Venous thromboembolism in pregnancy

Venous thromboembolism (VTE) includes deep vein thrombosis (DVT) and pulmonary embolism (PE). In pregnancy, deep vein thrombosis accounts for 75–80% of venous thromboembolism, the remainder are pulmonary embolisms. One half of these VTEs occur during pregnancy and the other half in the postpartum period. Venous thromboembolism is one of the leading causes of maternal mortality worldwide and is also the cause of significant maternal morbidity. This article discusses the risk factors for VTE in pregnancy, the management of the pregnant woman at risk both antenatally and postpartum and the acute management of VTE when it occurs during pregnancy.     

Pregnancy-related deaths due to pulmonary embolism in Sweden

BACKGROUND: The objective of this study was to report deaths from amniotic fluid embolism (AFE) and pregnancy-related venous thromboembolism (VTE), to study contributing factors, and to analyse mortality trends. METHODS: Using the Swedish Cause of Death Register (CDR), we identified all women aged 15-44, who died during 1990-1999, with VTE or AFE coded as the underlying or contributory cause of death. We scrutinised medical records, and women who had died during pregnancy or within 6 weeks of terminated pregnancy were included. We also used data from the Medical Birth Register (MBR) on incident and fatal cases. Mortality data from the 1970s and 1980s were based on previous studies, in which cases were identified through register linkage (CDR and MBR). RESULTS: Five women died of AFE and 10 of VTE - 6 in early pregnancy - during the 1990 s. Five of the cases were not registered as maternal deaths. Only 4 cases were reported as pregnancy-related deaths from pulmonary embolism (PE). Cesarean section/surgery without thromboprophylaxis, overweight, severe intercurrent disease, delays in seeking health care, and verbal miscommunication were contributing factors in the VTE cases. VTE mortality rates (pregnancy >28 weeks and/or a registered birth) were 1.0 (0.5-1.8), 0.8 (0.3-1.6), and 0.4 (0.1-1.0) per 100,000 live births during the 1970s, 1980s and 1990 s, respectively; the corresponding respective figures for AFE were 1.0 (0.5-1.8), 1.1 (0.6-2.1), and 0.5 (0.2-1.1) per 100,000 live births. The case fatality rate for VTE decreased from 4.5% in the 1970s, to 0.6% in the 1990 s, paralleled with quadrupled incidence. The case fatality rate for AFE was unaltered and high, around 45%, during those 3 decades. CONCLUSIONS: Mortality from pregnancy-related PE in Sweden is in the lowest range ever reported, and shows a downward trend during the 1990 s, with a shift towards early pregnancy. In order to monitor mortality trends, death certificate quality must improve, and registers must be linked routinely.     

妊娠相关静脉血栓栓塞症风险评估模型研究进展

妊娠相关静脉血栓栓塞症（pregnancy associated venous thromboembolism，PA-VTE）包括妊娠期和产褥期发生的静脉系统的血栓形成疾病，由深静脉血栓形成（deep vein thrombosis，DVT）和肺栓塞（pulmonary embolism，PE）组成的PA-VTE是发达国家孕产妇发病和死亡的主要原因。采用高效、便捷的风险评估模型评估PA-VTE的发病风险并进行分级预防是目前多个国家推荐的主要措施，但由于各国医学水平、经济发展和传统习惯的不同，各国相继开发风险评估模型或根据实际情况对其他国家的风险评估模型进行改良，进而对妊娠期及产褥期VTE风险进行个体化评估，并实施相应的血栓预防策略。通过回顾国内外的PA-VTE风险评估模型，旨在为我国进一步建立孕产妇的VTE防治指南提供依据，为产科医务工作者制定出适合我国产科人群的VTE风险评估模型提供参考。     

Evaluating patient values and preferences for thromboprophylaxis decision making during pregnancy: A study protocol

