Lung Ultrasound Pattern Is Normal during the Last Gestational Weeks: An Observational Pilot Study

Background/aims: The normal lung ultrasound (US) pattern during a regular pregnancy has not been evaluated extensively in the current literature. Pregnancy-related changes in the respiratory tract affect maternal predisposition to several respiratory complications; consequently, it is important to differentiate between a physiologic pattern during pregnancy and a pathologic lung pattern, due to respiratory failure. The goal of our study was to assess the normal US lung pattern in women without known comorbidities in the last weeks of pregnancy.

Methods: We conducted a prospective cross-sectional observational pilot study. Chest wall was examined in 8 areas, 1 scan for each area with women in supine position.

Results: One hundred fifty parturients were enrolled during the 36th-38th gestational weeks. None of the participants showed pleural effusion, pneumothorax or lung consolidation. None presented an interstitial syndrome US pattern. One hundred thirteen participants out of 150 (75%) showed A-lines in all the regions. The remaining 25% showed 1 or 2 B-lines in at least 3 regions. Only 2 participants showed 2 positive regions also.

Conclusions: We found that, in the majority of the women examined, the lung US pattern matches the physiological pattern in non-pregnant patients. Lung US assessment is a feasible and a helpful diagnostic tool during pregnancy.