The role of parity in medical abortion up to 49 days of amenorrhoea.

OBJECTIVE

To identify possible risk factors for failure of medical abortion.

METHOD: Retrospective study of data collected between 1 January 2001 and 31 December 2005, concerning 1850 women who, for medical abortion up to 49 days of amenorrhoea, had received 600 mg oral mifepristone followed 48 h later by 400 microg oral misoprostol and, if necessary, a second oral dose of 400 microg.

RESULTS

The method was effective in 97.1% of cases. Fifty four failures (2.9%) were recorded, including seven continuing pregnancies (0.4%). The global efficacy rate of this mifepristone-misoprostol regimen is among the best using similar treatment protocols. The proportion of failures augmented with parity.

CONCLUSION

This study suggests that parity is a major factor influencing the success of medical abortion. A greater parity of the patients was associated with a lower efficacy of treatment.