How does preference for natural childbirth relate to the actual mode of delivery? a population-based cohort study from Norway.

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.