Prenatal Measurements of Congenital Lung Malformations: Can They Predict Postnatal Size?

Prenatally diagnosed congenital lung malformations (CLMs) are monitored via ultrasound and measured by congenital pulmonary airway malformation volume ratios (CVRs) which can predict postnatal respiratory symptoms. This study compared CVR to postnatal lesion size to help guide prenatal counseling.

A retrospective chart review evaluated the prenatal imaging and postnatal outcomes for patients who were prenatally diagnosed with CLMs and had a postnatal computed tomography (CT) scan at one institution.

Fifty-seven patients were included. Four had symptoms requiring urgent resection. The remaining were discharged and had clinic follow-up with CT scan to determine next steps: five had no identified lesions, eight had lesions whose diagnosis did not warrant an operation, and 40 had lesions whose diagnosis rendered size a factor in operative decision-making. Of these 40, 26/40 patients (65%) underwent elective resection (median maximum CVR 0.97; median lesion size 4 cm) and 14/40 patients (35%) were observed without resection (median maximum CVR 0.5; median lesion size 3 cm). There was a positive correlation between prenatal CVR and postnatal lesion size, with R-squared = 0.46. Maximum CVRs were better than last CVRs when predicting whether postnatal CT size would fall above or below our institution's level of recommended resection, with an area under the curve of 0.85 and a CVR cut-point of 0.61.

For newborns with asymptomatic CLMs, higher maximum CVRs correlated with larger size on postnatal CT. A maximum CVR ≤0.6 was correlated with a smaller postnatal CT size that may be eligible for nonoperative management. While these results are not intended to recommend surgery based on higher CVRs alone, this information could potentially be used to reassure expectant parents whose babies' prenatal imaging demonstrate lower maximum CVRs.