A high LDH to AST ratio helps to differentiate pregnancy-associated thrombotic thrombocytopenic purpura (TTP) from HELLP syndrome

Investigating gastrointestinal disorders in pregnancy

This article reviews anatomical and physiological changes and alterations in reference intervals for laboratory tests in healthy pregnancy, pertinent to investigation of the gastrointestinal system. The safety of procedures and radiological investigations relevant to the investigation of gastrointestinal disorders in pregnancy are also reviewed.

Pregnancy as a susceptible state for thrombotic microangiopathies

Pregnancy and the postpartum period represent phases of heightened vulnerability to thrombotic microangiopathies (TMAs), as evidenced by distinct patterns of pregnancy-specific TMAs (e.g., preeclampsia, HELLP syndrome), as well as a higher incidence of nonspecific TMAs, such as thrombotic thrombocytopenic purpura or hemolytic uremic syndrome, during pregnancy. Significant strides have been taken in understanding the underlying mechanisms of these disorders in the past 40 years. This progress has involved the identification of pivotal factors contributing to TMAs, such as the complement system, ADAMTS13, and the soluble VEGF receptor Flt1. Regardless of the specific causal factor (which is not generally unique in relation to the usual multifactorial origin of TMAs), the endothelial cell stands as a central player in the pathophysiology of TMAs. Pregnancy has a major impact on the physiology of the endothelium. Besides to the development of placenta and its vascular consequences, pregnancy modifies the characteristics of the women's microvascular endothelium and tends to render it more prone to thrombosis. This review aims to delineate the distinct features of pregnancy-related TMAs and explore the contributing mechanisms that lead to this increased susceptibility, particularly influenced by the "gravid endothelium." Furthermore, we will discuss the potential contribution of histopathological studies in facilitating the etiological diagnosis of pregnancy-related TMAs.

Maternal morbidity and mortality in pregnant/postpartum women with suspected HELLP syndrome identifiable as probable thrombotic thrombocytopenic purpura or atypical hemolytic uremic syndrome by high LDH to AST ratio

OBJECTIVE

To describe findings in 8 women initially diagnosed as presumptive HELLP Syndrome, eventually confirmed as TTP/aHUS as distinguished by elevated calculated LDH:AST ratio > 22:1.

METHODS

All medicolegal files of patients evaluated between 1986 and 2015 with presumptive HELLP syndrome but later determined to have TTP/aHUS had LDH:AST ratios evaluated throughout care.

RESULTS

Fifty-eight pregnant/postpartum women presented with a diagnosis of presumptive HELLP syndrome. In the final analysis, 8 women had TTP/aHUS characterized by severe thrombocytopenia (<20 000/μl) at admission, rare epigastric pain, and the consistent demonstration of a very high calculated total LDH to AST ratio. This calculation greatly exceeded 22:1 with TTP/aHUS (mean = 32:1) versus 2:1 with HELLP and could be consistently demonstrated throughout care. Six of 8 women with TTP/aHUS died.

CONCLUSION

Correctly distinguishing between HELLP syndrome versus an imitator disorder continues to challenge obstetric specialists. This medicolegal data supplements prior findings supporting the concept of the LDH:AST ratio as a useful screening tool for clinicians to differentiate TTP/aHUS apart from HELLP syndrome in order to facilitate earlier hematology consultation, patient referral to tertiary care and emergent hemotherapy for these mothers.

Reference intervals for clinical biochemistry and haematology tests during normal pregnancy

BACKGROUND

Pregnancy induces physiological changes which affect biochemical and haematological parameters. As the significance of laboratory test results change throughout pregnancy, the reference interval (RI) or key result interpretive guide should be specific to pregnancy. This study sought to establish trimester-specific-RIs for routine biochemical and haematological tests in healthy white European women with singleton pregnancies with comparison to RIs for non-pregnant European adults.

