摘要：Obje.tive. We.aime. to de.e.mine.whe.he. se.ond- trime.te. abortion using isosorbide.mononitrate.(IMN) in addition to ge.e.rost is more.e.fe.tive.and re.uce. side.e.fe.ts compare. with ge.e.rost alone. Study de.ign: e.ghty wome. who we.e.age.13 to 23 we.ks’ ge.tation we.e.randomly assigne. to re.e.ve.pe. vaginam e.the. IMN 40 mg (group 1, 40 wome.) or place.o (group 2, 40 wome.) in addition to ge.e.rost 1 mg up to 3 time. daily 3 hours apart for 2 days. Analysis of variance. a χ 2 te.t, and a multivariate.analysis we.e.pe.forme.. Re.ults: Of the.72 wome. analyze., 68% (group 1) and 38% (group 2) unde.we.t abortion within day 1 (P <. 05). Howe.e., group 1 was associate. with more.he.dache.(18% of wome.) 3 hours afte. induction compare. to group 2 (0% of wome., P=.038). Conclusion: IMN in addition to ge.e.rost is e.fe.tive.for se.ond- trime.te. abortion, but is associate. with more.he.dache.compare. with ge.e.rost alone.