The unborn and newborn child. I. Risk factors predicting complicated delivery in a general population of 4,102 women.

Among the 56 risk factors (RF) in pregnant women, used by the Danish National Board of Health, those that can predict complicated delivery (CD) were identified. The significance of parity, maternal age, social class and civil status was also analysed. The material comprises a Danish county cohort of 4,102 deliveries. The 56 original RFs affected 56% of the population. Women (8.8%) with twin pregnancy, fetus in breech, footling and transverse lie, or having an elective cesarean section were analysed separately. The incidence of CD was otherwise 39%. Of all the women, 8.7% had only prepregnancy RFs with a CD rate of 52%; 19.2% had only pregnancy RFs other than special conditions mentioned with a CD rate of 52%; 3.6% had both prepregnancy and pregnancy RFs with a CD rate of 62%. When the special conditions separately analysed were included, 14 RFs of the original 56 were found to predict complicated delivery. These affected 40% of the population. Primiparity was also a RF. The conceptional age of a primipara raised the odds in favor of CD by a factor 1.09 for each year. Social class and civil status were of no significance for CD.