Pulmonary embolism in pregnancy

Pulmonary Embolism After in vitro Fertilization and Cesarean Section: Two Case Reports and Brief Review of the Literature

This paper reports two cases of postpartum pulmonary embolism in Taicang First People's Hospital affiliated to Soochow University. They share many similarities in age, fertilization way, birthing method, incidence of pulmonary embolism, treatment and prognosis. The main purpose is to inspire the current maternal PTE risk assessment, diagnosis and treatment, as well as to explore the existing limitations and problems.

Inhibitory effects of amniotic fluid on the activated protein C anticoagulation system in maternal plasma

Pulmonary thromboembolism (PTE) is one of the leading causes of maternal mortality. We previously reported that possible contamination of amniotic fluid (AF) into maternal circulation accelerated thrombin production and activated platelet function in maternal blood through the extrinsic pathway, which may be associated with the high incidence of PTE in early puerperium. However, it remains unclear whether the maternal anticoagulation system, e.g., the activated protein C (APC) pathway, contributes to the hypercoagulable condition induced by AF. Our previous study using an endogenous thrombin potential (ETP)-based assay revealed that sensitivity to APC was reduced during the postpartum first day, i.e., immediately after delivery, when parturients were supposed to be exposed to AF. Our aim is to investigate the susceptibility of maternal plasma to APC when mixed with AF. We collected plasma from 51 pregnant females and mixed with AF as well as APC. APC-sensitivity ratio (APC-sr) was calculated using the ETP-based assay. Addition of AF to maternal plasma showed a significant increase of ETP in the presence of APC. APC-sr was significantly increased, indicating decreased sensitivity to APC, after AF mixture to maternal plasma. The present APC-sr difference with AF contamination was smaller than that we reported previously in venous thromboembolism cases. The inhibitory effects of AF on the APC anticoagulation pathway may contribute, at least partly, to further promotion of thrombin production induced by AF. Combined with other classical thrombophilic risk factors, the present findings support possible involvements of AF exposure in the high incidence of PTE in early puerperium.

Pregnancy-adapted YEARS algorithm: can YEARS do more for pregnant women?

Venous thromboembolism (VTE), as a term that encompasses pulmonary embolism (PE) and deep vein thrombosis (DVT), is one of the leading causes of maternal morbidity and mortality [1], especially in developed countries, where PE takes second place after complications of hypertensive disorders [2]. When compared to non-pregnant women of similar age, pregnant women have an approximately four to five times higher risk of VTE [3], with an incidence of 1 in 1000 pregnancies [4]. Approximately 20–25% of VTE cases are caused by PE and 75–80% of cases are caused by DVT [5]. About 60% of DVT occurs antepartum, with the highest risk of antepartum pregnancy-associated VTE being in the third trimester.However, about 60% of PE occurs postpartum [3].

Pregnancy-adapted YEARS algorithm provides high certainty in ruling out pulmonary embolism and high efficiency in reducing the need for CTPAhttp://bit.ly/2GgH4sv

Radiologic Aspects of the Diagnosis of Pulmonary Embolism in Pregnancy

Pulmonary embolism in pregnancy is a leading cause of maternal mortality. The clinical presentation is often nonspecific, making imaging essential for accurate diagnosis. After reviewing the literature on the radiologic diagnosis of pulmonary embolism in pregnancy, we concluded that both computed tomography pulmonary angiography and lung perfusion scintigraphy are sensitive with high positive predictive values in the presence of high clinical suspicion, but lung perfusion scintigraphy is recommended given lower maternal breast exposure to ionizing radiation and lower fetal contrast exposure. However, if a chest x-ray is abnormal, computed tomography pulmonary angiography is preferred due to high nondiagnostic rates of lung perfusion scintigraphy.

Acute Pulmonary Embolism in a Teenage Female - A Case Report

Thrombophilia represents a tendency towards excessive blood clotting and the subsequent development of venous thromboembolism (VTE). VTE is a rare condition in children that comprises both deep venous thrombosis (DVT) and pulmonary embolism (PE). This paper reports the case of a 16-year-old girl, admitted to the Pediatrics Clinic No. 1, Tîrgu Mureș, Romania, for dyspnea, chest pain and loss of consciousness. Her personal history showed that she had had two orthopedic surgical interventions in infancy, two pregnancies, one spontaneous miscarriage and a recent caesarian section at 20 weeks of gestation for premature detachment of a normally positioned placenta associated with a deceased fetus. Laboratory tests showed increased levels of D-dimers. Angio-Computed Tomography (Angio-CT) showed multiple filling defects in both pulmonary arteries, establishing the diagnosis of PE. The laboratory tests were undertaken to assist in the diagnoses of a possible thrombophilia underlined a low level of antithrombin III. Antiphospholipid syndrome was ruled out and genetic tests revealed no specific mutation. Anticoagulant therapy was initiated with unfractionated heparin and afterwards subcutaneously low molecular heparin was prescribed for three months. Later it has been changed to oral therapy with acenocoumarol. The patient was discharged in good general status with the recommendation of life-long anticoagulation therapy. Thrombophilia is a significant risk factor for PE, and it must be ruled out in all cases of repeated miscarriage.

