h (P < 0.0001) were lower, whereas maternal satisfaction was higher (P = 0.046). There was no significant difference in VASdural-48 h, VASdural-72 h, urination function, strength recovery and hospitalization stay (P = 0.069; P = 0.667; P = 0.105; P = 0.133; P = 0.754, respectively) between the two groups.

CONCLUSIONS

Minimally invasive spinal anesthesia provided lower VASdural, VASdrual-24 h and a higher maternal satisfaction. Hence, it is considered as a safe, reliable and reasonable option for cesarean section parturients during maternal anticoagulation therapy with normal platelet count and coagulation time.

TRIAL REGISTRATION

This study was registered at www.ClinicalTrials.gov at November 11th, 2016 ( NCT02987192 ).

Molecular actions of heparin and their implications in preventing pre-eclampsia

Pre-eclampsia, a hypertensive disorder of pregnancy, continues to be a significant cause of global maternal morbidity. Low-dose aspirin remains the only standard-of-care prophylactic therapy for preventing pre-eclampsia, but is limited in efficacy. Heparin and its derivatives may further enhance the efficacy of aspirin therapy to prevent pre-eclampsia, but the mechanisms mediating this augmentative effect are not known. Although heparin is an anticoagulant agent, it also possesses many anticoagulant-independent properties that may be relevant in the prevention of pre-eclampsia, including effects on placental, vascular and inflammatory function. This review summarizes the non-anticoagulant properties of heparin, and extrapolates how these actions may influence the trajectory of pre-eclampsia pathogenesis as a means of pathway-specific therapy.

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.

Effects of low molecular weight heparin on the polarization and cytokine profile of macrophages and T helper cells in vitro

Low molecular weight heparin (LMWH) is widely used in recurrent miscarriage treatment. The anti-coagulant effects are established, while immunological effects are not fully known. Our aim was to assess LMWH effects on activation and polarization of central regulatory immune cells from healthy women, and on placenta tissues from women undergoing elective abortions. Isolated blood monocytes and T helper (Th) cells under different activation and polarizing conditions were cultured with or without LMWH. Flow cytometry showed that LMWH exposure induced increased expression of HLA-DR and CD206 in macrophages. This phenotype was associated with increased secretion of Th17-associated CCL20, and decreased secretion of CCL2 (M2-associated) and CCL22 (Th2), as measured by multiplex bead array. In accordance, LMWH exposure to Th cells reduced the proportion of CD25highFoxp3+ regulatory T-cells, intensified IFN-γ secretion and showed a tendency to increase the lymphoblast proportions. Collectively, a mainly pro-inflammatory effect was noted on two essential tolerance-promoting cells. Although the biological significancies of these in vitro findings are uncertain and need to be confirmed in vivo, they suggest the possibility that immunological effects of LMWH may be beneficial mainly at an earlier gestational age to provide an appropriate implantation process in women with recurrent miscarriage.

MXRA5 is decreased in preeclampsia and affects trophoblast cell invasion through the MAPK pathway

Preeclampsia causes gestational failure in a significant number of women annually. Insufficient trophoblast cell invasion plays an essential role in preeclampsia pathogenesis. Matrix-remodeling associated 5 (MXRA5) is a proteoglycan involved in adhesion and matrix remodeling. This study sought to explore the role of MXRA5 in trophoblast cell invasion. Preeclamptic villi were obtained for the delineation of MXRA5 expression. Specific MXRA5 siRNA and pcDNA3.1/MXRA5 were used to manipulate MXRA5 expression in HTR-8/SVneo. Cell viability was determined by MTT and apoptosis by flow cytometry. Cell invasion was evaluated using Matrigel invasion assay. MXRA5 expression was lower in preeclamptic villi and cytotrophoblasts. Silencing MXRA5 expression in HTR-8/SVneo decreased cell viability and invasion, which were augmented by MXRA5 overexpression. Furthermore, MXRA5 modulated N-cadherin, E-cadherin, MMP-2, and MMP-9 expression through p38 MAPK and ERK1/2 signaling transduction. In addition, the expression of MXRA5 was influenced by exogenous TNF-α but not by IFN-γ. Overexpression of MXRA5 attenuated HTR-8/SVneo apoptosis induced by TNF-α. MXRA5 is downregulated in preeclamptic cytotrophoblasts and can regulate trophoblast cell invasion via the MAPK pathway.

