Vaginal delivery for fetuses at risk of alloimmune thrombocytopenia?

Fetal and neonatal alloimmune thrombocytopenia: A rare case report of prenatal treatment

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare but serious condition. The first-line antenatal management of FNAIT consists of weekly IVIG with or without corticosteroids, ideally starting before 16 weeks of gestation.

Fetal neonatal alloimmune thrombocytopenia treatment with intravenous immunoglobulin: a challenge in pregnancy management and infection assessment ‒ case report

Objectives

Fetal and neonatal alloimmune thrombocytopenia is a rare condition associated with fetal and neonatal morbimortality. Prevention of recurrence includes intravenous immunoglobulin. One challenge in pregnancy surveillance remains the fact that maternal intravenous immunoglobulins therapy can result in false-positive infectious markers. The goal of this case report is to highlight the possible serological misdiagnosed infection associated with intravenous immunoglobulins therapy in pregnancy, and the difficulty of management in this time of a women’s life.

Case presentation

We report a case of a 38-year-old pregnant woman, with a previous affected child with fetal neonatal alloimmune thrombocytopenia. To prevent recurrence, intravenous immunoglobulin treatment was administered in early second trimester. In the second trimester routine analysis, a positive anti-treponemal test and a toxoplasmosis seroconversion occurred. Infection suspicion based on test positivity of some infectious agents, after passive acquired antibodies, can lead to anxiety and subsequent unnecessary treatment.

Conclusions

Clinicians and pathologists must be aware of the possible acquisition of these antibodies during treatment and be able to counsel patients receiving intravenous immunoglobulin. Managing possible infectious intercurrences in pregnancy remains a challenge.

Fetale und neonatale Alloimmunthrombozytopenie, Teil 2

Die fetale und neonatale Alloimmunthrombozytopenie (FNAIT) wird durch mütterliche Antikörper hervorgerufen, die gegen ein vom Vater ererbtes Blutgruppenmerkmal an fetalen Thrombozyten gerichtet sind. Während Teil 1 des Beitrags Ausgabe die Ätiologie, die Pathogenese und die Diagnostik der FNAIT thematisiert hatte, widmet sich dieser 2. Teil der Risikostratifizierung und Behandlung 1.

Non-invasive risk-assessment and bleeding prophylaxis with IVIG in pregnant women with a history of fetal and neonatal alloimmune thrombocytopenia: management to minimize adverse events

INTRODUCTION

In pregnant women with a history of fetal and neonatal alloimmune thrombocytopenia (FNAIT), prenatal intervention in subsequent pregnancies may be required to prevent fetal bleeding. Several invasive and non-invasive protocols have been published: amniocentesis for fetal genotyping, fetal blood sampling for the determination of fetal platelet count, intrauterine platelet transfusions, and weekly maternal i.v. immunoglobulin (IVIG) infusion with or without additional corticosteroid therapy. This is the first retrospective study that report the experience with a non-invasive protocol focused on side effects of maternal IVIG treatment and neonatal outcome.

METHODS

Pregnant women with proven FNAIT in history and an antigen positive fetus were treated with IVIG (1 g/kg/bw) every week. To identify potential IVIG-related hemolytic reactions isoagglutinin titer of each IVIG lot and maternal blood count were controlled. IVIG-related side effects were prospectively documented and evaluated. Furthermore, ultrasound examination of the fetus was performed before starting IVIG administration and continued regularly during treatment. Outcome of the index and subsequent pregnancy was compared. Corresponding data of the newborns were analyzed simultaneously.

RESULTS

IVIG was started at 20 weeks of gestation (median). Compared to the index pregnancy, platelet counts of the newborns were higher in all cases. No intracranial hemorrhage occurred (Index pregnancies: 1 case). Platelet counts were 187 × 10⁹/l (median, range 22-239, 95% CI) and one newborn had mild bleeding. No severe hemolytic reaction was observed and side effects were moderate.

CONCLUSION

Among pregnant women with FNAIT history, the use of non-invasive fetal risk determination and maternal IVIG resulted in favorite outcome of all newborns. Invasive diagnostic or therapeutic procedures in women with a history of FNAIT should be abandoned.

