RT Book, Section A1 Bush, Andrew A2 Kline, Mark W. SR Print(0) ID 1182915651 T1 Congenital Disorders of the Lower Airways and Mediastinum T2 Rudolph's Pediatrics, 23e YR 2018 FD 2018 PB McGraw-Hill Education PP New York, NY SN 9781259588594 LK accesspediatrics.mhmedical.com/content.aspx?aid=1182915651 RD 2024/04/18 AB Antenatal ultrasound and, increasingly, fetal magnetic resonance imaging (MRI) diagnose many congenital lung malformations, but we now have to decide what to do for a baby affected by an abnormality that may previously have escaped detection. Many lung lesions disappear or regress from the second trimester to term, and the outcome for such fetuses generally is good. Postnatal regression of lung malformations also has been described. The dilemma in the postnatal period is whether to opt for observation or surgery.