Obstetric and neonatal outcomes in pregnancies complicated by fetal lung masses: does final histology matter?

Fetal lung masses complicate approximately 1 in 2000 live births. Our aim was to determine whether obstetric and neonatal outcomes differ by final fetal lung mass histology. A review of all pregnancies complicated by a prenatally diagnosed fetal lung mass between 2009 and 2017 at a single academic center was conducted. All cases included in the final analysis underwent surgical resection and histology diagnosis was determined by a trained pathologist. Clinical data were obtained from review of stored electronic medical records which contained linked maternal and neonatal records. Imaging records included both prenatal ultrasound and magnetic resonance imaging. Fisher's exact test was used for categorical variables and the Kruskal-Wallis test was used for continuous variables. The level of significance was <.05. Of 61 pregnancies complicated by fetal lung mass during the study period, 45 cases underwent both prenatal care and postnatal resection. Final histology revealed 10 cases of congenital pulmonary airway malformation (CPAM) type 1, nine cases of CPAM type 2, and 16 cases of bronchopulmonary sequestration. There was no difference in initial, maximal, or final CPAM volume ratio between groups, with median final CPAM volume ratio of 0.6 for CPAM type 1, 0.7 for CPAM type 2, and 0.3 for bronchopulmonary sequestration ( = .12). There were no differences in any of the maternal or obstetric outcomes including gestational age at delivery and mode of delivery between the groups. The primary outcome of neonatal respiratory distress was not statistically different between groups ( = .66). Median neonatal length of stay following delivery ranged from 3 to 4 days, and time to postnatal resection was similar as well, with a median of 126 days for CPAM type 1, 122 days for CPAM type 2, and 132 days for bronchopulmonary sequestration ( = .76). In our cohort, there was no significant association between histologic lung mass subtypes and any obstetric or neonatal morbidity including respiratory distress.