Intermittent low-dose administration of prostaglandins intraamniotically in pathological pregnancies: A comparison with oxytocin and ergometrine

Abstract

The effects of prostaglandin F 2α on uterine contractility were compared with the effects of oxytocin and ergometrine. All patients had an intrauterine death. 5 patients were induced with prostaglandin F 2α, given intraamniotically in low doses, starting with 125 μg. Doses were increased in relation to uterine activity. 5 other patients were induced by intravenous administration of oxytocin and ergometrine. Uterine pressure was monitored by a transabdominal open-tip catheter system. Results were quantitated in tonus (mm Hg), amplitude (mm Hg), frequency (number of contractions per 10 min), Montevideo units, active and total pressure areas per 20 min. Possible biochemical and coagulation changes were controlled before, during and after induction. Changes did not occur. Intermittent increasing small doses of PGF 2α increased uterine activity exponentially. Hypertonia persisting longer than 5 min was seldom seen with oxytocin or with PGF 2α. Ergometrine increased frequency of uterine contractions, without influencing tonus, probably due to a specific effect on the ‘archemyometrium’. The induction-delivery interval was shorter in the PGF 2α group (range: 6–15 h) than in the oxytocin group (range: 7–24 h). In the latter group more inductions were necessary to complete delivery. Using PGF 2α in these small doses did not cause any side effects. With the intraamniotic injections, starting with 125 μg PGF 2α, clinical results are the same as those reported in the literature for high doses.