ABSTRACT: BACKGROUND: Pregnant women with prior venous thromboembolism (VTE) are at risk of recurrence. Low molecular weight heparin (LWMH) reduces the risk of pregnancy-related VTE. LMWH prophylaxis is, however, inconvenient, uncomfortable, costly, medicalizes pregnancy, and may be associated with increased risks of obstetrical bleeding. Further, there is uncertainty in the estimates of both the baseline risk of pregnancy-related recurrent VTE and the effects of antepartum LMWH prophylaxis. The values and treatment preferences of pregnant women, crucial when making recommendations for prophylaxis, are currently unknown. The objective of this study is to address this gap in knowledge. METHODS: We will perform a multi-center cross-sectional interview study in Canada (2 sites), USA, Norway and Finland. The study population will consist of 100 women with a history of lower extremity deep vein thrombosis (DVT) or pulmonary embolism (PE), and who are either pregnant, planning pregnancy, or may in the future consider pregnancy (women between 18 and 45 years). We will exclude individuals who are on full dose anticoagulation or thromboprophylaxis, who have undergone surgical sterilization, or whose partners have undergone vasectomy. We will determine each participant's willingness to receive LMWH prophylaxis during pregnancy through direct choice exercises based on real life and hypothetical scenarios, preference-elicitation using a visual analog scale ("feeling thermometer"), and a probability trade-off exercise. The primary outcome will be the minimum reduction (threshold) in VTE risk at which women change from declining to accepting LMWH prophylaxis. We will explore possible determinants of this choice, including educational attainment, the characteristics of the women's prior VTE, and prior experience with LMWH. We will determine the utilities that women place on the burden of LMWH prophylaxis, pregnancy-related DVT, pregnancy-related PE and pregnancy-related hemorrhage. We will generate a "personalized decision analysis" using participants' utilities and their personalized risk of recurrent VTE as inputs to a decision analytic model. We will compare the personalized decision analysis to the participant's stated choice. DISCUSSION: The preferences of pregnant women at risk of VTE with respect to the use of antithrombotic therapy remain unexplored. This research will provide explicit, quantitative expressions of women's valuations of health states related to recurrent VTE and its prevention with LMWH. This information will be crucial for both guideline developers and for clinicians.     

Hidden from view: violent deaths among pregnant women in the District of Columbia, 1988-1996

OBJECTIVE: Maternal mortality is underreported in the United States in part because traumatic deaths are not included in nationally reported maternal mortality ratios. The overall study goal was to compare women whose deaths had been reported to and investigated by a medical examiner and who had evidence of pregnancy to women without evidence of pregnancy in terms of socio-demographic information, toxicology results, and manner and cause of death. A secondary goal was to compare the pregnancy status and gestational age of women with evidence of pregnancy at the time of death in relation to the manner of death, with particular focus on women who died as a result of violent death. METHODOLOGY: Autopsy charts from 1988-1996 for 651 women aged 15 to 50 from the District of Columbia Office of the Chief Medical Examiner whose autopsies included examination of the uterus were reviewed. Medical examiners' classification of manner and specific causes of death were used as the main outcome measures. Overall, the sample reflected demographic characteristics of women of childbearing age in the District of Columbia, with 82% black, 74.6% unmarried, and 46.5% aged 20 to 34. RESULTS: Among the 651 autopsy charts evaluated, 30 (4.6%) documented evidence of pregnancy; 43.3% of the women who died due to homicide with evidence of pregnancy were not included in the 21 pregnancy-related deaths officially reported by the District of Columbia State Center for Health Statistics during the study period, and therefore, were also not included in national maternal mortality ratios. Although not statistically significant, 11% more homicides occurred among women with evidence of pregnancy as compared to non-pregnant women. Pregnant women who died a violent death were significantly more likely than non-pregnant women to have died due to gunshot trauma. A significant proportion of pregnant women were < 21 weeks gestation at the time of their death. Additionally, women in this sample with evidence of pregnancy were over 3 times more likely to have been teenagers compared to non-pregnant women. CONCLUSION: Medical examiner autopsy records identify violent pregnancy-associated deaths, many of which occur early in pregnancy and are missed by other enhanced case-finding techniques that require a record of a birth or fetal death. These deaths are usually excluded from reported maternal mortality ratios. Few studies have evaluated the prevalence of homicide in women of childbearing age, yet understanding the extent of less commonly associated causes of death during pregnancy such as homicide, may lead to improved identification of preventable problems that contribute to maternal morbidity and mortality. This study, which sheds new light on the identifying and reporting of maternal mortality, and specifically on homicide as a form of violence toward pregnant women, should be of particular interest for all women's health providers, as well as public health professionals, researchers, and advocates who are interested in the design, development, and evaluation of prevention programs, especially those directed toward preventable problems such as domestic violence.     