The role of aspirin, heparin, and other interventions in the prevention and treatment of fetal growth restriction

Fetal growth restriction and related placental pathologies such as preeclampsia, stillbirth, and placental abruption are believed to arise in early pregnancy when inadequate remodeling of the maternal spiral arteries leads to persistent high-resistance and low-flow uteroplacental circulation. The consequent placental ischaemia, reperfusion injury, and oxidative stress are associated with an imbalance in angiogenic/antiangiogenic factors. Many interventions have centered on the prevention and/or treatment of preeclampsia with results pertaining to fetal growth restriction and small-for-gestational-age pregnancy often included as secondary outcomes because of the common pathophysiology. This renders the study findings less reliable for determining clinical significance. For the prevention of fetal growth restriction, a recent large-study level meta-analysis and individual patient data meta-analysis confirm that aspirin modestly reduces small-for-gestational-age pregnancy in women at high risk (relative risk, 0.90, 95% confidence interval, 0.81-1.00) and that a dose of ≥100 mg should be recommended and to start at or before 16 weeks of gestation. These findings support national clinical practice guidelines. In vitro and in vivo studies suggest that low-molecular-weight heparin may prevent fetal growth restriction; however, evidence from randomized control trials is inconsistent. A meta-analysis of multicenter trial data does not demonstrate any positive preventative effect of low-molecular-weight heparin on a primary composite outcome of placenta-mediated complications including fetal growth restriction (18% vs 18%; absolute risk difference, 0.6%; 95% confidence interval, 10.4-9.2); use of low-molecular-weight heparin for the prevention of fetal growth restriction should remain in the research setting. There are even fewer treatment options once fetal growth restriction is diagnosed. At present the only management option if the risk of hypoxia, acidosis, and intrauterine death is high is iatrogenic preterm birth, with the use of peripartum maternal administration of magnesium sulphate for neuroprotection and corticosteroids for fetal lung maturity, to prevent adverse neonatal outcomes. The pipeline of potential therapies use different strategies, many aiming to increase fetal growth by improving poor placentation and uterine blood flow. Phosphodiesterase type 5 inhibitors that potentiate nitric oxide availability such as sildenafil citrate have been extensively researched both in preclinical and clinical studies; results from the Sildenafil Therapy In Dismal Prognosis Early-Onset Intrauterine Growth Restriction consortium of randomized control clinical trials are keenly awaited. Targeting the uteroplacental circulation with novel therapeutics is another approach, the most advanced being maternal vascular endothelial growth factor gene therapy, which is being translated into the clinic via the doEs Vascular endothelial growth factor gene therapy safEly impRove outcome in seveRe Early-onset fetal growth reSTriction consortium. Other targeting approaches include nanoparticles and microRNAs to deliver drugs locally to the uterine arterial endothelium or trophoblast. In vitro and in vivo studies and animal models have demonstrated effects of nitric oxide donors, dietary nitrate, hydrogen sulphide donors, statins, and proton pump inhibitors on maternal blood pressure, uteroplacental resistance indices, and angiogenic/antiangiogenic factors. Data from human pregnancies and, in particular, pregnancies with fetal growth restriction remain very limited. Early research into melatonin, creatine, and N-acetyl cysteine supplementation in pregnancy suggests they may have potential as neuro- and cardioprotective agents in fetal growth restriction.

