Has perinatal outcome improved after introduction of a guideline in favour of routine induction and increased surveillance prior to 42 weeks of gestation?: A cross-sectional population-based registry study

To investigate whether new national guidelines of routine induction of labour and increased surveillance in low risk pregnancies at 41 weeks of gestation as an alternative to expectant management until 42 weeks of gestation has improved perinatal outcome. A questionnaire-based study regarding local induction practices among all Danish delivery units and a cross-sectional population-based registry study based on data from the Danish Medical Birth Registry (DMBR) in the years 2009-2012. Primary outcomes were frequencies of induced labour and perinatal mortality; secondary outcomes were indicators of perinatal morbidity and instrumental delivery rates. The questionnaire data showed that 22 of the 24 Danish delivery units complied with the new guidelines in 2012. The study population retrieved from the DMBR included 36,845 low-risk pregnancies at or beyond 41 weeks of gestation. The number of labour inductions within the study population had doubled after implementation of the new guideline. The increased proportion of induced labour did not appear to influence perinatal morbidity or instrumental delivery rates. Perinatal mortality remained steady in the years 2009, 2010 and 2011 whereas a reduction of 60 % was seen in 2012. However, this change was not statistically significant (P = 0.10). This population-based study with a high reported adherence to the new national guideline found no changes in instrumental deliveries or perinatal outcomes after implementation of earlier routine induction of labour and increased surveillance in low risk pregnancies.