Ultrasound in congenital intracranial haemorrhage secondary to isoimmune thrombocytopaenia

The Sonographic Detection of Intracranial Hemorrhage Due to Alloimmune Thrombocytopenia

Alloimmune thrombocytopenia is a rare condition in which antibodies from the mother's circulation cross the placenta and destroy the platelets in the fetus. Approximately 14% of affected fetuses or neonates develop intracranial hemorrhage, leading to death or long-term central nervous system disabilities. After treating two such cases, 26 previously reported cases of alloimmune thrombocytopenia with intracranial hemorrhage were examined to discover if these hemorrhages exhibit a typical sonographic appearance, course, and time of hemorrhage. When intracranial hemorrhage occurs in cases of alloimmune thrombocytopenia, it has a typical appearance in 76% of cases: a large hematoma in the center of the cerebral hemisphere. There is no difference between genders in the occurrence of alloimmune thrombocytopenia unless hemorrhage occurs: 72% of neonates with alloimmune thrombocytopenia and intracranial hemorrhage are male. Intracranial hemorrhage occurs before labor and delivery in 76% of cases. Sonographers cannot depend on a history of the condition in previous pregnancies as an indication of alloimmune thrombocytopenia: only 35% of neonates with alloimmune thrombocytopenia and hemorrhage have previously affected siblings.

Intracranial hemorrhage in alloimmune thrombocytopenia: stratified management to prevent recurrence in the subsequent affected fetus

OBJECTIVE

We sought to prevent intracranial hemorrhage (ICH) through antenatal management of alloimmune thrombocytopenia.

STUDY DESIGN

A total of 33 women (37 pregnancies) with alloimmune thrombocytopenia and ICH in a previous child were stratified according to the timing of the previous child's ICH: extremely high risk (HR) (n = 8) had ICH <28 weeks, very HR (n = 17) between 28-36 weeks, and HR (n = 12) in the perinatal period. Treatment was initiated at 12 weeks with intravenous immunoglobulin 1 or 2 g/kg/wk, and if the fetal platelet count by cordocentesis was <30,000/mL despite treatment, prednisone and/or more intravenous immunoglobulin were added.

RESULTS

Five of 37 fetuses suffered ICHs. Two ICHs had platelet counts >100,000/mL, and 1 was grade I. The other 2 ICHs were unequivocal treatment failures; both were grade III-IV and resulted in fetal demise.

CONCLUSION

These findings demonstrate the success of stratified treatment in these HR patients, which tailored interventions according to the timing of the sibling's ICH.

Will it ever be possible to balance the risk of intracranial haemorrhage in fetal or neonatal alloimmune thrombocytopenia against the risk of treatment strategies to prevent it?

BACKGROUND AND OBJECTIVES

Intracranial haemorrhage (ICH) of the fetus or newborn is a severe complication of fetal or neonatal alloimmune thrombocytopenia (FNAIT). In order to attain management decisions to prevent ICH, the risk of ICH in successive pregnancies with thrombocytopenia, with or without a history of ICH, must be established.

MATERIALS AND METHODS

We performed a search of medline for ICH cases in untreated FNAIT pregnancies. After exclusion of cases with confounding factors, 24 reports, describing 62 pregnancies of 27 mothers, were eligible. In addition, two mothers with five pregnancies were included from our own case records. Observational studies were examined to estimate the risk of ICH in subsequent FNAIT pregnancies without a history of ICH. Finally, medline was searched for complication rates in the treatment of FNAIT pregnancies.

RESULTS

In 52% of the ICH cases, a previous sibling suffered from ICH. The recurrence rate of ICH in the subsequent offspring of women with a history of FNAIT with ICH was 72%[confidence interval (CI): 46-98%] without inclusion of fetal deaths and 79% (CI: 61-97%) with inclusion of fetal deaths. In 48% of the ICH cases, the previous sibling had thrombocytopenia but not ICH. Population studies revealed an overall ICH risk in thrombocytopenic infants of 11% (CI: 0.8-23%) without inclusion of fetal deaths and 15% (CI: 1.5-19%) with inclusion of fetal deaths. Assuming occurrence in 48%, the risk of ICH in a subsequent pregnancy following a history of FNAIT without ICH, was estimated to be 7% (CI: 0.5-13%). Invasive treatment strategies carry a risk of 2.8% (CI: 1.2-4.4%) on complications.

