Epidemiologic analysis of maternal factors and amniotic band defects

Abstract

BACKGROUND: The group of defects identified as amniotic bands includes amnion rupture sequence (ARS) and body wall complex (BWC). Little is known about risk factors for either ARS or BWC, except that maternal age has been shown to affect risk inversely. METHODS: The present analysis used data collected from 1976 to 1998 as part of an ongoing case control study of birth defects in the metropolitan areas of Boston, Philadelphia, and Toronto. There were 73 cases with ARS and 11 cases with BWC. ARS cases were further subdivided according to affected structures: there were 53 with only limbs affected (ARS-L) and 20 with nonlimb defects with or without limb defects (ARS-NL). The control group comprised 12,227 subjects with other major malformations. Mothers were interviewed within 6 months of delivery about demographic, reproductive, medical, and behavioral factors. RESULTS: Multivariate adjusted odds ratios for BWC were increased more than threefold for maternal age < 25 years and maternal education < 12 years, but neither estimate was statistically significant. Corresponding estimates for ARS-L and ARS-NL ranged from 1.3 to 1. 5 and also were not statistically significant. Cases were less likely to be white non-Hispanic than controls and the odds ratio for ARS-NL excluded the null. The multivariate adjusted odds ratio (MVOR) for unplanned pregnancy and BWC was 1.9 (95% confidence interval, 0.5-6.7) compared to 1.2 and 1.0 for ARS-L and ARS-NL, respectively. Neither parity nor maternal smoking was associated with any case group. The MVORs for first trimester acetaminophen use in relation to ARS-L and ARS-NL risks were 2.1 (1.1-3.9) and 3.4 (1.1-10.3), respectively. Such use was less common among BWC cases (MVOR was 0.4; 0.1-1.4). CONCLUSIONS: Risk estimates tended to be similar for ARS-L and ARS-NL cases but different for BWC cases, suggesting different etiologies. These data suggest that young maternal age, low maternal education, unplanned pregnancy, and non-white/non-Hispanic race/ethnicity might increase the risk of BWC in offspring. Increased risks for acetaminophen use should be interpreted with caution because they may be confounded by indication for use. © 2003 Wiley-Liss, Inc.