Prenatally diagnosed fetal thoracic malformations: a 5‐year experience

Abstract

Background: A 5‐year retrospective audit of cases referred to the Mater Mothers Hospital Fetal Medicine Unit with ultrasonographically identified thoracic anomalies was undertaken with specific reference to the distribution of pathologies, antenatal progress and outcomes of affected fetuses.Results: Twenty‐one fetuses with non‐cardiac, intrathoracic anomalies were identified and managed over a 5‐year period. Twelve demonstrated cystic mass lesions, seven echogenic lung masses were identified and one each of primary mediastinal shift (later found to be hypoplastic lung) and arterio–venous malformation of the lung. All lesions were unilateral. Antenatal diagnosis of congenital cystic adenomatoid malformations of the lung (CCAML) was made in the 12 cases of macrocystic lung lesions and proved correct in 10–1 was found at resection to be a bronchoplumonary sequestration (BPS) with associated AV malformation and chondromatous hamartoma, and one awaits follow up. Of the seven echogenic lung lesions, the antenatal diagnosis proved correct in only the two cases of BPS. Neonatal diagnoses included congenital diaphragmatic hernia (1), hybrid BPS/CCAM (1), resolving bronchial obstruction (2) and one loss to follow up with normal chest X‐ray. Complete resolution of the lesion occurred in five cases (mostly echogenic lesions). Polyhydramnios was found in only one case and resolved spontaneously – there were no cases of hydrops or fetal death. Neonatal outcomes included respiratory distress at birth (2), respiratory distress within 28 days (another two cases) and small for gestational age at birth (2/21). Thoracic CT scans were performed or awaited in all cases barring one loss to follow up with normal chest X‐ray. Some abnormalities were noted in all cases in which CT scan has been performed to date (15), including those cases with normal neonatal chest X‐ray and apparent antenatal resolution of ultrasound findings.Conclusion: While correct antenatal diagnosis can be made in many cases of cystic lung lesions, echogenic lung lesions may be difficult to diagnose correctly and adjunctive investigation such as MRI may prove beneficial. Postnatal CT scan should be considered as a routine for all antenatally diagnosed intrathoracic lesions regardless of apparent resolution of the lesion on antenatal ultrasound or apparently normal neonatal chest X‐ray.