Pregnancy risk increases from 41 weeks of gestation

Background. The aim of this study was to evaluate the mortality and morbidity of conservatively managed post-term pregnancies (gestation 294 days and beyond). Materials and methods. This is a population-based prospective study. The sample was comprised of all women (N=17 493) with a singleton pregnancy in one Norwegian county from 1989 to 1999, with a second-trimester ultrasound examination and delivery after 37 completed gestational weeks. Results. One thousand three hundred and thirty-six (7.6%) of the deliveries were post-term. In this group, the increase in perinatal mortality reached borderline significance [relative risk (RR) 2.0; 95% confidence interval 0.9-4.6]. Perinatal morbidity expressed as Apgar score