*            Department of Gynecology, Félix Guyon Hospital, 97400 Saint-Denis, Ile de la Réunion, France.
**          Gynecologist, Saint-Pierre, Reunion.
***        Department of neonatology, Félix Guyon Hospital, 97400 Saint-Denis, Ile de la Réunion, France.
****      Department of Radiology, Félix Guyon Hospital, 97400 Saint-Denis, Ile de la Réunion, France.

Fetal allo-immune thrombocytopenia (FAIT) is caused by maternal immunization against fetal platelet antigen. Intracerebral hemorrhage is the most deleterious consequence. We present a case of fetal allo-immune thrombocytopenia diagnosed by ultrasound examination, at 32 weeks.

Case report:

A 30-year-old G2P1, was referred at 33 weeks, because of intra-cerebral anomaly. The first and the second fetal sonography showed a normal fetus. The nuchal translucency was 1 mm (LCR = 65 mm). The triple test was 1/1700.

In our antenatal unit, the admission scan immediately revealed an intra-cerebral heteroechogenic structure, without peripherical vascularisation. The homolateral ventricule seemed compressed. A left ventriculomegaly was observed (14 mm). Coronal section showed the right cerebral lesion, probably hemorragic, with different hematomas inside. The size was 54 mm x 46 mm. Parasagital view confirmed our analysis. The corpus callosus and the pericallosus artery were present.

At 34 weeks, the size of the hematoma  had increased (> 6 cm). The posterior gap was normal.

A cerebral MRI confirmed the right hemispheric hematoma and the left ventriculomegaly. The cerebral gyration was normal without anomaly of the white substance.

The parents were informed about the bad fetal and post-natal prognosis. They met a neuro-pediatric specialist. At 35 weeks, the hematoma had increased (Figure 10, 11, Video clip).

The parents decided to end the pregnancy. An umbilical cord blood sampling. The mother had a normal platelet count. The diagnosis of fetal allo-immune thrombocytopenia was confirmed by the presence of HPA-1a antibodies in maternal serum. The fetal karyotype was 46X. The fetal platelet level was 5000 / ml.

Here are the images:

Figure 1-4:  At 32 weeks,  intra-cerebral hyperechogenic structure.  The homolateral ventricule seemed compressed.

Figure 5-7: Sagital view of the heterogenic mass at 32 weeks.

Figure 8, 9: The corpus callosus and the pericallosus artery were present.

Figure 10, 11: One weeks later, the hematoma  had increased in size.

Video clip:

Figure 12: The posterior gap was normal.

Figure 13-18: A cerebral MRI confirmed the right hemispheric hematoma and the left ventriculomegaly