In order to quantify the extent of the number of unregistered births and to identify the factors responsible for this, 2,893 interviews were carried out in a probabilistic sampling of homes in the urban area of Salvador, Bahia, in 1977. Thirty-two percent of the children under the age of 12 months identified in these interviews were still not registered. Excluding infants under 15 days of age, this percentage was 29.9%, and among children over 60 days old (the maximum period permitted by law) it fell to 27.5%. The intervening variables found to be positively associated with birth registration were maternal income, parental education, status of the residential area, coverage by social security, and baptism of the child. The probability of registration decreased at higher birth orders. Among the births registered, 41% were registered after the 15th day and 14% after the 60-day legal limit.
Birth certificates