METHODS

A retrospective analysis of a prospective longitudinal single-centre study of healthy pregnant women conducted between November 2018 and December 2020 in a tertiary academic hospital with approximately 3000 births annually. Inclusion criteria: signed informed consent, age ≥18 years, white European, body mass index (BMI) <25 kg/m2, blood pressure <140/90mmHg, non-smoker, no previous pathology or gestational diabetes. Trimester defined as T1: up to 13 weeks + 6 days, T2: 14-27 weeks + 6 days and T3: ≥28-41 weeks + 6 days. Baseline demographics, anthropometric and laboratory measurements were recorded. In total, 31 biochemical and 10 haematological ISO15189:2012 accredited tests were measured using Roche Cobas® and Sysmex XN-9100™ analysers, respectively. RIs were established according to the International Federation of Clinical Chemistry (IFCC) recommended method.

RESULTS

Apparently healthy pregnant women (n = 124) with bio-banked serum samples in each trimester were recruited. At the booking visit, 49.2% (n = 61) of participants were nulliparous, with median age of 34.4 (IQR: 31.3-37.3) years, gestational age of 89 (IQR: 84-93) days, BMI of 22.5 (IQR: 21.0-23.7) kg/m² and systolic and diastolic blood pressure of 116 (110-125) mmHg and 67 (61-75) mmHg, respectively.

CONCLUSIONS

Normative trimester-specific biological intervals for routinely requested biochemical and haematological medical laboratory tests were established. These RIs will be invaluable to result interpretation and the management of pregnant women.

Serum LDH values in hypertensive disorders of pregnancy and their association with maternal and neonatal morbidity: A meta-analysis

BACKGROUND

Serum lactate dehydrogenase has been extensively studied in hypertensive disorders of pregnancy. However, to date, its clinical usefulness in the field remains unknown. The present meta-analysis has been designed to evaluate differences in serum LDH values among patients with hypertensive disorders of pregnancy and to help determine its diagnostic accuracy as well its predictive accuracy in determining adverse pregnancy outcomes.

METHODS

We searched Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL and Google Scholar databases from their inception till 18 March 2021. Observational studies that assessed differences in serum LDH levels among women with hypertensive disorders of pregnancy and healthy controls were included. Meta-analysis was performed using Rstudio. Pooled mean differences (MD) were calculated with the Hartung-Knapp-Sidik-Jonkman. Meta-regression analyses, publication bias assessment and Trim and Fill function were also performed. The adequacy of the sample size was evaluated with Trial Sequential Analysis.

RESULTS

Fifty-two articles were included that comprised 5340 women with hypertensive disorders of pregnancy and 2890 healthy controls. The meta-analysis revealed significant differences among patients with preeclampsia (either mild or severe) compared with controls, as well as among patients with mild and severe preeclampsia. Significant asymmetry was noted after examining funnel plots, however, and the trim and fill analysis revealed that differences were significant only among cases with severe preeclampsia and healthy controls. Morbidity outcomes increased with LDH levels >600 IU/L and particularly when these exceeded 800 IU/L. However, confidence and prediction intervals indicated an underpowered sample size for the accurate determination of the odds of developing maternal morbidity.

CONCLUSION

Despite the extensive research in the field of hypertensive disorders of pregnancy, there is still lack of evidence concerning the diagnostic performance of serum LDH in clinical practice; hence, research should expand in this direction to evaluate its clinical utility.

Hemolysis, Elevated Liver Enzymes, and Low Platelet Count Syndrome With Severe Thrombocytopenia and Severe ADAMTS13 Activity Deficiency

BACKGROUND

Differentiating preeclampsia with hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome from thrombotic thrombocytopenic purpura (TTP) can present a diagnostic dilemma.

CASE

We report the case of a 34-year-old woman, G1P0, with monochorionic diamniotic twins who presented with new-onset blurry vision, hypertension, and a platelet count of 4×109/L. After a multidisciplinary discussion, a diagnosis of atypical HELLP syndrome was made, despite overlapping features concerning for TTP. Her platelet count and ADAMTS13 activity testing showed appropriate recovery after delivery, without plasma exchange therapy, supporting the diagnosis of HELLP syndrome.

CONCLUSION

Hemolysis, elevated liver enzymes, and low platelet count syndrome may present with severe thrombocytopenia and severe ADAMTS13 activity deficiency in ranges otherwise known to be more common with TTP.

