Perinatal and infant mortality: trends and risk factors in Norway 1967-90.

Abstract

Neither the infant nor the under 24 hours mortality rates in Norway improved in the 1980s. The late neonatal mortality rate did not improve significantly in either the 1980s or the 1970s. The postneonatal mortality rate rose steadily throughout the last 15 years. The major mortality declines for all age groups took place in the 1970s. In the 1980s, only the 1-7-day mortality improved significantly. As a result, Norway fell behind in the international ranking of perinatal and infant mortality. Disparities among the perinatal mortality rates of Norwegian counties diminished throughout the 1970s. In the 1980s, the county disparities intermittently increased. Postneonatal deaths represented an increasing proportion; in the late 1980s, they amounted to half of the infant deaths and one-third of the total perinatal and infant deaths. In 1988, the postneonatal mortality rate was about twice as high in Norway as in Finland, Iceland, or Sweden. Birth injuries and infections almost disappeared as causes of perinatal and infant death. Other perinatal causes also diminished substantially. The incidence of congenital anomalies remained stable. The incidence of sudden infant death syndrome (SIDS), the single cause with continuous rate rise, more than doubled. In the late 1980s, SIDS caused one-quarter of the infant and more than half of the postneonatal deaths. The share of perinatal deaths from placentoumbilical causes (mostly placenta previa and abruptio placentae) and maternal diseases increased substantially. The affluence of Norway surged in the late 1970s and the 1980s, but health care was not given a higher priority. About 80% of fertile women used contraceptives. The use of modern methods increased substantially; oral contraceptives, in particular. About 60,000 confinements and 15,000 legally induced abortions took place in Norway each year. The number of induced abortions increased in women in their twenties, but decreased in all other age groups. As the total fertility decreased, each woman, on average, gave birth to 1.9 children and experienced 0.5 legally induced abortion. Maternal mortality was reduced to nil. Fewer marriages were contracted, and the divorce rate more than doubled. As a result, more than 35% of all births now occur out of wedlock, as compared with 5% in the late 1960s. The individual importance of birth out of wedlock as a risk factor has been reduced substantially. The mean maternal age increased from 26 to 28 years. The proportion of births by teenage mothers dropped from 8 to 3%.(ABSTRACT TRUNCATED AT 400 WORDS)