Which prenatal patients with congenital cystic lung malformations should be treated with betamethasone (betamethasone)?

From the Guidelines

Prenatal patients with congenital cystic lung malformations, specifically those with microcystic congenital pulmonary airway malformation (CPAM), should be treated with betamethasone.

Treatment Details

• The recommended dose of betamethasone is 12.5 mg IM q24 h for 2 doses 1.
• This treatment is suggested for large microcystic CPAM that has resulted in nonimmune hydrops fetalis (NIHF).
• It is recommended that treatment be performed at a tertiary care center or center with expertise in relevant therapy.

Rationale

• The use of corticosteroids, such as betamethasone, has been shown to be beneficial in the management of microcystic CPAM associated with NIHF 1.
• The exact mechanism of action is not fully understood, but it is thought to help reduce the size of the CPAM and improve fetal outcomes.
• Macrocystic CPAM, on the other hand, may require fetal needle drainage of effusion or placement of thoracoamniotic shunt rather than corticosteroid treatment 1.

From the Research

Prenatal Patients with Congenital Cystic Lung Malformations

Prenatal patients with congenital cystic lung malformations who may benefit from treatment with betamethasone include:

• Those with microcystic congenital cystic adenomatoid malformations (CCAMs) and a high risk of hydrops or fetal demise 2
• Fetuses with large lung lesions, including CCAMs, who are at risk for cardiopulmonary compromise 3
• Patients with a congenital cystic adenomatoid malformation volume ratio (CVR) greater than 1.6 4, 2
• Those who have not responded to a single course of betamethasone and may benefit from multiple courses 5, 6

Characteristics of Patients Who May Benefit from Betamethasone

Patients who may benefit from betamethasone treatment have the following characteristics:

• Predominantly microcystic CCAM lesions 2
• High CVR (>1.6) 4, 2
• Presence of hydrops or nonimmune hydrops fetalis 2, 5
• Large lung lesions, including CCAMs, with a high risk of cardiopulmonary compromise 3

Treatment Outcomes

Treatment with betamethasone has been shown to:

• Reduce lesion size and resolve hydrops in some patients 2, 5
• Improve survival rates in high-risk patients 2, 5, 6
• Stabilize or improve disease progression in some patients 6
• Have variable effects on fetal lung lesion dimensions, with some studies showing no significant reduction 4