OBJECTIVES: to assess maternal risk factors associated with fetal acidosis. METHODS: a case-control type study was conducted of 188 neonates, of whom 47 comprised the case group (umbilical arterial pH <7.0) and 141 the control (umbilical arterial pH E7.1 <7.3). The study included only single-gestation neonates without congenital malformations. Both maternal and fetal variables were taken into consideration. Statistical analysis involved the calculation of the raw and adjusted Odds Ratio, Student's t-test, the chi-squared test and multivariate analysis using Enter-method non-conditional logistic regression. The level of statistical significance was set at p<0.05. RESULTS: in the case group higher percentages of caesarian sections and pre-term births were observed, involving almost five times as much intensive care and twenty-five times more likelihood of Apgar in the 5th minute <7. No association was observed between the groups and fetal presentation, mother's age, history of miscarriage, years of schooling of mother or attendance at prenatal sessions. After multivariate analysis, the only risk factors that remained significant were complications relating to the placenta or the umbilical cord. Deliveries involving complications relating to the placenta or the umbilical cord were three times more likely to involve fetal acidemia. CONCLUSIONS: acidemia among neonates was associated with a higher percentage of caesarians, premature births, a need for intensive care and treatment and an Apgar index of <7 in the 5th minute. After multivariate analysis, complications relating to premature displacement of the placenta and the umbilical cord were the only remaining risk factors associated with fetal acidemia.
Acidosis; Morbidity; Neonatal; Blood gas analysis