Successful treatment of pulmonary embolism-induced cardiac arrest by thrombolysis and targeted temperature management during pregnancy

Background

Thrombolysis for pulmonary embolism and targeted temperature management for cardiac arrest are controversial treatments in pregnancy.

Case

A 37‐year‐old woman at 23 weeks gestation presented with persistent dyspnea. She experienced cardiac arrest soon after arrival at the emergency room. Massive right ventricular dilatation on echocardiography during the transient return of spontaneous circulation suggested pulmonary embolism. We administered recombinant tissue plasminogen activator for suspected pulmonary embolism to successfully resuscitate the patient experiencing refractory cardiac arrest despite heparin infusion. After an additional dose of monteplase for persistent shock with remaining right ventricular dilatation on echocardiography, maternal hemodynamics dramatically improved, but fetal heart rate transiently decreased. Targeted temperature management was initiated for delayed recovery of consciousness. She fully recovered consciousness without neurological deficit. However, the fetus was aborted because of fetal hydrops.

Conclusion

Thrombolysis and targeted temperature management should be considered as treatment options for pulmonary embolism‐induced cardiac arrest during pregnancy.

[Chest pain at 32 weeks' gestation: pregnancy-related spontaneous coronary artery dissection]

A 32-year-old woman at 32 weeks gestation presented with cardiac arrest due to ventricular tachycardia following acute chest pain at home. After immediate defibrillation with return of spontaneous circulation (ROSC), an ST segment elevation myocardial infarction due to coronary artery dissection was confirmed. Two drug-eluting stents were implanted and she was placed on dual antiplatelet therapy (DAPT). The echocardiogram showed akinesis of the apex and anterior wall. The patients risk for stent thrombosis was considered high and therefore DAPT was continued until cesarean section at 35 weeks gestation. Intraoperatively she received two units of packed red blood cells, one platelet concentrate, 4 g fibrinogen and 2 g tranexamic acid. Left ventricular ejection fraction deteriorated 8 days after delivery and the patient developed congestive heart failure.

Examining the transplacental passage of apixaban using the dually perfused human placenta

Essentials Apixaban is a novel oral anticoagulant that has not been studied in pregnant patients. Our objective was to determine the rate and extent of the placental transfer of apixaban. Apixaban rapidly crosses the ex vivo term human placenta from maternal to fetal circulation. Fetal apixaban levels in vivo are estimated to be 35-90% of the corresponding maternal levels.

SUMMARY

Background Apixaban is a novel oral anticoagulant that is increasingly being prescribed to women of reproductive age. However, information regarding its placental transfer is non-existent. Objective To determine the rate and extent of placental transfer of apixaban, using the human placenta ex vivo. Methods Placentae collected after Caesarean or vaginal delivery of healthy term infants were perfused in the respective maternal and fetal circulation. At the start of the experiment, apixaban was added to the maternal circulation at a concentration of 150 ng mL(-1) , and samples from maternal and fetal reservoirs were collected over 3 h. Results There was a rapid decline of apixaban in the maternal compartment, followed by emergence in the fetal compartment with a median fetal-to-maternal drug concentration ratio of 0.77 (interquartile range [IQR], 0.76-0.81) and fetal concentration of 39.0 ng mL(-1) (IQR, 36.8-40.6) after 3 h (n = 5). The perfusion results were subsequently adjusted to account for differences in the concentration of plasma proteins in maternal and fetal blood, as apixaban remains highly bound to albumin and alpha-1 acid glycoprotein. After the adjustment, the predicted fetal-to-maternal ratio of total (bound plus unbound) apixaban concentrations in vivo ranged from 0.35 to 0.90. Conclusions We conclude that unbound apixaban rapidly crosses from the maternal to fetal circulation. We further predict that total apixaban concentrations in cord blood in vivo are 35-90% of the corresponding maternal levels, suggesting that apixaban could have a possible adverse effect on fetal and neonatal coagulation.

