PERINATAL MORTALITY AND SURVIVAL. II. COMPARISONS BETWEEN POPULATION GROUPS.

If the time span of risk of perinatal death is defined as the period from 20 weeks gestation through 27 days after birth, 97 out of 100 infants born in California during 1959 were born alive and survived the first month of life. The California State Department of Public Health made an analysis of descriptive items from 358,388 birth and 10,916 death certificates to identify demographic characteristics associated with perinatal mortality and survival. Maturity of the infant was the single most important factor; two-thirds of all perinatal mortality was among infants weighing 2,500 grams or less. An infant premature by any two of three criteria (birth weight, birth length or gestation) had less chance of surviving than an infant premature by only one; infants premature by all three measures had the poorest prospect of being born alive and surviving one month. Nonwhite premature infants fared better than white; Oriental infants of all weights showed remarkable survival capacity. Female infants of all races had a survival advantage over males up to weights of 4,501 grams or more.Certain "high-risk" groups of infants were identified: Infants premature by more than one criterion, Negro infants, infants who were one of a set of twins or triplets, infants born to older mothers or to very young multiparae, infants of mothers with four or more previous live births, those born by cesarean section, infants of families in low income occupations, infants of military personnel, infants born in county or federal hospitals, those born outside a hospital, those born to mothers who had no prenatal care and those born in northern, mountain counties.