Trends in cesarean birth rates in Iceland over a 19‐year period

Abstract

Background Cesarean birth (CB) rates have increased in high‐resource countries during the past two decades, yet it is not known whether CB rates have changed according to maternal age and/or gestational age. Methods All singleton live births in Iceland between 1997 and 2015 were identified from the Icelandic Medical Birth Registry (80 130). Rates of cesarean births (intrapartum and prelabor) were calculated overall and separately for maternal age groups and gestational age groups and by parity. Logit binomial regression was used to calculate odds ratios (ORs) and confidence intervals (CIs) for annual change in cesarean birth rates adjusted for maternal characteristics and clinical indication groups. Results The overall CB rate was 15.7% in 1997 and 15.8% in 2015; the CB rate did not change significantly during the study period. The overall CB rate for early‐term deliveries (37‐38 weeks) decreased for multiparas (annual aOR = 0.99 [95% CI = 0.98‐0.99]), and the preterm (<37 weeks) prelabor cesarean rate increased significantly (1.11 [1.09‐1.14]) for both primiparas and multiparas. For multiparas only, the intrapartum CB rate decreased (0.97 [0.97‐0.98]), whereas the prelabor CB rate increased, predominantly for women aged over 35 years (1.03 [1.02‐1.04]). Adjustment for clinical indication groups did not change these results. Conclusions Findings indicate a rise in prelabor cesarean for preterm births and women aged over 35 years (multiparas only). As adjustment for clinical indications did not affect these results, changes in obstetric practice are more likely to have affected these rate changes rather than changes in clinical indications.

Contributing indications to intrapartum and prelabor cesarean births in Iceland 1997‐2015

“…Thus, in recent years there has been a decrease in the relative contribution of more objective clinical indications and an increase in more subjective indications. This aligns with the increasing prelabor cesarean birth rate for multiparous women aged over 35 years in Iceland 2 …”

“…It appears therefore that there may be a shift away from more objective clinical indications toward more subjective indications, both in recent years and with increasing maternal age. In Iceland, the overall cesarean birth rate has not been increasing, 1 but the rate of prelabor cesarean birth has increased for multiparous women aged over 35, 2 perhaps reflecting the increase in contributing indications such as previous cesarean birth and fear of childbirth.…”

“…Around 4500 births occur in Iceland each year 11 with a cesarean birth rate of approximately 15%. This rate has remained relatively stable over the last 20 years 2 ; however, the rate of labor inductions has increased considerably 1 . For this study, data from singleton live‐births that occurred between 1 January 1997 and 31 December 2015 were retrieved from the Icelandic Medical Birth Registry (n = 80 130).…”

“…Evidence about cesarean birth indications and how they have changed over time could help shed light on the reasons for the rising cesarean birth rate globally and particularly in high‐resource countries. In Iceland, the overall cesarean birth rate has remained relatively stable over the last 20 years, 1 but the rate of prelabor cesarean birth has increased for multiparous women over age 35 2 . Previous studies have indicated a decrease in recent years in the contribution of indications such as malpresentation and maternal‐fetal indications, 3,4 alongside an increase in the contribution of indications such as previous cesarean birth 5‐8 .…”