The balloon can be inserted into the trachea via a fetoscope during pregnancy to enable the lungs to mature.* It is usually removed prenatally. Select your setup:
* Van der Veeken, L., Russo, F.M., De Catte, L. et al. Fetoscopic endoluminal tracheal occlusion and reestablishment of fetal airways for congenital diaphragmatic hernia. Gynecol Surg 15, 9 (2018). https://doi.org/10.1186/s10397-018-1041-9