Frecuencia de malformaciones congénitas renales y del tracto urinario y su asociación con factores maternos y del neonato.

Introduction: Congenital malformations of the kidney and urinary tract are very common and represent the main cause of chronic kidney failure in children. Objective: To determine the frequency of congenital malformations of the kidney and urinary tract and its association with maternal and neonate factors. Methods: A retrospective cohort study. Sociodemographic and clinical variables were collected, such as age, sex, diabetes, hypertension, obesity, volume alterations in the amniotic fluid, gestational age, and child weight. The association between these factors and congenital renal malformations was established using the chi-square or Fisher´s test. Relative risks with their respective confidence intervals were estimated and adjusted using binomial regression. Results: 2 137 patients were included; 54.4 % were men, the median gestational age was 38.8 weeks, interquartile range of 37.57 – 39.71). Median maternal age was 26 years, interquartile range of 21 – 30; 67 neonates (3.1 %) presented some malformation, the most frequent was the dilation of the urinary tract, found in 59 patients (93.6 %). Maternal factors such as polyhydramnios and oligohydramnios were shown to be associated with the appearance of malformations. Conclusion: The frequency of the malformations was high compared to that reported in the literature. Changes in the amount of amniotic fluid, especially polyhydramnios, were found as significant associated factors.