Prophylaxis of VTE in women – during assisted reproductive techniques

Venous thromboembolism associated with medically assisted reproduction (MAR): British fertility society policy and practice guidance for assessment and prevention

The association between Medically Assisted Reproduction (MAR) and thromboembolic complications has been reported widely in multiple published studies. Although venous thromboembolism (VTE) is not thought to be a common complication of MAR, it is associated with high morbidity and is often preventable. Since VTE usually occurs after completion of MAR treatment and is often managed outside of the treating fertility unit, these complications are likely to be underreported and there may be limited awareness of the risks among clinicians. As we continue to see a rise in the total number of MAR treatment cycles, particularly in women over 40 years of age, along with a steady increase in the number of fertility preservation cycles for both medical and social indications, it is likely that we will see an increase in absolute numbers of VTE complications. Currently, there is a lack of management guidance and reporting of VTE events associated with assisted conception treatment. The aim of this guidance is to provide clinicians with information on VTE risk factors, guidance on assessing VTE risk and the best practice recommendations on risk reducing strategies for individuals at risk of VTE undergoing ovarian stimulation and embryo transfer cycles.

A Cross-Sectional Analysis of Intimacy Problems, Stress Levels, and Couple Satisfaction among Women with Thrombophilia Affected by Recurrent Pregnancy Loss

Recurrent pregnancy loss (RPL) is one of the most challenging and difficult areas of reproductive treatment due to the immense emotional suffering inflicted on families and couples affected by RPL. As a result, it is predicted that couples experiencing recurrent pregnancy loss would have an increase in marital problems, stress levels, and anxiety, preventing them from achieving their family goals. The current cross-sectional study aimed to target pregnant women with thrombophilia with a history of RPL to observe their intimacy problems, stress levels, and couple satisfaction by completing a series of digital questionnaires. These patients were considered as the reference group, while the control group was formed by other women with thrombophilia and a history of RPL who eventually achieved pregnancy and gave birth. A total of 238 complete questionnaires were recorded (157 in the reference group and 81 in the control group). It was observed that women in the reference group who did not give birth had a significantly higher proportion of three or more pregnancy attempts (54.1% vs. 39.5%) and a significantly higher proportion of three more pregnancy losses (68.8% vs. 55.6%). It was observed that patients in the reference group were more likely to be emotion-oriented (42.7% vs. 27.2%). Also, women in the reference group had higher levels of dissatisfaction and lower levels of self-acceptance, pleasure, and marital quality scores. The total SII and DSCS scores were significantly lower than women with thrombophilia with a history of RPL who eventually gave birth. Women from the reference group had significantly greater intimacy problems and stress levels while having lower openness scores and self-esteem scores than women in the control group. It is possible that women with thrombophilia and recurrent pregnancy loss are more dissatisfied with their marriages than those who subsequently had one child. Since the financial status of those who achieved pregnancy was observed to be higher, it is likely that they achieved pregnancy by ART interventions, as they reported in questionnaires. It is important to target families afflicted by thrombophilia and other reasons for infertility to ease their access to ART therapies. By achieving their objectives, affected families will minimize dissatisfaction, divorce rates, and stress.

The ART of Thromboprophylaxis in the Prevention of Gestational Venous Thromboembolism

Assisted reproductive techniques (ART) allow infertile couples to conceive. Use of hormones to obtain a controlled ovarian stimulation and an adequate growth of the endometrium preparatory for embryo implantation are not riskless. Among others, thrombotic events can occur during the ovulation induction or pregnancy following ART. As the number of women approaching ART to conceive is steadily increasing, the issue of thrombotic risk in this setting is relevant. Data on the weight of each risk factor and on potential benefit of thromboprophylaxis are largely lacking. In this review, we discuss risk of venous thromboembolism during pregnancy following ART, with a focus on general (i.e.: age, body mass index, thrombophilia, bed rest, transfusions) and ART-specific (i.e., polycystic ovarian syndrome, ovarian hyperstimulation syndrome) risk factors. We also attempt to provide some suggestions to guide clinical practice, based on available data and studies performed outside ART.

