Print version ISSN 0034-8910
Rev. Saúde Pública vol.18 n.4 São Paulo Aug. 1984
Department of Epidemiology School of Public Health/USP
As infant mortality has been reduced, the deaths of children of less than one year of age have come to be concentrated in the weeks nearer birth, and the so-called "neonatal mortality" (during the first 28 days of life) has come to account, practically alone, for almost all infant deaths. This is what has been observed in developed countries or areas and, with the increase of that reduction the deaths have become even more concentrated, occuring almost exclusively during the first week of life (the early neonatal period). This is precisely what is observed in countries where infant mortality has already reached figures lower than 10 per 1,000 live-births, in some cases the figures reaching values lower than 7 per 1,000.
Both early neonatal deaths and late fetal deaths (stillbirths) are due to the same causes and factors, thence the importance of studying them together, which group constitutes what have come to be called "perinatal deaths", that is, those deaths occuring in the perinatal period. The term "perinatal" was proposed by Peller in 1940, who considered it necessary to analyse, as a single "statistical unit", the sum of stillbirths and the deaths occuring during the first postnatal week. In a 1965 publication this author wrote:. . . "Stillbirths and deaths which occur within a few days after birth have in common a complex of causes which differ from the pattern in older infants. For this reason, and because of customs, religious attitudes and laws concerning registration of birth which hampered international comparisons, 1 have since 1923 considered it necessary to analyse as one statistical unit the sum of stillbirths (late fetal deaths) and deaths during the first week ... in the 1940's 1 suggested that this unit be termed perinatal mortality . . . The term caught on in the early 1950's".
In order better to realize the importance of understanding what occurs in this period, it is interesting to note that in many countries at the present time, the number of perinatal deaths excedes that observed during the following 30 years, even though the perinatal period represents less than 0.5% of the average life span.
In Brazil, as well as in other countries where infant mortality stands high, it is important to know the causes and factors responsible for perinatal mortality. This, among us, reaches a very considerable figure, being much higher than that observed in developed areas, although it is relatively less important when compared to the infant mortality rates as a whole. Indeed, in countries where infant mortality falls between values of 8 and 15 per 1,000 live-births, perinatal mortality attains a rate of between 12 and 20 per 1,000 live-births and stillbirths. While infant mortality in the municipality of São Paulo, Brazil, was near 90 per 1,000 in 1976, and perinatal mortality was 40.5 per 1,000, these figures became, respectively, 52.4 and 28.8 per 1,000 in 1981.
Although we are in the phase of reducing the so-called "exogenous causes" of infant mortality, it is important to have a profound knowledge of the "endogenous" (or biological) causes and factors which are responsible for almost all infant deaths occuring during the first weeks of life. The study of perinatal mortality leads to the knowledge which would make it possible, by means the taking of specific action, to reduce this mortality and, therefore, infant mortality as a whole.
Hence the need for studies, unusual among us, which would open the way to a full understanding of perinatal mortality. In this issue of the Revista de Saúde Pública there is an article on "Perinatal Health in Pelotas, Rio Grande do Sul, Brazil: social and biological factors", by Fernando C. Barros and collaborators, with regard to which it is worth emphasizing the methodology used, based on the follow-up of births, at maternity hospitals, such as makes it possible to gather data concerning significant, variables such as: maternal age, smoking habits, prenatal care, previous pregnancies, birth-order, birth weight and so on. In addition, it permits one to get to know the causes of death, with greater reliability than is possible to judge from the sometimes insatisfactory completion of death certificates.
A similar study was carried out at the "WHO Collaborating Center for the Classification of Diseases in Portuguese" ("Brazilian Center for the Classification of Diseases") of the School of Public Health of the University of São Paulo (USP). Data concerning births at nine maternity hospitals (seven in the State of São Paulo, one in Rio de Janeiro and another in Florianópolis, Brazil, were collected and the findings are shortly due for publication.
The carrying out of similar projects in different areas of Brazil is an urgent necessity, since it would provide a better knowledge of perinatal morbidity and mortality among us, and would permit characterization of the maternal, fetal, maternal-fetal and environmental factors. It will only be by means of such knowledge that it will be possible to take action with a view to the reduction of perinatal mortality.
PELLER, S. Proper delineation of the neonatal period in perinatal mortality. Amer. J. publ. Hlth, 55: 1005-11, 1965.