Epidemiology and management of fetal and neonatal alloimmune thrombocytopenia

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a disease in pregnancy characterized by maternal alloantibodies directed against the human platelet antigen (HPA). These antibodies can cause intracranial hemorrhage (ICH) or other major bleeding resulting in lifelong handicaps or death. Optimal fetal care can be provided by timely identification of pregnancies at risk. However, this can only be done by routinely antenatal screening. Whether nationwide screening is cost-effective is still being debated. HPA-1a alloantibodies are estimated to be found in 1 in 400 pregnancies resulting in severe burden and fetal ICH in 1 in 10.000 pregnancies. Antenatal treatment is focused on the prevention of fetal ICH and consists of weekly maternal IVIg administration. In high-risk FNAIT treatment should be initiated at 12-18 weeks gestational age using high dosage and in standard-risk FNAIT at 20-28 weeks gestational age using a lower dosage. Postnatal prophylactic platelet transfusions are often given in case of severe thrombocytopenia to prevent bleedings. The optimal threshold and product for postnatal transfusion is not known and international consensus is lacking. In this review practical guidelines for antenatal and postnatal management are offered to clinicians that face the challenge of reducing the risk of bleeding in fetuses and infants affected by FNAIT.

Fetal and neonatal alloimmune thrombocytopenia: recommendations for evidence-based practice, an international approach

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) may result in severe bleeding, particularly fetal and neonatal intracranial haemorrhage (ICH). As a result, FNAIT requires prompt identification and treatment; subsequent pregnancies need close surveillance and management. An international panel convened to develop evidence-based recommendations for diagnosis and management of FNAIT. A rigorous approach was used to search, review and develop recommendations from published data for: antenatal management, postnatal management, diagnostic testing and universal screening. To confirm FNAIT, fetal human platelet antigen (HPA) typing, using non-invasive methods if quality-assured, should be performed during pregnancy when the father is unknown, unavailable for testing or heterozygous for the implicated antigen. Women with a previous child with an ICH related to FNAIT should be offered intravenous immunoglobulin (IVIG) infusions during subsequent affected pregnancies as early as 12 weeks gestation. Ideally, HPA-selected platelets should be available at delivery for potentially affected infants and used to increase the neonatal platelet count as needed. If HPA-selected platelets are not immediately available, unselected platelets should be transfused. FNAIT studies that optimize antenatal and postnatal management, develop risk stratification algorithms to guide management and standardize laboratory testing to identify high risk pregnancies are needed.

Foetal and neonatal alloimmune thrombocytopenia

Foetal or neonatal thrombocytopenia results from alloimmunisation during pregnancy. Maternal alloantibodies can be formed following exposure to paternally derived human platelet antigens (HPAs) on foetal platelets, in case of incompatible HPA type. These alloantibodies are of the immunoglobulin G subclass and can therefore enter the foetal circulation through active placental transport mediated by the neonatal Fc-receptor. After entering the foetal circulation, these alloantibodies can cause destruction of foetal platelets and potentially damage other foetal cells containing the specific antigen. Subsequent clinical presentation in foetuses or neonates can vary widely, from an asymptomatic thrombocytopenia to a broad spectrum of bleeding complications. Most frequently encountered are minor skin haemorrhages, such as hematomas or petechiae, but also more devastating haemorrhages can occur. Of these, an intracranial haemorrhage is the most feared complication because of its high risk of life-long major neurological handicaps or perinatal death.

Fetal and neonatal alloimmune thrombocytopenia: evidence based antenatal and postnatal management strategies

INTRODUCTION

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a relatively rare but potentially lethal disease, leading to severe bleeding complications in 1 in 11.000 newborns. It is the leading cause of thrombocytopenia in healthy term-born neonates. Areas covered: This review summarizes the antenatal as well as postnatal treatment, thus creating a complete overview of all possible management strategies for FNAIT. Expert commentary: The optimal antenatal therapy in order to prevent bleeding complications in pregnancies complicated by FNAIT is non-invasive treatment with weekly intravenous immunoglobulin (IVIG). Based on risk stratification, weekly doses of IVIG of 0.5 or 1.0g/kg should be administered started early in the second in high risk cases or at the end of the second trimester in low risk cases. The optimal postnatal treatment depends on the platelet count and the clinical condition of the newborn. Prompt administration of compatible platelet transfusion is the first treatment of choice in case of severe thrombocytopenia or active bleeding. In case matched platelets are not directly available, random platelets can also be administered initially to gain time until matched platelets are available. In case of persistent thrombocytopenia despite transfusions, IVIG 1.0-2.0g/kg can be administered.

Current perspectives on fetal and neonatal alloimmune thrombocytopenia - increasing clinical concerns and new treatment opportunities

Differences in platelet type between the fetus and the mother can lead to maternal immunization and destruction of the fetal platelets, a condition named fetal and neonatal alloimmune thrombocytopenia (FNAIT). FNAIT is reported to occur in ~1 per 1,000 live born neonates. The major risk is intracranial hemorrhage in the fetus or newborn, which is associated with severe neurological complications or death. Since no countries have yet implemented a screening program to detect pregnancies at risk, the diagnosis is typically established after the birth of a child with symptoms. Reports on broader clinical impact have increased clinical concern and awareness. Along with new treatment options for FNAIT, the debate around antenatal screening to detect pregnancies at risk of FNAIT has been revitalized.

