Epidemiology of Emergency Medical Services-Attended out-of-Hospital Deliveries and Complications in the United States.

Background: Prehospital obstetric events, including out-of-hospital deliveries and their complications, are a rare but high-risk event encountered by emergency medical services (EMS). Understanding the epidemiology of these encounters would help identify strategies to improve prehospital obstetric care. Our objective was to determine the characteristics of out-of-hospital deliveries and high-risk complications treated by EMS clinicians in the U.S.
Methods: We conducted a cross-sectional analysis of EMS patient care records in the 2018 and 2019 National EMS Information System Public Release Version 3.4 datasets. We included EMS activations after a 9-1-1 scene response for patients aged 12-50 years with evidence of an out-of-hospital delivery or delivery complication, or where the patient was a newborn aged 0-<6 h. We examined patient, community, emergency response, and clinical characteristics using descriptive statistics.
Results: Of the 56,735,977 EMS activations included in the 2018 and 2019 datasets, there were 8,614 out-of-hospital deliveries, 1,712 delivery complications, and 5,749 records for newborns. Most maternal (76%) out-of-hospital deliveries involved patients between the ages of 20-34 years, occurred on a weekday (73%), were treated by an advanced life support crew (85%), and occurred in a home or residence (73%). EMS-assisted field delivery was documented in 3,515 (34%) of all maternal activations but only 2% of activations with a delivery complication. Few patients received an EMS-administered medication (e.g., 0.4% received oxytocin). Supplemental oxygen was administered in 870 (15%) of newborn activations. Activations from counties with the most racial/ethnic diversity were more often treated by a BLS-level unit (16% vs. 12%, p  < 0.001), and activations from rural areas had significantly longer transport times (19.7 min [IQR 8.7, 32.8] vs. urban, 13.1 min [IQR 8.7, 19.7], p  < 0.001).
Conclusion: In this large, national repository of EMS patient care records from across the U.S., most activations for out-of-hospital delivery, delivery complication, or a newborn included only routine EMS care. There were potential disparities in level of care, clinical care provided, and measures of access to definitive care based on maternal and community factors. We also identified gaps in current practice, such as for postpartum hemorrhage, that could be addressed with changes in EMS clinical protocols and regulations.