Decline in stillbirths and perinatal mortality after implementation of a more aggressive induction policy in post-date pregnancies: A nationwide register study

INTRODUCTION: In 2011 the Danish national guidelines were changed towards a more aggressive induction and fetal surveillance policy from 1) induction of labor at gestational age (GA) of 42(+0) weeks and 2) no fetal surveillance after 40(+0) to 1) induction of labor between 41(+2) -41(+6) , 2) earlier induction at 41(+0) weeks in case of maternal age > 40 years or body mass index (BMI) > 35 kg/m(2) and 3) fetal surveillance at GA 41(+0) .

MATERIAL AND METHODS: This national cohort study included all pregnancies that reached 41(+0) weeks of gestation from 2008 to 2014 (N=102 167). Multivariate logistic regression analyses were used to estimate risks in the years after (2012-2014) versus before (2008-2010) new national guidelines, adjusted for maternal age, BMI, and parity.

RESULTS: We observed a decline in stillbirths from 0.9‰ to 0.5 ‰ (odds ratio (OR)adjusted 0.50, 95%CI;0.29-0.89, p=0.018). Furthermore a decline in perinatal deaths from 1.3‰ to 0.8‰ (ORadjusted 0.62, 95%CI;0.39-0.96, p=0.033) and vacuum extraction (ORadjusted 0.86, 95%CI;0.82-0.90, p=0.007) was observed. The risk of Cesarean section (ORadjusted 0.98, 95%CI;0.94-1.02, p=0.251), Apgar score below 7 at 5 minutes (ORadjusted 0.96, 95%CI;0.81-1.14, p=0.0.678) and admissions to the neonatal department (ORadjusted 1.04, 95%CI;1.00-1.14, p=0.064) did not change, while induction of labor increased from 28.2% to 42.6% (ORadjusted 1.89, 95%CI;1.84-1.95, p<0.001).

CONCLUSIONS: This study showed a decline in stillbirths and perinatal mortality after implementation of new Danish guidelines for post-date pregnancies. The risk of interventions as Cesarean section and vacuum extraction remained stable despite an increase in labor inductions. This article is protected by copyright. All rights reserved.