Neonatal thrombocytopenia: etiology, management and outcome

Thrombocytopenia is a very common hematological abnormality found in newborns, especially in preterm neonates. Two subgroups can be distinguished: early thrombocytopenia, occurring within the first 72 hours of life, and late thrombocytopenia, occurring after the first 72 hours of life. Early thrombocytopenia is associated with intrauterine growth restriction, whereas late thrombocytopenia is caused mainly by sepsis and necrotizing enterocolitis (NEC). Platelet transfusions are the hallmark of the treatment of neonatal thrombocytopenia. Most of these transfusions are prophylactic, which means they are given in the absence of bleeding. However, the efficacy of these transfusions in preventing bleeding has never been proven. In addition, risks of platelet transfusion seem to be more pronounced in preterm neonates. Because of lack of data, platelet transfusion guidelines differ widely between countries. This review summarizes the current understanding of etiology and management of neonatal thrombocytopenia.

Diagnosis and management of neonatal alloimmune thrombocytopenia in pregnancy

Neonatal alloimmune thrombocytopenia (NAIT) is the most common cause of severe thrombocytopenia in the healthy newborn, occurring in 1 in 1000 live births. NAIT is analogous to rhesus alloimmunization in pathophysiology; however, it often presents unexpectedly in first pregnancies. Presentation of NAIT varies from mild thrombocytopenia to life-threatening intracranial hemorrhage. It has been observed to be more severe in subsequent affected pregnancies. It is important that the diagnosis of NAIT be considered in the work-up of all cases of neonatal thrombocytopenia to determine the risk to future pregnancies and corresponding management plans. This article discusses the pathogenesis and incidence of NAIT and the antenatal and postnatal management of this condition.

Fetal intracranial haemorrhages caused by fetal and neonatal alloimmune thrombocytopenia: an observational cohort study of 43 cases from an international multicentre registry

OBJECTIVE

To characterise pregnancies where the fetus or neonate was diagnosed with fetal and neonatal alloimmune thrombocytopenia (FNAIT) and suffered from intracranial haemorrhage (ICH), with special focus on time of bleeding onset.

DESIGN

Observational cohort study of all recorded cases of ICH caused by FNAIT from the international No IntraCranial Haemorrhage (NOICH) registry during the period 2001-2010.

SETTING

13 tertiary referral centres from nine countries across the world.

PARTICIPANTS

37 mothers and 43 children of FNAIT pregnancies complicated by fetal or neonatal ICH identified from the NOICH registry was included if FNAIT diagnosis and ICH was confirmed.

PRIMARY AND SECONDARY OUTCOME MEASURES

Gestational age at onset of ICH, type of ICH and clinical outcome of ICH were the primary outcome measures. General maternal and neonatal characteristics of pregnancies complicated by fetal/neonatal ICH were secondary outcome measures.

RESULTS

From a total of 592 FNAIT cases in the registry, 43 confirmed cases of ICH due to FNAIT were included in the study. The majority of bleedings (23/43, 54%) occurred before 28 gestational weeks and often affected the first born child (27/43, 63%). One-third (35%) of the children died within 4 days after delivery. 23 (53%) children survived with severe neurological disabilities and only 5 (12%) were alive and well at time of discharge. Antenatal treatment was not given in most (91%) cases of fetal/neonatal ICH.

CONCLUSIONS

ICH caused by FNAIT often occurs during second trimester and the clinical outcome is poor. In order to prevent ICH caused by FNAIT, at-risk pregnancies must be identified and prevention and/or interventions should start early in the second trimester.

A review of the contemporary management of fetal and neonatal alloimmune thrombocytopenia in an Australian tertiary obstetric hospital

BACKGROUND

Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is the most common cause of severe perinatal thrombocytopenia, arising from the transplacental passage of maternal antibodies directed at paternally inherited antigens on fetal platelets.

AIM

To review the occurrence, management and perinatal outcomes of pregnancies complicated by FNAIT from a single tertiary obstetric hospital in Western Australia.

MATERIALS AND METHODS

The study was conducted as a retrospective review of cases with prenatally recognised FNAIT between 2001 and 2011, with the treatment modalities and outcomes analysed.

