Isolated atrioventricular canal defects: birth outcomes and risk factors: a population-based Hungarian case-control study, 1980-1996.

BACKGROUND

The role of possible environmental factors in the origin of congenital heart defects is unclear in the vast majority of patients. The objective of this study was to describe the birth outcomes and risk factors in isolated atrioventricular canal defect (AVCD) cases.

METHODS

Medically recorded birth outcomes, maternal age, parity, acute and chronic maternal diseases with related drug treatments and folic acid/multivitamin supplementation were evaluated in isolated AVCD cases. The diagnosis of AVCD was based on the autopsy report or surgical description in the population-based Hungarian Case-Control Surveillance of Congenital Abnormalities, between 1980 and 1996.

RESULTS

The birth outcomes and exposures of 77 isolated AVCD cases were compared with 38,151 controls without defect. Mean gestational age at delivery (38.6 week) and birth weight (2992 g), rate of preterm birth (20.8%) and low birthweight (23.4%) of cases with a female excess (59.7%) differed significantly from the controls. Mothers of cases had higher parity, higher prevalence of conduction disorders/cardiac dysrhythmias and chronic hypertension. The high doses of folic acid in early pregnancy associated with a reduced rate of AVCD.

CONCLUSIONS

Conduction disorders/cardiac dysrhythmias and chronic hypertension of mothers may have a role in the origin of AVCD, while high doses of folic acid in early pregnancy may reduce the risk of the development of AVCD. Birth Defects Research (Part A) 97:217-224, 2013. © 2013 Wiley Periodicals, Inc.