Estimation of perinatal mortalities in the world's countries from maternal mortalities.

Perinatal mortality was estimated by the regression equation log10 Y = 0.7826log10X + 0.08, obtained by perinatal mortality (Y) and maternal mortality (X) in Japan in 1960-1990. The error rate was approximately 9% in the estimation. Unpublished Japanese perinatal mortality in 1899-1947 was estimated from maternal mortality by using the equation, and appropriate results were obtained. Perinatal mortalities of the world's countries were estimated from their maternal mortalities listed in UNICEF reports with use of the above equation. Two peaks were noted in the country number distribution at 0-19 and 120-140 of estimated perinatal mortality. The mortality was 20-99 in 43% of 111 countries analyzed and 100 or more in 25%. The results suggest that further efforts should be made for the improvement of worldwide maternal and child health.