PERINATAL MORTALITY AND SURVIVAL. A COMPARISON OF EXPERIENCE IN CALIFORNIA IN 1949 AND 1959. I--STATISTICAL TRENDS.

The California State Department of Public Health has made an analysis of descriptive items from 369,304 birth and death certificates for 1959 and 252,400 certificates for 1949 in order to identify demographic characteristics associated with perinatal mortality and survival. If the time span of risk of perinatal death is defined as 20 weeks gestation through 27 days after birth, 97 of 100 infants born in California during 1949 and 1959 were born alive and survived the first month of life. Fetal and neonatal death rates decreased over the decade to new lows. Since most of the improvement was among infants that weighed 2,501 grams or more at birth, a greater proportion of all perinatal deaths occurred among premature infants in 1959 than 1949. Survival chances for premature infants remained 75 out of 100 total births. Trends shown by a comparison of the years 1949 and 1959 include a 47 per cent increase in number of births, proportionately more births to mothers under 20 and to women with four or more previous live births, more Negro births and fewer births outside a hospital. An important gain in perinatal survival was found among babies of multiparous mothers. All types of hospitals had lower fetal and neonatal mortality, but county hospitals showed the greatest improvement. Less populated areas lowered their perinatal death rates more than major metropolitan areas when average rates for 1945-1949 and 1955-1959 were compared.