Objective: To assess women's acceptability, the efficacy and side effects of sublingual versus vaginal administration of misoprostol in combination with mifepristone for medical abortion up to 13 weeks of gestation.
Design: Randomised controlled trial.
Setting: Aberdeen Royal Infirmary.
Population: Women undergoing medical abortion under the terms of the 1967 Abortion Act.
Methods: Mifepristone (200 mg) was given orally followed 36-48 hours later by misoprostol administration (sublingual: 600 microg; vaginal: 800 microg). A second dose of misoprostol 400 microg was given 3 hours later (sublingually or vaginally). Women between 9 and 13 weeks of gestation received a further (third) dose of misoprostol 400 microg (sublingually or vaginally), 3 hours later if abortion had not occurred.
Main outcome measures: Women's acceptability, efficacy of the regimen and side effects experienced.
Results: A total of 340 women were recruited (171 sublingual and 169 vaginal). A total of 70% of women in the sublingual group expressed satisfaction with the route of misoprostol administration; 18% answered 'Don't know' while 12% were dissatisfied, compared with 68%, 28% and 4%, respectively, in the vaginal group (P= 0.02). There was no significant difference in the need for surgical evacuation for women in the sublingual (3/158, 1.9%) and vaginal groups (4/156, 2.6%) (P= 0.70). Women receiving misoprostol sublingually were more likely to experience diarrhoea (P < 0.01), shivering (P < 0.01) and unpleasant mouth taste (P < 0.01).
Conclusions: Sublingual administration of misoprostol is an effective alternative to vaginal administration for medical abortion up to 13 weeks of gestation. The prevalence of prostaglandin-related side effects, however, was higher with this route of administration.