Preferential associated anomalies in 818 cases of microtia in South America.

The etiology of microtia remains unknown in most cases. The identification of patterns of associated anomalies (i.e., other anomalies that occur with a given congenital anomaly in a higher than expected frequency), is a methodology that has been used for research into the etiology of birth defects. We conducted a study based on cases of microtia that were diagnosed from more than 5 million live (LB)- and stillbirths (SB) examined in hospitals participating in ECLAMC (Latin American Collaborative Study of Congenital Malformations) between 1967 and 2009. We identified 818 LB and SB with microtia and at least one additional non-related major congenital anomaly (cases) and 15,969 LB and SB with two or more unrelated major congenital anomalies except microtia (controls). A logistic regression analysis was performed to identify the congenital anomalies preferentially associated with microtia. Preferential associations were observed for 10 congenital anomalies, most of them in the craniofacial region, including facial asymmetry, choanal atresia, and eyelid colobomata. The analysis by type of microtia showed that for anomalies such as cleft lip and palate, macrostomia, and limb reduction defects, the frequency increased with the severity of the microtia. In contrast, for other anomalies the frequency tended to be the same across all types of microtia. Based on these results we will integrate data on the developmental pathways related to preferentially associated congenital anomalies for future studies investigating the etiology of microtia.

Longitudinal, three-dimensional analysis of head shape in children with and without deformational plagiocephaly or brachycephaly.

OBJECTIVES: To assess 3-dimensional (3D) changes in head shape in infancy and at age 18 months in children with and without plagiocephaly or brachycephaly. STUDY DESIGN: Using a longitudinal design, we evaluated head shape using 3D surface imaging. We compared the head shapes of children with (1) diagnosed deformational plagiocephaly or brachycephaly (cases; n=233); (2) unaffected controls, with no evidence of dysmorphology (n=167); and (3) affected controls, who despite having no previous diagnosis demonstrated skull dysmorphology on 3D surface imaging (n=70). RESULTS: Cases had greater skull flattening and asymmetry than unaffected controls at both time points, as did controls with skull dysmorphology. In all groups, head shapes became less flat and more symmetric over time. Among cases, symmetry improved slightly more for those who received orthotic treatment. CONCLUSIONS: Although head shape improves over time for children with deformational plagiocephaly or brachycephaly, skull dysmorphology persists relative to unaffected controls. Further research is needed to clarify the extent to which these differences are detectable to clinicians and lay observers.

New severity indices for quantifying single-suture metopic craniosynostosis.

OBJECTIVE: To describe novel severity indices with which to quantify severity of trigonocephaly malformation in children diagnosed with isolated metopic synostosis. METHODS: Computed tomographic scans of the cranium were obtained from 38 infants diagnosed with isolated metopic synostosis and 53 age-matched control patients. Volumetric reformations of the cranium were used to trace two-dimensional planes defined by the cranium-base plane and well-defined brain landmarks. For each patient, novel trigonocephaly severity indices (TSI) were computed from outline cranium shapes on each of these planes. The metopic severity index based on measurements of interlandmark distances was also computed and a receiver operating characteristic analysis used to compare the accuracy of classification based on TSIs versus that based on the metopic severity index. RESULTS: The proposed TSIs are a sensitive measure of trigonocephaly malformation that can provide a classification accuracy of 96% with a specificity of 95%, in contrast with 82% of the metopic severity index at the same specificity level. CONCLUSIONS: We completed exploratory analysis of outline-based severity measurements computed from computed tomographic image planes of the cranium. These TSIs enable quantitative analysis of cranium features in isolated metopic synostosis that may not be accurately detected by analytic tools derived from a sparse set of traditional interlandmark and semilandmark distances.

Maternal and infant characteristics associated with prone and lateral infant sleep positioning in Washington state, 1996-2002.

OBJECTIVE: To identify factors predictive of either lateral or prone infant sleep positioning. STUDY DESIGN: We used data for 11340 mother-infant pairs from the Pregnancy Risk Assessment Monitoring System for infants born in Washington State, 1996 to 2002. We used predictive modeling to identify statistically significant (P < .05) predictors of lateral and prone sleep positioning. RESULTS: Factors associated with both high-risk sleep positions included infant's year of birth, maternal race and ethnicity, maternal county of residence, and maternal parity. Mother's being US-born (versus foreign-born) and male infant sex were predictive only of prone sleep positioning. Having Medicaid as primary insurance, receipt of government benefits, low infant gestational age, and low birth weight were predictive only of lateral sleep positioning. CONCLUSIONS: Factors predictive of either high-risk sleep position should be considered when devising public health intervention strategies for the prevention of SIDS.