Abstracts: ISEE 22nd Annual Conference, Seoul, Korea, 28 August–1 September 2010: Reproductive Health and Environment
Epidemiological studies suggest that exposure during pregnancy to disinfection by-products, mainly trihalomethanes (THMs), can increase the risk of congenital malformations; however, evidence is not conclusive. This study, funded under the EU Sixth Framework Programme for Research and Technological Development (FP6) (“HiWate” project), aimed to assess congenital anomalies risk associated with exposure to THMs during pregnancy.
A retrospective register-based case-control study was carried out in Emilia-Romagna region (Northern Italy). Data on chromosomal anomalies and different congenital anomalies (neural tube, cardiovascular, abdominal wall, cleft lip and palate, respiratory, genital organs, and urinary tract defects) occurred in the period 2002–2005 were extracted from the Regional Malformation Registry. Four Controls (newborns without malformations) were randomly selected form the Regional Birth Register and frequency matched to cases according to pregnancy period. The network supplying drinking water during the first trimester of pregnancy was identified on the basis of mother's address: THMs data, technical, and structural information (disinfection treatment, water type and quality) were linked to each subject.
A total of 6140 subjects; 1242 cases and 4984 controls, were included in the study: age, reproductive history, and zonal deprivation index distribution (Caranci index) resulted significantly different in mothers of cases and controls. Both total brominated-THMs and total THMs levels appeared very low: mean values were 3.8 (±3.6) and 3.2 (±2.6) μg/L, respectively and maximum values were 22.8 and 19.7 μg/L, respectively. No significant increased risks for the different congenital anomalies included in the study were observed, also after adjusting for potential confounders, in mother exposed to levels >10 μg/L of total brominated THMs or total THMs in comparison with mothers exposed to levels lower than 5 μg/L.
The low levels of THMs observed in drinking water in the study area did not appear to be associated with a significant increase in the risk of selected congenital malformation.