Thromboembolic complications associated with reproductive endocrinologic procedures

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.

Analysis of Thrombotic Adverse Reactions of COVID-19 AstraZeneca Vaccine Reported to EudraVigilance Database

The development of safe, effective, affordable vaccines against COVID-19 remains the cornerstone to mitigating this pandemic. Early in December 2020, multiple research groups had designed potential vaccines. From 11 March 2021, several European countries temporarily suspended the use of the Oxford-AstraZeneca vaccine amid reports of blood clot events and the death of a vaccinated person, despite the European Medicines Agency (EMA) and the World Health Organization's assurance that there was no indication that vaccination was linked. This study aimed to identify and analyse the thrombotic adverse reactions associated with the Oxford-AstraZeneca vaccine. This was a retrospective descriptive study using spontaneous reports submitted to the EudraVigilance database in the period from 17 February to 12 March 2021. There were 54,571 adverse reaction reports, of which 28 were associated with thrombotic adverse reactions. Three fatalities were related to pulmonary embolism; one fatality to thrombosis. With 17 million people having had the AstraZeneca vaccine, these are extremely rare events The EMA's Pharmacovigilance Risk Assessment Committee (18 March 2021) concluded that the vaccine was safe, effective and the benefits outweighed the risks. Conducting further analyses based on more detailed thrombotic adverse event reports, including patients' characteristics and comorbidities, may enable assessment of the causality with higher specificity.

Aseptic necrosis of the femoral head after pregnancy: a case report

A documented case of beginning aseptic necrosis of the femoral head associated with pregnancy together with a review of the literature about this rare complication of pregnancy is presented. The known risk factors of osteonecrosis are; steroid use, alcoholism, organ transplantation, especially after kidney transplant or bone marrow transplantation bone, systemic lupus erythematosus, dyslipidemia especially hypertriglyceridemia, dysbaric decompression sickness, drepanocytosis and Gaucher's disease. Among the less established factors, we mention procoagulations abnormalities, HIV infection, chemotherapy. We report a case of osteonecrosis of femoral head after pregnancy.

Fertility, Infertility and Thrombophilia

Hypercoagulation has been reported in some studies to be associated with reproductive failures, such as unexplained infertility, IVF implantation failure and recurrent fetal losses. Many pregnancy-related disorders have been interpreted as consequences of impaired microvascular function and might be viewed as a mild form of venous thromboembolic disease. In the absence of clinical guidelines, there is a need for an evidence base regarding thrombophilic screening and antithrombotic therapy in cases of reproductive failure. This article will focus on the controversial effect of congenital and acquired thrombophilia on human fertility, and will review the English literature for relevant studies identified by searching PubMed® results between January 1966–November 2010 using the key words: ‘thrombophilia‘, ‘fertility’ and ‘infertility‘.

Retinal vascular occlusion during in vitro fertilization

PURPOSE

To describe a case of human retinal vascular occlusion during in vitro fertilization.

METHODS

A single case report of a 30-year-old woman who developed decreased central vision in her left eye with inferonasal scotoma while on a gonadotropin-releasing hormone agonist treatment protocol.

RESULTS

The patient's laboratory tests and biochemical profile were normal. Fundoscopy revealed moderate tortuosity of both temporal vascular arcades and dilation of the inferior temporal vein with a blotchy hemorrhage. The superotemporal macular area was swollen and pale. Fluorescein angiography demonstrated an incomplete central retinal vein occlusion accompanied by branch retinal arterial occlusion in the left eye. Six months later, her vision improved to 20/32, and the retina recovered normal color.

CONCLUSION

Retinal vascular occlusion can occur during a controlled ovarian hyperstimulation with gonadotropin-releasing hormone agonists.

The “ART” of thromboembolism: A review of assisted reproductive technology and thromboembolic complications

Since its development over 25 years ago, the use of assisted reproductive technology (ART) is on the increase. Along with its use, are also reports of thromboembolic complications (TEC); these events could resulted in significant maternal morbidity and even mortality. In this article, we reviewed the general principles of ART. We also performed a search of all published cases of TEC associated with ART, and summarized the results of studies investigating underlying hemostatic changes with ART. The goal of this article is to provide non-fertility specialists an understanding of ART, so as to better manage TEC when they occur in predisposed patients. The most common ART procedure performed today, is in-vitro fertilization-embryo transfer (IVF-ET). The process of IVF involves the use of exogeneous hormones to achieve cycle control, stimulate the ovaries, and support implantation. During this process, supraphysiological estradiol levels can result. One major complication of this intervention, ovarian hyperstimulation syndrome (OHSS), can be associated with both arterial and venous thrombotic complications. These events (especially venous thrombosis) have also been reported to occur weeks after OHSS has resolved; and they can present in unusual sites (upper extremities) resulting in treatment challenges. From current available studies, it is clear that with ovarian stimulation, both the coagulation and fibrinolytic systems are activated. This activation appears to be exaggerated and prolonged with the development of OHSS. Whether these changes are sufficient by themselves to explain the occurrence of TEC is yet unknown. Future studies should be focused on defining the frequency and risk factors of these complications; provide a closer examination of the resultant changes in the coagulation cascade during ART, OHSS and early pregnancy; and investigating the appropriate treatment and thromboprophylaxis for patients undergoing a procedure considered "elective".