Prior Thromboembolic Disease and Assisted Reproductive Therapy

Assisted reproductive therapy (ART) increases the risk of venous thrombosis (VT) by 2- to 4-fold, whereas pregnancy increases the risk by 5- to 10-fold. Women with a history of VT undergoing ART are often suggested thromboprophylaxis. The literature is scarce and international guidelines are lacking. We made a review of the literature and base our suggestions primarily on expert opinions. We suggest women with a prior VT to use low-molecular-weight heparin as thromboprophylaxis starting from ovarian stimulation, throughout pregnancy, and 6 weeks postpartum. Assessment of VT risk should be done prior to ART. Adjustment of treatment to minimize the thrombotic risk, such as preventing ovarian hyperstimulation syndrome, single-embryo transfer, cryopreservation, and transfer of frozen embryos instead of fresh embryo in high-risk women, is suggested. Women with previous arterial thrombosis should continue aspirin during ART treatment, pregnancy, and postpartum.

Relationship Between Estradiol and Hemostasis Determined Through Thromboelastography Profile in Controlled Ovarian Stimulation Cycles

Purpose

We aimed to analyze the relationship between estradiol level and thromboelastography profile.

Patients and Methods

This prospective study with comparative analysis was performed on nineteen samples undergoing an IVF procedure in two fertility clinics in Bandung city. Blood samples taken on the second and twelfth days of the IVF cycle.

Results

There were significant differences in the value of estradiol, fibrin formation time (α), and coagulation index (CI) (p<0.05). Correlation tests showed no relationship and no significant correlation between an increased level of estradiol and coagulation index (CI) (r _s=0.054; p=0.827) and between an increased level of estradiol and fibrinolysis time (LY30) (r _s=-0.151; p=0.536). A moderate significant relationship was observed between age and coagulation index (CI) (r _s=-0.430; p=0.033) and between age and maximum amplitude (MA) (r _s=-0.494; p=0.032).

Conclusion

Supraphysiological estradiol levels in controlled ovarian stimulation cycles affect the coagulation index and change mainly the fibrin formation time.

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.

Cardiovascular problems associated with IVF therapy

We are now in the beginning of the fifth decade of in vitro fertilization (IVF) with more than ten million children born and an annual growth rate of half a million. It was recently found that there is a sevenfold increase in the incidence of pulmonary embolism (PE) during the first trimester of an IVF pregnancy as compared to spontaneous pregnancy. PE is a major cause of maternal mortality, and it is thus of outmost importance to understand the pathophysiological mechanism. The oestrogen surge during the ovarian stimulation has been hypothesized to be the initiating pathophysiological event. A support of this is a current report showing that embryo transfer performed directly after ovarian stimulation increased the risk of PE more than eightfold, whereas no such increase was noted after delayed embryo transfer. This increased risk coincides with a persisting increased oestrogen level. Further reported cardiovascular problems are arterial thromboses, pre-eclampsia and gestational hypertension. Global haemostasis tests change in the direction of increased coagulability, but mostly within normal limits. Cell-bound haemostasis and in particular platelet activation are less studied. However, a major increase in the number of microvesicles (MVs) and markers indicating platelet activation was reported during ovarian stimulation. We now need longitudinal data concerning haemostatic variables that extends into the first trimester. A major research focus should be to identify biomarkers that could be used already before instigation of IVF. Another way to avoid risk could be to delay embryo transfer by adapting a freeze-all strategy.

Recommendations of the Spanish Rheumatology Society for Primary Antiphospholipid Syndrome. Part II: Obstetric Antiphospholipid Syndrome and Special Situations

OBJECTIVE

The difficulty in diagnosis and the spectrum of clinical manifestations that can determine the choice of treatment for antiphospholipid syndrome (APS) has fostered the development of recommendations by the Spanish Society of Rheumatology (SER), based on the best possible evidence. These recommendations can serve as a reference for rheumatologists and other specialists involved in the management of APS.

METHODS

A panel of 4rheumatologists, a gynaecologist and a haematologist with expertise in APS was created, previously selected by the SER through an open call or based on professional merits. The stages of the work were: identification of the key areas for the document elaboration, analysis and synthesis of the scientific evidence (using the Scottish Intercollegiate Guidelines Network, SIGN levels of evidence) and formulation of recommendations based on this evidence and formal assessment or reasoned judgement techniques (consensus techniques).

RESULTS

Forty-six recommendations were drawn up, addressing 5main areas: diagnosis and evaluation, measurement of primary thromboprophylaxis, treatment for APS or secondary thromboprophylaxis, treatment for obstetric APS and special situations. These recommendations also include the role of novel oral anticoagulants, the problem of recurrences or the key risk factors identified in these subjects. This document reflects the last 25, referring to the areas of: obstetric APS and special situations. The document provides a table of recommendations and treatment algorithms.

