Comparison of extra-amniotic instillation of rivanol and PGF2alpha either separately or in combination followed by oxytocin for second trimester abortion.

Second trimester abortion was induced in 92 women by extra-amniotic instillation of Rivanol and/or PGF2alpha followed by intravenous oxytocin after 24 hours. All instillations were made via a catheter with a balloon filled with 30 ml and left in place until abortion, but never for more than 24 hours. Induction was started by Rivanol alone (n = 23), PGF2alpha alone (n = 23), Rivanol combined with PGF2alpha (n = 23), or Rivanol combined with half dose PGF2alpha (n = 23) and the patients were allotted to the different groups in a random manner. The Rivanol solution was instilled as a single dose but PGF2alpha was instilled every 2nd hour for 24 hours. The mean induction-abortion time was similar in all 4 groups but a number of patients given PGF2alpha alone or in combination with Rivanol aborted earlier than patients induced by Rivanol alone, during the period before intravenous oxytocin was administered. Gastrointestinal side effects were equally common after Rivanol as after PGF2alpha. With the methods and doses used in the present investigation PGF2alpha alone or combined with Rivanol with subsequent oxytocin had no over-all advantage over Rivanol.