What is severe maternal morbidity?

Severe maternal morbidity can be thought of as unintended outcomes of the process of labor and delivery that result in significant short-term or long-term consequences to a woman’s health. To date, there is not complete consensus among systems and professional organizations as to what conditions should represent severe maternal morbidity. Developing such a list in the future has clear utility. In the absence of consensus on a comprehensive list of conditions that represent severe maternal morbidity, institutions and systems should either adopt an existing screening criteria or create their own list of outcomes that merit review. Such lists may be based on the institutions’ evaluations of which adverse outcomes are consequential to their population. Table 1 presents an example of a list of conditions that represent severe maternal morbidity. In some cases, however, an identified morbidity actually may not prove to be severe morbidity after chart review. For example, if a parturient with complex congenital heart disease has a planned ICU admission to receive safe intrapartum care and does not ultimately require any significant intervention aside from observation, she would not be categorized as a patient with a severe morbidity. In contrast, a woman who develops acute heart failure requiring ICU admission and significant interventions to manage her heart failure would be considered a patient with a severe maternal morbidity. Identifying an outcome as a severe maternal morbidity does not suggest blame, nor does it mean that there will always be an opportunity for improvement. Reviewing such cases in detail to determine whether the morbidity may have been avoidable and whether it should prompt changes in systems for care provision is, however, a necessary and important step in efforts to ensure quality obstetric care. For example, although amniotic fluid embolisms are “unpredictable and unavoidable,” reviewing all such cases to evaluate responses to these unexpected life-threatening emergencies potentially can improve future responses.

What process can be used to identify cases with potential severe maternal morbidity that merit review?

Quality improvement efforts are predicated in part on identifying cases with potential severe maternal morbidity that merit review. Identifying such cases, however, is more complicated than reviewing maternal mortality, which is clearly defined and readily captured in death certificates and other reporting. Severe maternal morbidity, in contrast, is not always reported and may not be well coded in, or otherwise readily extracted from, record systems. Definitions of severe maternal morbidity that rely on diagnosis codes, such as the Centers for Disease Control and Prevention’s definition, may miss cases, have a relatively low positive predictive value (0.40) and, at a practical level, may be difficult for facilities to operationalize. Facilities should have a screening process in place to detect cases of severe maternal morbidity for review. The College and SMFM recommend using two criteria to screen for severe maternal morbidity: 1) transfusion of 4 or more units of blood and 2) admission of a pregnant or postpartum woman to an ICU. Investigators have demonstrated that these criteria have high sensitivity and specificity for identifying women with severe morbidity and a high positive predictive value (0.85) for identifying severe maternal morbidity.

Facilities should review all cases that meet at least one of these screening criteria to determine whether the case is truly a severe maternal morbidity; to characterize the events, diagnoses, and outcomes involved; and to determine if an identified morbidity is judged to have been potentially avoidable and, thus, present opportunities for system change and improved future performance. Not all cases that meet criteria for review will represent preventable severe morbidity; some cases of morbidity reflect the underlying health of a woman or her pregnancy and are thus unavoidable. The concept that not all cases meeting screening criteria will be true cases of severe maternal morbidity underscores the importance of reviewing each “screen-positive” case to identify those with true morbidity and, especially, those that may be deemed upon review to have been potentially avoidable.

When does severe maternal morbidity represent a sentinel event?

The Joint Commission defines a sentinel event as “a patient safety event (not primarily related to the natural course of the patient’s illness or underlying condition) that reaches a patient and results in any of the following: death, permanent harm, or temporary harm.” Simply screening positive for one of the two recommended screening criteria does not constitute a sentinel event. Instead, the Joint Commission noted that upon review of any case, the ultimate assessment may be that the case is not a sentinel event. For example, hemorrhage due to placenta previa would not qualify as a sentinel event because bleeding in this context is part of the natural course of the illness. As such, screen-positive cases or individual outcomes and diagnoses should not automatically be considered sentinel events. Context determined from detailed review is needed to determine if an individual case and outcome was correctly classified as a sentinel event. Just as the rate of ICU admission and transfusion of 4 or more units of blood should not automatically be labeled as sentinel events, their rates of occurrence should not be used as a quality metric. These screening criteria are the minimum recommended criteria and institutions may choose to incorporate additional screening criteria to highlight cases for detailed review at their own discretion.