How I treat thrombotic thrombocytopenic purpura in pregnancy

Thrombotic thrombocytopenic purpura (TTP) is an acute, life-threatening thrombotic microangiopathy (TMA) caused by acquired or congenital severe deficiency of ADAMTS13. Pregnancy is a recognized risk factor for precipitating acute (first or recurrent) episodes of TTP. Differential diagnosis with other TMAs is particularly difficult when the first TTP event occurs during pregnancy; a high index of suspicion and prompt recognition of TTP are essential for achieving a good maternal and fetal outcome. An accurate distinction between congenital and acquired cases of pregnancy-related TTP is mandatory for safe subsequent pregnancy planning. In this article, we summarize the current knowledge on pregnancy-associated TTP and describe how we manage TTP during pregnancy in our clinical practice.

Missing or making the timely diagnosis of acute fatty liver of pregnancy (AFLP): lessons learned

OBJECTIVE

To review the presenting signs, symptoms, laboratory findings, clinical courses, complications, and maternal outcomes in women determined on medicolegal review to have had acute fatty liver of pregnancy (AFLP).

METHODS

We retrospectively studied case files from women with medical and/or hypertensive complications of pregnancy which had been reviewed by the first author, deidentified and divested of legal documents so that only medical-related information was retained for later research and teaching purposes. Main outcomes are 12 lessons learned from this review to be offered for the future benefit of clinicians encountering patients with AFLP.

RESULTS

Eleven women with AFLP were identified within the 161 file database. Signs and symptoms present in 91-100% of women with AFLP were altered sensorium, a fast resting maternal pulse >100/min, gastrointestinal complaints, muscle pain and evidence of fetal compromise/stillbirth. Laboratory findings in 91-100% revealed abnormal liver, renal and coagulation tests, hyperuricemia, and very low serum glucose and albumin. A correct initial diagnosis of AFLP was made for only three women; the most common incorrect presumptive diagnosis was HELLP syndrome. Four women survived. Twelve major findings are discussed.

CONCLUSION

Rapid, timely and thorough evaluation of third trimester women presenting with A (Altered mental status changes/extreme sleepiness), F (Fast resting pulse >100 in the absence of fever or heart causation), L (Liver-related gastrointestinal complaints) and P (Pain as myalgias and body aches), often in association with evidence of fetal compromise or stillbirth, should initiate efforts to investigate a possible diagnosis of AFLP. Adoption of the concepts summarized including core initial laboratory testing, immediate patient transfer to tertiary care, and aggressive correction of consumptive coagulopathy could form the basis of a patient safety bundle to guide future management for patients with AFLP.

The University of Zimbabwe College of Health Sciences (UZ-CHS) BIRTH COHORT study: rationale, design and methods

BACKGROUND

Commencing lifelong antiretroviral therapy (ART) immediately following HIV diagnosis (Option B+), has greatly improved maternal-infant health. Thus, large and increasing numbers of HIV-infected women are on ART during pregnancy, a situation concurrently increasing numbers of HIV-exposed-uninfected (HEU) infants. Compared to their HIV-unexposed-uninfected (HUU) counterparts, HEU infants show higher rates of adverse birth outcomes, mortality, infectious/non-communicable diseases including impaired growth and neurocognitive development. There is an urgent need to understand the impact of HIV and early life ART exposures, immune-metabolic dysregulation, comorbidities and environmental confounders on adverse paediatric outcomes.

METHODS

Six hundred (600) HIV-infected and 600 HIV-uninfected pregnant women ≥20 weeks of gestation will be enrolled from four primary health centres in high density residential areas of Harare. Participants will be followed up as mother-infant-pairs at delivery, week(s) 1, 6, 10, 14, 24, 36, 48, 72 and 96 after birth. Clinical, socio-economic, nutritional and environmental data will be assessed for adverse birth outcomes, impaired growth, immune/neurodevelopment, vertical transmission of HIV, hepatitis-B/C viruses, cytomegalovirus and syphilis. Maternal urine, stool, plasma, cord blood, amniotic fluid, placenta and milk including infant plasma, dried blood spot and stool will be collected at enrolment and follow-up visits. The composite primary endpoint is stillbirth and infant mortality within the first two years of life in HEU versus HUU infants. Maternal mortality in HIV-infected versus -uninfected women is another primary outcome. Secondary endpoints include a range of maternal and infant outcomes. Sub-studies will address maternal stress and malnutrition, maternal-infant latent tuberculosis, Helicobacter pylori infections, immune-metabolomic dysregulation including gut, breast milk and amniotic fluid dysbiosis.

