Hospitals have become increasingly interested in maximizing patient throughput and bed utilization in all units to improve efficiency. To study tradeoffs in blocking and system efficiency, a simulation model using a path-based approach is developed for an obstetric unit. The model focuses on patient flow, considering patient classification, blocking effects, time dependent arrival and departure patterns, and statistically supported distributions for length of stay (LOS). The model is applied to DeKalb Medical's Women's Center, a large obstetrics hospital in Atlanta, GA, to analyze the hospital's readiness for potential changes to patient mix and patient volume. A comparison of results predicted by the simulation model and actual performance after implementation of "swing" rooms is presented, suggesting the value of implementing "swing" rooms to balance bed allocation.