Betamethasone Dosing for Fetal Lung Lesions

Standard Dosing Protocol

The American College of Obstetricians and Gynecologists recommends a dose of betamethasone 12 mg intramuscularly given as two doses 24 hours apart for fetal lung lesions 1, 2
For congenital pulmonary airway malformation (CPAM) with microcystic type that has resulted in nonimmune hydrops fetalis (NIHF), maternal administration of betamethasone 12.5 mg intramuscularly every 24 hours for 2 doses is recommended 3
For singleton pregnancies between 34 0/7 and 36 6/7 weeks of gestation at high risk of preterm birth, a single course of antenatal corticosteroids consisting of 2 doses of 12 mg of intramuscular betamethasone 24 hours apart is recommended 1, 2

Antenatal corticosteroids substantially reduce the risks of adverse neonatal complications, including death, respiratory distress syndrome, intraventricular hemorrhage, and sepsis 1
Administration in the late preterm period is associated with decreased need for respiratory support (11.6% vs 14.4%; relative risk [RR], 0.80) and decreased severe respiratory morbidity (8.1% vs 12.1%; RR, 0.67) 1, 4

For microcystic congenital pulmonary airway malformation (CPAM) that has resulted in nonimmune hydrops fetalis, maternal administration of corticosteroids is specifically recommended 3

Neonatal hypoglycemia is more common with betamethasone administration but is typically mild and self-limited (93% resolve within 24 hours) 1, 4
Caution should be exercised in pregnant patients with pregestational diabetes mellitus due to increased risk of neonatal hypoglycemia 4