Trends and factors in infant mortality in developed countries and the republics of the former Soviet Union

This work analyzes infant mortality declines over the past two decades in the developed countries and in the former Soviet Union and performs a multivariate analysis relating health and socioeconomic conditions and the status of women to infant mortality trends. The continuing decline of infant mortality rates in the developed countries has been somewhat surprising. In the early 1970s the infant mortality rate was under 15/1000 live births in only a handful of countries but by 1991 it was under 10/1000 in the great majority of developed countries and it reached about 5/1000 in Japan and Finland. The decline has however been slower in Eastern Europe and the former Soviet Union. Infant mortality rates around 1991 were estimated at 15.9 in Poland 20.2 in Yugoslavia 21.8 in the USSR and 25.7 in Romania significantly in excess of the average of 12.8 for the thirty countries considered. The declines were due primarily to declines in early neonatal mortality in the countries where infant mortality rates were low in 1970. The proportion of infant deaths in the neonatal period declined from around two-thirds to under 50% in these countries. In countries with relatively higher infant mortality rates in 1970 neonatal deaths now account for an increased proportion. Differences in the diagnosis of causes of death and in the importance of the "poorly defined" category in different countries and successive changes in the International Classification of Diseases hamper comparisons but it is clear that changes have occurred in the distribution of deaths by cause in the developed countries. In general congenital anomalies and perinatal causes predominate although their weight varies country by country. Underregistration of early deaths and uneven quality of data hamper internal and international comparisons in the republics of the former Soviet Union. Soviet mortality statistics generally exclude infants born alive after gestations of under 28 weeks or weighing less than 1000 g or measuring under 35 cm who die in the first week of life. Introduction of a certificate of perinatal death in the 1970s improved the situation to some extent. Underregistration of infant deaths affects primarily rural areas where births may occur at home. The most recent infant mortality rates in the former Soviet Union vary from 10.3/1000 in Lithuania to 46.6 in Turkmenistan. The former Soviet republics show profound dualism in the levels and structures by age and cause of infant deaths with the Baltic republics Belarus Ukraine and Russia more similar to the Western European countries. The Central Asian republics have high infant mortality rates comparable to those of some developing countries. Factor analysis using an array of indicators of economic and health development and of the status of women showed a strong correlation of these factors with infant mortality.