Abstract
BACKGROUND
Little is known about the occurrence of specific congenital malformations among offspring of mixed race‐ethnicity.
METHODS
Using data from a population‐based registry, we explored the occurrence of selected malformation phenotypes in offspring to parents who were of different race‐ethnicity. Data were derived from the California Birth Defects Monitoring Program, a population‐based active surveillance system for collecting information on infants and fetuses with congenital malformations using multiple source ascertainment. Approximately 2.6 million live births and stillbirths occurred during 1989–2000. Information on parental race‐ethnicity (non‐Hispanic white, Hispanic, black, and Asian) was obtained from birth certificates and fetal death files. Malformation phenotypes studied were spina bifida, anencephaly, cleft lip, cleft palate, tetralogy of Fallot, d‐transposition of great arteries, hypospadias, small intestinal atresia, preaxial polydactyly, microtia, and hypertrophic pyloric stenosis.
RESULTS
A total of 11.2% of births were to parents of mixed race‐ethnicity. Compared to births of parents who were both white, moderately increased risks (risk ratio ≥ 1.7) of anencephaly, polydactyly, and microtia, and decreased risks (risk ratio ≤ 0.6) of hypospadias and hypertrophic pyloric stenosis were observed among births of several mixed race‐ethnicity groups. For anencephaly, polydactyly, and microtia, but not other phenotypes, the risks were different depending on whether maternal versus paternal race‐ethnicity was considered. Risks observed between births of a nonwhite parent and a white parent and births of parents who were both nonwhite were similar for most malformation phenotypes.
CONCLUSIONS
Some malformation phenotypes appear to vary in their risk based on mixed racial‐ethnic groupings. Birth Defects Research (Part A), 2004. © 2004 Wiley‐Liss, Inc.