Misoprostol vaginal insert and Foley catheter in labour induction — single center retrospective observational study of obstetrical outcome

Abstract

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). 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. 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. 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.