CONCLUSIONS

The number of eligible publications on ICH in untreated FNAIT pregnancies is strikingly limited. The recurrence rate is high. As sufficient data on successive FNAIT cases without ICH are lacking, the occurrence of ICH in pregnancies with thrombocytopenia, but without ICH in a previous sibling, cannot be predicted. We estimate this risk to be 7%. This risk must be balanced against the risk of interventions in treatment strategies.

Prenatal intracranial hemorrhage and neurologic complications in alloimmune thrombocytopenia

Neonatal alloimmune thrombocytopenia results from platelet-antigen incompatibility between mother and fetus, leading to antibody-mediated destruction of fetal platelets. With a prevalence of 1 in 1000 births, approximately 4000 infants born in the United States each year develop neonatal alloimmune thrombocytopenia. Ten to 20% of affected neonates develop intracranial hemorrhage, with 25 to 50% occurring prenatally. We report three infants who developed prenatal hemorrhage. One died in utero, and the other two had cerebral porencephaly and neurologic deficits. Infants with neonatal alloimmune thrombocytopenia have elevated risks of perinatal death and neurologic complications, including cerebral palsy, hypotonia, cortical blindness, developmental delay, seizures, and psychomotor retardation. We also report our retrospective review of the New England Medical Center neonatal intensive care unit between 1990 and 1999. Using current management guidelines, including treatment of the mother with a weekly infusion of high-dose (1-2 g/kg) intravenous immunoglobulin and/or corticosteroids, all eight infants with neonatal alloimmune thrombocytopenia did well.

Feto-maternal alloimmune thrombocytopenia: a literature review and statistical analysis

Exploring prognostic factors that determine outcomes in fetomaternal alloimmune thrombocytopenia (FMAIT), a search of Medline was performed covering the years 1966 to April 1998. 376 articles were collected and reviewed; 140 articles contained the case histories of 297 mothers and 433 pregnancies that fulfilled entry criteria. More than 30 data variables were sought from these cases. The data were analysed using SPSS and Arcus Quickstat Biomedical. Nineteen different antigen incompatibilities were documented, the majority being human platelet antigen (HPA)-1a (77.3%), HPA-3a (3.5%) and HPA-5b (3.5%). The relative risk reduction (RRR) in mortality with any intervention was 57% (0.19-0.77) p = 0.009. Treatment of HPA-1a (PlA1) pregnancies with intravenous immunoglobulin (IVIG) increased the likelihood of a neurologically normal outcome, relative risk (RR) 1.68, confidence interval (1.3-2.2) p = 0.0003. Treatment of HPA-1a (PlA1) pregnancies with only antenatal complementary platelet transfusions increased the likelihood of a neurologically normal outcome, RR 1.63 (1.1-2.1) p = 0.01. Despite reviews of more than 400 cases of FMAIT, few prognostic variables are identifiable. Although IVIG appears to reduce the risk of intracranial haemorrhage (ICH), the dosage and timing of IVIG treatment was varied. This study highlights the need for standardised and directed research.

Perinatal ultrasonography and magnetic resonance imaging findings in congenital hydrocephalus associated with fetal intraventricular hemorrhage

OBJECTIVE

We present the case histories of three premature infants with congenital posthemorrhagic hydrocephalus.

STUDY DESIGN

The timing of the lesion was monitored in utero in two of the three cases. Magnetic resonance imaging studies (prenatal in one case, within 24 hours of birth in all three cases) established the duration of the lesions and thereby added to the ultrasonographic findings.

