The effects of pregnancy on nasal physiology

Nasal congestion that is not present before pregnancy represents a distinct clinical entity called pregnancy rhinitis. The aim of this study is to evaluate the clinical characteristics of nasal physiology over the course of pregnancy.

The study was conducted with 85 pregnant women and 26 nonpregnant controls. We measured nasal airway patency objectively via acoustic rhinometry (ARM) and anterior rhinomanometry (RMM) and subjectively via the Nasal Obstruction Symptom Evaluation (NOSE) scale in each trimester and compared the results to those of the controls.

The NOSE scores of control and pregnant women showed no difference (p = 0.866). Minimal cross-sectional area (MCA1; minimal cross sectional area at nasal valve and MCA2; minimal cross sectional area at the level where the head of inferior turbinate is placed) decreased significantly between the first and third trimesters: first trimester 0.37 cm(2), third trimester 0.31 cm(2). There was no difference between each trimester with regard to total nasal resistance. The correlation analysis between the NOSE score and both total volume and MCA1 in all patients showed no significance (r = -0.10, p = 0.318; r = -0.04, p = 0.654, respectively).

Pregnancy affects nasal physiology adversely and impairs nasal breathing in some women. However, based on the findings of this study, we concluded that this clinical entity may not be considered as a disease without complementary symptoms despite the presence of objective changes in nasal parameters.