CONCLUSIONS

Update of SER recommendations on APS is presented. This document corresponds to part II, related to obstetric SAF and special situations. These recommendations are considered tools for decision-making for clinicians, taking into consideration both the decision of the physician experienced in APS and the patient. A part I has also been prepared, which addresses aspects related to diagnosis, evaluation and treatment.

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.

Ovarian hyperstimulation syndrome: A review for emergency clinicians

INTRODUCTION

A great deal of literature has recently evaluated the prevention and management of ovarian hyperstimulation syndrome (OHSS) in the outpatient setting, but there remains a dearth of research evaluating OHSS in the emergency department (ED) and its management.

OBJECTIVE

This narrative review evaluates the underlying pathophysiology and clinical manifestations of OHSS and discusses approaches to patient care in the ED based on current literature.

DISCUSSION

OHSS is an iatrogenic complication caused by an excessive response to controlled ovarian stimulation during assisted reproductive cycles (ART). OHSS complicates up to 30% of ART cycles, and many of these patients seek initial care in the ED. Risk factors for the development of OHSS include age < 35, history of polycystic ovarian syndrome or previous OHSS, and pregnancy. Emergency physicians will be faced with several complications including ascites, abdominal compartment syndrome, renal dysfunction, acute respiratory distress syndrome, thromboembolic disease, and hemodynamic instability. Critical patients should be evaluated in the resuscitation bay, and consultation with the primary obstetrics/gynecology team is needed, which improves patient outcomes. This review provides several guiding principles for management of OHSS and associated complications.

CONCLUSIONS

OHSS occurs in up to 30% of IVF cycles and carries a high morbidity. Effective care of the OHSS patient begins with early diagnosis while evaluating for other diseases and complications. Understanding these complications and an approach to the management of OHSS is essential to optimizing patient care.

Is thromboprophylaxis cost effective in ovarian hyperstimulation syndrome: A systematic review and cost analysis

BACKGROUND

The majority of serious thromboembolic events occurring in assisted reproductive technologies (ART) are in women with ovarian hyperstimulation syndrome (OHSS).

OBJECTIVES

The purpose of this study was to present a thorough review and cost analysis regarding the use of venous thromboembolism (VTE) prophylaxis in OHSS to inform clinical management.

DATA SOURCES

Databases used were Pubmed and Embase, in addition to checking reference lists of retrieved articles (inception to November 2017).

METHODS

The systematic search strategy identified 365 titles and abstracts. Articles included in the qualitative synthesis had identified venous thrombosis incidence rates or ratios. A separate search for the cost model was conducted recognizing all associated complications of VTE. The decision tree was modeled to best fit the patient population and a sensitivity analysis was performed over a range of variables.

RESULTS

The cost of VTE event per OHSS patient not on prophylaxis was €5940 (range €3405 to €38,727), versus €4134 (€2705 to €23,192) per event per patient on prophylaxis, amounting to a saving of (€19 to €23,192) per VTE per patient. Sensitivity analysis found VTE prophyaxis to be cost effective if the incidence of VTE in the OHSS population was greater than 2.79%. Prophylactic therapy was cost effective through 16 weeks of treatment.

LIMITATIONS

OHSS is infrequent and hence, the incidence of VTE in patients with OHSS is low; therefore, the data used to inform the incidence of VTE in OHSS in the model carry some uncertainty. Further, low molecular weight heparin (LMWH) has side effects therefore individualization of care must be considered.

CONCLUSIONS

With the increasing incidence of infertility and requirement for ART, thromboembolism in OHSS poses a major health threat for patients. VTE prophylaxis using enoxaparin was cost effective in patients with severe OHSS over a wide range of costs and incidences. Prophylaxis was also cost effective through the completion of the first trimester of pregnancy.

Assisted Reproductive Techniques in a Patient with History of Venous Thromboembolism: A Case Report and Review of Literature

We report a patient with a history of venous thrombosis following oral contraceptive pills who was planned for in vitro fertilization (IVF)-intracytoplasmic sperm injection for male factor infertility. This article discusses the mechanisms for predisposition to thrombosis during assisted reproduction in patients at high risk. Assessment of risk before commencement of treatment, use of mild stimulation, antagonist protocol, avoiding ovarian hyperstimulation, use of gonadotropin-releasing hormone agonist trigger and avoiding exposure to human chorionic gonadotropin, frozen embryo transfer in a natural cycle, single embryo transfer, avoiding multiple pregnancy, and use of prophylactic or therapeutic anticoagulation are the various risk-reduction strategies that must be adopted during IVF treatment to reduce the risk of thrombosis to that of natural conception.