DISCUSSION

The University of Zimbabwe-College of Health-Sciences-Birth-Cohort study will provide a comprehensive assessment of risk factors and biomarkers for HEU infants' adverse outcomes. This will ultimately help developing strategies to mitigate effects of maternal HIV, early-life ART exposures and comorbidities on infants' mortality and morbidity.

TRIAL REGISTRATION

ClinicalTrial.gov Identifier: NCT04087239 . Registered 12 September 2019.

Validation of the PLASMIC score for predicting ADAMTS13 activity <10% in patients with suspected thrombotic thrombocytopenic purpura in Alberta, Canada

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP) is a life-threatening thrombotic microangiopathy (TMA) that requires prompt plasma exchange. Clinical prediction tools may facilitate decision-making in institutions with delayed turnaround time or limited access to ADAMTS13 assays. The PLASMIC score and Bentley score have been shown to predict severe ADAMTS13 deficiency with excellent sensitivity and specificity.

OBJECTIVES

To validate the PLASMIC score using a population of suspected TTP, and evaluate its discriminatory power in predicting severe ADAMTS13 deficiency in comparison with Bentley score and clinical gestalt.

METHODS

Adults presenting with suspected TTP in Alberta, Canada between 2008 and 2018 with available ADAMTS13 results were included. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for PLASMIC score, Bentley score and clinical gestalt. Receiver operator characteristics analysis assessed the performance of the scoring systems.

RESULTS

Among 163 individuals with suspected TTP, ADAMTS13 activity was available in 117 (72%). Severe ADAMTS13 deficiency <10% was present in 62 (53%). High-risk PLASMIC score (≥6) predicted severe ADAMTS13 deficiency with a sensitivity of 81.7%, specificity 71.4%, PPV 75.4% and NPV 78.4% (c-statistic 0.80). Intermediate-high risk Bentley score (≥20) had a lower sensitivity (59.5%) and higher specificity (93.9%) with similar c-statistic (0.77). Clinical gestalt had similar sensitivity as PLASMIC score but very low specificity (16.1%).

CONCLUSIONS

Both PLASMIC and Bentley scores had good discriminatory power in identifying severe ADAMTS13 deficiency in a Canadian TMA population compared to clinical gestalt. Integration into institutional clinical pathways may help supplement clinical judgment and reduce costs.

Combined Immature Platelet Fraction and Schistocyte Count to Differentiate Pregnancy-Associated Thrombotic Thrombocytopenic Purpura from Severe Preeclampsia/Haemolysis, Elevated Liver Enzymes, and Low Platelet Syndrome (SPE/HELLP)

The occurrence of thrombotic microangiopathy (TMA) in pregnancy is an unfortunate emergency condition. Proper diagnosis is mandatory which requires the consideration of two overlapping diagnoses: severe preeclampsia/haemolysis, elevated liver enzymes, and low platelet syndrome (SPE/HELLP) and thrombotic thrombocytopenic purpura (TTP). The long turn-around times of ADAMTS13 testing precludes the timely distinction between the two conditions. We aimed at evaluating schistocyte counts and immature platelet fraction (IPF%), as both increase in TMAs, to discriminate between TTP and SPE/HELLP of pregnancy. IPF% was measured using Sysmex XE-2100 automated hematology analyzer, and schistocyte counts were estimated microscopically as per the International Council for Standardization in Hematology-Schistocyte Working Group guidelines. The study included 30 pregnant patients with SPE/HELLP, 13 pregnant patients with TTP, and 30 women with normal pregnancy. The discrimination between the two patient categories was based on clinical judgment and TTP cases were identified using the PLASMIC score. TTP patients had higher values of IPF% than SPE/HELLP [19.5% (16.9-27.1) vs 13% (9.5-23.25); p < 0.001]; similar results were revealed regarding schistocyte counts [6.5% (3.9-8.6) vs 2.1% (1.6-3.5); p < 0.001]. IPF% and schistocyte counts were able to discriminate between TMA patients and normal pregnant women, and between and SPE/HELLP and TTP patients. Moreover, the discriminatory function of each was improved when the two parameters were used in combination. IPF% analysis should be used in conjunction with manual schistocyte counting in TMA cases to distinguish TTP pregnant patients from patients having SPE/HELLP.

