Which types of perinatal events are predictable? A look at a risk score model

This study describes the association of a risk factor model for complicated delivery, perinatal morbidity and perinatal mortality with each of various types of delivery complications, types of perinatal morbidity and causes of perinatal mortality. The material comprises a total cohort, 4,066 pregnant women with singletons in a Danish county, and their newborn infants, of whom 494 (12%) had clinical morbidity during the first 5 days of life; 28 (0.7%) died perinatally. A set of 20 risk factors, identifiable before pregnancy, at any time during the pregnancy or at term, was devised by joining existing models for prediction of complicated delivery and of perinatal morbidity and mortality. Metabolic and disproportion-related events were well predicted by the model, inertia-related ones less so, and placental conditions not at all, except for abruption. All types of neonatal morbidity (except sepsis) were well predicted, as were deaths. The strongest predictors of perinatal death were signs of hydramnios (RR = 16.1) and growth retardation (RR = 7.2). The 20 risk factors affected 43% of the population, predicting 57% of the unfavorable perinatal events.