Over the past years, the rates of labor induction have increased steadily, and at present
more than one in four births occurs after induced labor in Norway. There is evidence that
several groups of women benefit from labor induction, including those with preeclampsia (1),
postdate pregnancy, diabetes, a large-for-gestational-age fetus, gestational diabetes,
prelabor rupture of membranes at term, preterm prelabor rupture of membranes, twin pregnancy
and intrahepatic cholestasis of pregnancy.
At the same time, induction of labor is an independent risk factor for adverse obstetric
outcomes, including cesarean section, operative vaginal delivery, chorioamnionitis, labor
dystocia, prolonged labor, uterine rupture, and neonatal pH < 7.10. A recent Norwegian
nationwide clinical practice pilot evaluation demonstrated that the rate of intervention was
high, and that as many as 44% of women with labor induction experienced operative delivery.
Given that induction of labor is a common procedure (15 000 women per year in Norway) and
increases risk of several major obstetric complications, interventions that may reduce
operative births and facilitate safe deliveries are highly warranted.
Bicarbonate and butylscopolamine bromide have been used in smaller studies in order to
shorten labor. The medications seem to be safe with a low frequency of adverse events.
The rationale of the present study is therefore to assess the efficacy of oral bicarbonate
and intravenous butylscopolamine bromide on facilitating spontaneous (non-operative) delivery
in pregnant female participants with induction of labor.