N-Acetylcysteine Use in Pregnancy

Introduction to Mucolytic Therapy

The European Respiratory Society recommends that women with bronchiectasis and cystic fibrosis should continue routine therapy with mucolytics throughout pregnancy to maintain maternal stability, as the risks of undertreated respiratory disease with maternal hypoxia outweigh theoretical medication risks 1, 2
The principle underlying this recommendation is that fetal risk from uncontrolled maternal respiratory disease significantly exceeds any potential medication risk 1, 2
Maternal hypoxia from undertreated respiratory conditions has well-documented adverse fetal effects, making disease control the priority 1, 2

Standard mucolytic dosing (typically 600 mg orally 2-3 times daily) can be continued without dose adjustment 3

Patients should be counseled that maintaining respiratory stability protects both maternal and fetal health 1, 2
The European Respiratory Society/Thoracic Society of Australia and New Zealand 2020 Task Force provides guidance that for new initiation of mucolytic therapy during pregnancy, the clinical indication should be clear (e.g., recurrent exacerbations, significant sputum production affecting respiratory function) 1, 2

The sulfuric odor of N-acetylcysteine may be unpleasant and could exacerbate pregnancy-related nausea, though this is not a safety concern 4