124-POS

Abstract

Objectives To compare long-term cardiovascular mortality in mothers whose firstborn offspring had folate-related malformations with mothers whose firstborns were non-malformed, and to evaluate if women’s total reproduction modified the associations. Methods Data from the Norwegian Medical Birth Registry and Cause of Death Registry were linked to study cardiovascular mortality among women with first singleton births in 1967–2002 ( N = 1,016,654). Births were linked to their mothers, and 83.8% women continued reproducing. Cox regression analysis was used to estimate associations between folate-related malformations (neural tube defects, oral clefts, cardiac defects) in first births and cardiovascular mortality at age 40–69 years, adjusting for maternal age, education, pregnancy year, and taking account of women’s following births. Results Women with folate-related malformations in their firstborns ( N = 7319) had increased cardiovascular mortality (adjusted hazard ratio relative women with non-malformed firstborns (adjHR) = 1.6; 95% confidence interval 1.1, 2.5). Taking account of women’s total reproduction, women with malformed first births who stopped reproducing had 7 times higher cardiovascular mortality than mothers with non-malformed first births who continued (adjHR 7.0 (4.1–12.2)). In contrast, mothers with malformed firstborns who continued reproducing did not have increased cardiovascular mortality: adjHR 0.9 (0.42–1.69). Conclusions The increased cardiovascular mortality in women whose firstborns had folate-related malformations is confined to women with only one birth. Disclosures K. Klungsoyr: None. L.A. DeRoo: None. S. Hernandez-Diaz: None. N. Morken: None. R. Skjaerven: None.