Recurrent pregnancy loss: current perspectives

Recurrent pregnancy loss is an important reproductive health issue, affecting 2%–5% of couples. Common established causes include uterine anomalies, antiphospholipid syndrome, hormonal and metabolic disorders, and cytogenetic abnormalities. Other etiologies have been proposed but are still considered controversial, such as chronic endometritis, inherited thrombophilias, luteal phase deficiency, and high sperm DNA fragmentation levels. Over the years, evidence-based treatments such as surgical correction of uterine anomalies or aspirin and heparin for antiphospholipid syndrome have improved the outcomes for couples with recurrent pregnancy loss. However, almost half of the cases remain unexplained and are empirically treated using progesterone supplementation, anticoagulation, and/or immunomodulatory treatments. Regardless of the cause, the long-term prognosis of couples with recurrent pregnancy loss is good, and most eventually achieve a healthy live birth. However, multiple pregnancy losses can have a significant psychological toll on affected couples, and many efforts are being made to improve treatments and decrease the time needed to achieve a successful pregnancy. This article reviews the established and controversial etiologies, and the recommended therapeutic strategies, with a special focus on unexplained recurrent pregnancy losses and the empiric treatments used nowadays. It also discusses the current role of preimplantation genetic testing in the management of recurrent pregnancy loss.

OLR1 and Loxin Expression in PBMCs of Women with a History of Unexplained Recurrent Miscarriage: A Pilot Study

AIMS

The aim of this study was to evaluate the expression of OLR1 and its alternative splicing isoform Loxin in unexplained recurrent miscarriage (uRM).

METHODS

Sixty-three women of reproductive age were recruited and were divided into four groups: 18 pregnant and 23 non-pregnant women with uRM, and 12 pregnant and 10 non-pregnant women with physiological pregnancies. Complementary DNA derived from peripheral blood mononuclear cells (PBMCs) was analyzed by quantitative real-time PCR to evaluate the expression of OLR1 and Loxin. Oxidized low-density lipoproteins (ox-LDLs) were assayed from serum by a commercially available kit.

RESULTS

Pregnant uRM women presented with a higher, though not significant, OLR1/Loxin ratio and a higher ox-LDLs serum level (p ≤ 0.05) compared with pregnant control women. OLR1 and Loxin levels were significantly decreased in non-pregnant uRM women compared with the control (OLR1: 0.00018 vs. 0.00043, p ≤ 0.005; Loxin: 0.00018 vs. 0.00060, p ≤ 0.005, respectively). Loxin expression decreased by about two-thirds (p ≤ 0.005) in pregnant women compared with non-pregnant control women. A higher expression of OLR1 in pregnant women compared with non-pregnant women with uRM (p ≤ 0.05) was observed, but no variation in Loxin expression was observed.

CONCLUSIONS

The results of this study show an association of peripheral OLR1 and Loxin expression levels in uRM women, and they suggest the possible existence of an uncontrolled oxidative stress in these women in the first trimester of pregnancy.

Modulation of antiphospholipid antibodies-induced trophoblast damage by different drugs used to prevent pregnancy morbidity associated with antiphospholipid syndrome

PROBLEM

Women with antiphospholipid antibodies (aPLs) present a risk of pregnancy morbidity (PM), vascular thrombosis (VT), or both (PM/VT). aPLs affect trophoblast function, and the aim of this study was to determine the modulation of this aPL-induced damage by different drugs.

METHOD OF STUDY

IgG was obtained from women with PM and PM/VT positive to aPLs. Binding of IgG to trophoblastic cells, proliferation, mitochondrial membrane integrity, and trophoblast invasion were assessed. The effect of enoxaparin, aspirin, and aspirin-triggered lipoxin (ATL) were evaluated as well as signal transducer and activator of transcription 3 (STAT3) phosphorylation.

RESULTS

IgG from women with aPLs strongly binds to trophoblastic cells. Integrity of mitochondrial membrane was reduced, and proliferation was increased by IgG-PM/VT. Both IgG-PM and IgG-PM/VT decreased trophoblast invasion, which was restored by enoxaparin, aspirin, and ATL. IgG-PM triggered reduction in STAT3 phosphorylation.

CONCLUSION

Some drugs used to prevent aPL-induced PM modulated the alteration of trophoblast function.

