[Dose study of methyl carboprost suppository for planned delivery at term]

To investigate clinical reasonable dose of methyl carboprost suppository (15-methyl-PGF2 alpha) for induction of labor.

A total of 150 gravidas with singleton pregnancy and cephalic presentation, accepted for induction of labor, were randomly allocated into 3 groups: group 1, 15-methyl-PGF2 alpha 0.100 mg (n = 50); group 2, 0.125 mg (n = 50); and group 3, 0.200 mg (n = 50).

The success rates of induction were 90.0%, 94.0% and 100.0% for group 1, 2 and 3, respectively. As cervical Bishop score < or = 5, the cases needed oxytocin intravenous infusion during the active phase were 48.5%, 40.7% and 5.0%, respectively; cervical Bishop score > or = 6, the cases were 11.8%, 13.0% and 0.0%, respectively. There were 3 cases of precipitate delivery in group 2 and 3. No uterine hyperstimulation occurred in group 1 and 2, while 3 cases of uterine hyperstimulation in group 3.

(1) A single maximum dose of 15 methyl-PGF2 alpha for term labor induction should be < 0.200 mg. (2) The different dose was chosen according to cervical Bishop score, i.e. 0.200 mg or 0.125 mg for Bishop score < or = 5, and 0.100 mg for Bishop score > or = 6.