Pulmonary Disease and Critical Illness in Pregnancy

Ghada Bourjeily, MD

Andrew Levinson, MD, MPH

Pregnancy is a unique and exciting period in a woman's or a couple's life. Though the vast majority of pregnancies are healthy and uncomplicated, some can be quite complicated and even catastrophic. Maternal mortality remains a major burden around the world. The World Health Organization made the reduction of maternal, infant, and child mortality a priority in its healthy people 2020 campaign. As expected, maternal mortality rates are much lower in the Western world than in underdeveloped countries and decreasing in most. However, mortality rates have been on the rise in the United States in the 21st century and continue to show significant racial discrepancies. It has been hypothesized that the rise in mortality may be due to the obesity epidemic having impacted the United States earlier than other Western countries. It is also possible that the high rates of racial inequality, the higher percentage of poor people, and a good proportion of pregnancies occurring at an advanced maternal age may all play a role in the relatively higher rates of maternal mortality. Finding effective solutions to maternal mortality continues to be a challenge.

As clinicians, our responsibility is to get educated about pregnancy and to learn about intricacies and nuances in the care of gravidas. Though medical specialists may not always be at the frontline of the care of pregnant women, they are often asked to assist in diagnosing and treating medical conditions in pregnancy. Analyses of trends in maternal mortality in the United Kingdom have found that the proportion of cases with substandard care was significantly elevated in maternal deaths, accounting for more than 50% in some instances. It is most likely that substandard care is related to multiple factors, including inherent concerns for the fetus, uncertainties regarding diagnostic testing and medication safety, and ambiguities regarding appropriate medication dosing, diagnostic test ordering, and laboratory test interpretation.

Pregnancy is associated with profound physiological changes. These changes may exacerbate some preexisting conditions such as chronic heart and lung disease but can also result in some new complications such as pulmonary embolism. Understanding pregnancy physiology is key to managing pregnant women. In addition, though medical specialists are not asked to manage the birth of a high risk or critically ill patient, they need to understand the physiology of labor and delivery so that they can optimize the respiratory and critical care of their pregnant patient in an effort to minimize complications occurring during an event of profound hemodynamic, cardiovascular, and respiratory challenges.

This issue of Seminars in Respiratory and Critical Care Medicine is dedicated to lung disease in pregnancy and the management of pregnant women in the intensive care unit (ICU). The issue reviews pregnancy and labor and delivery physiology as they relate to pulmonary and pulmonary vascular disease and ICU management. Decisions around drug prescriptions and imaging studies are also reviewed. Specific conditions such as asthma, pulmonary embolism, interstitial lung disease, tuberculosis, and pulmonary hypertension are reviewed in detail in addition to general management principles and the management of obstetric disorders and mortality prediction in the ICU.

A common theme throughout these articles is that pulmonologists and intensivists can, in collaboration with obstetric providers, work effectively toward reducing complications and improving outcomes of pregnant women. Understanding the unique physiological changes throughout pregnancy, as well as the diagnostic and treatment dilemmas, and challenges in pulmonary and critical care medicine as they relate to pregnancy will ultimately help to improve both maternal and fetal outcomes.