Prevention and management of ovarian hyperstimulation syndrome

The Ovarian Hyperstimulation Syndrome (OHSS) represents one of the biggest nightmares of all physicians involved in Assisted Reproductive Technologies (ART). Every year, several hundreds of women are hospitalized and to date several deaths have been reported. The pivotal event in the development of OHSS is the disruption of capillary integrity that results in leakage of intravascular fluid and proteins into third space. On the molecular level, human chorionic godadotropin (HCG) either exogenous or endogenous, functions as the triggering point for the production of vascular endothelial growth factor (VEGF) that is the main mediator to increase permeability on the vascular bed. Spontaneous OHSS has also been reported, either due to inappropriate activation of a mutant FSH receptor or due to very high levels of HCG during pregnancy. The available evidence on the several preventive and therapeutic approaches with special attention to level 1 evidence when available is also presented. OHSS is a self-resolving condition and the main role of the physician is to correct and maintain the intravascular volume, to support renal function and respiration and prevent thrombotic events. An algorithm on the management of OHSS on an outpatient basis and in the hospital is based on the previous mentioned principles.

Exogenous Sex Hormones and Thrombophilia

Worldwide, hundreds of millions of women use exogenous estrogens in contraceptives or for postmenopausal hormone replacement. Exogenous estrogens increase the risk for venous and arterial thrombosis. This article reviews the use of exogenous sex hormones in women with thrombophilia.

Need for an Urgent Ultrasound Examination for Neck Lump

Thromboembolic phenomenon is rare but serious consequence of ovarian hyperstimulation syndrome (OHSS) and in vitro fertilization (IVF) treatment. We present a case of thrombosis of the right internal jugular vein presenting as a neck lump to the ENT department. Ultrasonography of the neck and upper extremity revealed thrombosis of right internal jugular vein. The patient was started on low molecular weight heparin, which resulted in resolution of her clinical condition. Interestingly, the majority of cases after OHSS involve thrombosis of the upper extremities. ENT surgeons, general physicians, and infertility experts should consider this in the differential diagnosis of neck swellings, particularly after OHSS and IVF treatment, and in this case report, we emphasis the need for an urgent ultrasound of the neck in such patients.

Effect of urinary versus recombinant follicle-stimulating hormone on platelet function and other hemostatic variables in controlled ovarian hyperstimulation

OBJECTIVE

To determine the effect of urinary versus recombinant FSH on platelet function and hemostatic variables in women undergoing controlled ovarian hyperstimulation cycles.

DESIGN

Randomized clinical study.

SETTING

Major university-based infertility and in vitro fertilization unit and hemostasis laboratory.

PATIENT(S)

Ten healthy women (in vitro study), and 24 women undergoing routine controlled ovarian hyperstimulation cycles (in vivo study), randomly assigned to receive either urinary (u-FSH) or recombinant gonadotropin (r-FSH).

INTERVENTION(S)

In vitro study: effect of preincubation of plasma with u-FSH or r-FSH, in the presence or absence of estradiol, on platelet function and coagulation parameters. In vivo study: Changes in platelet function and coagulation parameters after treatment with u-FSH or r-FSH during controlled ovarian hyperstimulation cycles.

MAIN OUTCOME MEASURE(S)

Platelet aggregation and ATP release, activated protein C resistance ratio, free protein S.

RESULT(S)

In vitro study: Platelet aggregation and ATP release were significantly inhibited by u-FSH relative to r-FSH in both the presence and absence of estradiol (P=.047). In vivo study: Platelet function was significantly inhibited after treatment with u-FSH (P=.05) but not with r-FSH. In both studies, small changes of minor clinical significance were noted in activated protein C resistance and free protein S levels.

CONCLUSION(S)

The different platelet response to u-FSH and r-FSH may have clinical implications in selected patients, especially those at risk of thromboembolic complications, in decisions regarding the appropriate medication for controlled ovarian hyperstimulation cycles.

