The use of prostaglandin E2 (PGE2) for induction of labour in women with unfavourable
cervices is well-established1. There are, however, potential side effects to prostaglandins,
in particular the risk of uterine hypertonicity which may affect fetal outcome. In theory a
mechanical ripening based on dilatation of the cervix as well as induction of production of
endogenous prostaglandin has potentially less influence on the fetal outcome but a Cochrane
review from 2001 scrutinized studies on mechanical ripening versus placebo/no treatment or
prostaglandin E2. They conclude there is insufficient data to evaluate the effectiveness in
terms of likelihood of vaginal delivery in 24 hours, and emphasise the need for large sample
size studies and substantive outcomes. Two later randomised studies compared mechanical
ripening to PGE2 and found discrepant results regarding time from induction to delivery.
The primary purpose of the present study was in a randomized design to compare the efficacy
of double-balloon catheter versus vaginal PGE2 (minprostin 3 mg) on induction of labour,
duration of birth and fetal outcome. Secondary analyses were to evaluate the results for
various subgroups, i.e. primipara/multipara, gemelli, vaginal birth after caesarean, preterm
birth and intra uterine growth restriction.