妊娠相关静脉血栓栓塞症防治策略及中国实践

妊娠期和产褥期是静脉血栓栓塞症(VTE)明确的危险因素。妊娠相关VTE主要根据临床症状和体征、加压超声、肺通气/灌注扫描和CT肺动脉造影确诊。其防治首选低分子肝素,少数特殊患者使用普通肝素优于低分子肝素,溶栓治疗或放置下腔静脉滤器应严格把握指征。其中VTE的分娩期处理极具挑战性,需要产科、麻醉科、新生儿科以及血液科多科协作。近年来中国的VTE发生率有增高趋势,但缺乏实际的发病率数据以及有关VTE防治策略的研究,因此建立适合中国孕产妇的防治策略并采取多学科协作诊治的方式尤为重要。     

Recommendations for the diagnosis and treatment of deep venous thrombosis and pulmonary embolism in pregnancy and the postpartum period

Venous thromboembolism (VTE) in pregnancy and the postpartum is an important cause of maternal morbidity and mortality; yet, there are few robust data from clinical trials to inform an approach to diagnosis and management. Failure to investigate symptoms suggestive of pulmonary embolism (PE) is a consistent finding in maternal death enquiries, and clinical symptoms should not be relied on to exclude or diagnose VTE. In this consensus statement, we present our recommendations for the diagnosis and management of acute deep venous thrombosis (DVT) and PE. All women with suspected DVT in pregnancy should be investigated with whole leg compression ultrasonography. If the scan is negative and significant clinical suspicion remains, then further imaging for iliofemoral DVT maybe required. Imaging should be undertaken in all women with suspected PE, as the fetal radiation exposure with both ventilation/perfusion scans and CT pulmonary angiography is within safe limits. Low-molecular-weight heparin (LMWH) is the preferred therapy for acute VTE that occur during pregnancy. In observational cohort studies, using once-daily regimens appears adequate, in particular with the LMWH tinzaparin; however, pharmacokinetic data support twice-daily therapy with other LMWH and is recommended, at least initially, for PE or iliofemoral DVT in pregnancy. Treatment should continue for a minimum duration of six months, and until at least six weeks postpartum. Induction of labour or planned caesarean section maybe required to allow an appropriate transition to unfractionated heparin to avoid delivery in women in therapeutic doses of anticoagulation.     

Current management of thromboembolism in pregnancy and puerperium

Venous thromboembolism (VTE) remains the leading cause of maternal death. Today, various risk factors and conditions are known to increase the risk for VTE associated with pregnancy. Having identified the individual risk of a pregnant women, appropriate preventive measures can be taken. If VTE occurs during pregnancy, an appropriate immediate diagnostic work-up is essential in order to avoid further complications. For deep vein thrombosis (DVT) the diagnostic tool of choice is color-coded duplex-sonography, for pulmonary embolism (PE) perfusion/ventilation lung scan can be used. Integrating a detailed individual and family history, the presence of thrombophilia or other risk factors, a risk stratification can be undertaken. These risk categories are defined in the present paper and the appropriate treatment measures are described. As oral anticoagulants cross the placenta and may cause embryopathy in any trimester, oral anticoagulants should be avoided throughout pregnancy. Therefore, heparin is the anti-coagulant of choice for pregnant women, with low molecular weight heparins (LMWH) having distinctive pharmacological advantages over unfractionated heparins. Besides a potential for bleeding, the main side effects of heparin include heparin-induced thrombocytopenia which prompts for platelet monitoring, especially in the first weeks of heparin treatment, and, secondly, heparin-induced osteoporosis, which is a potential sequel of long-term heparin administration. Even though there are abundant reports in the literature on the use of LMWH in pregnant women, that show that they are safe and effective, LMWH are not specifically licensed for the use in pregnancy.     

