The airway becomes more difficult to manage, for numerous reasons.
Chapter 64 (pp. 684) General obstetric emergencies by Winnie TP Wan and Tony Gin
Chapter 65 (pp. 692) Severe pre-existing disease in pregnancy by Jeremy P Campbell and Steve M Yentis
Munnur, Uma, Ben de Boisblanc, and Maya S. Suresh. "Airway problems in pregnancy." Critical care medicine 33.10 (2005): S259-S268.
Jeejeebhoy, Farida M., et al. "Management of cardiac arrest in pregnancy: a systematic review." Resuscitation 82.7 (2011): 801-809.
Kodali, Bhavani-Shankar, et al. "Airway changes during labor and delivery."Anesthesiology 108.3 (2008): 357-362.