RESULTS

All three patients demonstrated a similar pattern of lesions, consisting of (1) unilateral germinal matrix hemorrhage with cystic resorption, (2) residual blood in the cerebrospinal fluid with a "granular" ependymal reaction, (3) asymmetric ventriculomegaly predominating on the side of the hemorrhage with mild atrophy and periventricular cysts, and (4) partial hypoplasia of the ipsilateral thalamus. On the basis of two cases in which information about the pregnancy was available and in which fetal oligohydramnios without ruptured membranes was detected, we assume that this pattern of lesions may have resulted from a hypoxic-ischemic episode followed by intraventricular hemorrhage.

CONCLUSIONS

Because these three infants with congenital hydrocephalus were born during a period of only 18 months in a perinatal center serving a region with 16,000 live births per year, we speculate that a posthemorrhagic cause for congenital hydrocephalus underestimated.

Severe fetomaternal alloimmune thrombocytopenia presenting with fetal hydrocephalus

We report two patients where the finding of isolated fetal hydrocephalus led to the detection of severe fetal thrombocytopenia, using fetal blood sampling. Serological investigation led to the diagnosis of fetomaternal alloimmune thrombocytopenia (FMAIT) due to anti-HPA-1a. Both women had had previous unsuccessful pregnancies probably due to FMAIT; one had had four miscarriages at 17-18 weeks' gestation. The other had had one previous pregnancy complicated by severe fetal anaemia, and eventually hydrocephalus developed and the fetus died without the diagnosis of FMAIT being considered. Subsequent pregnancies in the two women were also affected by FMAIT, but prenatal treatment, predominantly with serial fetal platelet transfusions, resulted in a successful outcome in both cases. These observations suggest that FMAIT should be suspected if there is isolated fetal hydrocephalus, unexplained fetal anaemia, or recurrent miscarriages. The accurate diagnosis of FMAIT is important because recent advances in prenatal management can improve the outcome of subsequently affected pregnancies.

Hemostatic complications in renal disorders of the young

This review focuses on the hemorrhagic and thrombotic complications sometimes associated with the most common renal disorders in children. A Medline search of the literature was conducted from 1966 to January 1995, using combinations of key words appropriate for each disorder. Additional references were located through the bibliographies of the publications and recent journals were searched independently. The most common renal disorders with hemostatic complications in children were: renal vein thrombosis (268 children in 80 publications), hemolytic uremic syndrome (473 children in 29 publications), nephrotic syndrome (4,158 children in 51 publications), renal transplantation (3,976 children in 14 publications), glomerulonephritis (20 publications), end-stage renal disease, and dialysis (22 publications). The age distribution, clinical presentation, etiology, diagnosis, treatment, and outcome of the affected children were analyzed for each disorder. Children with inherited pre-thrombotic disorders usually do not present during childhood unless there is a secondary risk factor. Similarly, most children with renal disease do not develop thromboembolic complications. Therefore, when a child with a renal disorder develops a thromboembolic event, evaluation for an inherited pre-thrombotic disorder should be seriously considered. Guidelines for the use of heparin and warfarin in these children (both therapeutically and prophylactically) are given. At this time, the risk/benefit of thrombolytic therapy in children is not known and a general recommendation for thrombolytic therapy cannot be made.

Perinatal intracranial hemorrhage due to severe neonatal alloimmune thrombocytopenic purpura (NAITP) associated with anti-Yukb (HPA-4a) antibodies

Neonatal alloimmune thrombocytopenic purpura (NAITP) is one of the causes of thrombocytopenia in the newborn period. The thrombocytopenia is caused by maternal transplacental antiplatelet alloantibodies. We report a case of NAITP in a newborn infant having subarachnoid hemorrhage. Examination of platelet antibodies revealed anti-Yukb, that is, human platelet antigen (HPA)-4a incompatibility. Cranial ultrasound and brain magnetic resonance imaging revealed subarachnoid hemorrhage in the temporal region inferior to the cephalohematoma. The lesion seemed to have been sustained during delivery. The patient was treated with high-dose gamma-globulin and several transfusions of random donor platelets and showed a good clinical course. This is the second reported case of NAITP associated with the Yuk antigen system having intracranial hemorrhage.

