Influence of maternal parity, age, and ethnicity on risk of esophageal atresia in the infant in a population-based study.

BACKGROUND: The etiology of esophageal atresia (EA) is virtually unknown. We hypothesized that the maternal factors low parity, high age, and white ethnicity are involved.

METHODS: A Swedish nationwide, population-based, case-control study was nested in a cohort of newborn children in 1982 to 2004. Among 2,305,858 deliveries, 722 cases of EA and 3610 controls were included. Conditional logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Matching, stratification, and multivariable regression were used to adjust for potential confounding.

RESULTS: A more than 30% decreased risk of EA was found for mothers delivering their second (OR, 0.68; 95% CI, 0.56-0.83) or third child (OR, 0.64; 95% CI, 0.49-0.83) compared to primiparous mothers. Children of women giving birth when 35 to 40 years and older than 40 years showed a 2-fold (OR, 2.09; 95% CI, 1.09-3.99) and 3-fold (OR, 3.04; 95% CI, 1.37-6.74) increased risk of EA, respectively, compared to those of mothers younger than 20 years. This association remained when chromosomal abnormality cases were excluded (P = .004). There was a 66% increase in risk of isolated EA in children of mothers of white (OR, 1.66; 95% CI, 1.06-2.61), compared to mothers who are not of white ethnicity.

CONCLUSIONS: This study indicates an increased risk of EA in children of mothers having their first delivery, of older age, and of white ethnicity.