Objectives: Induction of labour is one of the most common procedures used in obstetrics and its prevalence tends to increase. In patients with an unripe cervix (Bishop score < 7) pre-induction procedures are used before the start of oxytocin induction. Currently there is no consensus among scientific societies on the optimal way of pre-induction. We have conducted a single-centre retrospective observational study comparing obstetric induction results of patients after 37 weeks of gestation who were pre-induced with misoprostol vaginal insert (MVI) with 200 μg of misoprostol (Misodel - Ferring Pharmaceuticals Poland) or Foley catheter (20 F, 60 mL baloon).
Material and methods: We have reviewed the medical records of 503 patients (group A pre-induced MVI - 135 patients, group B pre-induced Foley catheter - 368 patients) who were in a single, full-term pregnancy, pre-induced due to unripe cervixes (Bishop score < 7) with a Foley catheter or Misodel (MVI 200 μg). We compared obstetric results between groups.
Results: Group A patients had a lower chance of using oxytocin in labour induction/augmentation (OR = 0.21 95% CI = 0.13-0.32), and a greater chance of surgical delivery by caesarean section (OR = 2.14 95% CI = 1.42-3.23) and vacuum extraction (OR = 3.29 95% CI = 1.08-10.00). Group A patients also had a greater chance of abnormal CTG (OR = 2.66 95% CI = 1.5-4.7) compared to group B. The groups did not differ in terms of meconium stained amniotic fluid and postpartum haemorrhage. The percentage of children born with a pH from umbilical cord blood < 7.2 and < 7.1 and newborns of medium general condition (Apgar 4-7) did not differ between the groups.
Conclusions: Neonatological results of children from Foley catheters and MVI induced delivery do not differ. Patients pre-induced with MVI rarely require labour augmentation with oxytocin. MVI-preinduced patients have a better chance of having a delivery by CS or VE compared to the Foley catheter.
Keywords: Foley catheter; cervical ripening; dinoproston; induction of labour; misoprostol.