RESULTS

Over the 10-year period, 20 cases of clinically significant FNAIT in 13 women were managed at our centre. Three cases were complicated by antenatal intracranial haemorrhage (15%), and in all 3, this was the presenting feature leading to diagnosis. In 17/20 (85%) cases, anti-HPA 1a was the responsible antibody, with the remainder being anti-HPA 5b. In 16/17 cases with pre-pregnancy recognition, intravenous gammaglobulin (IVGG) was administered antenatally (gestation at commencement ranging from 13 to 26 weeks) with adjuvant prednisolone in three cases. Postnatal treatment (IVGG or platelet transfusion) was provided in 4/16 cases. There was no intracranial haemorrhage or demise in any case receiving prenatal therapy.

CONCLUSIONS

FNAIT is a rare and serious condition. In our small single-centre study, there was variability in the therapeutic strategies, although IVGG was central to all prenatally managed pregnancies. None of the treated pregnancies was complicated by intracranial haemorrhage or fetal death. There is a need for ongoing refinement of FNAIT management protocols, both in the prenatal and in the postnatal period.

Antenatal interventions for fetomaternal alloimmune thrombocytopenia

BACKGROUND

Fetomaternal alloimmune thrombocytopenia results from the formation of antibodies by the mother which are directed against a fetal platelet alloantigen inherited from the father. The resulting fetal thrombocytopenia (reduced platelet numbers) may cause bleeding, particularly into the brain, before or shortly after birth. Antenatal treatment of fetomaternal alloimmune thrombocytopenia includes the administration of intravenous immunoglobulin (IVIG) and/or corticosteroids to the mother to prevent severe fetal thrombocytopenia. IVIG and corticosteroids both have short-term and possibly long-term side effects. IVIG is also costly and optimal regimens need to be identified.

OBJECTIVES

To determine the optimal antenatal treatment of fetomaternal alloimmune thrombocytopenia to prevent fetal and neonatal haemorrhage and death.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (28 February 2011) and bibliographies of relevant publications and review articles.

SELECTION CRITERIA

Randomised controlled studies comparing any intervention with no treatment, or comparing any two interventions.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility, trial quality and extracted data.

MAIN RESULTS

We included four trials involving 206 people. One trial involving 39 people compared a corticosteroid (prednisone) versus IVIG alone. In this trial, where analysable data were available, there was no statistically significant differences between the treatment arms for predefined outcomes. Three trials involving 167 people compared IVIG plus a corticosteroid (prednisone in two trials and dexamethasone in one trial) versus IVIG alone. In these trials there was no statistically significant difference in the findings between the treatment arms for predefined outcomes (intracranial haemorrhage; platelet count at birth and preterm birth). Lack of complete data sets and important differences in interventions precluded the pooling of data from these trials.

AUTHORS' CONCLUSIONS

The optimal management of fetomaternal alloimmune thrombocytopenia remains unclear. Lack of complete data sets for two trials and differences in interventions precluded the pooling of data from these trials which may have enabled a more developed analysis of the trial findings. Further trials would be required to determine optimal treatment (the specific medication and its dose and schedule). Such studies should include long-term follow up of all children and mothers.

A review of pathophysiology and current treatment for neonatal alloimmune thrombocytopenia (NAIT) and introducing the Australian NAIT registry

Fetomaternal or neonatal alloimmune thrombocytopenia (NAIT) is a rare but serious condition associated with significant fetal and neonatal morbidity and mortality. The most useful predictor of severe disease is a history of a sibling with an antenatal intracranial haemorrhage. However, NAIT can occur during the first pregnancy and may not be diagnosed until the neonatal period. Antenatal treatment options include maternal intravenous immunoglobulin (IVIG) and corticosteroid treatment, fetal blood sampling (FBS) and intrauterine platelet transfusion (IUT) and early delivery. FBS (with or without IUT) can be used to direct and monitor response to therapy, and to inform mode and timing of delivery. However, this procedure is associated with significant risks, including fetal death, and is generally now reserved for high-risk pregnancies. This review highlights the current understanding of the epidemiology and pathophysiology of NAIT and summarises current approaches to investigation and management. It also introduces the newly established Australian NAIT registry. Owing to the relative rarity of NAIT, accruing sufficient patient numbers for studies and clinical trials at an institutional level is difficult. This national registry will provide an opportunity to collect valuable information and inform future research on this condition.