Changes in biochemical tests in pregnancy and their clinical significance

Interpretation of laboratory investigations relies on reference intervals. Physiological changes in pregnancy may result in significant changes in normal values for many biochemical assays, and as such results may be misinterpreted as abnormal or mask a pathological state. The aims of this review are as follows: 1. To review the major physiological changes in biochemical tests in normal pregnancy. 2. To outline where these physiological changes are important in interpreting laboratory investigations in pregnancy. 3. To document the most common causes of abnormalities in biochemical tests in pregnancy, as well as important pregnancy-specific causes.

Evaluation of Hemolysis as a Severe Feature of Preeclampsia

Hemolysis predisposes to adverse pregnancy outcomes. Yet, there are limited data on hemolysis in hypertensive disorders of pregnancy other than hemolysis, elevated liver enzymes, and low platelet count syndrome. To evaluate the prevalence and impact of hemolysis in hypertensive disorders of pregnancy, we performed a retrospective cohort study at a single center (October 2013-May 2017), among women screened for hemolysis using lactate dehydrogenase (LDH) levels. We compared LDH levels by hypertensive disorder (chronic hypertension, gestational hypertension, preeclampsia, and preeclampsia with severe features) and evaluated impact on adverse pregnancy outcomes. Data were analyzed by χ² or t test, ANOVA, test of medians, and logistic regression. Among 8645 deliveries, 1188 (13.7%) had a hypertensive disorder. Of these, 812 (68.4%) had LDH measurement before delivery: chronic hypertension (n=152); gestational hypertension (n=209); preeclampsia (n=216); and preeclampsia with severe features (n=235). LDH ≥400 U/L (≥1.6× normal) was more common in preeclampsia with severe features compared with other hypertensive disorders of pregnancy (9.8% versus 2.3%; P<0.001); adjusted odds ratio 4.52 (95% confidence interval, 2.2-9.2; P<0.001). LDH ≥400 U/L was associated with adverse maternal outcomes (41.7% versus 15.3%; P<0.001), adjusted odds ratio 3.05 (95% confidence interval, 1.4-6.7; P=0.006), and adverse neonatal outcomes (eg, preterm birth 59.4% versus 22.5%; P<0.001). We find that elevated LDH levels are associated with adverse maternal and neonatal outcomes in hypertension and preeclampsia, independent of hemolysis, elevated liver enzymes, and low platelet count syndrome. Therefore, elevated LDH levels (≥1.6× normal or ≥400 U/L) may be considered a severe feature of preeclampsia.

Review article: Investigations and the pregnant woman in the emergency department - part 1: Laboratory investigations

Accurate assessment of the pregnant patient in the ED depends on knowledge of physiological changes in pregnancy, and how these changes may impact on pathology tests, appearance on point-of-care ultrasound and electrocardiography. In addition the emergency physician needs to be cognisant of disorders that are unique to or more common in pregnancy. Part 1 of this review addresses potential deviations in laboratory investigation reference intervals resulting from physiological alterations in pregnancy, and the important causes of abnormal laboratory results in pregnancy. Part 2 will address the role of point-of-care ultrasound in pregnancy, physiological changes that may affect interpretation of point-of-care ultrasound, physiological changes in electrocardiography, and the safety of radiological procedures in the pregnant patient.

