Epidemiologic features and clinical subgroups of anotia/microtia in Texas

✍ Scribed by Mark A. Canfield; Peter H. Langlois; Ly M. Nguyen; Angela E. Scheuerle

• Publisher: John Wiley and Sons
• Year: 2009
• Tongue: English
• Weight: 115 KB
• Volume: 85
• Category: Article
• ISSN: 1542-0752
• DOI: 10.1002/bdra.20626

✦ Synopsis

Abstract

BACKGROUND:

Few studies have investigated the epidemiologic features of clinically defined subgroups of anotia/microtia.

METHODS:

Data on cases of anotia and/or microtia among 1999–2005 deliveries were obtained from the Texas Birth Defects Registry, a population‐based active surveillance system. We determined crude and adjusted associations between selected factors and seven clinical subgroups of anotia/microtia.

RESULTS:

In total, 742 cases were diagnosed with anotia and/or microtia, corresponding to a prevalence of 2.86 per 10,000 live births. Of those, 45% had no other major birth defect (“isolated”), 77% were unilateral, and 22% bilateral. Anotia alone made up 6%, whereas microtia made up 94%. Birth prevalence was higher with increasing maternal age and among Mexico‐born Hispanics. Compared to white mothers, Hispanic mothers were two‐to‐three times more likely to have infants with all but the syndromic and bilateral groups (adjusted prevalence ratios [aPRs] = 2.05–2.61). Non‐Hispanic blacks had significantly lower risk for total anotia/microtia, and for the isolated, unilateral, and microtia subgroups (aPRs = 0.42–0.64). Less educated mothers were three‐to‐four times more likely to have children with anotia (aPRs = 2.98 for less than high school, 3.97 for high school graduates). Males were more likely to be born with total anotia/microtia and with syndromic, unilateral, and microtia subtypes (aPRs = 1.27–1.41).

CONCLUSIONS:

In Texas, most anotia/microtia cases were in the unilateral and microtia groups, and 45% were isolated. Several clinical subgroups exhibited higher prevalence in males and among older mothers. Relative to whites, blacks were at lower risk and Hispanics (especially Mexico‐born mothers) were at higher risk for selected types of anotia/microtia. Birth Defects Research (Part A) 2009. © 2009 Wiley‐Liss, Inc.