Abstract: Background: In Norway, intervention in childbirth has increased from 3 percent in 1967 to 37 percent in 2006. The objectives of this study were, first, to estimate to which extent women who expressed a preference for natural birth actually were delivered vaginally without interventions, and second, to estimate the influence that emotions and maternal background factors have on the mode of delivery.
Methods: We used data from 39,475 pregnancies of participants in the Norwegian Mother and Child Cohort Study in which the pregnant woman had expressed a preference for natural birth, and linked these data with the pregnancy outcome as registered in the population-based Medical Birth Registry of Norway during 2000 to 2006. The influence of maternal factors on the mode of delivery was estimated with log-binomial regression models, stratified by parity.
Results: Among primiparas, 29.3 percent delivered vaginally without interventions (natural birth), 56.1 percent gave birth vaginally with interventions, and 14.5 percent had a cesarean section. The strongest predictor for actually having a natural birth was age below 25 years, having more than 12 years’ education, carrying a single fetus, and having a low score for anxiety and depression. Among multiparas, 61.1 percent gave birth vaginally without interventions, 30.6 percent vaginally with interventions, and only 8.3 percent had a cesarean section. The effects of maternal age, education, and anxiety or depression on the outcome were smaller for multiparas than for primiparas.
Conclusions: The chance of actually having a natural birth for women with a preference for a natural birth is much greater for multiparas than for primiparas. The factors that influence the chance of having a natural birth are different for primiparas and multiparas. (BIRTH 37:1 March 2010)