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 μg; vaginal: 800 μg). A second dose of misoprostol 400 μg was given 3 hours later (sublingually or vaginally). Women between 9 and 13 weeks of gestation received a further (third) dose of misoprostol 400 μg (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.