Effect of motor vehicle crashes on adverse fetal outcomes

OBJECTIVE: To assess the effect of maternal involvement in motor vehicle crashes on the likelihood of adverse pregnancy outcomes and to estimate the effect of seatbelt use in reducing the occurrence of those outcomes. METHODS: Statewide motor vehicle crash, birth, and fetal death records from 1992 to 1999 were probabilistically linked. Logistic regression was used to compare the likelihood of adverse birth and fetal outcomes including low birth weight, prematurity, placental abruption, fetal distress, excessive bleeding, fetal death, and other complications among pregnant women in crashes and those not in crashes. RESULTS: Of 322,704 single live resident births, 8938 mothers (2.8%) experienced a crash during pregnancy. Pregnant women using seatbelts were not significantly more at risk for adverse fetal outcomes than pregnant women not in crashes. However, pregnant women who did not wear seatbelts during a crash were 1.3 times more likely to have a low birth weight infant than pregnant women not in a crash (95% confidence interval [CI] 1.0, 1.6) and twice as likely to experience excessive maternal bleeding than belted pregnant women in a crash (95% CI 1.0, 4.2). Forty-five of 2645 fetal deaths were linked to a motor vehicle crash, with unbelted pregnant women 2.8 times more likely to experience a fetal death than belted pregnant women in crashes (95% CI 1.4, 5.6). CONCLUSION: Pregnant women should be counseled to wear seatbelts throughout pregnancy and reduce crash risk.     

Placental growth hormone is increased in the maternal and fetal serum of patients with preeclampsia.

OBJECTIVES: Placental growth hormone (PGH) is a pregnancy-specific protein produced by syncytiotrophoblast and extravillous cytotrophoblast. No other cells have been reported to synthesize PGH Maternal. PGH Serum concentration increases with advancing gestational age, while quickly decreasing after delivery of the placenta. The biological properties of PGH include somatogenic, lactogenic, and lipolytic functions. The purpose of this study was to determine whether the maternal serum concentrations of PGH change in women with preeclampsia (PE), women with PE who deliver a small for gestational age neonate (PE + SGA), and those with SGA alone. STUDY DESIGN: This cross-sectional study included maternal serum from normal pregnant women (n = 61), patients with severe PE (n = 48), PE + SGA (n = 30), and SGA alone (n = 41). Fetal cord blood from uncomplicated pregnancies (n = 16) and PE (n = 16) was also analyzed. PGH concentrations were measured by ELISA. Non-parametric statistics were used for analysis. RESULTS: (1) Women with severe PE had a median serum concentration of PGH higher than normal pregnant women (PE: median 23,076 pg/mL (3473-94 256) vs. normal pregnancy: median 12 157 pg/mL (2617-34 016); p < 0.05), pregnant women who delivered an SGA neonate (SGA: median 10 206 pg/mL (1816-34 705); p < 0.05), as well as pregnant patients with PE and SGA (PE + SGA: median 11 027 pg/mL (1232-61 702); p < 0.05). (2) No significant differences were observed in the median maternal serum concentration of PGH among pregnant women with PE and SGA, SGA alone, and normal pregnancy (p > 0.05). (3) Compared to those of the control group, the median umbilical serum concentration of PGH was significantly higher in newborns of preeclamptic women (PE: median 356.1 pg/mL (72.6-20 946), normal pregnancy: median 128.5 pg/mL (21.6-255.9); p < 0.01). (4) PGH was detected in all samples of cord blood. CONCLUSIONS: (1) PE is associated with higher median concentrations of PGH in both the maternal and fetal circulation compared to normal pregnancy. (2) Patients with PE + SGA had lower maternal serum concentrations of PGH than preeclamptic patients without SGA. (3) Contrary to previous findings, PGH was detectable in the fetal circulation. The observations reported herein are novel and suggest that PGH may play a role in the mechanisms of disease in preeclampsia and fetal growth restriction.     

HIV and maternal mortality

The majority of the 17 million women globally that are estimated to be infected with HIV live in Sub-Saharan Africa. Worldwide, HIV-related causes contributed to 19 000–56 000 maternal deaths in 2011 (6%–20% of maternal deaths). HIV-infected pregnant women have two to 10 times the risk of dying during pregnancy and the postpartum period compared with uninfected pregnant women. Many of these deaths can be prevented with the implementation of high-quality obstetric care, prevention and treatment of common co-infections, and treatment of HIV with ART. The paper summarizes what is known about HIV disease progression in pregnancy, specific causes of HIV-related maternal deaths, and the potential impact of treatment with antiretroviral therapy on maternal mortality. Recommendations are proposed for improving maternal health and decreasing maternal mortality among HIV-infected women based on existing evidence.     