Thrombotic disorders: diagnosis and treatment

Hematologists are increasingly involved in the diagnosis and management of patients with venous and arterial thromboembolic disorders. There have been major advances in recent years in our understanding of the central role of hypercoagulability in the pathogenesis of thrombosis. This has led to new approaches to the diagnosis of patients at risk for thrombosis and the development of more rational antithrombotic strategies. In Section I, Dr. Andrew Schafer reviews current concepts of acquired and inherited hypercoagulable states. It is now recognized that most, if not all, patients with venous thromboembolism have a genetic basis for the disorder ("thrombophilia"). The level of lifelong, baseline hypercoagulability in any individual may be determined by the type(s) and number of thrombophilia(s) that are inherited. Clinical episodes of thrombosis are precipitated by acquired thrombogenic triggers, which may be overt (e.g., pregnancy) or subclinical. In Section II, Dr. Mark Levine discusses the complex problem of thrombosis in patients with cancer. The goals of treating acute venous thromboembolism in cancer patients are to prevent recurrence, minimize the risk of anticoagulant-induced bleeding, and improve quality of life. New developments have improved treatment of venous thromboembolism in these patients, including outpatient therapy and secondary prevention with low-molecular-weight heparin. In Section III, Dr. Barbara Konkle reviews the diagnosis and management of thrombotic complications associated with pregnancy and hormonal therapy. Patient management is discussed based on data on thrombotic risks associated with hormonal treatment of infertility, pregnancy and the post-partum period in women with and without underlying thrombophilic risk factors. In Section IV, Dr. Clive Kearon discusses the management of anticoagulation before and after elective surgery. In the past, there has been no consensus on the perioperative management of anticoagulation for patients who require long-term warfarin therapy. This review considers the expected risks and benefits of different approaches to anticoagulation in patients who require warfarin because of atrial fibrillation, a mechanical heart valve, or a history of venous thromboembolism.

Diagnosis of deep vein thrombosis and pulmonary embolism in pregnancy

Venous thromboembolism (VTE) is a major cause of maternal morbidity and mortality. Because unrecognized and untreated pulmonary embolism (PE) can result in maternal mortality, physician vigilance for this disease should remain high. The diagnosis of both PE and deep vein thrombosis (DVT) in the pregnant patient, as in the nonpregnant patient, requires the use of accurate objective imaging. However, unlike the nonpregnant population, there is a paucity of trials evaluating the safety and accuracy of objective testing for PE or DVT diagnosis in pregnant patients--likely because of concerns surrounding the use of ionizing radiation associated with diagnostic tests during pregnancy. Regardless of extrapolating results from studies in the nonpregnant population, the use of compression leg ultrasound and ventilation-perfusion (VQ) scanning during pregnancy is central to the diagnosis of DVT and PE, respectively. Data on the utility of structured clinical models or D-dimer testing for the diagnosis of DVT or PE during pregnancy is currently unavailable. Future research is urgently needed to validate the use of current approaches and perhaps define safer and more accurate strategies to reduce maternal morbidity from this disease.

Internal jugular vein thrombosis after assisted conception therapy

Superovulation therapy during assisted conception may result in a hypercoagulable state. Five cases of upper extremity venous thrombosis were identified in women who conceived after ovarian stimulation for in vitro fertilization (IVF). They presented between 7 and 10 weeks' gestation with neck pain and swelling. Three had been treated for ovarian hyperstimulation syndrome and two had evidence of inherited thrombophilia. Four patients received thromboprophylaxis before presentation. Although thrombosis is an uncommon complication of IVF, patients should be counselled before treatment. Thrombophilia screening may be considered for 'high-risk' patients, although current regimes for thromboprophylaxis remain suboptimal.

Central retinal artery occlusion associated with severe ovarian hyperstimulation syndrome

PURPOSE

Ovarian hyperstimulation syndrome (OHSS) is a serious iatrogenic complication of ovulation induction. It is a potentially lethal condition, with severe complications which include ovarian enlargement, and massive fluid redistribution from the vascular system into free spaces resulting in ascites, pleural effusion, electrolyte imbalance, hemoconcentration, hypovolemia, oliguria, and adult respiratory distress syndrome. Thromboembolism is a rare but extremely serious complication.

CASE REPORT

We report a case of severe OHSS, presenting with central retinal artery occlusion (CRAO).

DISCUSSION

This combination has not been reported previously.

Cerebral embolism and hormone replacement therapy

Few studies have focused on the relationship between hormone replacement therapy (HRT) for postmenopausal women or those with breast cancer and the occurrence of cerebral embolism. Results are conflicting as to whether there is a link between the two. We describe three patients who experienced cerebral embolism during HRT. A 73-year-old woman had a transient ischemic attack (TIA) 6 years prior to the present admission. She then took HRT oestrogen plus medroxyprogesterone acetate for about 6 years. The HRT had been prescribed by a gynaecologist for amelioration of postmenopausal symptoms. Six years after beginning HRT, she experienced sudden onset left hemiparesis due to cerebral embolism. Two other patients had been taking HRT for breast cancers. One, a 47-year-old woman, had taken medroxyprogesterone acetate for more than one year, for recurrence of breast cancer. She had developed sudden complete left hemiparesis due to an embolism at the carotid bifurcation. The other patient, a 72-year-old woman who was taking tamoxifen citrate for prevention of breast cancer relapse, experienced cerebral embolism just 2 months after beginning tamoxifen. The risk of cerebral embolism in those on HRT should be emphasized, along with the beneficial effects in terms of postmenopausal symptoms and prevention of breast cancer recurrence.

[Evaluation of thomboembolic risk before ovarian stimulation: what balance? What prevention?]

The pathophysiology of thrombotic events remains unclear among women undergoing ovulation induction. In this review, present knowledge is summarized from the literature. Prospective studies are needed to determine risk factors and therapeutic approach of these thrombotic complications.