High failure rates of medical termination of pregnancy after introduction to a large teaching hospital.

The success rates of medical termination of pregnancy in two time periods (2000-2001 and 2002-2003) were compared to assess the effectiveness of medical abortion introduction to a large academic tertiary medical center. The success rates were markedly reduced over time (87.0% vs. 79.3%) probably owing to the difficulty in defining clear sonographic criteria for treatment failure and the complexity of a follow-up program implemented at a large teaching hospital by a broad staff with widely varying experience and knowledge of the new procedure.