[Birth weight and hospital mortality among liveborn infants, 1975-1996]. / Peso ao nascer e mortalidade hospitalar entre nascidos vivos, 1975-1996.

OBJECTIVE: To assess the trend of birth weight and hospital mortality rate of newborns, in a maternity hospital of Campinas, SP. METHODS: A total of 215,435 births of a maternity hospital in Campinas, S. Paulo State, Brazil, was studied between 1976 and 1996. Information was collected from registration files and annual reports of medical care. All the newborns from that period were included. The causes of death that occurred before the discharge, regardless the age, were analyzed. For data analysis, Epi info 6.01 method was used. RESULTS: Birth weight distribution remained the same for the 22 years period studied. Low birth weight was seen in about 9% of newborns, and accounted for 82% of hospital deaths in 1996. Below average weight was observed in about 24% of the newborns. We could notice an improvement in survival for those who had a birth weight between 1,000 g and 1,999 g. In 1975, 13.3% of those with weights between 1,000 g and 1,499 g survived and 73.8% of those who weighed between 1,500 g and 1,999 g. In 1996, survival rates increased to 69. 1% and 87.7% respectively. Hospital mortality rate among infants whose weight was below 1,000 g remained high, between 78.9% and 100%, even in the 90's. There was a reduction of hospital mortality rates from 17 to 11 per thousand live births. CONCLUSIONS: There was not any change in the distribution of birth weight despite improvements in life conditions of Campinas population. The decrease in mortality rates is due to improvement in health care which is very expensive. There is a need of other studies to allow why birth weight distribution remained the same.

[Birth weight and maternal characteristics at the Maternity of Campinas along 25 years] / Peso ao nascer e características maternas ao longo de 25 anos na Maternidade de Campinas.

OBJECTIVE: To study the secular trends of birthweight and maternal characteristics at the Maternity of Campinas, São Paulo, Brazil, from 1971 to 1995. METHODS: The authors studied 18,262 newborns in the Maternity of Campinas. Birthweight and maternal characteristics were analyzed comparing changes occurred every 5 years. The data were analyzed by chi-square test, analysis of variance, multivariate logistic regression, and population attributable risk. RESULTS: The results showed a positive trend for birthweight only in the period between 1976 and 1980 (P<0.05). The frequency of low birthweight was constant, remaining around 8.0%, but towards the end of the studied period, it started to be predominantly seen among preterm newborns. The frequency of favorable weight was below 70.0%. The authors observed an increase in the number of pregnant adolescents, pregnant women working outside home, unmarried mothers, cesarean sections, frequency of preterms, and decrease of parity (P<0.05). The maternal characteristics associated with low birthweight were: unmarried status, maternal age of 17 years old or less, maternal age of 35 years or more, public medical-hospital assistance, nonwhite skin color, primiparity, multiparity, and female newborns. In the 90s, 44.3% of low birthweight was attributed to preterm newborns. CONCLUSIONS: Even with a positive development of the general conditions considered important to improve population s health, birthweight has not increased, probably as a reflex of other changes that held back this advance.

[Is adolescent pregnancy a risk factor for low birth weight?] / A gravidez na adolescência é fator de risco para o baixo peso ao nascer?

OBJECTIVE: This paper was designed to study the pregnancy in adolescence as a risk factor for low birth weight.METHODOLOGY: A case-control study was designed, including 354 mothers whose babies' weight was less than 2.5 kg and another group of the same size, with babies of 3.0 kg or more. All deliveries took place at Maternidade de Campinas, and all mothers were interviewed and compared. Besides mother's age, other variables that could offer risk of low birth weight were also evaluated. A multiple logistic regression analysis was applied, to control possible influences of these variables.RESULTS: Adolescents accounted for 22.9% of the mothers whose babies had low birth weight. The risk of low birth weight among this group (OR=0.72; 95%IC=0.45-1.14; p=0.16) was not considered greater when compared with that of mothers between 20 and 34 years old (before and after correction for income, marital status, educational level, race, previous pregnancies, prenatal assistance, exposure to smoking and caffeine, arterial hypertension, weight prior to pregnancy and employment). Complementary analysis showed that pregnancy in adolescence is a protection factor against intrauterine growth retardation (OR=0.24; 95%IC =0.10-0.56; p= 0.001).CONCLUSION: In this population, pregnancy in adolescence did not represent a greater risk for occurrence of low birth weight, when others factors like psychosocial, pre-gestational risks, smoking and poor prenatal care were controlled for.