Thrombocytopenia in pregnancy: differential diagnosis, pathogenesis, and management

Human Granulocytic Anaplasmosis During Pregnancy: Case Series and Literature Review

We describe the clinical and laboratory manifestations and pregnancy outcomes of 6 women who received a diagnosis of human granulocytic ehrlichiosis during pregnancy. Human granulocytic ehrlichiosis did not seem to present in a fulminant fashion, and all treated patients had excellent responses to rifampin or doxycycline therapy. Perinatal transmission was documented in 1 neonate, who responded well to treatment. There do not appear to be any long-term adverse sequelae in children born from these pregnancies (mean follow-up duration, 21 months).

The antiphospholipid syndrome as a disorder initiated by inflammation: implications for the therapy of pregnant patients

Arterial thrombosis, venous thrombosis and morbidity during pregnancy, or a combination of these events, are clinical outcomes associated with antiphospholipid antibodies produced by patients with antiphospholipid syndrome (APS). Our understanding of the etiology and pathogenesis of the syndrome is limited, but it has generally been considered a thrombophilic disease and treatment has focused on anticoagulation. Agents such as aspirin and heparin, administered alone or in combination, are empirical treatments that are used in the management of obstetric patients with APS. Clinical features, such as heart valve abnormalities, thrombocytopenia and livedo reticularis, suggest multiple pathogenic mechanisms and provide other therapeutic targets. Findings from research in animal models of APS challenge the dogma that this syndrome is a noninflammatory, thrombotic disease and provide evidence that activation of complement is crucial for complications in pregnancy. These studies, in addition to evidence of inflammatory-mediated tissue damage in placentae of patients with APS, suggest that therapy should also be directed towards preventing inflammation. This Review describes the potential mechanisms of tissue injury by antiphospholipid antibodies, the management of pregnant patients with APS and how heparin therapy might inhibit the pathogenic mediators of disease.

Uteroplacental ischemia results in proteinuric hypertension and elevated sFLT-1

Preeclampsia is a complication of pregnancy with significant morbidity and mortality for the mother and the fetus. Presumptions are made that placental hypoxia has a causative role in the clinical syndrome. Furthermore, soluble fms-like tyrosine kinase 1 (sFLT-1) has been shown to have a role in the maternal syndrome of preeclampsia. We investigated the relationship between uteroplacental ischemia (UPI), the maternal clinical syndrome of preeclampsia and sFLT-1 in non-human primates. The induction of UPI in a pregnant non-human primate resulted in the development of a clinical entity analogous to human preeclampsia. This was illustrated by the increase in blood pressure, development of proteinuria, and renal histological changes identical to human preeclampsia. A significant elevation in the placental and peripheral blood mononuclear cell sFLT-1 mRNA expression was noted, translating to a significant elevation in circulating sFLT-1. Thus, this sequence suggests that a pathogenic reduction in placental perfusion results in the development of the maternal syndrome of preeclampsia and an increase in circulating sFLT-1, which is derived both from placental and extra-placental sources.

Predictors of idiopathic thrombocytopenic purpura in pregnant women presenting with thrombocytopenia

OBJECTIVE

Idiopathic thrombocytopenic purpura (ITP) and gestational thrombocytopenia (GT) are common causes of thrombocytopenia during pregnancy. Despite an ever-increasing experience with these disorders, differentiation between the two entities still remains a diagnostic challenge. The current study attempted to identify the antenatal predictors of ITP for pregnant women.

METHODS

Between January 1999 and June 2005, a total of 58 pregnant women with a presumptive diagnosis of either ITP or GT were recruited for the study. All of them had platelet counts of less than 100 x 10(9)/L. The predictors of ITP were evaluated by comparison between the two disorders.

RESULTS

The detection of thrombocytopenia prior to 28 weeks of gestation and platelet counts <50 x 10(9)/L at its diagnosis remained independently predictive of ITP (P<0.001 and P=0.004, respectively). The combined analysis of these two factors provided a 96.0% sensitivity and a specificity of 75.8%.

CONCLUSION

The onset time of thrombocytopenia and platelet count at its presentation remain the strongest predictors of ITP for pregnant women. The combination model using these factors may be useful for the early prediction of ITP.

Moderate to severe thrombocytopenia during pregnancy

OBJECTIVE

The objective was to investigate obstetric risk factors, complications, and outcomes of pregnancies complicated by moderate to severe thrombocytopenia.

MATERIALS AND METHODS

A retrospective case-control study comparing 199 pregnant women with moderate to severe thrombocytopenia (platelet count below 100x10(9)/l) with 201 pregnant women without thrombocytopenia, who delivered between January 2003 to April 2004. Stratified analysis, using the Mantel-Haenszel procedure was performed in order to control for confounders.

RESULTS

The main causes of thrombocytopenia were gestational thrombocytopenia (GT) (59.3%), immune thrombocytopenic purpura (ITP) (11.05%), preeclampsia (10.05%), and HELLP (Hemolysis, elevated liver enzymes and low platelet count) syndrome (12.06%). Women with thrombocytopenia were significantly older (30.7+/-5.9 versus 28.7+/-5.7; p=0.001) compared with patients without thrombocytopenia, and had higher rates of labor induction (OR=4.0, 95% CI=2.2-7.6, p<0.001) and preterm deliveries (OR=3.5, 95% CI=1.9-6.5, p<0.001). Even after controlling for labor induction, using the Mantel-Haenszel technique, thrombocytopenia was significantly associated with preterm delivery (weighted OR=3.14, 95% CI=1.7-6.0, p<0.001). Higher rates of placental abruption were found in pregnant women with thrombocytopenia (OR=6.2, 95% CI=1.7-33.2, p=0.001). In a comparison of perinatal outcomes, higher rates of Apgar scores <7 at 5 min were noted in infants of mothers with thrombocytopenia (OR=6.3, 95% CI=1.8-33.8, p=0.001), intrauterine growth restriction (IUGR; OR=4.6, 95% CI=1.5-19.1, p=0.003), and stillbirth (65/1000 versus 0 p<0.001). These adverse perinatal outcomes were found in rare causes of thrombocytopenia such as disseminated intravascular coagulation (DIC), familial thrombotic thrombocytopenic purpura (TTP), anti-phospholipid antibodies (APLA) syndrome, and myeloproliferative disease, and not among patients with GT.

CONCLUSIONS

Moderate to severe maternal thrombocytopenia points to a higher degree of severity of the primary disease, which increases perinatal complications. However, the adverse outcome is specifically attributed to preeclampsia, HELLP syndrome, and rare causes, while the perinatal outcome of GT and ITP is basically favorable. Special attention should be given to patients with thrombocytopenia due to preeclampsia, HELLP syndrome, and rarer causes during pregnancy.

Analgésie péridurale obstétricale chez une patiente présentant une macrothrombocytopénie familiale

Epidural analgesia is often considered as risk of epidural haematoma in a patient with thrombocytopenia. In this observation, uncomplicated epidural analgesia was performed in a pregnant woman with hereditary macrothrombocytopenia. She received continuous epidural labour analgesia for a vaginal delivery with a platelet count at 63x10(9)/l but platelets with high mean platelet volume (20fL) and normal function. No neurological sequelae or excessive bleeding occurred.