Understanding the utilization of Maternal Intensive Care Units (MICUs) is crucial for optimizing patient outcomes, managing severe maternal morbidity (SMM), and facilitating effective resource allocation. Despite the importance of ICU care within obstetrics, comprehensive data evaluating utilization patterns by delivery method is sparse. This study aims to determine the proportion of delivery hospitalizations leading to ICU admissions, identify the indications for these admissions, and analyze the factors associated with them.
A retrospective cohort study was conducted utilizing delivery hospitalization data from the Premier Database spanning from October 1, 2015, to December 31, 2020. The reasons for ICU admissions were characterized according to the Centers for Disease Control and Prevention (CDC)-defined SMM events. The modes of delivery were categorized as: vaginal birth, intended cesarean birth (cesarean without a trial of labor), and intrapartum cesarean birth (cesarean following a trial of labor). Multivariable logistic regression was applied to evaluate factors influencing ICU admissions. A secondary analysis was also performed to ascertain ICU admission rates among patients with and without SMM and associated comorbidities.
The analysis included 4.7 million delivery hospitalizations, comprising 3,261,071 (68.1%) vaginal births, 539,670 (11.3%) intrapartum cesarean births, and 988,932 (20.6%) intended cesarean births. A total of 35,837 patients (0.75%) necessitated ICU admission, broken down to 16,490 (0.51%) for vaginal births, 8,243 (1.53%) for intrapartum cesarean births, and 11,104 (1.12%) for intended cesarean births. Non-transfusion SMM occurred in 18,552 patients (0.39%). Among those admitted to the ICU, 6574 patients (18.4%) had non-transfusion SMM events, while 27,329 (76.3%) did not meet the SMM criteria. The leading SMM events requiring ICU care included acute respiratory distress syndrome (7.0%), ventilation (6.7%), shock (6.1%), hysterectomy (6.0%), and disseminated intravascular coagulopathy (4.0%). Multivariable analysis revealed intrapartum cesarean and intended cesarean deliveries correlated with higher odds of ICU admission compared to vaginal births, with adjusted odds ratios of 1.87 (95% CI: 1.81-1.94) and 1.46 (95% CI: 1.41-1.52), respectively. Notable associations for ICU admission included transfusion of ≥4 units of packed red blood cells (aOR 116.3) and conditions like cardiomyopathy (18.5), severe preeclampsia (6.72), pulmonary hypertension (6.53), arrhythmias (3.99), and preterm birth (3.55). The secondary analysis indicated that SMM rates were significantly higher in patients with comorbidities (0.9%) versus those without (0.2%). Additionally, patients with comorbidities showed higher ICU admission rates across delivery modes compared to their counterparts without comorbidities.
Approximately one in every 135 delivery hospitalizations results in an ICU admission according to this U.S. database. Both intrapartum and intended cesarean deliveries present an elevated risk of ICU admission compared to vaginal deliveries. Among the evaluated factors, significant transfusion needs emerged as the strongest predictor for ICU admission. These insights emphasize the necessity for early detection and preparation for potential complications associated with intrapartum cesarean birth and highlight the importance of proactive planning for obstetric critical care.
Conflicts of interest and funding sources may be reviewed in the DISCLOSURES section at the end of the article.