Thrombosis following ovarian hyperstimulation syndrome

The aim of this review is to analyse the pathophysiology and complications of thrombosis in conjuction with ovarian hyperstimulation syndrome (OHSS) following ovulation induction and to suggest practical guidelines usefull for the prevention and treatment. Although the incidence of thrombosis varies from 0.2% among in vitro fertilization (IVF) cycles and up to 10% for severe cases of the syndrome, it represents the most dangerous complication of OHSS. Different changes in haemostatic markers have been found to create a state of hypercoagulability, but no single standard test is available to estimate the state of thrombosis. The role of markers for thrombophilia is controversial. Thromboses are mostly venous (67-75%) involving upper limbs and neck, then arterial (25-33%) which are mainly intracerebral. The predominant sites of venous thromboembolism in the upper part of the body may be explained by higher concentrations of estrogens drained through lymphatic ducts from ascites and by compression of rudimentary branchyal cysts. Once early diagnosis is established, it is crucial to use an anticoagulant treatment with heparin proceeded with thromboprophylaxis. However, identification of patients at risk and preventive measures of OHSS are the best means in reducing the risk of thrombosis after ovarian stimulation.

Plasma concentrations of D-dimer and outcome of in vitro fertilization

Background

The activation of blood coagulation could contribute to the failure of in-vitro fertilization (IVF) techniques. The aim of this study was to assess the predictive value of D-dimer levels for pregnancy outcome in women undergoing IVF.

Findings

A prospective study was performed in 105 women undergoing IVF. D-dimer was measured before and one week after the administration of recombinant human chorionic gonadotropin (r-hCG). The primary outcome of the study was clinical pregnancy. The mean age was 36 years (range 26 to 43 years). The main indications for IVF were infertility due to a tubaric (n = 21, 20%) or male factor (n = 37, 35%) and idiopathic infertility (n = 30, 29%) which altogether accounted for 84% of the total. Clinical pregnancy was achieved by 40/105 (38%) women of whom 32 (80%) delivered a live child. On the day of r-hCG administration, D-dimer concentrations were significantly higher in patients not achieving a clinical pregnancy (141 ng/dL vs. 115 ng/dL, p = 0.035) which remained statistically significant after correction for age and indications for IVF in multivariable analysis (p = 0.032). One week after r-hCG, the levels of D-dimer were significantly increased both in women with and without a clinical pregnancy with no differences between the groups (748 ng/dL vs. 767 ng/dL, p = 0.88).

Conclusions

D-dimer concentrations seem to predict a higher risk of pregnancy failure in women undergoing IVF. If confirmed in future prospective studies, D-dimer could help identifying a group of patients who could benefit from prophylaxis to increase the pregnancy success rate.

Pregnancy-Related Venous Thromboembolism

Pregnancy is associated with an increased risk of venous thromboembolism (VTE), with a reported incidence ranging from 0.49 to 2 events per 1000 deliveries. Risk factors include advanced maternal age, obesity, smoking, and cesarian section. Women with a history of previous VTE are at a 4-fold higher risk of recurrent thromboembolic events during subsequent pregnancies. Additionally, the presence of concomitant thrombophilia, particularly factor V Leiden (homozygosity), prothrombin gene mutation (homozygosity), or antiphospholipid syndrome (APS), increases the risk of pregnancy-related VTE. Low-molecular-weight heparin (LMWH) and unfractionated heparin (UFH) are the drugs of choice for anticoagulation during pregnancy. LMWH is preferred due to ease of use and lower rates of adverse events. Women with high thromboembolic risk particularly those with a family history of VTE should receive antepartum thromboprophylaxis. Women with low thromboembolic risk or previous VTE caused by a transient risk factor (ie, provoked), who have no family history of VTE, may undergo antepartum surveillance. Postpartum anticoagulation can be considered in women with both high and low thromboembolic risk.

