Maternal age and risk of cesarean section in women with induced labor at term - a Nordic register-based study

Abstract Introduction Over the last decades, induction of labor has increased in many countries along with increasing maternal age. We assessed the effects of maternal age and labor induction on cesarean section at term among nulliparous and multiparous women without previous cesarean section. Material and methods We performed a retrospective national registry-based study from Denmark, Finland, Iceland, Norway and Sweden including 3 398 586 deliveries between 2000 and 2011. We investigated the impact of age on cesarean section among 196 220 nulliparous and 188 158 multiparous women whose labor was induced, had single cephalic presentation at term and no previous cesarean section. Confounders comprised country, time-period and gestational age. Results In nulliparous women with induced labor the rate of cesarean section increased from 14.0% in women less than 20 years of age to 39.9% in women 40 years and older. Compared to women aged 25-29 years, the corresponding relative risk were 0.60 (95% confidence interval (CI); 0.57 to 0.64) and 1.72 (95% CI; 1.66 to 1.79). In multiparous induced women the risk of cesarean section was 3.9% in women less than 20 years rising to 9.1% in women 40 years and older. Compared to women aged 25-29 years, the relative risk were 0.86 (95% CI; 0.54 to 1.37) and 1.98 (95% CI; 1.84 to 2.12), respectively. There were minimal confounding effects of country, time-period and gestational age on risk for cesarean section. Conclusions Advanced maternal age is associated with increased risk of cesarean section in women undergoing labor induction with a single cephalic presentation at term without a previous cesarean section. The absolute risk of cesarean section is 3-5 times higher across 5-year age groups in nulliparous relative to multiparous women having induced labor.Peer reviewe

Cesarean section trends in the Nordic Countries - a comparative analysis with the Robson classification.

To access publisher's full text version of this article click on the hyperlink belowThe cesarean rates are low but increasing in most Nordic countries. Using the Robson classification, we analyzed which obstetric groups have contributed to the changes in the cesarean rates.Retrospective population-based registry study including all deliveries (3 398 586) between 2000 and 2011 in Denmark, Finland, Iceland, Norway and Sweden. The Robson group distribution, cesarean rate and contribution of each Robson group were analyzed nationally for four 3-year time periods. For each country, we analyzed which groups contributed to the change in the total cesarean rate.Between the first and the last time period studied, the total cesarean rates increased in Denmark (16.4 to 20.7%), Norway (14.4 to 16.5%) and Sweden (15.5 to 17.1%), but towards the end of our study, the cesarean rates stabilized or even decreased. The increase was explained mainly by increases in the absolute contribution from R5 (women with previous cesarean) and R2a (induced labor on nulliparous). In Finland, the cesarean rate decreased slightly (16.5 to 16.2%) mainly due to decrease among R5 and R6-R7 (breech presentation, nulliparous/multiparous). In Iceland, the cesarean rate decreased in all parturient groups (17.6 to 15.3%), most essentially among nulliparous women despite the increased induction rates.The increased total cesarean rates in the Nordic countries are explained by increased cesarean rates among nulliparous women, and by an increased percentage of women with previous cesarean. Meanwhile, induction rates on nulliparous increased significantly, but the impact on the total cesarean rate was unclear. The Robson classification facilitates benchmarking and targeting efforts for lowering the cesarean rates