Database Autopsy: An Efficient and Effective Confidential Enquiry into Maternal Deaths in Canada

BackgroundMaternal death surveillance in Canada relies on hospitalization data, which lacks information on the underlying cause of death. We developed a method for identifying underlying causes of maternal death, and quantified the frequency of maternal death by cause.MethodsWe used data from the Discharge Abstract Database for fiscal years 2013 to 2017 to identify women who died in Canadian hospitals (excluding Quebec) while pregnant or within 1 year of the end of pregnancy. A sequential narrative based on hospital admission(s) during and after pregnancy was constituted and reviewed to assign the underlying cause of death (based on the World Health Organization's framework). Maternal deaths (i.e., while pregnant or within 42 days after the end of pregnancy) and late maternal deaths (i.e., more than 42 days to a year after the end of pregnancy) were examined separately.ResultsWe identified 85 maternal deaths. Direct obstetric causes included 8 deaths (9%) related to complications of spontaneous or induced abortion; 9 (11%), to hypertensive disorders of pregnancy; 15 (18%), to obstetric hemorrhage; 11 (13%), to pregnancy-related infection; 16 (19%), to other obstetric complications; and <5 (<6%), to complications of management. There were 21 (25%) maternal deaths with indirect obstetric causes, and <5 (<6%) with undetermined causes. Of 120 late maternal deaths, 16 (13%) had direct obstetric causes, among them, 9 deaths by suicide (56%). One hundred late maternal deaths (83%) had indirect obstetric causes; and <5 (<4%) had undetermined causes.ConclusionsThe majority of maternal deaths in Canada have direct obstetric causes, whereas most late maternal deaths have indirect obstetric causes. Suicide is an important direct cause of late maternal death.     

Epidemiology of Pregnancy-associated Venous Thromboembolism: A Population-based Study in Canada

ObjectiveTo estimate the frequency of, and to identify risk factors for, pregnancy-associated venous thromboembolism (VTE), including deep vein thrombosis (DVT) and pulmonary embolism (PE) requiring hospitalization.MethodsWe conducted a population-based cohort study (N = 3 852 569) using the Discharge Abstract Database of the Canadian Institute for Health Information (CIHI), for the fiscal years 1991–1992 to 2005–2006. All women with pregnancy-related hospitalizations in Canada (excluding Quebec and Manitoba) were identified. DVT and PE rates were calculated using the number of hospital deliveries (i.e., cohort of women at risk) as the denominator for the antepartum and peripartum (labour and delivery) hospitalizations and for postpartum readmissions. Risk factors for DVT/PE were identified using logistic regression.ResultsDuring the antepartum, peripartum, and postpartum periods, 5.4, 7.2, and 4.3 VTE cases per 10 000 pregnancies, respectively were observed. The total incidence of DVT was 12.1 per 10 000 pregnancies (0.26 deaths per 100 000), and the rate for PE was 5.4 per 10 000 (0.96 deaths per 100 000). The strongest risk factors for DVT occurrence during the peripartum period were thrombophilia (adjusted odds ratio [aOR] 15.4; 95% CI 10.8–22.0), a past history of circulatory disease, and major puerperal infection, whereas those for PE were previous DVT (aOR 56.9; 95% CI 40.9–79.1), heart disease (aOR 43.4, 95% CI 35.0–53.9), antiphospholipid syndrome, past history of circulatory disease, transfusion, and major puerperal infection.ConclusionCases of VTE and associated deaths occur most frequently during the peripartum period. Although mortality from pregnancy-associated VTE is low, maternal characteristics and other factors can be used to identify women at risk for VTE.     

