Characteristics and outcome of unplanned out-of-institution births in Norway from 1999 to 2013: a cross-sectional study.

Abstract

To study the incidence, maternal characteristics and outcome of unplanned out-of-institution births (= unplanned births) in Norway. Register-based cross-sectional study. All births in Norway (n = 892 137) from 1999 to 2013 with gestational age ≥22 weeks. Analysis of data from the Medical Birth Registry of Norway from 1999 to 2013. Unplanned births (n = 6062) were compared with all other births (reference group). The annual incidence rate of unplanned births was 6.8/1000 births and remained stable during the period of study. Young multiparous women residing in remote municipalities were at the highest risk of experiencing unplanned births. The unplanned birth group had higher perinatal mortality rate for the period, 11.4/1000 compared with 4.9/1000 for the reference group (incidence rate ratio 2.31, 95% confidence interval 1.82-2.93, p < 0.001). Annual perinatal mortality rate for unplanned births did not change significantly (p = 0.80) but declined on average by 3% per year in the reference group (p < 0.001). The unplanned birth group had a lower proportion of live births in all birthweight categories. Live born neonates with a birthweight of 750-999 g in the unplanned birth group had a more than five times higher mortality rate during the first week of life, compared with reference births in the same birthweight category. Unplanned births are associated with adverse outcome. Excessive mortality is possibly caused by reduced availability of necessary medical interventions for vulnerable newborns out-of-hospital.