Abstract
BACKGROUND There is a paucity of information about risk factors for the human eye anomalies anophthalmia and microphthalmia. In this populationโbased caseโcontrol study we investigated whether periconceptional intakes of supplemental folic acid, dietary folate, vitamin A, and several other nutrients were associated with these eye defects. METHODS This study included data on deliveries that had estimated due dates from 1997โ2002 and were part of the National Birth Defects Prevention Study (the National Birth Defects Prevention Study is a populationโbased caseโcontrol study of a wide spectrum of birth defects, incorporating data from 10 birth defects surveillance systems in the United States [Arkansas, California, Georgia/Centers for Disease Control and Prevention, Iowa, Massachusetts, New Jersey, New York, North Carolina, Texas, and Utah]). Cases were those infants or fetuses born with either anophthalmia or microphthalmia. Liveborn infants without major malformations were eligible as controls. Maternal interviews were conducted, primarily by telephone, in English or Spanish. Participation in the interview was 71% among case mothers and 68% among control mothers. Interviews were completed with 89 case mothers and 4,143 control mothers. A shortened version of the food frequency questionnaire from the Nurse's Health Study was used to assess frequency of intake of 58 food items during the year before pregnancy. RESULTS Our results did not indicate reduced risks for these eye malformations associated with maternal intake of vitamin supplements containing folic acid. The data did not show an association between malformation risk and higher or lower intakes of vitamin A. We also did not observe strong evidence that an abundance or a lack of dietary intake of any other nutrient was associated with increased risk of the studied eye malformations. CONCLUSIONS Our observations contribute to a limited body of findings on these rare eye defects. ยฉ 2007 WileyโLiss, Inc.