Effects of anticoagulant therapy on pregnancy outcomes in patients with thrombophilia and previous poor obstetric history

This study investigates the effects of anticoagulant therapy on pregnancy outcomes in 204 patients with thrombophilia and previous poor obstetric outcomes. Patients with poor obstetric history (pre-eclampsia, intrauterine growth retardation, fetal death, placental abruption, recurrent pregnancy loss) and having hereditary thrombophilia were included in this study. Poor obstetric outcomes were observed more frequently in patients who had not taken anticogulant therapy compared with treated group. Live birth rate, gestational age at birth and Apgar scores were significantly higher in the treated group when compared with the untreated group. There were no significant differences in terms of birthweight, mode of delivery and admission rates to the neonatal intensive care unit (NICU). Low-molecular-weight heparin (LMWH) plus acetylsalicylic acid (ASA) had higher gestational age at birth, Apgar scores, live birth rate and a lower abortion rates when compared with controls; in contrast, no significant difference was observed in terms of birthweight, mode of delivery, obstetric complications and admission rates to NICU. There were no significant differences between control group and both LMWH only and ASA only groups in terms of gestational age at birth, Apgar scores, birthweight, mode of delivery, obstetric complications and admission rates to NICU. Only LMWH group had higher live birth rate as compared with control group. The use of only ASA did not seem to affect the perinatal complication rates and outcomes. In conclusion, anticoagulant therapy with both LMWH and ASA seems to provide better obstetric outcomes in pregnant women with thrombophilia and previous poor obstetric outcomes.

Microvesicles of pregnant women receiving low molecular weight heparin improve trophoblast function

INTRODUCTION

Microvesicles including exosomes and microparticles, participate in the placental-maternal crosstalk in normal pregnancies and gestational vascular complications (GVC). Low molecular weight heparin (LMWH) is known to reduce the risk of placenta-mediated pregnancy complications. This study was aimed to characterize microvesicles of pregnant women receiving LMWH and explore microvesicle involvement in trophoblast and endothelial cell function.

MATERIALS AND METHODS

Microvesicles were isolated from blood samples obtained from non-pregnant women, healthy pregnant women (HP) and pregnant woman treated with LMWH. Microvesicle protein contents were assessed by protein array and ELISA. Microvesicle effects on early stage trophoblasts, term trophoblasts and endothelial cell migration, angiogenesis and apoptosis were evaluated.

RESULTS

Microvesicles derived from the group treated with LMWH contained higher levels of several proangiogenic proteins compared to those of HP women. Exposure of endothelial cells to circulating microvesicles derived from HP and LMWH treated groups induced significantly higher cell migration and branch tube formation compared to untreated cells. The effect of microvesicles from HP- and LMWH groups on early-stage trophoblast migration was similar. Microvesicles derived from these two study groups significantly decreased early-stage trophoblast apoptosis, while microvesicles derived from the HP-group (but not from the LMWH-group) significantly increased the term trophoblast apoptosis (TUNEL assay) compared to untreated cells.

CONCLUSION

Therapy with LMWH affects patients' microvesicle content, leading to normalization of invasion, angiogenesis activity and survival of endothelial and trophoblast cells in vitro. The effects of LMWH on microvesicles may point to an additional mechanism of heparin action in high-risk pregnancy.

Induction of forkhead box M1 (FoxM1) by EGF through ERK signaling pathway promotes trophoblast cell invasion

Successful placentation depends on the proper invasion of extravillous trophoblast (EVT) cells into maternal tissues. Previous reports have demonstrated that FoxM1 is oncogenic and plays important roles in angiogenesis, invasion, and metastasis. However, little is known about the roles of FoxM1 in the invasion of EVT cells. EGF, as a growth factor (epidermal growth factor), has been studied extensively in reproduction. JAR cells are a reliable model for studying early invasive trophoblast regulation. We have observed the relationship between EGF and FoxM1 in JAR cells by using specific inhibitors for the intervention in and study of potential signal pathways. We have also tested the ability of JAR cells to be influenced by the expression of FoxM1. Our data indicate that EGF promotes FoxM1 expression through the ERK signal pathway. Over-FoxM1 expression upregulates the ability of JAR cells to migrate and invade and vice versa. Our investigation of FoxM1 should provide new insights into the molecular mechanisms of EVT invasion.

