Termination of second trimester pregnancy with a long‐acting vaginal pessary containing 15‐methyl‐PGF2α methyl ester

This report summarizes the results of three studies comprising 1147 second trimester patients admitted to 11 different centres for termination of pregnancy. In the first study, mainly early second trimester patients received one long‐acting vaginal pessary containing 3.0 mg 15‐methyl‐PGF 2α methyl ester, in the second study the pessary was randomly compared with intraamniotic administration of 2.5 mg 15‐methyl‐PGF 2α in late second trimester patients (after the 15th week of gestation), and in the third study the same type of patients received the long‐acting pessary complemented, if necessary at 24 h, with intramuscular injections of 15‐methyl‐PGF 2α (0.2–0.4 mg every third hour) for up to 12 h. The efficacy of the long‐acting pessary was related to the duration of pregnancy. In patients 15 weeks or less pregnant, the frequency of abortion was 81.2% within 30 h; in pregnancies greater than 15 weeks duration the success was 73.3% (P < 0.05). Both vaginal administration of the long‐acting pessary containing 15‐methyl‐PGF 2α methyl ester and intraamniotic administration of 15‐methyl‐PGF 2α were equally effective during the first 24 h following start of therapy. However, within the next 6 h, the intraamniotic administration was found to be significantly superior, especially in patients with a more advanced pregnancy. To achieve an efficacy comparable to the intrauterine treatment, it was necessary to add intramuscular injections of 15‐methyl‐PGF 2α . This combined treatment resulted, however, in an increased frequency of cervical laceration. The results of the present study indicate that a treatment with a long‐acting pessary is useful in second trimester pregnancy up to the 15th week of gestation, when puncture of the amniotic sac is difficult. After the 15th week of pregnancy, intraamniotic administration of 15‐methyl‐PGF 2α appears to be a more effective method with less side effects despite the invasive route of administration. The long‐acting pessary in conjunction with intramuscular supplement is equally effective if appropriately given.