Nature of the brain lesion in fetal allo-immune thrombocytopenia

Study of three fetuses with allo-immune thrombocytopenia, one with autopsy findings, and comparison with existing data have permitted speculation on the nature of the initial lesion within the brain. The commonest first bleeding site is probably underneath the molecular layer of the cerebral cortex, often within the temporal lobe. Small haemorrhages may appear to be (sub)pial, but expansion will lead to so-called subarachnoid haematoma. Communication with the adjacent lateral ventricle will contribute to post-haemorrhagic hydrocephalus. Occasionally, the initial haemorrhage is within the ventricle; such a pattern may lead to post-haemorrhagic hydrocephalus, often with a porencephalic component. In utero follow-up of fetuses at risk for allo-immune thrombocytopenia will have to focus on superficial cerebral haemorrhage for early detection of brain involvement.

Management of fetal alloimmune thrombocytopenia by weekly in utero platelet transfusions

Alloimmune neonatal thrombocytopenia (ANT) may cause intracranial haemorrhage in utero as well as at delivery. Recent management has concentrated on attempts to minimise fetal thrombocytopenia and prevent its complications. This report describes further experience with the use of repeated intravascular transfusions of compatible platelets in utero. The patient studied had already had one infant with intracranial haemorrhage due to ANT. In her next pregnancy, weekly intra-uterine platelet transfusions were given from 26 weeks, but intra-uterine death occurred at 30 weeks after the mother had a heavy fall. In her most recent pregnancy, weekly intravascular transfusions of platelets were given by cordocentesis from 29 to 34 weeks. The fetal platelet count was maintained above 30 X 10(9)/l for almost all of the last 6 weeks of pregnancy before delivery of a normal infant by Caesarean section at 35 weeks' gestation. This approach is effective in preventing severe fetal thrombocytopenia in the last trimester of pregnancy and is contrasted with alternative treatments of ANT. Further data are required to determine the efficacy and risks of these treatments.

Management of alloimmune neonatal and antenatal thrombocytopenia

Neonatal and antenatal alloimmune thrombocytopenia is induced by maternal antibodies against platelet-specific fetal antigens. This disease is rare but potentially severe because of intracranial bleedings which may occur during pregnancy or around birth. In the last decade our knowledge of this disorder has markedly advanced. New techniques are used in platelet immunology. New platelet antigens involved in these perinatal thrombocytopenias have recently been discovered. A group of women likely to produce the responsible platelet antibodies has been genetically defined as regards the PLA1 antigen. The quality of the sonographies and the possibility of performing cord vein puncture in early pregnancy afford a new approach in the management of perinatal alloimmune thrombocytopenias. But more must be done to prevent the complications of this disease.

Congenital blindness, porencephaly, and neonatal thrombocytopenia: a report of four cases

Four unrelated infants with neonatal thrombocytopenia associated with congenital blindness and porencephaly have been seen over an 18-year period. The association of congenital blindness with neonatal thrombocytopenia has not previously been reported. All children had clinical purpura in the neonatal period; in three cases, thrombocytopenia was confirmed, while in one case, the diagnosis of thrombocytopenia was presumptive; in two cases, there was evidence of circulating maternal serum platelet isoantibodies. Extensive investigation for intrauterine infection was negative in the three cases with confirmed thrombocytopenia. The thrombocytopenia resolved spontaneously after the neonatal period. It is postulated that the porencephalies were the consequence of prenatal cerebrovascular episodes. The etiology of the optic atrophy is unclear. Serial cranial ultrasound investigation is recommended for all neonates with thrombocytopenia, even if neurologically asymptomatic in the neonatal period, and serial prenatal cranial ultrasound investigation is recommended for infants of mothers with a history of having previously had infants with neonatal isoimmune thrombocytopenia.