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

Abstract

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 μg oral misoprostol and, if necessary, a second oral dose of 400 μg.

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.

Keywords:

• Medical abortion
• Mifepristone
• Misoprostol
• Risk factors
• Failure
• Parity
• Human chorionic gonadotrophin (hCG)