Patent foramen ovale (PFO), stroke and pregnancy

Patent foramen ovale (PFO)-related stroke is increasingly recognized as an important etiology of ischemic embolic stroke-accounting for up to 50% of strokes previously considered 'cryptogenic' or with an unknown mechanism. As a 'back door to the brain,' PFO can allow venous clots to enter arterial circulation via interatrial right-to-left shunting, potentially resulting in ischemic stroke. We observe that clinically, PFO-related stroke affects women of childbearing age, and that pregnancy-owing to major changes in hemocoagulative, hormonal, and cardiovascular parameters-can enhance stroke risks. However, no systematic study has been performed and little is known regarding complications, pregnancy outcomes and treatment for PFO-related stroke during pregnancy. To identify and characterize the complications and clinical outcomes related to PFOs during pregnancy, we performed a literature review and analysis from all reported cases of pregnancy with PFO-related complications in the medical literature from 1970 to 2015. We find that during pregnancy and post-partum, PFO is associated with complications affecting multiple organs, including the brain, heart and lung. The three principal complications reported are stroke, pulmonary emboli and myocardial infarction. In contrast to other pregnancy-related stroke etiologies, which peak during later pregnancy and postpartum, PFO-related stroke peaks during early pregnancy (first and second trimester-60%), and most patients had good neurological outcome (77%). In patients with PFO with recurrent stroke during pregnancy, additional key factors include high-risk PFO morphology (atrial septal aneurysm), larger right-to-left shunt, multiple gestation and concurrent hypercoagulability. Compared to strokes of other etiologies during pregnancy, most PFO stroke patients experienced uneventful delivery (93%) of healthy babies with a good clinical outcome. We conclude with recommended clinical treatment strategies for pregnant patients with PFO suggested by the data from these cases, and the clinical experience of our Cardio-Neurology Clinic.

Large D-Dimer Fluctuation in Normal Pregnancy: A Longitudinal Cohort Study of 4,117 Samples from 714 Healthy Danish Women

Introduction. D-dimer levels increase throughout pregnancy, hampering the usefulness of the conventional threshold for dismissing thromboembolism. This study investigates the biological fluctuation of D-dimer in normal pregnancy. Methods. A total of 801 healthy women with expected normal pregnancies were recruited. D-dimer was repeatedly measured during pregnancy, at active labor, and on the first and second postpartum days. Percentiles for each gestational week were calculated. Each individual D-dimer was normalized by transformation into percentiles for the relevant gestational age or delivery group. The range in percentage points during the pregnancy and the delivery was calculated, and reference intervals were calculated for each pregnancy trimester, during vaginal delivery and scheduled and emergency cesarean section, and for the first and second day postpartum. Results. D-dimer increased during pregnancy; the maximal fluctuation was approximately 20 percentile points in approximately half of the women. In one out of ten women, the D-dimer values fluctuated by more than 50 percentile points. Conclusions. Due to the biological variation in D-dimer within each individual woman during normal pregnancy, repeated D-dimer measurements are of no clinical use in the evaluation of thromboembolic events during pregnancy.

Pregnancy outcome after exposure to the novel oral anticoagulant rivaroxaban in women at suspected risk for thromboembolic events: a case series from the German Embryotox Pharmacovigilance Centre

BACKGROUND

New oral anticoagulants are increasingly used in women of childbearing age, but apart from one case report there is no published experience with rivaroxaban exposure during pregnancy.

METHODS

From October 2008 to December 2014, the German Embryotox Pharmacovigilance Centre identified 63 exposed pregnancies among 94 requests concerning rivaroxaban use during childbearing age. Follow-up included paediatric checks until 6 weeks after birth.

RESULTS

All pregnancies with completed follow-up were exposed at least during the first trimester. Treatment indications included venous thromboembolism, knee surgery, and atrial fibrillation. 37 pregnancies were prospectively ascertained and resulted in six spontaneous abortions, eight elective terminations of pregnancy, and 23 live births. All women had discontinued rivaroxaban after recognition of pregnancy, mostly in the first trimester, but in one woman treatment continued until gestational week 26. There was one major malformation (conotruncal cardiac defect) among the 37 prospectively ascertained pregnancies in a woman with complex medication and a previous foetus with cardiac malformation without exposure to rivaroxaban. Only one case of bleeding concerning a retrospective report of surgery for missed abortion was observed in our case series.

CONCLUSION

Our results might give reassurance to those women, who were inadvertently exposed to rivaroxaban in early pregnancy. However, our limited cohort size does not allow ruling out an increased malformation risk and does not support the use of rivaroxaban during pregnancy. In all cases of (inadvertent) rivaroxaban exposure during 1st trimester, anticoagulation regimen should be reconsidered and a detailed ultrasound assessment recommended to confirm normal foetal development.