| Summary: | Rates of birth defects across multiple ICD-9 categories have been shown to be higher in Canadian Inuit populations when compared to non-Inuit populations, using birth defect rates in Alberta, Canada as a baseline for comparison. Preliminary results from a recent (2000-2005) analysis comparing rates of birth defects in Nunavut to those of Yukon, Northwest Territories and the rest of Canada support a higher rate of birth defects in Nunavut, largely because of a higher rate of heart defects (Orlaw, unpublished data). Furthermore, a chart review of all births from Baffin Island in the same time period, (n=2015) confirmed that even after folic acid fortification, the rate of echocardiography-confirmed heart defects remains three times higher than in Alberta. This study uses case control methodology from the same chart review to determine if prenatally reported maternal risk factors were associated with major congenital malformations. Cases (n=77) were selected on the basis of having a confirmed major congenital malformation without chromosome anomaly in ICD 9 categories 740-759. The next four normal births from the same community were selected as controls (n=307) for each case. Using odds ratios (OR) and 95% confidence intervals (CI) for significance, self-reported alcohol consumption, smoking, and marijuana use in any quantity were individually analyzed for an association with major congenital malformations. Maternal age, prenatal vitamin use, and term vs preterm gestation were also compared. Of these, alcohol consumption was significantly associated with major malformations (OR-2.2,CI:1.02-4.87). In addition, infants with major malformations were 6 times more likely to be premature (OR-6.35,CI:3.15-12.80). No other factors were significant. A sub-analysis of the same maternal factors in association with only cardiac defects revealed only preterm birth as having a significant positive association with cardiac defects (PDA and PFO excluded) (OR-11.59,CI:3.32-40.5). Documented marijuana use was almost, but not quite, ...
|
|---|