Thrombotic microangiopathies of pregnancy: Differential diagnosis

Thrombotic microangiopathy (TMA) disorders are characterized by microangiopathic hemolytic anemia, thrombocytopenia and end-organ injury. In pregnancy and postpartum, TMA is most commonly encountered with HELLP (hemolysis, elevated liver enzymes, low platelet count syndrome) or preeclampsia with severe features, but rarely TMA is due to thrombotic thrombocytopenic purpura (TTP) or atypical hemolytic uremic syndrome (aHUS). Due to overlapping clinical and laboratory features, TTP and aHUS are often mistaken for preeclampsia or HELLP. Unfortunately, delays in appropriate diagnosis and treatment may be life-threatening. Our objective is to alert obstetrician-gynecologists, certified nurse midwives, family medicine providers, and subspecialty consultants, to the range of TMA disorders that may occur in and around pregnancy. To do this, we have provided a review of individual disorders that comprise the differential diagnosis of pregnancy TMA, and we have proposed a systematic approach to make an accurate diagnosis with readily available clinical and laboratory data. In complex or critical cases, we recommend a multidisciplinary team approach (e.g., Critical Care, Hematology, Maternal Fetal Medicine, Nephrology) to expedite diagnosis and treatment, which may be life-saving.

Microangiopathies in pregnancy

Thrombotic thrombocytopenic purpura (TTP) is a potentially reversible, life-threatening medical emergency. We present a case of a 21-year-old female with evidence of haemolytic anaemia based on the presence of positive markers of haemolysis. Negative Coomb's test, thrombocytopenia and placental infarcts raised suspicion for a thrombotic microangiopathy. She was diagnosed with TTP and managed with emergency plasma exchange. Her recovery was immediate.A presumptive diagnosis of TTP should be based on the presence of microangiopathic haemolytic anaemia with thrombocytopenia and plasma exchange should be initiated while complete work up is pending. Using the regular pentad solely for diagnosis of TTP will lead to underdiagnosis of many cases and should be avoided.Several microangiopathies can be seen during pregnancy including TTP/atypical haemolytic uraemic syndrome, HELLP syndrome, pre-eclampsia, disseminated intravascular coagulopathy and antiphospholipid antibody syndrome. Distinction between each type will be the focus of our discussion as treatment decisions differ accordingly.

Microangiopathic hemolytic anemia in pregnancy

Microangipathic hemolytic anemia (MAHA) is a serious diagnosis and difficult to manage in pregnant patients as multiple life threatening conditions could present with MAHA. ADAMTS13 enzyme activity can be affected during pregnancy with multiple factors. A persistent extremely low ADAMTS13 enzyme activity levels, without an inhibitor, after the delivery was an important factor to establish the diagnosis. We present a case of likely congenital ADAMST13 deficiency that manifested for the first time in a pregnant woman at week 37 of pregnancy.

The Differential Diagnosis of Thrombocytopenia in Pregnancy

BACKGROUND

Thrombocytopenia is, after anemia, the second most common abnormality of the complete blood count in pregnancy, with a reported frequency of 6.6% to 11.2%. It has many causes. Thrombocytopenia should be diagnostically evaluated as early as possible in pregnancy, so that the obstetrical management can be accordingly planned to minimize harm to the mother and child. As the various underlying diseases share clinical features and laboratory findings, the differential diagnosis is often a difficult interdisciplinary challenge.

METHODS

In this article, we review pertinent literature (2000-January 2015) retrieved by a selective search in PubMed.

RESULTS

Gestational thrombocytopenia is the most common type, accounting for 75% of cases, followed by severe pre-eclampsia/HELLP syndrome (hemolysis, elevated liver enzymes, low platelet count) in 15-22% and autoimmune thrombocytopenia (ITP) in 1-4%. Gestational thrombocytopenia and ITP differ in the bleeding history, the severity of thrombocytopenia, the frequency of neo - natal thrombocytopenia, and the rate of normalization of the platelet count after delivery. The HELLP syndrome and rarer microangiopathic hemolytic anemias (e.g., thrombotic thrombocytopenic purpura) can be differentiated on the basis of their main clinical features, such as hypertension/proteinuria and upper abdominal pain, the severity of hemolysis and thrombocytopenia, the degree of transaminase elevation, and the rapidity of postpartum remission of the clinical and laboratory findings. A stepwise diagnostic procedure should be followed to distinguish further causes, e.g., to differentiate thrombocytopenia due to infection, autoimmune disease, or drugs from thrombocytopenia due to a rare hereditary disease.

