Prenatal features
In 28 cases (37 %) ultrasound examination detected a feeding systemic arterial supply and the proposed diagnosis was BPS in 24 patients and hybrid malformation in 4. Thirteen (46 %) of them showed mediastinal shift, while ascites developed in 1 case at 22 weeks’ of gestation (Figure 1 ). Because of the persistence of the ascites, a drain was placed at 28th week of gestation. In this case, postnatal diagnosis was BPS.
In 47 cases (63%) no systemic feeding arterial supply was identified prenatally and the diagnosis of other malformations was proposed: 7 BC, 19 PCM, 15 CLE and 6 without defined prenatal diagnosis. Five (11%) of them had mediastinal shift. In one case, the hyperechoic image was associated with a cystic mass since first ultrasound examination at 14 weeks’ of gestation. A compressive BC was suspected with hydropic changes and a cystic-amniotic shunt was placed at 22 weeks’ (Figure 2 ). The aspect remained stable until birth at 29 weeks’.
Among all 75 patients, mediastinal shift was observed in 18 cases (24%). Prenatal procedure was required in two cases because of symptomatic compression, as described above.
The identification of a systemic arterial supply was significantly more associated with mediastinal shift (46% vs 10%, p = 0.0007).