Effects of misoprostol on uterine contractility following

BACKGROUND: The effect of misoprostol administered by different routes on pregnant uterine contractility was investigated. METHODS: Thirty-two women with a pregnancy between 8 and 11 weeks of gestation requesting ter-mination of pregnancy were recruited. Misoprostol was administered either orally (0.4 mg), vaginally (0.4 mg) or sublingually (0.2 or 0.4 mg) according to consecutive allocation. Intrauterine pressure was recorded using a Grass polygraph connected to a pressure transducer 30 min before misoprostol was given and for 4 h thereafter. At the end of the recording, suction curettage was performed. RESULTS: The ®rst effect observed was an increase in uterine tonus, which occurred after a signi®cantly shorter time following oral (7.8 min) and sublingual (10.7± 11.5 min) than after vaginal (19.4 min) treatment. The time to maximum tonus elevation was also signi®cantly shorter (39.5, 47.1±51.7 and 62.2 min for the three groups respectively). Regular uterine contractions developed in all subjects following sublingual and vaginal administration but not after oral administration. The increase in uterine activity measured in Montevideo Units was signi®cantly higher after 2 h and thereafter for sublingual and vaginal treatment than for oral misoprostol. CONCLUSIONS: Based on recording of uterine activity, sublingual misoprostol acts as rapidly as oral treatment, while development of contractions was similar to that seen following vaginal administration. Key words: misoprostol/pregnancy/sublingual administration/uterine contractilit