Unique Airway Considerations and Risks When Treating Pregnant Patients

Pregnant patients exhibit various unique characteristics that first responders must account for during treatment.

A significant challenge responders encounter when treating pregnant women is navigating difficult airway anatomy and possible risks during airway management. The rate of failed intubation in pregnant patients is four to eight times higher than in nonpregnant patients, and this is largely due to anatomical changes, hormone production, and aspiration risks that occur during pregnancy.

Responders must be equipped with the right suction devices and intubation techniques to address these challenges and perform the safest treatment possible for pregnant patients and their babies.

Unique airway considerations in pregnant women

Pregnant women undergo several unique anatomical changes each trimester that affect their airway functioning and safety during medical treatment. Several changes in the respiratory system impact airway anatomy, including capillary distillation resulting from gestational hormones that cause congestion in the nasopharynx, larynx, trachea, and bronchi, producing more fluids in the airway.

As a woman’s uterus continues to expand and grow during pregnancy, the diaphragm elevates approximately four centimeters, allowing it to take on more respiratory functions, and causing the intra-abdominal part of the stomach and esophagus to be displaced to the left of the diaphragm, further affecting airway anatomy and function.

Treatment and intubation risks

The risk of aspiration, or accidentally breathing food or fluid into the lungs, is high in pregnant patients during airway management, especially when the patient is in the supine position, has received sedative drugs during treatment, or is experiencing reduced pressure of the esophageal sphincter, higher gastric volumes, or delayed gastric emptying.

If a definitive airway is not established during treatment, hand ventilation with a bag and mask may result in gastric distention and further increase the risk of aspiration in a patient.

The reduction of chest wall compliance in pregnant patients is another risk factor to look out for during treatment, as it can lead to rapid oxygen desaturation during airway management.

Additionally, life-threatening conditions including eclampsia, preeclampsia and pulmonary edema can result in pregnancy-specific hypoxic respiratory failure when not addressed correctly.

Successful treatment and management methods

Identifying and addressing difficult airway factors is sometimes challenging, but many first responders find success using the 3-3-2 rule, which involves three simple assessments for predicting intubation difficulty.

Although most responders are aware that pregnant patients have more difficult airways to work with than nonpregnant patients, practicing this method with your team will help them become more familiar with identifying difficult airway features and making treatment decisions accordingly when treating pregnant patients.

The steps for the 3-3-2 rule include:

• 3: You should be able to fit three fingers between the upper and lower teeth of a patient with an open mouth. Ask the patient to open their mouth and place three fingers vertically between their incisors or do it yourself. If this is impossible, the narrow space may make it more difficult to visualize the glottis or insert the laryngoscope.
• 3: An additional three fingers that fit between the tip of the mandible and the anterior neck help estimate the size of the submandibular region. A distance less than three fingers suggests a narrower angle, which will make it more difficult to insert a tube. It also suggests that there is less space for the tongue next to the throat, potentially occluding the pharynx further.
• 2: Two fingers should fit between the base of the mandible and the thyroid notch on the anterior portion of the neck. A larynx positioned too highly in the neck makes laryngoscopy more challenging because of the acute angle between the larynx and the base of the tongue. It will also be more difficult and may be impossible, to see the larynx.

Careful planning and assessment are fundamental for conducting successful and safe airway management in pregnant women. Some essential ways to plan and assess airway risk factors in pregnant patients include:

• Performing careful airway assessments on all patients prior to treatment
• Using regional airway management or awake intubation techniques to anticipate and treat the difficult airway
• Using a laryngeal mask to avoid difficult airway situations or recover from failed airway management attempts

Want to learn more? Read this blog for tips on airway management techniques for treating difficult airways in pregnant women and other challenging patient demographics.

Editor's Note: This blog was originally published in March 2023. It has been re-published with additional up to date content.