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Periconceptional Folic Acid Supplementation and Infant Risk of Congenital Heart Defects in N orway 1999–2009
Author(s) -
Leirgul Elisabeth,
Gildestad Trude,
Nilsen Roy Miodini,
Fomina Tatiana,
Brodwall Kristoffer,
Greve Gottfried,
Vollset Stein Emil,
Holmstrøm Henrik,
Tell Grethe S.,
Øyen Nina
Publication year - 2015
Publication title -
paediatric and perinatal epidemiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.667
H-Index - 88
eISSN - 1365-3016
pISSN - 0269-5022
DOI - 10.1111/ppe.12212
Subject(s) - medicine , pregnancy , folic acid , relative risk , confidence interval , risk factor , obstetrics , pediatrics , genetics , biology
Background The birth prevalence of congenital heart defects ( CHDs ) has decreased in C anada and Europe. Recommended intake of folic acid in pregnancy is a suggestive risk‐reducing factor for CHDs . We investigated the association between periconceptional intake of folic acid supplements and infant risk of CHDs . Methods Information on maternal intake of folic acid supplements before and during pregnancy in the Medical Birth Registry of N orway 1999–2009 was updated with information on CHD diagnoses from national health registers and the Cardiovascular Diseases in N orway Project. The association between folic acid intake and infant risk of CHD was estimated as relative risk ( RR ) with binomial log linear regression. Results Among 517 784 non‐chromosomal singleton births, 6200 children were identified with CHD and 1153 with severe CHD . For all births, 18.4% of the mothers initiated folic acid supplements before pregnancy and 31.6% during pregnancy. The adjusted RR for severe CHD was 0.99 [95% confidence interval [ CI ] 0.86, 1.13] comparing periconceptional intake of folic acid with no intake. Specifically, RR for conotruncal defects was 0.99 [95% CI 0.80, 1.22], atrioventricular septal defects 1.19 [95% CI 0.78, 1.81], left ventricular outflow tract obstructions 1.02 [95% CI 0.78, 1.32], and right ventricular outflow tract obstructions 0.97 [95% CI 0.72, 1.29]. Birth prevalence of septal defects was higher in the group exposed to folic acid supplements with RR 1.19 [95% CI 1.10, 1.30]. Conclusions Periconceptional folic acid supplement use showed no association with severe CHDs in the newborn. An unexpected association with an increased risk of septal defects warrants further investigation.