GEOGRAPHIC HETEROGENEITY IN BIRTH DEFECTS PREVALENCE RATES IN SOUTH AMERICA

GILI, JUAN ANTONIO; POLETTA, FA; COMAS, B; BALDO, CC; LOPEZ-CAMELO, JORGE SANTIAGO

BUENOS AIRES

Congreso; Clearinghouse 37th Annual Meeting.; 2010

International Clearinghouse for Birth Defects Surveillance and Research

Background: The study of geographic differences in birth prevalence rates (BPR) could be an approach in the study of etiology of congenital anomalies. Aim: To identify geographic clusters of birth defects and analyze associated risk factors in each identified cluster. Methods: A total of 128,160 malformed were diagnosed from 4,586,569 newborn analyzed since 1982 to 2007 by the 118 hospitals from the ECLAMC program. For each malformed newborn a healthy newborn with the same sex and from the same hospital was selected as control. Non-predefined geographical areas with significantly unusual malformation BPR were identified with Kulldorf and Nagarwalla’s spatial scan statistic, employing number of cases and births, and exact location of each hospital. Furthermore, OR and their 95%CI for potential risk factors were calculated in each identified cluster. Results: It was detected geographic areas with high-BPR in 24 groups of malformation studied. Geographic areas with at least a three-fold increase in the BPR were identified by the following birth defects: Abdominal wall defect, Anencephaly, Cephalocele, Ciclopy, Cleft lip +/-palate, Cleft palate, Diaphragmatic hernia, Esophageal atresia, Gastroschisis, Hydrocephalus, Microtia, Omphalocele, Pectoral defects, Pes equinovarus, Pes talovalgus, Preaxial polydactyly and Spina bifida. Conclusions: This methodology could be an efficient approach to identify environmental and/or genetics factors involved in birth defect causality.