Fetal thrombocytopenia

Fetal thrombocytopenia is most often caused by maternal alloantibodies against fetal platelets crossing the placenta and resulting in platelet destruction. This condition, known as fetal and neonatal alloimmune thrombocytopenia, is usually detected after the birth of a symptomatic child who shows signs of bleeding in the skin or in the brain. In the most severe cases, intracranial hemorrhage leads to severe handicap or death. The challenge for the clinician is to provide preventive treatment in the next pregnancy. The current cornerstone of this treatment is maternal intravenous administration of immunoglobulins during the second half of pregnancy.

Noninvasive antenatal management of fetal and neonatal alloimmune thrombocytopenia: safe and effective

OBJECTIVE

To describe the outcome of pregnancies with fetal and neonatal alloimmune thrombocytopenia (FNAIT) in relation to the invasiveness of the management protocol.

DESIGN

Retrospective analysis of prospectively collected data from a national cohort.

SETTING

Leiden University Medical Centre, the national centre for management of severe red cell and platelet alloimmunisation in pregnancy.

POPULATION

Ninety-eight pregnancies in 85 women with FNAIT having a previous child with thrombocytopenia with (n= 16) or without (n= 82) an intracranial haemorrhage (ICH).

METHODS

Our management protocol evolved over time from (1) serial fetal blood samplings (FBS) and platelet transfusion (n= 13) via (2) combined FBS with maternal intravenous immunoglobulins (n= 33) to (3) completely noninvasive treatment with immunoglobulins only (n= 52 pregnancies, resulting in 53 neonates). Perinatal outcome was assessed according to the three types of management.

MAIN OUTCOME MEASURES

Occurrence of ICH, perinatal survival, gestational age at birth and complications of FBS.

RESULTS

All but one of 98 pregnancies ended in a live birth; none of the neonates had an ICH. The median gestational age at birth was 37 weeks (range 32-40). In groups 1 and 2, three emergency caesarean sections were performed after complicated FBS, resulting in two healthy babies and one neonatal death.

CONCLUSION

Noninvasive antenatal management of pregnancies complicated by FNAIT appears to be both effective and safe.

Antenatal interventions for fetomaternal alloimmune thrombocytopenia

BACKGROUND

Fetomaternal alloimmune thrombocytopenia occurs when the mother produces antibodies against a platelet alloantigen that the fetus has inherited from the father. A consequence of this can be a reduced number of platelets (thrombocytopenia) in the fetus, which can result in bleeding whilst in the womb or shortly after birth. In severe cases this bleeding may lead to long-lasting disability or death. Antenatal management of fetomaternal alloimmune thrombocytopenia centres on preventing severe thrombocytopenia in the fetus. Available management options include administration of intravenous immunoglobulins or corticosteroids to the mother or intrauterine transfusion of antigen compatible platelets to the fetus. All options are costly and need to be assessed in terms of potential risk and benefit to both the mother and an individual fetus.

OBJECTIVES

To determine the optimal antenatal treatment of fetomaternal alloimmune thrombocytopenia to prevent fetal and neonatal haemorrhage and death.

SEARCH STRATEGY

We searched the Cochrane Pregnancy and Childbirth Group trials register (February 2004), EMBASE (1980 to February 2004) and bibliographies of relevant publications and review articles.

SELECTION CRITERIA

Randomised controlled studies comparing any intervention, including corticosteroids with no treatment, or comparing any two interventions.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed eligibility, trial quality and extracted data.

MAIN RESULTS

One study met the inclusion criteria (54 pregnant women). This trial compared intravenous immunoglobulins plus corticosteroid (dexamethasone) with intravenous immunoglobulins alone. No significant differences were reported between the treatment and control groups, in any outcome measured: mean platelet count at birth (weighted mean difference (WMD) 14.10 x 10 9/l, 95% confidence interval (CI) -30.26 to 58.46), mean gestational age at birth (WMD -0.50 weeks, 95% CI -2.69 to 1.69), mean rise in platelet count from first to second fetal blood screen (WMD -3.50 x 10 9/l, 95% CI -24.62 to 17.62) and mean rise in platelet count from birth to first fetal blood screen (WMD 24.40 x 10 9/l (95% CI -14.17 to 62.97)). This trial had adequate methodological quality; however the method used to calculate sample size was inappropriate: therefore the power calculation was not sufficient to determine any significance in differences between the treatment groups.

AUTHORS' CONCLUSIONS

There are insufficient data from randomised controlled trials to determine the optimal antenatal management of fetomaternal alloimmune thrombocytopenia. Future trials should consider the dose of intravenous immunoglobulins, the timing of initial treatment, monitoring of response to treatment by fetal blood sampling, laboratory measures to define pregnancies with a high risk of intercranial haemorrhage, management of non-responders and long-term follow up of children.