PREVENTION AND TREATMENT OF VENOUS THROMBOEMBOLISM (VTE) IN OBSTETRICS

OBJECTIVE: to identify risk factors for venous thromboembolism (VTE) in the peripartum period and to provide guidelines for risk assessment and thromboprophylactic measures for VTE in pregnant women. Guidelines for diagnostic testing and for acute and long term treatment of VTE are also provided.OPTIONS: specific subgroups of pregnant women are defined and appropriate prophylactic measures are outlined. OUTCOMES: venous thromboembolism remains a major cause of morbidity and mortality in pregnancy and the postpartum period. Identification of risk and adequate prophylaxis can decrease the incidence of VTE.EVIDENCE: evidence was gathered using Medline (National Library of Medicine) to identify relevant studies and from bibliographies of articles thus identified.RECOMMENDATIONS: although evidence is lacking to date from Grade I studies (properly controlled randomized studies) in pregnant patients, there is good evidence to support the role of prophylaxis in reducing the incidence of VTE in patients identified to be at risk in the non-pregnant population (II B). Based on risk assessment more patients should be considered for thromboprophylaxis, including women with a past history of a VTE and a known thrombophilia on long-term anticoagulation, women with a past history of a VTE, women with a known thrombophilia who have never experienced a VTE and potentially considered in women at the time of Caesarean section (II B; III C). The occurrence of VTE is effectively reduced by the use of low dose unfractionated heparin. Experience with low molecular weight heparin and pregnancy is building, but is limited at present. Unfractionated heparin remains the standard for the treatment of VTE in pregnancy at the present time. Following initial heparinization for the treatment of VTE, patients should be continued on anticoagulation throughout pregnancy and for six to 12 weeks postpartum or a total of three months of anticoagulation (II A).     

Incidence,clinical characteristics,and timing of objectively diagnosed venous thromboembolism during pregnancy

Objective: To determine the incidence, timing, and associated clinical characteristics of objectively diagnosed pregnancy-associated venous thromboembolism (VTE).Methods: A retrospective review of VTE cases occurring between 1978 and 1996 was performed. Cases of deep venous thrombosis (DVT) and pulmonary embolism (PE) were identified by ICD-9 discharge diagnosis code and review of antepartum and coagulation laboratory databases. Study inclusion criteria required the objective diagnosis of VTE with either Doppler ultrasound, impedance plethysmography, pulmonary angiography, ventilation-perfusion scanning, or CT/MRI.Results: Among 268,525 deliveries there were 165 (0.06%) episodes of VTE (1/1627 births). There were 127 cases of DVT and 38 cases of PE. Only 14% (23/165) had a prior history of DVT or PE. Most DVTs occurred in the left leg (104/127, 81.9%). Nearly three quarters of the DVTs (95/127, 74.8%) occurred in the antepartum period. Among the antepartum DVT cases, half were detected prior to 15 weeks of gestation (47/95, 49.5%), with only 28 cases occurring after 20 weeks (P < .0001). The majority of the PEs occurred in the postpartum period (23/38, 60.5%). There were only 3 maternal deaths due to PE, all associated with cesarean section. Only 1 patient developed PE while on heparin therapy for DVT while 11 others had complications attributable to heparin use.Conclusion: Most pregnancy-related VTE occurs in the antepartum period. The risk of deep venous thrombosis appears to begin early in pregnancy, even before the second trimester. The highest risk period for pulmonary embolism is after cesarean delivery. Maternal complications of heparin anticoagulation during pregnancy are rare.     

Causes of maternal death. A 10-year case analysis]

The causes of maternal deaths in our hospital from 1981 to 1989 were analysed. There were 12,819 live births and 6 maternal deaths during this period, a maternal mortality rate of 46.69/per 100,000. The main cause of maternal deaths was acute fatty liver of pregnancy (50%), and next cardiac disease, acute hemorrhagic necrotic pancreatitis and hemorrhage of subarachnoid space (each 16.67%). There was no death due to obstetric hemorrhage, pregnancy induced hypertension syndrome or ectopic pregnancy. It is suggested that needle biopsy of the liver should be done for pregnant women with jaundice of unknown cause. Pregnant women with cardiac disease should be under the care of both obstetrician and internist in collaboration and cesarean section is indicated when the woman's cardiac function remains at grade 3 or 4.     

