Malformaciones del aparato urinario en recién nacidos de la maternidad Hospital Clínico de la Universidad de Chile / Urinary tract malformations in the department of obstetrics of the Universidad de Chile clinical hospital, in the period 1982-1997

RESUMO

Background: The prevalence of urinary malformations at birth is steadily increasing, probably due to the availability of better diagnostic techniques Aim: To assess the prevalence of renal agenesis, hidroureteronephrosis and polycystic kidney at birth in the obstetric wards of the University of Chile Clinical Hospital. Patients and methods: As a part of the Latin American Collaborative Study of Congenital Malformations, 54.039 consecutive births at the Maternity, between January 1982 and December 1997, were studied. Results: Eighty three newborns had urinary tract malformations (15.3/10000). Fourteen (2.6/10000) had renal agenesis, 34 (6.3/10000) had hidroureteronephrosis and 35 (6.5/10000) had polycystic kidney. Eleven percent of these children were stillbirths and 35 percent died in the first days of life. Fifty six percent were male, 34 percent female and 10 percent had ambiguous sex. Mean birth weight was 2750 g, mean gestational age was 35.4 weeks and mean maternal age was 28 years old. Twenty three percent of mothers had a history of previous abortions, 8 percent had a history of stillbirths and 10 percent a history of metrorrhagia during the first trimester of pregnancy. Twenty five percent of children had a relative with a malformation and 48 children had other associated malformations such as pulmonary hypoplasia, external malformations caused by extreme oligoamnios or internal malformations such as utereral, urinary bladder, uretral or external genitalia agenesis. Conclusions: The prevalence of urinary malformations in this hospital was higher than in other hospitals participating in the collaborative study. This difference could be due to an under registration of malformations in other hospitals