Time trends in caesarean section rates and associations with perinatal and neonatal health: a population-based cohort study of 1 153 789 births in Norway

Abstract

Objectives To study caesarean section (CS) rates and associations with perinatal and neonatal health in Norway during 1999–2018. Design Population-based cohort study. Setting Medical Birth Registry of Norway. Participants 1 153 789 births and 1 174 066 newborns. Methods CS, intrapartum, perinatal and neonatal mortality rates expressed as percentages (%) or per mille (‰) with 95% CIs. Primary and secondary outcome measures CS rates in the Robson Ten-Group Classification System; intrapartum, perinatal and neonatal mortality rates. Results The overall CS rate increased from 12.9% in 1999 to 16.7% in 2008 (p<0.001), and then reduced to 15.8% in 2018 (p<0.001). The largest reductions were observed in Robson groups 2 and 4. In Robson group 2, the planned CS rate decreased from 9.6% in 2007–2008 to 4.6% in 2017–2018, the intrapartum CS rate decreased from 26.6% in 2007–2008 to 22.3% in 2017–2018. In Robson group 4, the planned CS rate decreased from 16.1% in 2007–2008 to 7.6% in 2017–2018, and the intrapartum CS rate decreased from 7.8% in 2007–2008 to 5.2% in 2017–2018. The intrapartum fetal mortality rate decreased from 0.51 per 1000 (‰) in 1999–2000 to 0.14‰ in 2017–2018. Neonatal mortality decreased from 2.52‰ to 1.58‰. Conclusions CS rates in Norway increased between 1999 and 2008, followed by a significant reduction between 2008 and 2018. At the same time, fetal and neonatal mortality rates decreased. Norwegian obstetricians and midwives have contributed to maintaining a low CS rate under 17%. These findings indicate that restricting the use of CS is a safe option for perinatal health.