Venous thromboembolism in women: a specific reproductive health risk

BACKGROUND Venous thromboembolism (VTE) is a specific reproductive health risk for women. METHODS Searches were performed in Medline and other databases. The selection criteria were high-quality studies and studies relevant to clinical reproductive medicine. Summaries were presented and discussed by the European Society of Human Reproduction and Embryology Workshop Group. RESULTS VTE is a multifactorial disease with a baseline annual incidence around 50 per 100 000 at 25 years and 120 per 100 000 at age 50. Its major complication is pulmonary embolism, causing death in 1-2% of patients. Higher VTE risk is associated with an inherited thrombophilia in men and women. Changes in the coagulation system and in the risk of clinical VTE in women also occur during pregnancy, with the use of reproductive hormones and as a consequence of ovarian stimulation when hyperstimulation syndrome and conception occur together. In pregnancy, the risk of VTE is increased ~5-fold, while the use of combined hormonal contraception (CHC) doubles the risk and this relative risk is higher with the more recent pills containing desogestrel, gestodene and drospirenone when compared with those with levonorgestrel. Similarly, hormone replacement therapy (HRT) increases the VTE risk 2- to 4-fold. There is a synergistic effect between thrombophilia and the various reproductive risks. Prevention of VTE during pregnancy should be offered to women with specific risk factors. In women who are at high risk, CHC and HRT should be avoided. CONCLUSIONS Clinicians managing pregnancy or treating women for infertility or prescribing CHC and HRT should be aware of the increased risks of VTE and the need to take a careful medical history to identify additional co-existing risks, and should be able to diagnose VTE and know how to approach its prevention.

Acute portal vein thrombosis complicating in vitro fertilization

OBJECTIVE

To describe a case of acute portal vein thrombosis after IVF treatment.

DESIGN

Case report.

SETTING

University teaching hospital.

PATIENT(S)

A 39-year-old woman experienced worsening, right upper quadrant pain several days after oocyte retrieval; ET was withheld. Imaging studies revealed acute portal vein thrombosis with extension into the splenic and superior mesenteric veins.

INTERVENTION(S)

Therapeutic anticoagulation; no ET was performed.

MAIN OUTCOME MEASURE(S)

Improvement in symptoms, accurate diagnosis of condition.

RESULT(S)

Decreased size of portal vein thrombosis and partial vessel recanalization.

CONCLUSION(S)

Thromboembolic events are a rare complication of assisted reproductive technology (ART). In women who present with upper abdominal pain during ART, portal vein thrombosis should be considered in the differential diagnosis.

No evidence that assisted reproduction increases the risk of thrombosis: a Danish national cohort study

BACKGROUND

Case reports have reported venous and arterial thromboses in women undergoing assisted reproduction. No large systematic studies on the risk of thrombosis have been published. The objective of our study was to investigate whether the risk of thrombosis is increased in women undergoing assisted reproduction.

METHODS

A national register-based cohort study was conducted on all women undergoing IVF or ICSI treatment in Denmark from 1994 to 2005. Data were obtained from the National Patient Registry and the IVF Registry. Women with prior malignant or cardiovascular disease were excluded. Thrombosis occurring within the first 6 and 12 months after assisted reproduction was considered potentially related to the treatment. Thromboses during pregnancy as well as the pregnancy-related diagnoses were excluded from the statistical analysis. The incidence rates of venous and arterial thromboses were compared with previously published estimates of the risk of thrombosis among young Danish women.

RESULTS

We analyzed 30 884 Danish women undergoing 75 141 treatments from 1994 to 2005. The mean age of the women at first treatment was 32.3 years. The delivery rate per cycle was 22%. The incidence rate ratio, with 95% confidence interval (CI), of venous thrombosis within 6 months was 0.95 (CI: 0.38-1.95). The incidence rate ratio of arterial thrombosis within 6 months was 0.36 (CI: 0.04-1.30).

CONCLUSIONS

Our study showed no evidence that assisted reproduction increases the risk of thrombosis.

VTE, thrombophilia, antithrombotic therapy, and pregnancy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

The use of anticoagulant therapy during pregnancy is challenging because of the potential for both fetal and maternal complications. This guideline focuses on the management of VTE and thrombophilia as well as the use of antithrombotic agents during pregnancy.

METHODS

The methods of this guideline follow the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines in this supplement.