Enoxaparin for prevention of unexplained recurrent miscarriage: a multicenter randomized double-blind placebo-controlled trial

It is common practice in many centers to offer antithrombotic medications to women with unexplained recurrent miscarriage, in the presence or absence of inherited thrombophilia. Although no benefit of aspirin vs placebo has been clearly demonstrated, a double-blind placebo-controlled trial on the effect of low-molecular-weight heparin is lacking. We enrolled 258 pregnant women with a history of unexplained recurrent miscarriage (≥2 consecutive miscarriages before 15 weeks' gestation) and a negative thrombophilia workup. They were randomly assigned to receive one daily subcutaneous injection of enoxaparin 40 mg or placebo until 35 weeks' gestation. We included 256 women (mean age 32 years, ≥3 miscarriages: 72%; mean gestational age 39 days of amenorrhea) in the intention-to-treat analysis; 66.6% of 138 who received enoxaparin had a live birth vs 72.9% of 118 who received placebo. The absolute difference was -6% (95% CI, -17.1 to 5.1), excluding a 10% increase in the rate of live-birth on enoxaparin (P = .34). In this first randomized, double-blind, placebo-controlled trial, enoxaparin (40 mg once daily) did not improve the chance of a live birth in nonthrombophilic women with unexplained recurrent miscarriage. This trial is registered at www.ClinicalTrials.gov as #NCT00740545 and the French National Health and Drug Safety Agency (EudraCT #2006-003350-18).

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.

Overview of low molecular weight heparin for preventative treatment of adverse obstetric outcomes related to abnormal placentation

Different proportions of cases of preterm and severe preeclampsia, placental abruption, fetal growth restriction, and fetal death share a common causal pathway of abnormal placental implantation. Documentation of an association between the risk of such adverse pregnancy outcomes (APOs) and inherited thrombophilias prompted initial studies to evaluate the benefit of anticoagulants for the prevention of recurrences both in patients with and without inherited thrombophilias. Prenatal administration of low molecular weight heparin (LMWH) has been evaluated in case control, cohort and randomized clinical trials. The evidence suggests a benefit of LMWH in the reduction of recurrences of APOs, with a number needed to treat of 6 (95% confidence interval: 4-10) to prevent one case of recurrent APOs. Such benefit is independent of the presence of inherited thrombophilias or the administration of low dose aspirin. Further studies are needed to establish the optimal duration for the prophylaxis, to better delineate the mechanism of action of LMWH and to explore the role, if any, of maternal serum markers and uterine artery Doppler findings in the modulation of the LMWH prophylaxis.

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.

The effect of hereditary versus acquired thrombophilia on triple test Down's syndrome screening

OBJECTIVE

To compare the profile of mid gestation triple test serum markers between a cohort of women with history of pregnancy complications with hereditary versus acquired thrombophilia. All were treated with low molecular weight heparin (LMWH) prior to 12 weeks' gestation.

METHODS

A retrospective analysis of second trimester maternal serum screening results for Down syndrome was performed comparing women with inherited versus acquired thrombophilia, all treated with LMWH. The test results were calculated from the combination of triple serum markers and maternal age, and expressed as a multiple of the gestation normal medians (MoM). Results in the study groups were compared with MoM values calculated from our local population (controls).

RESULTS

The median human chorionic gonadotropin (hCG) level was higher only in the acquired thrombophilia group (N = 47) as compared with the control group (1.3 vs. 0.99 MoM, P = 0.005), and not different between the hereditary thrombophilia group (N = 60) (1.1 MoM) and the control group. Alpha-fetoprotein and unconjugated estriol MoMs did not differ between women with inherited (0.95, 0.97), acquired thrombophilia (0.99, 0.90), and controls (1.01, 0.98), respectively.

