Factors associated with stillbirth in a school maternity in Pernambuco: a case control study

PURPOSE: to investigate the main factors associated with fetal death in the city of Recife, Pernambuco, Brazil. METHODS: an observational, case-control study, including cases attended from June 1st 2004 to 31st March 2005. A number of 116 stillbirth cases and 472 live birth controls, with deliveries assisted at the service, were included. The cases were identified in the record book from the delivery room. The puerperium women were identified by the name and register number at a puerperium infirmary. The controls were selected, using the puerperium infirmary neighborhood criterion, identifying the beds with numbers immediately lower (two patients) and higher (two patients) than the patient's, as far as they had delivered live babies. In case they did not agree to participate in the research, the next beds with numbers consecutively lower or higher were approached. The chi(2) association and Fisher's exact tests were used when necessary to test the association between the independent (predictive) and dependent (stillborn) variables, considering 5% as the significance level. To determine the association strength, the estimate of relative risk for case-control cases, Odds Ratio (OR) was used, with 95% as the confidence interval (CI). Logistic regression analysis according to the hierarchy model was done to control confounding factors. RESULTS: the fetal mortality rate corresponded to 24.4 by 1,000 births. After the multivariate analysis, the variables which kept significantly associated with fetal death were: malformation (OR=7.5; CI=3.2-17.4), number of pre-natal appointments lower than six (OR=4.4; CI=2.5-7.5), hemorrhagic syndromes (OR=2.9; CI=1.45.7), attendance in another hospital unit along the 24 hours which preceded the patient's admission in the institution (OR=2.9; CI=1.8-4.6), mothers' age over or equal to 35 years old (OR=2.2; CI=1.0-4.9) and schooling lower than eight years (OR=1.6; CI=1.02-2.6). CONCLUSIONS: it was found a high fetal mortality coefficient, the main factors associated with death were: malformation, number of pre-natal appointments lower than six, hemorrhagic syndromes, history of attendance previous to the hospital admission, mothers' age over or equal to 35 and schooling lower than eight years.