CONCLUSION

The early interdisciplinary evaluation of thrombocytopenia in pregnancy is a prerequisite for the optimal care of the mother and child. The development of evidence-based recommendations for interdisciplinary management should be a goal for the near future.

Incidence of obstetrical thrombotic thrombocytopenic purpura in a retrospective study within thrombocytopenic pregnant women. A difficult diagnosis and a treatable disease

Background

Thrombotic thrombocytopenic Purpura (TTP) defined as ADAMTS-13 (A Disintegrin And Metalloprotease with ThromboSpondin type 1 domain 13) activity <10 % is a rare aetiology of thrombocytopenia during pregnancy, although the precise incidence is unknown. During pregnancy, the diagnosis of TTP is crucial as it has high feto-maternal morbidity-mortality and requires urgent plasma exchange. The purpose of this study was to assess the incidence of TTP retrospectively and to describe case presentations and follow-up.

Methods

A monocentric retrospective study (2008–2009) was conducted among pregnant women followed in a tertiary care obstetrical unit who experienced at least one episode of severe thrombocytopenia (platelets ≤75 G/L) during 2008 and 2009. In cases of uncertain aetiology of thrombocytopenia, ADAMTS-13 activity was assessed by the full length technique.

Results

Among 8,908 deliveries over the 2 year period, 79 women had a platelet count nadir ≤75 G/L. Eighteen had a known aetiology of thrombocytopenia and 11 were lost to follow-up. Among 50 remaining patients, ADAMTS-13 activity was undetectable (<5 %) in 4, consistent with the diagnosis of TTP. Platelet count spontaneously normalized in 3 patients after delivery. None presented focal cerebral involvement. Three of the four, who were primipara patients, had a sustained severe deficiency in the absence of anti-ADAMTS-13 antibodies, and ADAMTS-13 gene sequencing indicated a constitutive deficiency. The fourth, a multipara patient, had an acquired, auto-immune TTP. Placental pathology in the three primipara patients showed severe and non-specific ischemic lesions. Two patients lost their babies shortly after birth. In subsequent pregnancies in these two patients, prophylactic plasma infusion initiated early with increasing volume throughout pregnancy prevented TTP relapse, improved placental pathology, and led to normal delivery.

Conclusions

The prevalence of TTP among thrombocytopenic pregnant women is high, up to 5 % in a tertiary unit. Platelet count normalization after delivery does not eliminate TTP. Clinicians should be aware of TTP during pregnancy, and, even if assessed retrospectively, ADAMTS-13 assessment is of particular importance for identifying patients with congenital TTP. In these patients, preventive plasma infusion and/or exchange can dramatically improve foetal prognosis, resulting in successful childbirth.

Differentiation between severe HELLP syndrome and thrombotic microangiopathy, thrombotic thrombocytopenic purpura and other imitators

Pre-eclampsia complicated by severe HELLP (hemolysis, elevated liver enzymes and low platelet count) syndrome is a multi-organ disease, and can be difficult to differentiate from thrombotic microangiopathy (appearing as thrombotic thrombocytopenic purpura or hemolytic uremic syndrome), acute fatty liver, systemic erythematous lupus, antiphospholipid syndrome and severe sepsis. Many papers have highlighted the risks of misdiagnosis resulting in severe consequences for maternal health, and this can be fatal when thrombotic thrombocytopenic purpura is misdiagnosed as severe HELLP syndrome. The aim of this paper is to propose relevant markers to differentiate pre-eclampsia complicated by severe HELLP syndrome from its imitators, even in the worrying situation of apparently indistinguishable conditions, and thereby assist clinical decision-making regarding whether or not to commence plasma exchange. Relevant identifiers to establish the most accurate diagnosis include the frequency of each disease and anamnestic data. Frank hemolysis, need for dialysis, neurological involvement and absence of disseminated intravascular coagulation are indicative of thrombotic microangiopathy. The definitive marker for thrombotic thrombocytopenic purpura is undetectable ADAMTS 13 activity.