CONCLUSION

In the interpretation of second trimester maternal serum screening, consideration should be given to the higher hCG maternal serum levels that may occur in women with acquired thrombophilia, even those treated early in pregnancy with LMWH. The higher hCG serum levels may signal the possibility of placental dysfunction, rather than fetal aneuploidy.

Emerging nonanticoagulant role of low molecular weight heparins on extravillous trophoblast functions and on heparin binding-epidermal growth factor and cystein-rich angiogenic inducer 61 expression

OBJECTIVE

To examine the effects of low molecular weight heparins (LMWHs) on extravillous trophoblast (EVTC) invasiveness and on EVTC expression/secretion of heparin binding-EGF (HB-EGF) and cystein-rich angiogenic inducer 61 (Cyr61), both of which are involved in the process of EVTC invasion. Furthermore, to investigate the intracellular DNA binding activity of activator protein (AP)-1.

DESIGN

Experimental study.

SETTING

Department of Obstetrics Gynecology, Università Cattolica del Sacro Cuore, Rome, Italy.

PATIENT(S)

Cultures of primary EVTC cells isolated from patients with first trimester unexplained recurrent miscarriage.

INTERVENTION(S)

The effects of LMWHs on EVTC invasiveness were examined by an in vitro matrigel invasion assay. Matrix metalloprotease-2 activity (MMP-2) was examined by gelatin zimography. HB-EGF and Cyr61 expression and secretion were studied by Western blot analysis and ELISA assay. AP-1 activity was measured through a multiwell colorimetric assay.

MAIN OUTCOME MEASURE(S)

The EVTC invasiveness, the expression/secretion of HB-EGF and Cyr61 proteins, and the AP-1 DNA binding activity in the presence of increasing concentrations of LMWHs were investigated.

RESULT(S)

Both LMWHs, and primarily tinzaparin, increased EVTC invasiveness, by enhancing the MMP-2 proteolytic activity, and induced the expression/secretion of HB-EGF and Cyr61 in EVTC. This effect was mediated by an increased DNA binding activity of AP-1.

CONCLUSION(S)

Both LMWHs are able to promote EVTC development because they are able to stimulate the EVTC invasive properties. Our results may provide a possible biological rationale for the clinical use of LMWH for placental-mediated pregnancy complications unrelated to prothrombotic disorders.

Comparison of uterine artery Doppler in pregnant women with thrombophilia treated by LMWHs and without thrombophilia

OBJECTIVE

The aim of this study was to use uterine artery Doppler ultrasonography to investigate the cases of women with thrombophilia who used LMWH during the 18-22-week period of gestation.

METHODS

This retrospective study was conducted at our university between January 2005 and July 2010. 64 patients were treated with low-dose LMWHs (enoxaparine 40 mg) from the beginning of pregnancy until 36 weeks of gestation. Fifty control subjects were also included in this study. Transabdominal ultrasound examination and bilateral uterine artery Doppler measurements pulsatility index (PI), resistive index (RI), and systole/diastole measurement (S/D) were performed during the 18-22-weeks period of gestation.

RESULTS

No significant differences were found between the groups with respect to maternal age or gestational age at the time of uterine artery Doppler. However, the mean PI (1.07 ± 0.46 for LMWH group and 0.91 ± 0.31 for control, p = 0.036) and the mean RI (0.59 ± 0.12 for LMWH group and 0.54 ± 0.10 for control, p = 0.021) were significantly higher in the trombophilia group.

CONCLUSION

Women with trombophilia still have an increased mean PI and RI, as determined by uterine artery Doppler ultrasonography during the 18-22-week period of gestation, even if they use LMWH.

Recurrence and severity of abnormal pregnancy outcome in patients treated by low-molecular-weight heparin: a prospective pilot study

OBJECTIVE

This prospective pilot study assesses the recurrence rate and severity of abnormal pregnancy outcome (APO), excluding early pregnancy complications, in pregnant patients, without acquired thrombophilia, treated by prophylactic doses of low-molecular-weight heparin (LMWH), independently from their congenital thrombophilic condition.