Thromboprophylaxis during pregnancy and the puerperium: highlights from current guidelines

Venous thromboembolism (VTE) is one of the leading causes of maternal deaths worldwide. Mortality and morbidity of VTE are potentially preventable, since two-thirds of these women have identifiable risk factors and may benefit from appropriate thromboprophylaxis. Individual and careful assessment of the personal and family history as well as the assessment of pre-existing and new-onset/transient risk factors during pregnancy and after delivery are mandatory for an effective prevention of VTE. Current guidelines (American College of Chest Physicians 2008, AWMF-Guideline 003/001 2009 and the Royal College Guideline No. 37 2009) provide practical recommendations for risk stratification regarding low, intermediate and high risk conditions. At high risk are women with previous VTE or thrombophilia. Corresponding to risk stratification grade C recommendations have been made for VTE prophylaxis during pregnancy and the puerperium. Prophylaxis with low molecular weight heparin (LMWH) should begin as early in pregnancy as practical. In women with lower risk mobilisation, avoidance of dehydration and mechanical methods (e. g., graduated compressive stockings) are sufficient. After delivery women with intermediate risk should be given LMWH for 7 days, women at high risk for 6 weeks or as long as additional risk factors are present. All women who have additional risk factors and who have had an elective Caesarean section should receive prophylactic LMWH for 7 days as should also all women who have had a Caesarean section in labour or an emergency Caesarean section. At the onset of labour, in case of any vaginal bleeding, prior to induction of labour or 12 h before an elective Caesarean section, antenatal LMWH prophylaxis should be discontinued, LMWH prophylaxis can be continued for 4-6 h after vaginal and for 6-12 h after Caesarean delivery when the women do not have an increased risk of haemorrhage. Current guidelines recommend than LMWH are the agents of choice for antenatal thromboprophylaxis; in comparison to unfractionated heparin, LMWH are associated with a substantially lower risk of heparin-induced thrombocytopenia and osteoporosis. Both oral anticoagulants and heparin are safe when breast-feeding.     

妊娠合并肺栓塞的诊断与治疗

目的 探讨孕期和产后导致肺栓塞的高危因素,肺栓塞临床表现、诊断和治疗方法。方法 回顾性分析2例妊娠合并肺栓塞的患者的临床资料。结果 第1例患有先天性心脏病,于孕39周临产后,由于心脏负担加重而行剖宫产术。术后10d突发心动过速、呼吸急促、紫绀和呼吸困难而即刻死亡。临床考虑为肺栓塞。第2例患者孕35周双胎,由于严重的围产期心脏病而行剖宫产术,手术中产妇死亡。尸体检查证实为肺栓塞。结论 孕期和产后肺栓塞死亡率极高;心脏病及心脏病史、剖宫产手术是妊娠合并肺栓塞的诱因;临床高度可疑肺栓塞者,应尽早进行全面检查,并进行抗凝、溶栓治疗。     

Risk of venous thrombo-embolic events in pregnant patients with cancer

Objective: Venous thromboembolism (VTE) is one of the leading causes of pregnancy-associated death in the Western world. Cancer is a known risk factor for thrombosis outside of pregnancy. The objective of this study is to evaluate the effect of cancer on the risk of VTE, including deep vein thrombosis (DVT) and pulmonary embolism (PE) in pregnancy.

Methods: We conducted a retrospective population-based cohort study using the Health Care Cost and Utilization Project database from 2003 to 2011. Risk of developing DVT, PE and VTE among pregnant patients with the 10 most prevalent malignancies was measured using unconditional logistic regression analysis.

Results: A total of 2826 women were identified with underlying malignancies, among our study cohort of 7?917?453 women. Risk of VTE was increased among pregnant patients with cervical cancer (OR 8.64, 95% CI (2.15–34.79)), ovarian cancer (OR 10.35, 95% CI (1.44–74.19)), Hodgkin’s disease (OR 7.87, 95% CI (2.94–21.05)) and myeloid leukemia (OR 20.75, 95% CI (6.61–65.12)). There was no increased risk of VTE among women with brain cancer, thyroid cancer, melanoma and lymphoid leukemia.

Conclusion: Many cancers may increase risk of VTE in pregnancy. Appropriate thromboprophylaxis should be considered in some of these women, particularly those with hematological malignancies and gynecologic cancers.