BUSCLAB - Buscopan to Prevent Slow Progress in Labor

Inclusion Criteria: * ≥18 years * Primiparous women * Spontaneous onset of labor * Active phase of labor * ≥37 weeks of gestation * Vertex position * Crossing the alert line, i.e. cervical dilatation of less than one cm per hour in the active phase of first stage of labour (cervix dilation ≥3 - \<10 cm) * Signed informed consent and expected cooperation of the patients for the treatment and follow up must be obtained and documented according to ICH GCP and national and local regulations Exclusion Criteria: * Multiple gestation * Elective cesarean section * Women in labor already receiving oxytocin when crossing the alert line * Fully dilated cervix when crossing the alert line * Preeclampsia defined as blood pressure ≥140/90 and proteinuria (1 or more on a urine dipstick on more than one occasion) with debut after 20 weeks of pregnancy * Known intestinal stenosis, ileus or megacolon * Persisting maternal tachycardia (heart rate \>130 beats per minute) * Known maternal myasthenia gravis * Persisting fetal tachycardia (fetal heart rate baseline \>170 beats per minute) * Hypersensitivity to any of the ingredients in IMP or placebo (butylscopolamine bromide or sodium chloride) * Women with heart disease who are under surveillance with heart rate monitoring during labor * Known fetal heart disease * Untreated glaucoma