METHODS

We recruited a cohort of 128 pregnant patients with previous APO; 100 of whom with APO and intrauterine growth restriction (IUGR) and 28 with maternal APO only. LMWH treatment was started at recruitment. Composite cross-over recurrence rate IUGR, gestational hypertension, preeclampsia, help syndrome, abruptio placenta were analyzed. The main outcome measure was severe APOs with iatrogenic delivery ≤ 32 weeks of gestation.

RESULTS

Median gestational age at LMWH treatment was 20 weeks. Severe APO decreased in treated pregnancies from 45% to 4% (relative risk = 0.3, confidence interval 95% = 0.2-0.8). This value was not significantly different in thrombophilic and nonthrombophilic patients. When severe and minor complications were analyzed altogether, the recurrence rate was 28%. In patients with APO and fetal growth restriction (FGR) in the index pregnancy, newborn weights were significantly better in the treated pregnancy: 1090 g (1035-1145) vs. 850 g (535-1200), p < 0.01.

CONCLUSIONS

Prophylactic regimen of LMWH significantly reduced the recurrence rate of severe composite APO in pregnancies affected in the index pregnancy by APO and FGR or small for gestational age newborns. This result was independent from the patients' inherited thrombophilic conditions.

Anticoagulants affect matrix metalloproteinase 9 levels in blood samples of stroke patients and healthy controls

OBJECTIVES

Matrix metalloproteinase-9 (MMP-9) represents a promising marker for acute stroke management. In clinical studies MMP-9 has been quantified by ELISA using differing protocols. We aimed to establish a valid protocol by evaluation of preanalytics.

DESIGN AND METHODS

Blood from stroke patients (n=28) and healthy controls (n=28) was drawn into tubes containing different anticoagulants (EDTA, citrate, lithium-heparin (heparin) and heparin with proteinase inhibitors) and processed after 0, 60 and 240 min. MMP-9 plasma protein and mRNA from mononuclear leukocytes were determined.

RESULTS

In regard to anticoagulants used, samples showed different MMP-9 protein baseline values and kinetics. Stable MMP-9 protein concentrations were only measured from EDTA samples. Particularly in samples with proteinase inhibitors protein and mRNA concentrations increased over time. Kinetics did not differ between patients and controls.

CONCLUSIONS

Preanalytics plays a key role for determination of MMP-9. EDTA seems to be a valid anticoagulant for MMP-9 protein measurement.

Effects of low molecular weight heparin and heparin-binding epidermal growth factor on human trophoblast in first trimester

OBJECTIVE

To evaluate the effects of low molecular weight heparin (LMWH) and heparin-binding epidermal growth factor (HB-EGF) on the biological function of human trophoblast in first trimester.

DESIGN

Control experiment.

SETTING

Two academic-based reproductive centers.

PATIENT(S)

The first trimester human placentas (gestational age, 5-10 weeks) from patients who underwent electively induced abortions.

INTERVENTION(S)

Cultured trophoblast treated with LMWH or LMWH and HB-EGF.

MAIN OUTCOME MEASURE(S)

The biological function (proliferation, invasion, and differentiation) of trophoblast and the interaction between LMWH and HB-EGF on trophoblast in vitro.

RESULT(S)

1) At a dose of 0.25 IU/mL-2.5 IU/mL LMWH promoted trophoblast proliferation, enhanced their invasion, and increased hCG secretion. The LMWH had little effect or the opposite effect at other concentrations. These differences were statistically significant. 2) Combined use of LMWH and HB-EGF significantly promoted proliferation and invasion, but there was no difference in hCG secretion compared with solo LMWH or solo HB-EGF.

CONCLUSION(S)

The LMWH exerts a cytoprotective effect by regulating trophoblast proliferation, invasion, and differentiation. The HB-EGF is an important factor in the effects of LMWH on trophoblast function.

