J Matern Fetal Neonatal Med. 2026 Dec;39(1):2728784. doi: 10.1080/14767058.2026.2728784. Epub 2026 Sep 7.
ABSTRACT
Nasal breathing is an underrecognized and poorly understood component of maternal physiology. Pregnancy remodels nearly every physiologic system, yet whether breathing occurs through the nose or mouth is often overlooked. The nose undergoes hormonally driven adaptations beginning early in gestation. Rising estrogen and progesterone engorge the nasal turbinates, increase mucosal edema, and progressively raise nasal airflow resistance. These changes are frequently dismissed as benign; however, they may carry consequences that extend beyond congestion. This narrative review examines the physiologic functions of the nose in pregnancy, the consequences of impaired nasal airflow, and breathing-based, mechanical, and behavioral strategies intended to preserve nasal function and support maternal health. Nasal breathing conditions inspired air, delivers sinus-derived nitric oxide that supports pulmonary vasodilation and host defense, and participates in the carbon dioxide homeostasis that sustains the maternal-fetal diffusion gradient. Progressive nasal obstruction may contribute to mouth breathing, snoring, sleep fragmentation, and sleep-disordered breathing, conditions associated with hypertensive disorders of pregnancy, gestational diabetes, and other adverse maternal and perinatal outcomes. Nasal breathing practices (pranayama) have been shown to provide therapeutic benefit in the non-pregnant population. Slow nasal breathing, including alternate nostril breathing, has shown favorable effects on respiratory rate, blood pressure, autonomic regulation, sleep, and perceived well-being in preliminary pregnancy studies. Humming-based breathing practices increase nasal nitric oxide and produce acute cardiovascular responses during practice that differ from post-intervention or longer-term effects. Cooling breathing techniques also influence hemodynamic function, whereas energizing practices and breath retention remain insufficiently studied in pregnancy. Mechanical and behavioral approaches, including external nasal dilators, saline irrigation, humidification, and positional strategies, improve nasal patency and symptoms but have not been shown to prevent or treat pregnancy-related sleep-disordered breathing. Mouth taping remains investigational because pregnancy-specific safety and efficacy data are absent. Future studies should objectively characterize nasal function, distinguish among specific breathing techniques, and evaluate maternal symptoms, sleep, autonomic and blood pressure trajectories, fetal growth, and perinatal outcomes. Recognizing the route and pattern of breathing as potentially modifiable dimensions of maternal respiratory physiology may provide new insight into pathways contributing to pregnancy complications and identify opportunities for nonpharmacologic intervention.
PMID:42705916 | DOI:10.1080/14767058.2026.2728784