RESULTS

We recommend low-molecular-weight heparin for the prevention and treatment of VTE in pregnant women instead of unfractionated heparin (Grade 1B). For pregnant women with acute VTE, we suggest that anticoagulants be continued for at least 6 weeks postpartum (for a minimum duration of therapy of 3 months) compared with shorter durations of treatment (Grade 2C). For women who fulfill the laboratory criteria for antiphospholipid antibody (APLA) syndrome and meet the clinical APLA criteria based on a history of three or more pregnancy losses, we recommend antepartum administration of prophylactic or intermediate-dose unfractionated heparin or prophylactic low-molecular-weight heparin combined with low-dose aspirin (75-100 mg/d) over no treatment (Grade 1B). For women with inherited thrombophilia and a history of pregnancy complications, we suggest not to use antithrombotic prophylaxis (Grade 2C). For women with two or more miscarriages but without APLA or thrombophilia, we recommend against antithrombotic prophylaxis (Grade 1B).

CONCLUSIONS

Most recommendations in this guideline are based on observational studies and extrapolation from other populations. There is an urgent need for appropriately designed studies in this population.

Update on management of ovarian hyperstimulation syndrome

Ovarian hyperstimulation syndrome (OHSS) is a relatively common complication of ovarian stimulation and can be life threatening. The pathophysiology of OHSS is characterized by increased capillary permeability, leading to leakage of fluid from the vascular compartment, with third-space fluid accumulation and intravascular dehydration. The increased intra-abdominal pressure indicated that OHSS may be considered a compartment syndrome. Vascular endothelial growth factor, also known as vascular permeability factor, has emerged as one of the mediators intrinsic to the development of OHSS. Conventional management is focused on supportive care until the spontaneous resolution of the condition. The standard of care for treatment-monitoring of appropriate clinical parameters, fluid balance management, thrombosis prophylaxis, and ascites treatment-should prevent severe morbidity in most cases. This review will cover inpatient and outpatient management. The potential therapeutic approach targeting the vascular endothelial growth factor system will be discussed.

Low-Molecular-Weight Heparin in Women with Repeated Implantation Failure

Implantation failure is common in assisted reproduction techniques (ART). The role of low-molecular-weight heparin (LMWH) is a matter of debate as a potential factor to improve implantation. Aim: To evaluate the pregnancy rate in patients with or without heparin administration. Materials & methods: We performed a retrospective observational analysis of patients with at least two IVF/intracytoplasmic sperm injection cycles with implantation failure, screened for inherited thrombophilia and submitted to further ART cycles with or without administration of LMWH. A total of 265 patients fulfilled the enrollment criteria. Of these 149 (56%) were primary infertile and 116 (44%) were secondary infertile. Their mean age was 36.3 ± 3.6 years. We analyzed basal FSH, smoking habit, gene variants for inherited thrombophilia (i.e., MTHFR C677T, prothrombin G202A10G and factor V Leiden). The patients underwent 569 new ART cycles: 512 (90%) without and 57 (10%) with LMWH. Results: In total 105 clinical pregnancies were observed in 569 cycles (18.8%). The pregnancy rate was 17.19% (88/512) in patients not treated with LMWH and 29.52% (17/57) in the LMWH-treated group (p = 0.006). In women over 36 years of age the pregnancy rate was 15.53% (50/322) in nontreated versus 35.71% (10/28) in treated cycles (p = 0.007), while no difference was found in younger women. No statistical difference was found between the presence of inherited thrombophilia and pregnancy rate in treated and untreated cycles. Discussion: significantly higher pregnancy rate in patients with previous ART implantation failures was observed with LMWH. Our results confirm no relation among inherited thrombophilia and pregnancy rate in patients with previous IVF implantation failures. These findings should be confirmed by randomized controlled trials before use of LMWH for ART cycles is recommended.

[Thrombosis and assisted reproductive techniques (ART)]

Assisted reproductive techniques (ART) concern procedures designed to increase fertility of couples: artificial insemination, in vitro fertilization (IVF), either classical or after intracytoplasmic sperm injection (ICSI), transfer of frozen embryos, or gamete intrafallopian transfer. Their use has greatly increased these last years. They may be associated with severe ovarian hyperstimulation syndrome and one possible major complication is venous or arterial thrombosis. Thromboses are rare but potentially serious with important sequellae. They are mostly observed in unusual sites such as head and neck vessels and the mechanism is still unknown although hypotheses have been proposed. This review is an update of our knowledge and an attempt to consider guidelines for the prevention and treatment of ART-associated thromboses, which frequently occur when the woman is pregnant. Prevention of severe ovarian hyperstimulation by appropriate stimulation procedures, detection of women at risk of hyperstimulation and of women at high risk of thrombosis should allow reduction of the risk of thrombosis, possibly by administration of a thromboprophylaxis at a timing and dose which can be only determined by extrapolation.