Effect of Low Molecular Weight Heparins (LMWHs) on antiphospholipid Antibodies (aPL)-mediated inhibition of endometrial angiogenesis

Antiphospholipid syndrome (APS) is an autoimmune disorder characterized by vascular thrombosis and/or pregnancy morbidity in the presence of circulating antiphospholipid antibodies (aPL). Different pathogenic mechanisms for aPL-mediated pregnancy failure have been proposed. In particular a direct effect of aPL on both maternal and fetal side of the placental tissue has been reported, since their reactivity with β2-glycoprotein I (β2GPI) makes them adhere to trophoblast and human endometrial endothelial cell (HEEC) membranes. β2GPI can be recognized by aPL that, once bound, interfere with both trophoblast functions and with the HEEC differentiation.APS patients can be successfully treated with Low Molecular Weight Heparin (LMWH). Recent reports suggest that LMWH acts through mechanisms alternative to its well known anticoagulant effect, because of its ability to bind β2GPI. In our previous studies, we showed that LMWH is able to reduce the aPL binding to trophoblasts and restore cell invasiveness and differentiation. So far, however, no study has described its effects on endometrial angiogenesis.The aim of our research was to evaluate whether two LMWHs, tinzaparin and enoxaparin, have an effect on the aPL-inhibited endometrial angiogenesis. This prompted us to investigate: (i) in vitro HEEC angiogenesis through a Matrigel assay; (ii) VEGF secretion by ELISA; (iii) matrix metalloproteinase-2 (MMP-2) activity by gelatin zymography; (iv) Nuclear Factor-κB (NF-κB) DNA binding activity by colorimetric assay; (v) STAT-3 activation by a sandwich-ELISA kit. Furthermore, using an in vivo murine model we investigated the LMWHs effects on angiogenesis.We demonstrated that the addition of LMWHs prevents aPL-inhibited HEEC angiogenesis, both in vitro and in vivo, and is able to restore the aPL inhibited NF-κB and/or STAT-3 activity, the VEGF secretion and the MMPs activity.The demonstration of a beneficial role for LMWHs on the aPL-inhibited HEEC angiogenesis might provide additional mechanisms whereby this treatment protects early pregnancy in APS.

Expression pattern of matrix metalloproteinases in human gynecological cancer cell lines

Background

Matrix metalloproteinases (MMPs) are involved in the degradation of protein components of the extracellular matrix and thus play an important role in tumor invasion and metastasis. Their expression is related to the progression of gynecological cancers (e.g. endometrial, cervical or ovarian carcinoma). In this study we investigated the expression pattern of the 23 MMPs, currently known in humans, in different gynecological cancer cell lines.

Methods

In total, cell lines from three endometrium carcinomas (Ishikawa, HEC-1-A, AN3 CA), three cervical carcinomas (HeLa, Caski, SiHa), three chorioncarcinomas (JEG, JAR, BeWo), two ovarian cancers (BG-1, OAW-42) and one teratocarcinoma (PA-1) were examined. The expression of MMPs was analyzed by RT-PCR, Western blot and gelatin zymography.

Results

We demonstrated that the cell lines examined can constitutively express a wide variety of MMPs on mRNA and protein level. While MMP-2, -11, -14 and -24 were widely expressed, no expression was seen for MMP-12, -16, -20, -25, -26, -27 in any of the cell lines. A broad range of 16 MMPs could be found in the PA1 cells and thus this cell line could be used as a positive control for general MMP experiments. While the three cervical cancer cell lines expressed 10-14 different MMPs, the median expression in endometrial and choriocarcinoma cells was 7 different enzymes. The two investigated ovarian cancer cell lines showed a distinctive difference in the number of expressed MMPs (2 vs. 10).

Conclusions

Ishikawa, Caski, OAW-42 and BeWo cell lines could be the best choice for all future experiments on MMP regulation and their role in endometrial, cervical, ovarian or choriocarcinoma development, whereas the teratocarcinoma cell line PA1 could be used as a positive control for general MMP experiments.