Triad of Idiopathic Thrombocytopenic Purpura, Preeclampsia, and HELLP Syndrome in a Parturient: A Rare Confrontation to the Anesthetist

Idiopathic thrombocytopenic purpura (ITP) with HELLP represents a rare complication that requires combined care of obstetrician, anesthesiologist, hematologist, and neonatologist. At 37-week gestation a 35-year-old parturient (G2A1P0) a known case of chronic ITP presented with severe pregnancy induced hypertension (PIH), thrombocytopenia, and elevated liver enzymes. We describe successful anesthetic management of this patient who was taken for emergency caesarean section.

Anterior Ischemic Optic Neuropathy as a Manifestation of HELLP Syndrome

Thrombotic microangiopathies (TMAs) are a group of disorders characterized by occurrence of thrombi of fibrin and/or platelets with microvascular occlusion and organ ischemia especially the kidney and brain. Hemolysis with a microangiopathic blood smear, elevated liver enzymes, and low platelet count (HELLP syndrome) is a type of TMA peculiar to pregnancy and may be associated with neurological complications. Visual complications in HELLP are usually related to cortical blindness. We present the first case of HELLP associated with bilateral anterior ischemic optic neuropathy (AION) and blindness which resolved with plasma exchange.

Role of lectin-like oxidized low density lipoprotein-1 in fetoplacental vascular dysfunction in preeclampsia

The bioavailability of nitric oxide (NO) represents a key marker in vascular health. A decrease in NO induces a pathological condition denominated endothelial dysfunction, syndrome observed in different pathologies, such as obesity, diabetes, kidney disease, cardiovascular disease, and preeclampsia (PE). PE is one of the major risks for maternal death and fetal loss. Recent studies suggest that the placenta of pregnant women with PE express high levels of lectin-like oxidized LDL receptor-1 (LOX-1), which induces endothelial dysfunction by increasing reactive oxygen species (ROS) and decreasing intracellular NO. Besides LOX-1 activation induces changes in migration and apoptosis of syncytiotrophoblast cells. However, the role of this receptor in placental tissue is still unknown. In this review we will describes the physiological roles of LOX-1 in normal placenta development and the potential involvement of this receptor in the pathophysiology of PE.

Hematologic complications of pregnancy

Pregnancy induces a number of physiologic changes that affect the hematologic indices, either directly or indirectly. Recognizing and treating hematologic disorders that occur during pregnancy is difficult owing to the paucity of evidence available to guide consultants. This review discusses specifically the diagnosis and management of benign hematologic disorders occurring during pregnancy. Anemia secondary to iron deficiency is the most frequent hematologic complication and is easily treated with oral iron formulations; however, care must be taken not to miss other causes of anemia, such as sickle cell disease. Thrombocytopenia is also a common reason for consulting the hematologist, and distinguishing gestational thrombocytopenia from immune thrombocytopenia (ITP), preeclampsia, HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets), or thrombotic thrombocytopenic purpura (TTP) is essential since the treatment differs widely. Occasionally the management of mother and infant involves the expeditious recognition of neonatal alloimmune thrombocytopenia (NAIT), a condition that is responsible for severe life-threatening bleeding of the newborn. Additionally, inherited and acquired bleeding disorders affect pregnant women disproportionately and often require careful monitoring of coagulation parameters to prevent bleeding in the puerperium. Finally, venous thromboembolism (VTE) during pregnancy is still largely responsible for mortality during pregnancy, and the diagnosis, treatment options and guidelines for prevention of VTE during pregnancy are explored.

Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy

OBJECTIVE

This guideline summarizes the quality of the evidence to date and provides a reasonable approach to the diagnosis, evaluation and treatment of the hypertensive disorders of pregnancy (HDP).

EVIDENCE

The literature reviewed included the previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines from 2008 and their reference lists, and an update from 2006. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT) and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2006 and March 2012. Articles were restricted to those published in French or English. Recommendations were evaluated using the criteria of the Canadian Task Force on Preventive Health Care and GRADE.