Factors associated with caesarean section in women referred for preinduction - a nested case-control study in...

Induction of labour is a beneficial perinatal procedure, but may be associated with some risks. The aim of this study was to identify factors associated with the need for Caesarean section in women referred for preinduction with dinoprostone and misoprostol.

It was a retrospective cohort study of 560 pregnant women who underwent labour induction for medical reasons. Analyses were performed separately in the dinoprostone and misoprostol group. Above other characteristics, the diameters of the pelvis and abdominal circumference of pregnant women were analysed.

There were some mothers' characteristics like age, weight, BMI, presence of hypothyroidism or diabetes, which were not associated with Caesarean section deliveries. Women in the misoprostol group with gestational age less than 38 weeks had an increased risk of Caesarean section (OR 2.189; p = 0.041). The analyses of combined effect of mothers age and parity history showed 6.7 (in dinoprostone group) and over 10 times (in misoprostol group) increased the risk of Caesarean section in nulliparous women over 35 years of age.

The increased risk of Caesarean delivery in the dinoprostone group was combined with the intertrochanteric dimensions such as the mother's height measuring less than 165 cm, nulliparity and hypertension. In the misoprostol group, strong risk factors for Caesarean delivery were mothers aged 35 years or more, gestational age less than 38 weeks and nulliparity and hypertension as in dinoprostone group. The oxytocin infusion had increased the risk of Caesarean section only in the combined dinoprostone and misoprostol group. Further high-quality studies are warranted.